September 2024
Do Residents Believe that Onchocerciasis Transmission Was Eliminated? Results of A Post-Treatment Surveillance Knowledge, Attitude, and Practices Survey in Three Foci of Uganda
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Lauri Bernard, Annet T. Khainza, Edson Byamukama, Moses Katabarwa, Jenna Coalson, Gregory S. Noland, and Frank O. Richards Jr.
Decription: In Uganda, 15 of 17 foci have interrupted transmission of onchocerciasis (river blindness) and stopped mass drug administration (MDA) of ivermectin. This 2016 study describes the results of a knowledge, attitude, and practices survey regarding river blindness among participants (N = 1,577) 3–5 years after ivermectin MDA was halted in three foci: Imaramagambo halted in 2012, Kashoya-Kitomi in 2013, and Mt. Elgon in 2011. The study showed high levels of composite knowledge (focus-specific range: 66.8–81.2%) related to river blindness transmission, signs, symptoms, and treatment. However, 38.1% of respondents did not know that blackflies transmitted river blindness. Notably, 72.2% claimed they had not been informed why MDA was stopped, 56.3% did not believe river blindness had been eliminated, and 83.1% wanted ivermectin MDA to resume. During the 3–5 year post-treatment surveillance period, only 27.7% (438 of 1,577) reported being informed of what to do once treatments stopped, with the most knowledgeable hailing from the Mt. Elgon focus (47.9%). This study reinforces the need for programs to intensify health education and information dissemination when MDA is stopped. Programs must remind residents that although biting insects may persist, they no longer transmit river blindness. Incorporating messages about the elimination of river blindness into community health education campaigns can help improve the community’s perceptions related to the disease’s absence and the ending of a long-standing MDA intervention.
September 2024
Integrated Serosurveillance for Onchocerciasis, Lymphatic Filariasis, and Schistosomiasis in North Darfur, Sudan
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Jenna E. Coalson, Gregory S. Noland, Andrew W. Nute, Erica Brook Goodhew, Diana L. Martin, Zeinab Abdalla, Isam Zarroug, Soheir Gabralla, Hassan Ahmed Hassan Ahmed Ismail, William Evan Secor, Elizabeth Kelly Callahan, Angelia M. Sanders, Balgesa Elshafie, and Scott D. Nash
Description: Sudan is endemic for multiple neglected tropical diseases, including trachoma, onchocerciasis (OV), lymphatic filariasis (LF), and schistosomiasis (SCH). In 2019, dried blood spot samples were collected for a baseline trachoma serosurvey in three localities (El Seraif, Kotom, and Saraf Omrah) in North Darfur State. None were classified previously as OV- or LF-endemic, although low levels of SCH had been identified in all three. Approximately 30 households from 25 communities in each locality were selected by multistage cluster random sampling. Collections of DBSs were analyzed by multiplex bead assay for antibodies to multiple pathogens. This paper presents data on OV (Ov16), LF (Wb123, Bm14, Bm33), and SCH (soluble egg antigen [SEA], Sm25) antibodies among 8,322 individuals from 2,119 households. The survey-adjusted seroprevalence estimates for Ov16 were <0.3% in all localities. Lymphatic filariasis–antigen seroprevalences were discordant. Seroprevalence estimates ranged from 4.6–6.0% (Wb123), 0.99–1.4% (Bm14), and 29.2–33.3% (Bm33). Schistosomiasis seroprevalence estimates among school-aged children ranged from 2.7–8.0% (SEA) and 10.9–15.6% (Sm25). Ov16 seropositivity was low and supported the localities’ classification as nonendemic. The results suggested LF exposure, but discordance between antigens, challenges defining seropositivity thresholds, and the absence of programmatic guidance based on antibody serology alone for Wuchereria bancrofti indicate a need for remapping surveys to confirm transmission. Schistosomiasis antibody levels were high enough to warrant further mapping to guide treatment decisions. The lack of gold standards limited interpretation of results, particularly for LF, but in resource-challenged areas, integrated serological surveillance offers the possibility of efficient monitoring of exposure to multiple diseases.
September 2024
Scorecard Approach to Eliminate Onchocerciasis in Venezuela
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Oneida Camacho, Carlos Botto, Dalila Ríos, Benny Barrios, Sharly Ceballos, Oscar Noya-Alarcón, Miguel Fernández, Yseliam Tovar, Nestor J. Villamizar, Lindsay Rakers, Frank Richards, and María Eugenia Grillet
Description: In the Americas, onchocerciasis has been eliminated in 11 of 13 endemic foci by mass administration of ivermectin. The remaining at-risk population resides in a contiguous cross-border transmission zone located in the Amazon jungle in northwest Brazil and southern Venezuela, known as the Yanomami Focus Area. Here, we describe the development and implementation of a data-driven tool, called the Scorecard Approach (SCA), for the 393 communities that comprise the Venezuela South Focus. The SCA was first applied in 2018 and is reassessed on an annual basis. This operational strategy seeks to prioritize communities with low ivermectin coverage while taking into account the nature and variation of other epidemiological and logistical variables. Numeric scores are assigned for each factor and added together to yield a composite score for each community that is categorized as high, medium, or low priority. In this way, the SCA serves as a valuable and comprehensive strategy for planning, monitoring, and maximizing programmatic efficiency. In addition, it has allowed the country to face the main challenges of this endemic area: its remoteness, its large areas of territory to cover, the semi-nomadic nature of the Yanomami people, and their continuous cross-border movements. For 2022, the SCA categorized 54 (13.7%), 108 (27.5%), and 231 (58.8%) communities as high, medium, and low priority, respectively. The results presented here show that prioritizing communities at risk and with greatest needs increases the feasibility of interrupting the transmission of onchocerciasis by 2025 in the last endemic focus in the Americas.
September 2024
Progress Toward Onchocerciasis Elimination in Brazil
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: João Luiz Pereira de Araujo, Dalila Ríos, Maria Eugenia Grillet, Alda Maria da Cruz, Lindsay Rakers, Frank Richards, Heriberto Francis Schuertz, and Sandra Maria Barbosa Durães
Description: The single onchocerciasis-endemic focus in the remote Amazon rainforest is shared by Brazil and Venezuela and affects primarily the indigenous Yanomami people. Regional elimination of onchocerciasis is challenged by the magnitude and inaccessibility of this area. In Brazil, 272 onchocerciasis-endemic communities are operationally organized through 21 health centers (“polos bases”). Mass drug administration of ivermectin began in 1995, with 36 effective biannual rounds (≥85% coverage of the eligible population) through 2022. The national onchocerciasis program maintains community-level monitoring to prioritize treatment activities and epidemiological surveys. The Onchocerciasis Elimination Program for the Americas and the WHO onchocerciasis elimination guidelines have helped Brazil move toward its goal of stopping ivermectin treatment by 2025 and verifying transmission elimination by 2030. Additional challenges to the Brazilian onchocerciasis program include cross-border movements and insecurity due to illegal mining and inter-community conflicts. The new government in Brazil offers hope given its commitment to the equity of indigenous people and preservation of the Amazon environment.
Aug. 1, 2024
The Interruption of Transmission of Onchocerciasis in Abia, Anambra, Enugu, and Imo States, Nigeria: The Largest Global Onchocerciasis Stop-Treatment Decision to Date
Published by Pathogens.
Authors: Cephas Ityonzughul, Adamu Sallau, Emmanuel Miri, Emmanuel Emukah, Barminas Kahansim, Solomon Adelamo, George Chiedo, Samuel Ifeanyichukwu, Jenna E. Coalson, Lindsay Rakers, Emily Griswold, Chukwuemeka Makata, Fatai Oyediran, Stella Osuji, Solomon Offor, Emmanuel Obikwelu, Ifeoma Otiji, Frank O. Richards Jr., Gregory S. Noland
Abstract: Onchocerciasis causes severe morbidity in sub-Saharan Africa. Abia, Anambra, Enugu, and Imo states of Nigeria were historically classified meso- or hyperendemic and eligible for ivermectin mass drug administration (MDA). After ≥25 years of annual and biannual MDA, serological and entomological assessments were conducted to determine if Onchocerca volvulus transmission was interrupted. Dried blood spots collected in October 2020 from ≥3167 children 5–9 years old in each state were screened for O. volvulus-specific Ov16 antibody by enzyme-linked immunosorbent assay. Additionally, 52,187 Simulium damnosum heads (≥8845 per state) collected over 12 months between 2021 and 2022 were tested by pooled polymerase chain reaction (PCR) for O-150 DNA. Among seven seropositive children, four were found for follow-up skin snip PCR to confirm active infection. Three were negative and the fourth was excluded as he was visiting from an endemic state. The final seroprevalence estimates of each state had 95% upper confidence limits (UCL) < 0.1%. All fly pools were negative by O-150 PCR, giving a 95% UCL infective fly prevalence < 0.05% in each state. Each state therefore met the World Health Organization epidemiological and entomological criteria for stopping MDA effective January 2023. With 18.9 million residents eligible for MDA, this marked the largest global onchocerciasis stop-treatment decision to date.
Oct. 4, 2023
A Tribute to the Global Health Legacy of Jimmy and Rosalynn Carter (PDF)
Published by The American Journal of Tropical Medicine and Hygiene; 109(4), 2023, pp. 713–714 doi:10.4269/ajtmh.23-0641.
Authors: Kashef Ijaz and Julie Jacobson.
Abstract: The global public health legacy of former U.S. President Jimmy Carter and First Lady Rosalynn Carter cannot be overstated. For more than 50 years, they have leveraged the power of their characters and connections to advance public health in the United States and around the world.
May 2023
Onchocerciasis in Nigeria 1: History of Control Efforts (PDF)
Published by the Nigerian Journal of Parasitology, Special Issue No. 1, May 2023.
Authors: B. E. B. Nwoke, Nse Akpan, Vitaliano Cama, Uwem Ekpo, Alamveabee Idyorough, Margaret A. Mafe, Hayward Mafuyai, Emeka Makata, Emmanuel Miri, Kenneth Opara, and Frank O. Richards.
Nigeria is the most endemic country for onchocerciasis in the world and accounts for about 40% of the global cases. With about 50 million persons in over 40,000 communities at risk, it has been recognized as a communicable disease that is not only a social problem but also a major threat to productivity and the economy of the country. It is especially prevalent among the poor rural farmers, ‘‘people at the end of the road’’ living around the vector breeding sites who produce the bulk of our food and industrial raw materials.
Nov. 30, 2022
Two Nigerian States (Plateau and Nasarawa) Have Eliminated Transmission of Human Onchocerciasis—A Report of Post-ivermectin Mass Drug Administration Surveillance
Published by The American Journal of Tropical Medicine and Hygiene; 108(1), 2022, pp. 37–40 doi:10.4269/ajtmh.22-0491.
Authors: Emmanuel S. Miri, Abel Eigege, Barminas Kahansim, Kenrick Nwodu, Yohana Sambo, Bulus Mancha, Solomon Adelamo, John Umaru, Jonathan Kadimbo, Jacob Danboyi, Hayward Mafuyai, Emeka Makata, Nse Akpan, Joel Akilah, Michael Igbe, Jenna Coalson, Lindsay Rakers, Emily Griswold, Thomas R. Unnasch, B. E. B. Nwoke, Gregory S. Noland, and Frank O. Richards, Jr.
Transmission of Onchocerca volvulus (causing “river blindness”) was interrupted in two states of Nigeria (Plateau and Nasarawa) in 2017 in accordance with 2016 WHO guidelines. Ivermectin mass drug administration was halted in January 2018, and posttreatment surveillance activities were conducted over a 3-year period. Vector Simulium damnosum s.l. flies were collected during the 2019 (39 sites) and 2020 (42 sites) transmission seasons.
June 24, 2021
Reaching the Criteria to Stop Onchocerciasis Mass Drug Administration: Ethiopia, Nigeria, and Uganda Pave the Way (PDF)
Published by USAID’s Act to End NTDs | East program, led by RTI International, as part of the Act to End NTDs | East Technical Brief Series.
Authors: Upendo Mwingira (RTI International); Alyssa Jordan (RTI International), Moses Katabarwa (The Carter Center), Frank Richards (The Carter Center)
This brief describes how Ethiopia, Nigeria, and Uganda addressed these steps, providing examples for other country programs working to stop OV MDA. To eliminate human onchocerciasis transmission of the filarial parasite Onchocerca volvulus (OV), endemic countries undertake a multi-step process. One of the most challenging steps for endemic countries is breaking the cycle of transmission to the point where MDA can be stopped. This special publication and accompanying toolbox were launch during an expert virtual event (PDF) on June 24, 2021.
Jan. 11, 2021
Optimization Of Slash And Clear Community-Directed Control Of Simulium Damnosum Sensu Stricto In Northern Uganda
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Benjamin Jacob, Denis Loum, Denis Munu, Thomson Lakwo, Edson Byamukama, Peace Habomugisha, Eddie W. Cupp, and Thomas R. Unnasch
Onchocerciasis, caused by infection with Onchocerca volvulus, has been targeted for elimination by 2030. Currently, onchocerciasis elimination programs rely primarily on mass distribution of ivermectin. However, ivermectin alone may not be sufficient to achieve elimination in some circumstances, and additional tools may be needed. Vector control has been used as a tool to control onchocerciasis, but vector control using insecticides is expensive and ecologically detrimental.
Sept. 21, 2020
Assessing Hypoendemic Onchocerciasis in Loa loa Endemic Areas of Southeast Nigeria
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Lindsay J. Rakers, Emmanuel Emukah, Barminas Kahansim, Bertram E. B. Nwoke, Emmanuel S. Miri, Emily Griswold, Emmanuel Davies, Cephas Ityonzughul, Chukwuma Anyaike, Perpetual Agbi and Frank O. Richards
The parasitic infection onchocerciasis has a devastating impact on quality of life. Spread by repeated bites of black flies of Simulium species, Onchocerca volvulus larvae can mature into adult worms that group together to form nodules under the skin, from which fertilized females release embryos (microfilariae, or “mf”), which cause eye disease that can lead to blindness and skin disease with maddening itching. Because the black fly vector breeds near well-oxygenated fast-flowing water, the disease is often colloquially referred to as “river blindness.” Nigeria has the greatest number of onchocerciasis cases among the 31 endemic countries.
Aug. 10, 2020
Elimination of Simulium neavei-Transmitted Onchocerciasis in Wambabya-Rwamarongo Focus of Western Uganda
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Moses N Katabarwa, Peace Habomugisha, Annet Khainza, David Oguttu, Edson Byamukama, James Katamanywa, Thomson Isingooma, Fredrick Bwenume, Christine Nahabwe, Monica Ngabirano, Paul Akampurira, Lauri Bernard, Thomas R Unnasch, Frank Richards
Wambabya-Rwamarongo onchocerciasis focus is one of the eight foci Uganda verified using the WHO verification guidelines. The approach for elimination was twice yearly treatment with ivermectin for every round, treating at least 90% of all the eligible population. This was in combination with vector elimination using Abate® since elimination nationwide policy was launched.
March 30, 2020
Historical Elimination of Onchocerciasis from Victoria Nile Focus in Central Uganda Verified Using WHO Criteria
Published by The American Journal of Tropical Medicine and Hygiene; 102(6): 1411–1416. doi: 10.4269/ajtmh.20-0064
Authors: Moses N Katabarwa; Peace Habomugisha; Annet Khainza; David Oguttu ; Edson Byamukama; James Katamanywa; Christine Nahabwe; Monica Ngabirano; Paul Akampurira; Lauri Bernard; Thomas R Unnasch; and Frank Richards.
Uganda has verified elimination of seven onchocerciasis foci since 2007 when the nationwide onchocerciasis elimination policy was launched. However, the Victoria Nile focus (which was eliminated in the early 1970s) had not been verified. The objective of this study was to verify this focus to the WHO verification guidelines and bring it in line with recently eliminated foci. Vector control with dichlorodiphenyltrichloroethane was the main intervention used at the Victoria Nile from the 1950s to the 1970s. Historical fly collection sites along River Nile were identified for recent fly collection.
March 30, 2020
Post-Treatment Surveillance for Lymphatic Filariasis in Plateau and Nasarawa States, Nigeria: Results of Transmission Assessment Surveys
Published by The American Journal of Tropical Medicine and Hygiene; 102(6): 1404–1410. doi:10.4269/ajtmh.20-0020
Authors: Abel Eigege, Gregory S. Noland , Solomon E. Adelamo, Kenrick Nwodu ,Adamu Sallau , John Umaru, Bulus S. Mancha, Emmanuel Davies, Jacob Danboyi, Jonathan A. Kadimbo , Yisa A. Saka, Ifeoma Anagbogu, Emmanuel S. Miri. and Frank O. Richards Jr.
Following the halt of mass drug administration (MDA) for lymphatic filariasis (LF), the WHO recommends at least 4 years of post-treatment surveillance (PTS) to confirm that transmission recrudescence or importation does not occur. The primary means of evaluation during PTS is repeated transmission assessment surveys (TASs) conducted at 2- to 3-year intervals after TAS-1 stop-MDA surveys. This study reports the results of TAS-2 and TAS-3 surveys in Plateau and Nasarawa states (pop. 6.9 million) of Nigeria divided into a minimum of seven evaluation units (EUs) per TAS.
March 6, 2020
Data-driven Modelling and Spatial Complexity Supports Heterogeneity Based Integrative Management for Eliminating Simulium Neavei Transmitted River Blindness (PDF)
Published by Nature Research Scientific Reports.
Authors: Edwin Michael, Morgan E. Smith, Brajendra K. Singh, Moses N. Katabarwa, Edson Byamukama, Peace Habomugisha, Thomson Lakwo, Edridah Tukahebwa, and Frank O. Richards
Concern is emerging regarding the challenges posed by spatial complexity for modelling and managing the area-wide elimination of parasitic infections. While this has led to calls for applying heterogeneity-based approaches for addressing this complexity, questions related to spatial scale, the discovery of locally-relevant models, and its interaction with options for interrupting parasite transmission remain to be resolved.
March 2020
The Interruption of Transmission of Human Onchocerciasis by an Annual Mass Drug Administration Program in Plateau and Nasarawa States, Nigeria (PDF)
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Frank O. Richards, Jr., Abel Eigege, John Umaru, Barminas Kahansim, Solomon Adelamo, Jonathan Kadimbo, Jacob Danboyi, Hayward Mafuyai, Yisa Saka, Gregory S. Noland, Chukwuma Anyaike, Michael Igbe, Lindsay Rakers, Emily Griswold, Thomas R. Unnasch, B. E. B. Nwoke, and Emmanuel Miri
Plateau and Nasarawa states in central Nigeria were endemic for onchocerciasis. The rural populations of these two states received annual ivermectin mass drug administration (MDA) for a period of 8–26 years (1992–2017). Ivermectin combined with albendazole was given for 8–13 of these years for lymphatic filariasis (LF); the LF MDA program successfully concluded in 2012, but ivermectin MDA continued in areas known to have a baseline meso-hyperendemic onchocerciasis. In 2017, serological and entomological assessments were undertaken to determine if MDA for onchocerciasis could be stopped in accordance with the current WHO guidelines.
Feb 6, 2020
The Galabat-Metema Cross-border Onchocerciasis Focus: The First Coordinated Interruption of Onchocerciasis Transmission in Africa
Published by PLOS | Neglected Tropical Diseases.
Authors: Moses N. Katabarwa, Isam M. A. Zarroug, Nebiyu Negussu, Nabil M. Aziz, Zerihun Tadesse, Wigdan A. Elmubark, Zainab Shumo, Kadu Meribo, Hashim Kamal, Aderajew Mohammed, Yewondwossen Bitew, Tewodros Seid, Firdaweke Beke, Frank Richards.
Onchocerciasis transmission across international borders is not uncommon, yet a coordinated cross border stops mass drug administration (MDA) decision has not been documented.
Oct. 24, 2019
Accelerating River Blindness Elimination by Supplementing MDA with a Vegetation “Slash and Clear” Vector Control Strategy: a Data Driven Modeling Analysis (PDF)
Published by Nature Research Scientific Reports.
Authors: Morgan E. Smith, Shakir Bilal, Thomson L. Lakwo, Peace Habomugisha, Edridah Tukahebwa, Edson Byamukama, Moses N. Katabarwa, Frank O. Richards, EddieW. Cupp, Thomas R. Unnasch & Edwin Michael
Attention is increasingly focusing on how best to accelerate progress toward meeting the WHO’s 2030 goals for neglected tropical diseases (NTDs). For river blindness, a major NTD targeted for elimination, there is a long history of using vector control to suppress transmission, but traditional larvicide-based approaches are limited in their utility. One innovative and sustainable approach, “slash and clear,” involves clearing vegetation from breeding areas, and recent field trials indicate that this technique very efectively reduces the biting density of Simulium damnosum s.s.
July 15, 2019
Commentary 1: The Positive Influence the Onchocerciasis Elimination Program for the Americas Has Had on Africa Programs
Published by Infectious Diseases of Poverty.
Authors: Frank O. Richards, B. E. B. Nwoke, Isam Zarroug, Edridah Tukahebwa, Nebiyu Negussu, T. B. Higazi, David Oguttu, Zerihun Tadesse, Emmanuel Miri, Nabil Aziz, Peace Habomugisha and Moses Katabarwa.
A recent article "Is onchocerciasis elimination in Africa feasible by 2025: a perspective based on lessons learnt from the African control programmes" in Infectious Diseases of Poverty claimed that undue influence on African programs by concepts developed by the Onchocerciasis Elimination Program of the Americas (OEPA) is detrimental to stopping mass drug administration (MDA) in Africa. This claim is made despite a record year for MDA stoppage in four African countries of > 3.5 million treatments in 2018, far exceeding any past OEPA or African Program for Onchocerciasis Control (APOC) stop MDA success.
May 2019
Comparison of Reported and Survey-based Coverage in Onchocerciasis Programs over a Period of Eight Years in Cameroon and Uganda (PDF)
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Moses N. Katabarwa, Emily Griswold, Peace Habomugisha, Albert Eyamba, Edson Byamukama, Philippe Nwane, Annet Khainza, Lauri Bernard, Paul Weiss, and Frank O. Richards
Mass drug administration (MDA) with ivermectin must reach a high treatment coverage (90% of the eligible population) if onchocerciasis is to be eliminated. Questions have been raised as to whether reported treatment figures reaching such high coverage are reliable. Sample surveys are proposed as the method of choice for “validating” reported coverage figures. The purpose of this study was to compare the district-level MDA coverage reported by programs with contemporaneous surveys of randomly selected respondents living in those same districts.
Nov. 19, 2018
Substantiating Freedom from Parasitic Infection by Combining Transmission Model Predictions with Disease Surveys (PDF)
Published by Nature Communications.
Authors: Edwin Michael, Morgan E. Smith, Moses N. Katabarwa, Edson Byamukama, Emily Griswold, Peace Habomugisha, Thomson Lakwo, Edridah Tukahebwa, Emmanuel S. Miri, Abel Eigege, Evelyn Ngige, Thomas R. Unnasch, and Frank O. Richards
Stopping interventions is a critical decision for parasite elimination programs. Quantifying the probability that elimination has occurred due to interventions can be facilitated by combining infection status information from parasitological surveys with extinction thresholds predicted by parasite transmission models. Here we demonstrate how the integrated use of these two pieces of information derived from infection monitoring data can be used to develop an analytic framework for guiding the making of defensible decisions to stop interventions.
Commentary 2: Elimination of Onchocerciasis in Africa by 2025: The Need for a Broad Perspective
Published by Infectious Diseases of Poverty.
Authors: Ed Cupp, Mauricio Sauerbrey, Vitaliano Cama, Mark Eberhard, Patrick J. Lammie, and Thomas R. Unnasch.
In response to the recent publication “Is onchocerciasis elimination in Africa feasible by 2025: a perspective based on lessons learnt from the African control programmes” by Dadzie et al., it is important to clarify and highlight the positive and unequivocal research and operational contributions from the American experience towards the worldwide elimination of human onchocerciasis (river blindness).
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Sept. 19, 2018
Operational Performance of the Onchocerca volvulus “OEPA” Ov16 ELISA Serological Assay in Mapping, Stop Mass Drug Administration, and Posttreatment Surveillance Surveys
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Frank O. Richards, Jr., Moses Katabarwa, Firdaweke Bekele, Zerihun Tadesse, Aderajew Mohammed, Mauricio Sauerbrey, Alfredo Dominguez-Vazquez, Mario A. Rodriguez-Perez, Nadia A. Fernandez-Santos, Nidia Rizzo, Harland R. Schuler Martınez, Raquel Lovato Silva, Zoraida Morales Monroy, Peace Habomugisha, David W. Oguttu, Issam M. A. Zarroug, Nabil A. Aziz, and Thomas R. Unnasch.
Onchocerciasis is a neglected tropical disease targeted for elimination. The World Health Organization (WHO) has developed guidelines for the verification of onchocerciasis elimination that include entomological and epidemiological criteria. The latter require demonstrating with statistical confidence that the infection prevalence in children is less than 0.1%, necessitating an assay with a high degree of specificity. We present an analysis of the performance of the Onchocerciasis Elimination Program for the Americas (OEPA) version of the Ov16 ELISA when used under operational conditions.
Aug. 27, 2018
Community-directed Vector Control to Supplement Mass Drug Distribution for Onchocerciasis Elimination in the Madi Mid-North Focus of Northern Uganda (PDF)
Published by PLOS Neglected Tropical Diseases.
Authors: Benjamin G. Jacob, Denis Loum, Thomson L. Lakwo, Charles R. Katholi, Peace Habomugisha, Edson Byamukama, Edridah Tukahebwa, Eddie W. Cupp, Thomas R. Unnasch
Onchocerciasis a neglected tropical disease that historically has been a major cause of morbidity and an obstacle to economic development in the developing world. It is caused by infection with Onchocerca volvulus, which is transmitted by black flies of the genus Simulium. The discovery of the potent effect of Mectizan (ivermectin) on O. volvulus microfilariae and the decision by its manufacturer to donate the drug for onchocerciasis spurred the implementation of international programs to control and, more recently, eliminate this scourge.
June 21, 2018
Evaluation of Treatment Coverage and Enhanced Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis in Five Local Government Areas Treating Twice Per Year in Edo State, Nigeria (PDF)
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Emily Griswold, Abel Eigege, Cephas Ityonzughul, Emmanuel Emukah, Emmanuel S. Miri, Ifeoma Anagbogu, Yisa A. Saka, Saliu Kadiri, Solomon Adelamo, Paul Ugbadamu, Clement Ikogho, and Frank O. Richards
The western region of Edo state in southern Nigeria is highly endemic for onchocerciasis. Despite years of mass drug administration (MDA) with ivermectin (IVM), reports suggest persistently high prevalence of onchocerciasis, presumably because of poor coverage. In 2016, twice-per-year treatment with IVM (combined with albendazole for lymphatic filariasis in the first round where needed) began in five local government areas of Edo state. We undertook a multistage cluster survey within 3 months after each round of MDA to assess coverage.
May 10, 2018
In Southern Nigeria Loa Loa Blood Microfilaria Density is Very Low Even in Areas with High Prevalence of Loiasis: Results of a Survey Using the New LoaScope Technology (PDF)
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Emmanuel Emukah, Lindsay J. Rakers, Barminas Kahansim, Emmanuel S. Miri, Bertram E. B. Nwoke, Emily Griswold, Yisa Saka, Ifeoma Anagbogu, Emmanuel Davies, Cephas Ityonzughul, Michael D’Ambrosio, Matthew Bakalar, Daniel A. Fletcher, Thomas Nutman, Joseph Kamgno, and Frank O. Richards Jr.
Ivermectin treatment can cause central nervous system adverse events (CNS-AEs) in persons with very high-density Loa loa microfilaremia (³ 30,000 mf/mL blood). Hypoendemic onchocerciasis areas where L. loa is endemic have been excluded from ivermectin mass drug administration programs (MDA) because of the concern for CNS AEs. The rapid assessment procedure for L. loa (RAPLOA) is a questionnaire survey to assess history of eye worm.
March 1, 2018
The Role of the NGDO Coordination Group for the Elimination of Onchocerciasis
Published by International Health.
Authors: Elizabeth Elhassan, Yaobi Zhang, Simon Bush, David Molyneux, Martin K.H. Kollmann, Yao Sodahlon, and Frank Richards.
With the paradigm shift from control of disease to elimination of onchocerciasis transmission, the NGDO Coordination Group for the Control of Onchocerciasis shifted its orientation and repositioned itself to build on the successes of the past to finish the job it began over 25 years ago.
March 1, 2018
The Role of National Committees in Eliminating Onchocerciasis
Published by International Health.
Authors: Emily Griswold, Thomas Unnasch, Mark Eberhard, Bertram E.B. Nwoke, Zoraida Morales, Edridah Muheki Tukahebwa, Biruck Kebede, Ifeoma Anagbogu, Moses Katabarwa, Peace Habomugisha, Zerihun Tadesse, Emmanuel S. Miri, Darin Evans, Daniel Cohn, Elizabeth Elhassan and Frank Richards.
National onchocerciasis elimination committees help ministries of health complete the pathway to verification of elimination of onchocerciasis (river blindness). In this article, we provide suggestions for organizing NOECs and examples of four such committees that have successfully operated in Africa and the Americas.
March 1, 2018
After 70 Years of Fighting an Age-old Scourge, Onchocerciasis in Uganda, the End is in Sight
Published by International Health.
Authors: Moses N. Katabarwa, Thomson Lakwo, Peace Habomugisha, Thomas R. Unnasch, Rolf Garms, Lauri Hudson-Davis, Edson Byamukama, Annet Khainza, Johnson Ngorok, Edridah Tukahebwa and Frank O. Richards.
In 2007 Uganda launched a transmission elimination policy based on twice-per-year treatment and vector control/elimination, with a goal of eliminating river blindness nationwide by 2020.
March 1, 2018
Progress Toward Elimination of Onchocerciasis in the Americas
Published by International Health.
Authors: Mauricio Sauerbrey, Lindsay J. Rakers, and Frank O. Richards, Jr.
The success of the Onchocerciasis Elimination Program for the Americas has had a great influence on programs in Africa, especially Sudan and Uganda. The successes in the Americas have also greatly influenced WHO guidelines for onchocerciasis transmission elimination.
Nov. 23, 2017
Mass Administration of Ivermectin in Areas Where Loa loa Is Endemic
Published by New England Journal of Medicine.
Author: Frank O. Richards Jr.
An innovative cell-phone–based device (the LoaScope) was used to rapidly identify persons with very high L. loa microfilariae counts (>20,000 mf per milliliter) and exclude them from ivermectin treatment. In a district in Cameroon where L. loa infection is highly endemic, more than 16,000 participants were tested with the LoaScope; testing led to the identification of 340 persons at high risk for serious adverse events and their exclusion from ivermectin treatment. Proper use of the LoaScope cell-phone device can help avoid adverse reactions to ivermectin in areas where Loa loa infection is known to exist.
Oct. 11, 2017
Evaluation of Community-directed Operation of Black Fly Traps for Entomological Surveillance of Onchocerca Volvulus Transmission in the Madi-Mid North Focus of Onchocerciasis in Northern Uganda (PDF)
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Denis Loum, Charles R. Katholi, Thomson Lakwo, Peace Habomugisha, Edridah M. Tukahebwa, and Thomas R. Unnasch
Entomological measures of transmission are important metrics specified by the World Health Organization to document the suppression and interruption of transmission of Onchocerca volvulus, the causative agent of onchocerciasis. These metrics require testing of large numbers of vector black flies. Black fly collection has relied on human landing collections, which are inefficient and potentially hazardous. As the focus of the international community has shifted from onchocerciasis control to elimination, replacement of human landing collections has become a priority.
Oct. 2, 2017
Molecular Identification of Onchocerca spp. Larvae in Simulium damnosum sensu lato Collected in Northern Uganda
Published by The American Journal of Tropical Medicine and Hygiene; 97(6):1843-1845. doi: 10.4269/ajtmh.17-0525.
Authors: Guilherme G. Verocai, Hassan K. Hassan, Thomson Lakwo, Peace Habomugisha, Moses N. Katabarwa, Stephen Begumisa, Philbert Clouds, James Katamanywa, Christine Nahabwe, Thomas R. Unnasch
Previous studies have demonstrated that the presence of larvae of other filarial species in Simulium damnosum sensu lato can distort estimates of transmission potential for Onchocerca volvulus in West Africa. However, studies conducted in foci of onchocerciasis in West Central Uganda indicated that larvae other than O. volvulus were not common in vectors collected there.
April 24, 2017
Upon entering an age of global ivermectin-based integrated mass drug administration for neglected tropical diseases and malaria
Published by Malaria Journal; Malar J. 2017 Apr 24. 16(1):168. doi: 10.1186/s12936-017-1830-z
Authors: Frank O. Richards Jr.
Ivermectin mass drug administration (MDA) in humans to reduce malaria vectors is yet another use for this remarkable medicine whose discoverers shared the 2015 Nobel Prize in Medicine with the discoverer of artemisinin. The malaria community should join those who have long used ivermectin MDA in an integrated battle to break transmission of three vector-borne parasitic diseases.
April 21, 2017
Securing America’s Legacy in the Fight Against Neglected Tropical Diseases
Published by The Hill.
Author: Ambassador (ret.) Mary Ann Peters
Global progress against malaria, HIV/AIDS, and other infectious diseases often makes headlines across our nation and around the world. And it should. Yet news rarely captures one of the biggest global health successes to date: our country’s efforts to eliminate neglected tropical diseases (NTDs).
March 23, 2017
Skin snips have no role in programmatic evaluations for onchocerciasis elimination: a reply to Bottomley et al.
Published by Parasit Vectors. 2017 March 23. 10(1):154. doi: 10.1186/s13071-017-2090-z
Authors: Eberhard ML, Cupp EW, Katholi CR, Richards FO, Unnasch TR
A critique of the recommendation that skin snips be used for post-MDA surveillance of formerly endemic onchocerciasis areas is provided. After considering several fundamental aspects of the use of this methodology within the context of prolonged mass distribution of ivermectin, we argue that skin-snipping has no value for monitoring onchocerciasis elimination programs.
Dec. 26, 2016
Interruption of the transmission of Onchocerca volvulus in the Kashoya-Kitomi focus, western Uganda by long-term ivermectin treatment and elimination of the vector Simulium neavei by larviciding
Published by Acta Tropica; 2017; 167: 128–136
Authors: T. Lakwo, R.Garms, J. Wamani, E.M. Tukahebwa, E.Byamukama, A.W. Onapa, E.Tukesiga, J. Katamanywa, S. Begumisa, P. Habomugisha, D. Oguttu, E. Byamukama, F. Richards, T.R. Unnasch, M. Katabarwa
Uganda is the only country in sub-Saharan Africa whose onchocerciasis elimination programme extensively uses vector control and biannual treatment with ivermectin. The purpose of this study was to assess the impact of combined strategies on interrupting onchocerciasis transmission in the Kashoya-Kitomi focus.
Nov. 2, 2016
The First Confirmed Elimination of an Onchocerciasis Focus in Africa: Abu Hamed, Sudan
Published by The American Journal of Tropical Medicine and Hygiene.
Authors: Zarroug IM, Hashim K, El-Mubark WA, Shumo ZA, Salih KA, El-Nojomi NA, Awad HA, Aziz N, Katabarwa M, Hassan HK, Unnasch TR, Mackenzie CD, Richards F, Higazi TB.
Mass treatment with ivermectin for onchocerciasis was stopped in 2012 in Abu Hamed, an isolated focus on the River Nile in northern Sudan. A 3-year posttreatment surveillance (PTS) ensued, at the end of which an evaluation was conducted in 2015 following the current World Health Organization guidelines for verification of onchocerciasis elimination. Vector black flies were collected from sentinel breeding sites and finger-prick bloodspots were collected from children ≤ 10 years of age resident in 35 communities within the focus.
June 24, 2016
A Knowledge, Attitudes and Practices Survey Conducted Three Years after Halting Ivermectin Mass Treatment for Onchocerciasis in Guatemala
Published by PLoS Neglected Tropical Diseases; doi: 10.1371/journal.pntd.0004777
Authors: Frank O. Richards Jr., Robert E. Klein, Oscar de León, Renata Mendizábal-Cabrera, Alba Lucía Morales, Vitaliano Cama, Carol G. Crovella, Carlos E. Díaz Espinoza, Zoraida Morales, Mauricio Sauerbrey, Nidia Rizzo.
Mass drug administration (MDA) with ivermectin for onchocerciasis was provided in Guatemala’s Central Endemic Zone (CEZ) over a 24 year period (1988–2011). Elimination of Onchocerca volvulus transmission was declared in 2015 after a three year post MDA surveillance period (2012–2014) showed no evidence of recrudescence. The purpose of the present study was to evaluate the knowledge, attitudes and practices (KAP) towards onchocerciasis and ivermectin among residents in the post endemic CEZ.
May 23, 2016
The Imaramagambo Onchocerciasis Focus in Southwestern Uganda: Interruption of Transmission after Disappearance of the Vector Simulium neavei and Its Associated Freshwater Crabs
Published by Am J Trop Med Hyg. 2016 Aug 3;95(2):417-25. doi: 10.4269/ajtmh.16-0181. Epub 2016 May 23
Authors: Katabarwa MN, Katamanywa J, Lakwo T, Habomugisha P, Byamukama E, Oguttu D, Nahabwe C, Ngabirano M, Tukesiga E, Khainza A, Tukahebwa E, Unnasch TR, Richards FO, Garms R.
It was not until early 1990s that, when the Imaramagambo focus of southwest Uganda was mapped, mass treatment with a single annual dose of ivermectin for onchocerciaisis control commenced. However, comprehensive investigations on its transmission were launched after a nationwide policy for onchocerciasis elimination in 2007.
Feb. 6, 2016
Presence of Wuchereria bancrofti microfilaremia despite 7 years of annual ivermectin monotherapy mass drug administration for onchocerciasis control: a study in north-west Ethiopia
Published by Pathog Glob Health. 2015; 109 (7):344-51
Authors: Endeshaw T, Taye A, Tadesse Z, Katabarwa MN, Shafi O, Seid T, Richards FO Jr.
There is considerable interest in determining whether mass drug administration (MDA) with ivermectin for onchocerciasis control will eliminate coendemic lymphatic filariasis (LF). The objective of this study was to determine the prevalence of LF microfilaremia in onchocerciasis endemic districts that had received 7 years of MDA with ivermectin.
Oct. 26, 2015
One Hundred Years After Its Discovery in Guatemala by Rodolfo Robles, Onchocerca volvulus Transmission Has Been Eliminated from the Central Endemic Zone (PDF)
Published by the American Journal of Hygiene and Tropical Medicine and reposted with permission.
Authors: Frank Richards Jr., Nidia Rizzo, Carlos Enrique Diaz Espinoza, Zoraida Morales Monroy, Carol Guillermina Crovella Valdez, Renata Mendizabal de Cabrera, Oscar de Leon, Guillermo Zea-Flores, Mauricio Sauerbrey, Alba Lucia Morales, Dalila Rios, Thomas R. Unnasch, Hassan K. Hassan, Robert Klein, Mark Eberhard, Ed Cupp, and Alfredo Dominguez.
We report the elimination of Onchocerca volvulus transmission from the Central Endemic Zone of onchocerciasis in Guatemala, the largest focus of this disease in the Americas and the first to be discovered in this hemisphere by Rodolfo Robles Valverde in 1915.
July 7, 2015
Community-Directed Interventions are Practical and Effective in Low-Resource Communities: Experience of Ivermectin Treatment for Onchocerciasis Control in Cameroon and Uganda, 2004-2010
Published by International Health and posted with permission.
Authors: Moses N. Katabarwa, Peace Habomugisha, Albert Eyamba, Edson Byamukama, Philippe Nwane, Alex Arinaitwe, Julius Musigire, Ruth Tushemereirwe, and Annet Khainza.
The community-directed intervention (CDI) approach has improved treatment coverage in onchocerciasis-affected communities. However, there is still a lot to learn. This study assessed its performance, and highlighted the lessons learnt so far.
May 30, 2015
Onchocerciasis and Lymphatic Filariasis Elimination in Africa: It's About Time
Published by The Lancet.
Authors: Darin S. Evans, Thomas R. Unnasch, Frank O. Richards
About 164 million Africans are at risk of onchocerciasis, and for more than two decades, mass drug administration with ivermectin has been the primary drug to control it.1 In 2010, WHO and the World Bank African Programme for Onchocerciasis Control (APOC) announced a strategic transition from onchocerciasis morbidity control to Onchocerca volvulus transmission elimination and set an elimination goal of 2025 for most of Africa.
May 21, 2015
The Contributions of Onchocerciasis Control and Elimination Programs Toward the Achievement of the Millennium Development Goals (PDF)
Published by PLOS: Neglected Tropical Diseases; doi: 10.1371/journal.pntd.0003703.
Authors: Caitlin Dunn, Kelly Callahan, Moses Katabarwa, Frank Richards, Donald Hopkins, P. Craig Withers Jr., Lucas E. Buyon, Deborah McFarland.
Onchocerciasis control is considered to be one of the most successful and cost-effective public health campaigns ever launched. In addition to improving to the health and well-being of millions of individuals, these programs also lead to improvements in education, agricultural production, and economic development in affected communities.
May 14, 2015
PLOS Collections | 40 Years of the APOC Partnership
Published by PLOS Neglected Tropical Diseases, info:doi/10.1371/journal.pntd.0003562.
In 1974 the Onchocerciasis Control Program (OCP) began its mission to control river blindness (onchocerciasis) in Africa, transitioning into the African Program for Onchocerciasis Control (APOC) in 1995. The launch of this collection coincides with the 41st anniversary of one of the most successful Private-Public-Partnership for health in Africa and describes all facets of the successes leading to the effective control of river blindness: partnerships, funding, distribution strategies, monitoring and evaluation, lessons learned, and advocacy. This partnership is unique in the involvement of a broad range of financial, scientific, and operational partners, with crucial roles played by a private sector drug donation and by a network of 15 NGOs.
Over the past two decades, these factors have been replicated and other companies have initiated donation programs of drugs to support other control and elimination efforts for neglected tropical diseases (NTDs). OCP and APOC have been so successful that blindness caused by onchocerciasis is no longer a public health problem in most of the countries. The Partnership now reaches more than 100 million people annually across Africa to control the disease. Today, billions are treated worldwide for NTDs and even larger partnerships have formed to improve collaboration and to ensure that the world's poorest populations have access to medicines for NTDs and strengthened health systems to improve health and fight poverty.
Oct. 11, 2014
Onchocerciasis Control in the Democratic Republic of Congo: Challenges in a Post-War Environment
Published by Tropical Medicine & International Health, 2014; doi:10.1111/tmi.12397.
Authors: J-C. Makenga Bof, V. Maketa, D. K. Bakajika, F. Ntumba, D. Mpunga, M. E. Murdoch, A. Hopkins, M. M. Noma, H. Zouré, A. H. Tekle, M. N. Katabarwa, and P. Lutumba.
The authors evaluated onchocerciasis control activities in the Democratic Republic of Congo (DRC) in the first 12 years of community-directed treatment with ivermectin (CDTI). They found that challenges to CDTI in DRC have been serious adverse reactions to ivermectin in loiasis co-endemic areas and political conflict.
Sept. 18, 2014
Status of Onchocerciasis Transmission after More Than a Decade of Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis Elimination in Central Nigeria: Challenges in Coordinating the Stop MDA Decision
Published by PLoS Neglected Tropical Diseases. PLoS Negl Trop Dis 8(9): e3113. doi:10.1371/journal.pntd.0003113
Authors: Darin S. Evans, Kal Alphonsus, Jon Umaru, Abel Eigege, Emmanuel Miri, Hayward Mafuyai, Carlos Gonzales-Peralta, William Adamani, Elias Pede, Christopher Umbugadu, Yisa Saka, Bridget Okoeguale, Frank O. Richards.
Both lymphatic filariasis and onchocerciasis are treated with ivermectin-based mass drug administration (MDA) regimens in Africa. Where the infections are co-endemic, ivermectin treatments cannot be stopped until both infection transmission cycles are broken. This report follows a previous determination that the LF transmission cycle had been interrupted in five districts (LGAs in Nigeria) but evidence was needed on the status of the onchocerciasis transmission cycle prior to halting MDA.
April 24, 2014
Twice-Yearly Ivermectin for Onchocerciasis: The Time is Now
Published by The Lancet Infectious Diseases.
Authors: Moses Katabarwa, Frank Richards.
The evidence for successful interruption of onchocerciasis transmission from the Americas, and Sudan and Uganda in Africa, provides clear justification for African onchocerciasis programmes to move rapidly from annual to twice-yearly treatment with ivermectin, at least in some areas. At a minimum, twice-yearly dosing should be instituted where annual mass drug administration has not interrupted transmission after 10 years, or in new areas that have never been treated with ivermectin so as to hasten interruption of transmission. These minimum standards are in line with the new policies of the African Programme for Onchocerciasis Control for onchocerciasis elimination with several African countries (including Nigeria, Ethiopia, Uganda, and Sudan) having stated a goal of eliminating the disease by 2020.
April 4, 2014
The impact of Merowe Dam on Simulium hamedense vector of onchocerciasis in Abu Hamed focus - Northern Sudan
Published by Parasites & Vectors, doi:10.1186/1756-3305-7-168.
Authors: Isam MA Zarroug, Arwa H Elaagip, Sara A Abuelmaali, Hanan A Mohamed, Wigdan A ElMubarak, Kamal Hashim, Tong Chor M Deran, Nabil Aziz, and Tarig B Higazi.
Abu Hamed, the northernmost onchocerciasis focus in the world, is located along the River Nile banks in the Nubian Desert. Merowe Dam, the largest hydropower project in Africa, was built west of Abu Hamed focus in 2009. The impact of the Dam on onchocerciasis and its black fly vectors in Abu Hamed focus was measured in this study. The artificial lake of the Dam flooded all the breeding sites in the western region of the focus and no aquatic stages and/or adult black fly activity were established in the study area upstream of the Dam. The Dam seems to have positive impact on onchocerciasis and its black fly vectors in Abu Hamed focus.
April 1, 2014
The Disappearance of Onchocerciasis Without Intervention in Tigray Region in Northwest Ethiopia
Published by Pathogens and Global Health.
Authors: M. Katabarwa, T. Endeshaw, A. Taye, Z. Tadesse, F.Richards.
Onchocerciasis in Tigray Region in Northwest Ethiopia disappeared without any interventions. In a study conducted in 1981 showed that onchocerciasis was endemic in the villages of Baaker, Bewal, Heligen, Umhager, and Humera town of Kafta Humera District in Mi'irabawi Zone of Tigray Region, northwestern Ethiopia. Compared to the baseline survey conducted 28 years previously, nodule prevalence among adults had decreased from 2.0% to 1%, and microfilaria rate from 24.6% to 0% (P < 0.0001). In children, no nodules were observed, and microfilaria prevalence was 0% (compared to 2.8% in 1981, P < 0.05). Absence of infection in adults and children indicated that onchocerciasis transmission had disappeared without MDA or entomological intervention.
March 31, 2014
Transmission of Onchocerca Volvulus by Simulium Neavei in Mount Elgon Focus of Eastern Uganda Has Been Interrupted (PDF)
Published by the American Journal of Tropical Medicine and Hygiene, 2014 doi:10.4269/ajtmh.13-0501.
Authors: Moses Katabarwa,* Tom Lakwo, Peace Habomugisha, Stella Agunyo, Edson Byamukama, David Oguttu, Richard Ndyomugyenyi, Ephraim Tukesiga, Galex Orukan Ochieng, Francis Abwaimo, Ambrose Onapa, Dennis W. K. Lwamafa, Frank Walsh, Thomas R. Unnasch, and Frank O. Richards.
The study determined that Simulium neavei-transmitted onchocerciasis in Mount Elgon onchocerciasis focus had been interrupted. Blood spots from 3,051 children obtained in 2009 were analyzed for exposure to Onchocerca volvulus immunoglobulin G4 antibodies. Fresh water crab host captures and black flies collected indicated their infestation with larval stages of S. neavei and presence or absence of the vector, respectively.
Feb. 5, 2014
Serosurveillance to Monitor Onchocerciasis Elimination: The Ugandan Experience
Published by the American Journal of Tropical Medicine and Hygiene.
Authors: David Oguttu, Edson Byamukama, Charles R. Katholi, Peace Habomugisha, Christine Nahabwe, Monica Ngabirano, Hassan K. Hassan, Thomson Lakwo, Moses Katabarwa, Frank O. Richards, and Thomas R. Unnasch.
Uganda is the only African country whose onchocerciasis elimination program uses a two-pronged approach of vector control and mass drug distribution. The Ugandan program relies heavily upon the use of serosurveys of children to monitor progress toward elimination. The program has tested over 39,000 individuals from 11 foci for Onchocerca volvulus exposure, using the Ov16 ELISA test. The data show that the Ov16 ELISA is a useful operational tool to monitor onchocerciasis transmission interruption in Africa at the World Health Organization (WHO) recommended threshold of < 0.1% in children.
Dec. 16, 2013
Onchocerciasis Serosurveillance in Uganda (PDF)
Published by the American Journal of Tropical Medicine and Hygiene, 2013; doi:10.4269/ajtmh.13-0546.
Authors: David Oguttu, Edson Byamukama, Charles R. Katholi, Peace Habomugisha, Christine Nahabwe, Monica Ngabirano, Hassan K. Hassan, Thomson Lakwo, Moses Katabarwa, Frank O. Richards, and Thomas R. Unnasch.*
The Ugandan onchocerciasis elimination program relies heavily upon the use of serosurveys of children to monitor progress toward elimination. The program has tested over 39,000 individuals from 11 foci for Onchocerca volvulus exposure, using the Ov16 ELISA test. The data show that the Ov16 ELISA is a useful operational tool to monitor onchocerciasis transmission interruption in Africa at the World Health Organization (WHO) recommended threshold of < 0.1% in children.
Sept. 12, 2013
River Blindness Success in Colombia Blazes Trail for Others to Eliminate the Disease
Published in Impatient Optimists, The Bill & Melinda Gates Foundation.
Author: Dr. Frank Richards
Colombia is the first nation in the Americas to eliminate onchocerciasis, also known as river blindness disease. This milestone not only ensures people in the Colombian community of Naicioná no longer suffer its symptoms - unbearable itching, skin lesions, diminished vision and potential blindness - but also paves the way for other countries in Latin America to wipe out the parasitic disease. The Carter Center - through its Onchocerciasis Elimination Program for the Americas (OEPA) has been working closely with ministries of health in all six affected Latin American countries since absorbing the River Blindness Foundation in 1996.
July 25, 2013
Validation of a Remote Sensing Model to Identify Simulium damnosum s.l. Breeding Sites in Sub-Saharan Africa (PDF)
Published by the PLoS Neglected Tropical Diseases and is reprinted with permission. PLoS Negl Trop Dis 7(7): e2342. doi:10.1371/journal.pntd.0002342
Authors: Benjamin G. Jacob, Robert J. Novak, Laurent D. Toe, Moussa Sanfo, Daniel A. Griffith, Thomson L. Lakwo, Peace Habomugisha, Moses N. Katabarwa, Thomas R. Unnasch.
Recently, most onchocerciasis control programs have begun to focus on elimination. Developing an effective elimination strategy relies upon accurately mapping the extent of endemic foci. In areas of Africa that suffer from a lack of infrastructure and/or political instability, developing such accurate maps has been difficult. The goal of this study was to conduct ground validation studies to evaluate the sensitivity and specificity of a remote sensing model developed to predict S. damnosum s.l. breeding sites.
May 20, 2013
Transmission of Onchocerca volvulus Continues in Nyagak-Bondo Focus of Northwestern Uganda after 18 Years of a Single Dose of Annual Treatment with Ivermectin (PDF)
Published by the American Journal of Tropical Medicine and Hygiene, 2013 doi: 10.4269/ajtmh.13-0037
Authors: Moses N. Katabarwa,* Tom Lakwo, Peace Habomugisha, Stella Agunyo, Edson Byamukama, David Oguttu, Ephraim Tukesiga, Dickson Unoba, Patrick Dramuke, Ambrose Onapa, Edridah M. Tukahebwa, Dennis Lwamafa, Frank Walsh, and Thomas R. Unnasch.
The objective of the study was to determine whether annual ivermectin treatment in the Nyagak-Bondo onchocerciasis focus could safely be withdrawn. Press release: May 20, 2013 - Onchocerciasis (River Blindness) Could Make Comeback in Northwestern Uganda if Annual Drug Administrations to Fight Parasitic Disease Are Stopped, New Study Shows >
March 25, 2013
Fifteen Years of Annual Mass Treatment of Onchocerciasis with Ivermectin Have Not Interrupted Transmission in the West Region of Cameroon
Published by J Parasitol Res.; Volume 2013, Article ID 420928, 12 pages; http://dx.doi.org/10.1155/2013/420928
Authors: Katabarwa MN, Eyamba A, Nwane P, Enyong P, Kamgno J, Kueté T, Yaya S, Aboutou R, Mukenge L, Kafando C, Siaka C, Mkpouwoueiko S, Ngangue D, Biholong BD, Andze GO
We followed up the 1996 baseline parasitological and entomological studies on onchocerciasis transmission in eleven health districts in West Region, Cameroon. Annual mass ivermectin treatment had been provided for 15 years. Follow-up assessments which took place in 2005, 2006, and 2011 consisted of skin snips for microfilariae (mf) and palpation examinations for nodules.
Jan. 3, 2013
Disease Eradication
Published by the New England Journal of Medicine, Vol 368 No. 1.pp. 53-64. Doi:10.1056/NEJMra1200391
Author: Donald R. Hopkins.
Since the last case of naturally-occurring smallpox in 1977, there have been three major international conferences devoted to the concept of disease eradication. Several other diseases have been considered as potential candidates for eradication, but the World Health Organization (WHO) has targeted only two other diseases for global eradication after smallpox. In 1986, WHO's policy-making body, the World Health Assembly, adopted the elimination of dracunculiasis (Guinea worm disease) as a global goal, and it declared eradication of poliomyelitis a global goal in 1988. Although both diseases now appear to be close to eradication, the fact that neither goal has been achieved after more than two decades, and several years beyond the initial target dates for their eradication, underscores the daunting challenge of such efforts, as does the failure of previous attempts to eradicate malaria, hookworm, yaws and other diseases. "Disease Eradication" was published as part one of "A Global View of Health – An Unfolding Series."Read the overview of the series >
July 6, 2012
Transmission of Onchocerciasis in Wadelai Focus of Northwestern Uganda Has Been Interrupted and the Disease Eliminated (PDF)
Published byt the Journal of Parasitology Research,volume 2012 (2012), article ID 748540, 7 pages. It is reprinted with permission.
Authors: Moses N. Katabarwa, Frank Walsh, Peace Habomugisha, Thomson L. Lakwo, Stella Agunyo, David W. Oguttu, Thomas R. Unnasch, Dickson Unoba, Edson Byamukama, Ephraim Tukesiga, Richard Ndyomugyenyi, and Frank O. Richards.
Wadelai, an isolated focus for onchocerciasis in northwest Uganda, was selected for piloting an onchocerciasis elimination strategy that was ultimately the precursor for countrywide onchocerciasis elimination policy.
March 2, 2012
Guide to detecting a potential recrudescence of onchocerciasis during the post treatment surveillance period: the American paradigm
Published by Research and Reports in Tropical Medicine. 2012: 3: 21–33
Authors: Program Coordinating Committee and OEPA staff; Cupp E, Ault, Dominguez, Eberhard, Grillet M, Morales, Nicholls, Richards F, Sauerbrey
Control and elimination of human onchocerciasis using mass drug administration of ivermectin (Mectizan®) has proceeded with marked gains over the past 10 years, more so in the Americas than in Africa. In the Americas, the initial focus on elimination of ocular morbidity has shifted to interruption of transmission, and the program has refined both the process leading up to interruption of transmission as well as the critical period following cessation of mass drug administration to document that there is no recrudescence of transmission.
Feb. 1, 2012
Lymphatic filariasis in western Ethiopia with special emphasis on prevalence of Wuchereria bancrofti antigenaemia in and around onchocerciasis endemic areas
Published by Trans R Soc Trop Med Hyg. Feb 2012: 106(2):117-27
Authors: Welelta Shiferaw, Tadesse Kebede, Patricia M. Graves, Lemu Golasa, Teshome Gebre, Aryc W. Mosher, Abiot Tadesse, Heven Sime, Tariku Lambiyo, K.N. Panicker, Frank O. Richards, Asrat Hailu
Lymphatic filariasis is known to be endemic in Gambella Region, western Ethiopia, but the full extent of its endemicity in other regions is unknown. A national mapping program for Ethiopia was initiated in 2008. This report summarizes initial data on the prevalence of Wuchereria bancrofti antigenaemia based on surveys carried out in a sampled population of 11 685 individuals living in 125 villages (112 districts) of western Ethiopia.
Dec. 6, 2011
Seventeen Years of Annual Distribution of Ivermectin Has Not Interrupted Onchocerciasis Transmission in North Region, Cameroon (Login required.)
Published by the American Journal of Tropical Medicine and Hygiene, 2011 vol. 85 no. 6 1041-1049. doi: 10.4269/ajtmh.2011.11-0333.
Authors: Moses N. Katabarwa, Albert Eyamba, Philippe Nwane, Peter Enyong, Souleymanou Yaya, Jean Baldiagaï, Théodore Kambaba Madi, Abdoulaye Yougouda, Gervais Ondobo Andze, and Frank O. Richards.
Since 1996, The Carter Center has provided ongoing assistance to Cameroon Ministry of Health (MOH) for distribution of ivermectin for onchocerciasis control in endemic areas of North Region, taking over a project that was launched by the MOH and the River Blindness Foundation in 1992. The African Program for Onchocerciasis Control (APOC) joined The Carter Center in supporting North Cameroon from 1998 to 2003. APOC was designed to substantially financially support delivery of an annual dose of ivermectin through community-directed treatment with ivermectin (CDTI) for 5 years. The objective was to establish a mechanism for sustained delivery of an annual dose of ivermectin, thereby achieving reduction of prevalence and transmission to a point where onchocerciasis would no longer be of public health or socioeconomic concern.
Dec. 1, 2011
Cost-Effectiveness of Triple Drug Administration (TDA) With Praziquantel, Ivermectin and Albendazole For the Prevention of Neglected Tropical Diseases in Nigeria
Published by the Annals of Tropical Medicine and Parasitology, 105(8). Online signup is required to read the full article.
Authors: Evans, D; Mcfarland, D; Adamani, W; Eigege, A; Miri, E; Schulz, J; Pede, E; Umbugadu, C; Ogbu-Pearse, P; Richards, F O.
Onchocerciasis, lymphatic filariasis (LF), schistosomiasis and soil transmitted, helminthiasis (STH) are all co-endemic in Nigeria. Annual mass drug administration (MDA) with ivermectin (for onchocerciasis), albendazole (for STH and with ivermectin for LF) and praziquantel (for schistosomiasis) is the WHO-recommended treatment strategy for preventive chemotherapy. Separate delivery rounds for distribution of these drugs have been the usual approach to MDA. All three drugs, however, have now been shown to be clinically and programmatically safe for co-administration with what has come to be known as triple drug administration (TDA). We examined the cost savings of converting from separate delivery rounds to TDA in two states in Nigeria.
Oct. 25, 2011
Onchocerciasis in the Americas: From Arrival to (Near) Elimination (PDF)
Published by Parasites & Vectors, 2011, 4:205. doi:10.1186/1756-3305-4-205. This article is reprinted with permission.
Authors: Ken Gustavsen, Adrian Hopkins, and Mauricio Sauerbrey.
Once endemic to six countries in the Americas (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela), onchocerciasis is on track for interruption of transmission in the Americas by 2012, in line with Pan American Health Organization resolution CD48.R12. The success of this public health program is due to a robust public-private partnership involving national governments, local communities, donor organizations, intergovernmental bodies, academic institutions, non-profit organizations and the pharmaceutical industry. The lessons learned through the efforts in the Americas are in turn informing the program to control and eliminate onchocerciasis in Africa.
September 2011
Elimination of human onchocerciasis: History of progress and current feasibility using ivermectin (Mectizan®) monotherapy
Published by Acta Tropica, 2011 doi:10.1016/j.actatropica.2010.08.009
Authors: Ed W. Cupp, Mauricio Sauerbrey, and Frank O. Richards Jr.
Ivermectin has proven exceedingly effective because it is highly efficacious against Onchocerca volvulusmicrofilariae, the etiological agent of onchocercal skin and ocular disease and the infective stage for the vector. For these reasons, the drug was donated by the Merck Company for regional control programs in Africa and the Americas. Recurrent treatment with ivermectin at semi-annual intervals also impacts adult worms and result in loss of fecundity and increased mortality.
Nov. 1, 2010
Emergence of Onchocerca Volvulus From Skin Mimicking Dracunculiasis Medinensis (PDF)
Published by the American Journal of Tropical Medicine and Hygiene, 83(6), 2010, pp. 1348-1351.
Authors: Mark L. Eberhard, Ernesto Ruiz-Tiben, Andrew S. Korkor, Sharon L. Roy, and Philip Downs.
We describe 11 cases of suspected Dracunculus medinensis infection in which the worm recovered was identified as Onchocerca volvulus. Identification was based on morphology of the examined specimen.
May 5, 2010
Effects of Annual Mass Treatment with Ivermectin for Onchocerciasis on the Prevalence of Intestinal Helminths (PDF)
Published by Am. J. Trop. Med. Hyg., 83(3), 2010, pp. 534-541. doi:10.4269/ajtmh.2010.10-0033; Copyright © 2010 by The American Journal of Tropical Medicine and Hygiene. Reprinted with permission.
Authors: Julie Gutman, Emmanuel Emukah, Njideka Okpala, Chinyere Okoro, Andrew Obasi, Emmanuel S. Miri, and Frank O. Richards, Jr.
We evaluated the effect of annual ivermectin (IV) distribution for onchocerciasis on the prevalence of soil transmitted helminth (STH) infections in school-aged (SAC) and preschool-aged (PAC) children by comparing children in villages that had received treatment for 13 years to those from socioeconomically similar villages in untreated areas.
May 4, 2010
Does Onchocerciasis Transmission Take Place in Hypoendemic Areas? A Study in North Region of Cameroon (PDF)
Published by The Journal of Tropical Medicine and International Health, volume 15 no 5 pp 645–652 May 2010. This peer reviewed version is reprinted with permission.
Authors: Moses N Katabarwa, Albert Eyamba, Mouhamadou Chouaibou, Peter Enyong, Thomas Kuété, Souleymanou Yaya, Abdoulaye Yougouda, Jean Baldiagaï, Kambaba Madi, Gervais Ondobo Andze, and Frank Richards.
Community-directed treatment with ivermectin (CDTI) for onchocerciasis control is targeted to meso and hyperendemic areas in Africa. Below the threshold, communities are considered hypoendemic and mass treatment is not recommended. As policy begins to shift from control to elimination, hypoendemic areas' role in maintaining Onchocerca volvulus needs re-examination. The study determined whether independent transmission occurs in a hypoendemic area in the north region of Cameroon.
April 1, 2010
Traditional Kinship System Enhanced Classic Community-Directed Treatment With Ivermectin (CDTI) for Onchocerciasis Control in Uganda (PDF)
Published by Transactions of the Royal Society of Tropical Medicine and Hygiene104 (2010) 265–272.
Authors: Moses N. Katabarwa, Peace Habomugisha, Stella Agunyo, Alanna C. McKelvey, Nicholas Ogweng, Solomon Kwebiiha, Fredrick Byenume, Ben Male and Deborah McFarland.
The challenges of community-directed treatment with ivermectin (CDTI) for onchocerciasis control in Africa have been: maintaining a desired treatment coverage, demand for monetary incentives, high attrition of community distributors and low involvement of women. This study assessed how challenges could be minimised and performance improved using existing traditional kinship structures.
Jan. 15, 2010
Lack of Active Onchocerca volvulus Transmission in the Northern Chiapas Focus of Mexico (PDF)
Published by Am. J. Trop. Med. Hyg., 83(1), 2010, pp. 15–20 doi:10.4269/ajtmh.2010.09-0626; Copyright © 2010 by The American Journal of Tropical Medicine and Hygiene. Reprinted with permission.
Authors: Mario A. Rodríguez-Pérez , Thomas R. Unnasch , Alfredo Domínguez Vázquez , Alba L. Morales-Castro ,Frank Richards Jr. , Graciela P. Peña-Flores , María Eugenia Orozco-Algarra, and Gibert Prado-Velasco.
The northern Chiapas onchocerciasis focus has undergone 11 years of ivermectin mass treatment. No evidence of microfilariae in the cornea and/or anterior chamber of the eye or in skin snips was seen in residents examined in 2006 in two sentinel communities (upper limit of the 95% confidence interval [UL 95% CI] = 0.5% and 0.3%, respectively).
Dec. 1, 2009
Monitoring Ivermectin Distributors Involved in Integrated Health Care Services Through Community-Directed Interventions – a Comparison of Cameroon and Uganda Experiences Over a Period of Three Years, 2004-2006, (PDF)
Published by The Journal of Tropical Medicine and International Health, volume 15 no 2 pp 216-223. This peer reviewed version is reprinted with permission.
Authors: Moses Katabarwa, Peace Habomugisha, Albert Eyamba, Stella Agunyo, and Catherine Mentou.
Community-directed interventions (CDI) is an approach where the community is given adequate information to get involved in decision-making, organization and mobilization of resources to tackle any challenges that affect its health. This study assesses and compares the effectiveness of ivermectin distributors in attaining 90 percent treatment coverage of the eligible population with each additional health activity they take up.
Nov. 22, 2009
Interruption of Transmission of Onchocerca volvulus in the Oaxaca Focus, Mexico (PDF)
Published by Am. J. Trop. Med. Hyg., 83(1), 2010, pp. 21-27, doi:10.4269/ajtmh. 2010.09-0544; Copyright © 2010 by The American Journal of Tropical Medicine and Hygiene. Reprinted with permission.
Authors: Mario A. Rodríguez-Pérez, Thomas R. Unnasch, Alfredo Domínguez-Vázquez, Alba L. Morales-Castro, Graciela P. Peña-Flores, María E. Orozco-Algarra, Juan I. Arredondo-Jiménez, Frank Richards, Jr., Miguel A. Vásquez-Rodríguez, and Vidal García Rendón.
All endemic communities of the Oaxaca focus of onchocerciasis in southern Mexico have been treated annually or semi-annually with ivermectin since 1994. In-depth epidemiologic assessments were performed in communities during 2007 and 2008. None of the 52,632 Simulium ochraceum s.l. collected in four sentinel communities was found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in an upper bound of the infection rate in the vectors of 0.07/2,000.
Sept. 5, 2009
Sustainability of Ivermectin Distribution Programmes
Published by The Lancet, Volume 374, Issue 9692, pgs. 785 - 786, and is reprinted with permission.
Authors: Lindsay J Rakers, Emmanuel Emukah, Jude Onyenama d, Grace Amah, Nnenna Ukairo, Uche Enyinnaya, Emmanuel Miri, Frank Richards
Onchocerciasis causes skin and eye disease that can be prevented by an annual dose of ivermectin. The African Programme for Onchocerciasis Control (APOC) was originally founded on the premise that, after 5 years with external funding provided jointly through a World Bank Trust Fund and a non-governmental organisation (NGO) partner, community-directed treatment with ivermectin would continue "completely independent of external support for upwards of 15 years."
March 31, 2009
Successful Interruption of Transmission of Onchocerca volvulus in the Escuintla-Guatemala Focus, Guatemala (PDF)
Published by the PLoS Journal of Neglected Tropical Diseases and is reprinted with permission. PLoS Negl Trop Dis 3(3): e404. doi:10.1371/journal.pntd.0000404.
Authors: Rodrigo J. Gonzalez, Nancy Cruz-Ortiz, Nidia Rizzo, Jane Richards, Guillermo Zea-Flores, Alfredo Dominguez, Mauricio Sauerbrey, Eduardo Catu´, Orlando Oliva, Frank O. Richards Jr, Kim A. Lindblade.
Elimination of onchocerciasis (river blindness) through mass administration of ivermectin in the six countries in Latin America where it is endemic is considered feasible due to the relatively small size and geographic isolation of endemic foci. We evaluated whether transmission of onchocerciasis has been interrupted in the endemic focus of Escuintla- Guatemala in Guatemala, based on World Health Organization criteria for the certification of elimination of onchocerciasis. Read the press release>
Oct. 7, 2008
Pan American Health Organization Passes Resolution to Interrupt Transmission of River Blindness in Latin America by 2012
Published by The Carter Center
Author: Emily Staub
In an effort to eliminate river blindness (onchocerciasis) from the Western Hemisphere, the Pan American Health Organization (PAHO) issued an urgent call to interrupt the disease's transmission by 2012.
Sept. 1, 2008
The Onchocerciasis Elimination Program for the Americas (OEPA) (PDF)
Published by the Annals of Tropical Medicine & Parasitology, Vol. 102, Supplement No. 1, pp 25–29(5) (2008) and is reprinted with permission.
Authors: M. Sauerbrey
Human onchocerciasis (river blindness) occurs in 13 foci distributed among six countries in Latin America (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela), where about 500,000 people are considered at risk.
Sept. 1, 2008
After a Decade of Annual Dose of Mass Ivermectin Treatment in Cameroon and Uganda, Onchocerciasis Transmission Continues (PDF)
Published by Tropical Medicine and International Health, Volume 13, no. 9, pp 1–8. © 2008 Blackwell Publishing Ltd.
Authors: Moses Katabarwa, Albert Eyamba, Peace Habomugisha, Tom Lakwo, Same Ekobo, Joseph Kamgno, Thomas Kuete, Richard Ndyomugyenyi, Ambrose Onapa, Mkpouwoueiko Salifou, Marcelline Ntep and Frank O. Richards.
To evaluate the effectiveness of 10 years' annual single dose ivermectin treatment on onchocerciasis transmission in hyperendemic areas of Cameroon and Uganda.
June 1, 2008
Dracunculiasis, Onchocerciasis, Schistosomiasis, and Trachoma (PDF)
Published by the Annals of the New York Academy of Sciences, 1136: 45-52 (2008), Issue - Reducing the Impact of Poverty on Health and Human Development: Scientific Approaches.
Authors: Donald R. Hopkins, Frank O. Richards, Jr, Ernesto Ruiz-Tiben, Paul Emerson, P. Craig Withers, Jr.
The four diseases discussed in this chapter (dracunculiasis, onchocerciasis, schistosomiasis, and trachoma) are among the officially designated "Neglected Tropical Diseases," and each is also both the result of and a contributor to the poverty of many rural populations. To various degrees, they all have adverse effects on health, agricultural productivity, and education (Originally published Online: 25 Jul 2008. The definitive version is available at wiley.com).
March 1, 2008
Short Report: Could Neurocysticercosis Be the Cause of "Onchocerciasis-Associated" Epileptic
Seizures? (PDF)
Published by Am. J. Trop. Med. Hyg., 78(3), 2008, pp. 400–401. Copyright © 2008 by The American Journal of Tropical Medicine and Hygiene.
Authors: Moses Katabarwa,* Tom Lakwo, Peace Habumogisha, Frank Richards, and Mark Eberhard.
We conducted a nodule prevalence survey in four onchocerciasis sentinel communities in Moyo and two in Kanungu districts of Uganda. Seven (33.3%) out of 21 excised "onchocercomas" (nodules) in Moyo District and excised onchocercomas from four of six persons in Kanungu District turned out to be cysts of Taenia solium.
Jan. 1, 2008
Evidence for Suppression of Onchocerca volvulus Transmission in the Oaxaca Focus in Mexico (PDF)
Published by Am. J. Trop. Med. Hyg., 78(1), 2008, pp. 147–152, Copyright © 2008 by The American Journal of Tropical Medicine and Hygiene.
Authors: Mario A. Rodríguez-Pérez,* Cristian Lizarazo-Ortega, Hassan K. Hassan, Alfredo Domínguez-Vásquez, Jorge Méndez-Galván, Patricia Lugo-Moreno, Mauricio Sauerbrey, Frank Richards Jr., and Thomas R. Unnasch.
The overall goal of the Onchocerciasis Elimination Program in the Americas (OEPA) is to eliminate onchocerciasis as a public health problem, culminating in the elimination of the infection in the six disease-endemic countries of Latin America. To assist in this process, the World Health Organization (WHO) has developed a series of guidelines to certify that an area is free of onchocerciasis.
Nov. 2007
No Depletion of Wolbachia from Onchocerca volvulus after a Short Course of Rifampin and/or Azithromycin
Published by Am J Trop Med Hyg. Nov 2007: 77(5): 878-882.
Authors: Richards F, Amann J, Arana B, Punkosdy G, Klein R, Blanco C, Lopez B, Mendoza C, Domínguez A, Guarner J, Maguire JH, Eberhard M.
Endosymbionic Wolbachia bacteria inside adult Onchocerca volvulus worms (causing river blindness) are necessary for female worm fertility. We evaluated whether rifampin and/or azithromycin used in a five-day course could kill Wolbachia.
Oct. 1, 2006
Successful integration of insecticide-treated bed net distribution with mass drug administration in Central Nigeria (PDF)
Published by Am J Trop Med Hyg; 75: 4: 650-5. Copyright © 2006 by The American Journal of Tropical Medicine and Hygiene
Authors: Blackburn BG, Eigege A, Gotau H, Gerlong G, Miri E, Hawley WA, Mathieu E, Richards F.
Malaria remains a major public health problem in subSaharan Africa.1 Though all segments of society are afflicted, children under 5 years of age (U5) and pregnant women (PW) suffer most of the morbidity and mortality. The World Health Organization’s Roll Back Malaria (RBM) initiative aims to decrease the burden of disease through 3 proven interventions: prompt management of presumed malaria cases, intermittent preventative treatment of pregnant women, and widespread use of insecticide-treated bed nets (ITNs).
July 15, 2005
Mass ivermectin treatment for onchocerciasis: lack of evidence for collateral impact on transmission of Wuchereria bancrofti in areas of co-endemicity
Published by Filaria J. July 15, 2005: 4: 6.
Authors: Richards F, Eigege A, Pam D, Alphonsus K, Lenhart A, Oneyka JO, Jinadu MY, Miri ES.
There has long been interest in determining if mass ivermectin administration for onchocerciasis has 'unknowingly' interrupted lymphatic filariasis (LF) transmission where the endemicity of the two diseases' overlaps. We studied 11 communities in central Nigeria entomologically for LF by performing mosquito dissections on Anopheline LF vectors.
April 1, 2005
Community-directed interventions strategy enhances efficient and effective integration of health care delivery and development activities in rural disadvantaged communities of Uganda
Published by Tropical Medicine & International Health Volume 10 Issue 4 Page 312 - April 2005
Authors: M. N. Katabarwa, P. Habomugisha, F. O. Richards Jr and D. Hopkins, The Carter Center, Atlanta GA, USA.
The community-directed interventions (CDI) strategy achieved a desired coverage of the ultimate treatment goal (UTG) of at least 90% with ivermectin distribution for onchocerciasis control, and filled the gap between the health care services and the communities.
Jan. 1, 2005
Significant Decrease in the Prevalence of Wuchereria Bancrofti Infection in Anopheline Mosquitoes Following the Addition of Albendazole to Annual, Ivermectin-Based, Mass Treatments in Nigeria (PDF)
Published in Annals of Tropical Medicine and Parasitology; 99: 155-64.
Authors: Richards, F., Pam, D., Kal, A., Gerlong, G., Oneyka, J., Sambo, Y., Danboyi, J., Ibrahim, B., Terranella, A., Kumbak, D., Dakul, A., Lenhart, A., Rakers, L., Umaru, J., Mafuyai, H., Jinadu, M., Miri, E., and Eigege, A.
Jan. 1, 2005
Editorial: Whither Onchocerciasis Control in Africa? (PDF)
Published by Am. J. Trop. Med. Hyg., 2005 Jan;72(1):1-2. (No abstract available). PMID: 15728857
Authors: D. R. Hopkins, F.O. Richards, and M. Katabarwa, The Carter Center, Atlanta, Georgia; Centers for Disease Control and Prevention, Atlanta, Georgia.
Infection with the vector-borne filarial parasite Onchocerca volvulus causes chronic skin and eye lesions, often progressing to blindness, and imposes an immense burden on affected populations.1,2 Most of those who have or are at risk of this infection are African.
Nov. 2004
The Effects of Long-Term Community Level Treatment with Ivermectin (Mectizan®) on Adult Onchocerca volvulus in Latin America
Published by Am J Trop Med Hyg. Nov 2004; 71: 602-7.
Authors: Cupp, EW, Duke B, Mackenzie C, Guzmán JR, Vieira JC, Mendez-Galvan J, Castro J, Richards F, Sauerbrey M, Dominguez A, Eversole RR, Cupp MS.
The objective of this study was to examine nodules from Mexico, Guatemala, and Ecuador collected over a one-year period (2001) to determine the effects of semi-annual ivermectin treatments on Onchocerca volvulus macrofilarial populations.
Oct. 2004
Missed Treatment Opportunities in Onchocerciasis Mass Treatment Programs for Pregnant and Breast-Feeding Women in Southeast Nigeria
Published by Annals Trop Med Parasitol. 2004: 98: 697-702.
Authors: Maduka C, Nweke L, Miri E, Amazigo U, Richards F.
During annual rounds of mass treatment against onchocerciasis, women who are pregnant or nursing neonates should not to be offered ivermectin. The aim of the present study was to determine how many women were not treated, as a result of this policy, in four villages in south-eastern Nigeria.
August 20, 2004
Report from the Thirteenth InterAmerican Conference on Onchocerciasis, Cartagena de Indias, Columbia
Published by Wkly Epidemiol Rec. Aug 20, 2004: 79(34): 310-312.
Authors: World Health Organization
The thirteenth annual InterAmerican Conference on Onchocerciasis (IACO 2003) was held in Cartagena de Indias, Colombia, on 18–20 November 2003. The meeting was organized by the Colombian Ministry of Health and OEPA, with financial support from The Carter Center, Lions Clubs International Foundation, PAHO and Merck & Co., Inc.
June 26, 2004
Kinship Structure and Health-Care Improvement in Sub-Saharan Africa
Published by The Lancet, Volume 363, Number 9427, as a letter to the editor.
In sub-Saharan Africa, inadequate resources, poor planning and management, and high poverty levels are so pervasive that apathy is almost the order of the day. Public-health indices from Africa attest to this.1,2Even where success has been achieved, its sustainability has not been assured.
Jan. 1, 2004
A Longitudinal Study of Impact of Repeated Mass Ivermectin Treatment on Clinical Manifestations of Onchocerciasis in Imo State, Nigeria (PDF)
Published by American Journal of Tropical Medicine and Hygiene 2004; 70:556-61.
Authors: E.C. Emukah, E. Osuoha, E.S. Miri, J. Onyenama, U. Amazigo, C. Obijuru, N. Osuji, J. Ekeanyanwu, S. Amadiegwu, K. Korve, F. Richards.
We conducted a cohort study on impact of effects of eight years of annual ivermectin mass treatment administered in eight villages in Imo State, Nigeria. Physical and visual acuity examinations carried out in 462 persons in 1995, prior to the launching of mass drug administration with ivermectin, were compared with re-examinations of 411 (89%) of these same individuals in 2002. We found that gross visual impairment decreased from 16% to 1%, nodult prevalence decreased from 59% to 18%, and papular dermatitis was reduced from 15% to 2%. No change was seen in leopard skin rates (14%). the only incident lesions were three subjects from a single community having the appearance of new nodules (e.g., nodules not identified in the 1995 examinations). Differences in community coverage did not appear to influence the benefit from treatment of individual residents.
Oct. 24, 2003
A Framework for Decision-Making for Mass Distribution of Mectizan® in Areas Endemic for Loa loa
Published by Filaria J. 2003: 2(Suppl 1): S9
Authors: Addiss D, Rheingans R, Twum-Danso N, Richards F.
The occurrence of Loa loa encephalopathy following mass treatment of onchocerciasis with Mectizan(R) has adversely affected onchocerciasis control efforts in central Africa. Persons with very high densities of L. loa microfilaremia are at increased risk of encephalopathy, but little is known about the geographic distribution of these persons within central Africa.
Feb. 7, 2003
Final report of the Conference on the eradicability of Onchocerciasis
Published in Filaria Journal, 2003 doi: 2(1):2
Authors: Yankum Dadzie, Maria Neira, and Donald R. Hopkins.
Sixty-four experts from a variety of disciplines attended a Conference on the Eradicability of Onchocerciasis at The Carter Center, in Atlanta GA, held January 22-24, 2002. The Conference, which was organized by The Carter Center and the World Health Organization, with funding from the Bill & Melinda Gates Foundation, addressed the question: "Is onchocerciasis (River Blindness) eradicable with current knowledge and tools?" Former US President Jimmy Carter attended part of the final plenary proceedings on January 24.
Sept. 1, 2002
Ten years of NGDO action against river blindness
Published by Trends in Parasitology. 2002: 18(9): 378-380.
Authors: Drameh P, Richards F, Cross C, Etya’ale D, Kassalow J.
For a decade, a dozen non-governmental development organizations (NGDOs) have organized themselves into a Geneva-based coordination group with the goal of global control of onchocerciasis through mass distribution of ivermectin (Mectizan®).
March 2002
The achievements and challenges of the African Programme for Onchocerciasis Control (APOC)
Published by Annals Trop Med Parasitol. 2002: 96(Supp 1): S15-S28.
Authors: Seketeli A, Adeoye G, Eyamba A, Nnoruka E, Drameh P, Amazigo UV, Noma M, Agboton F, Aholou Y, Kale OO, Dadzie KY.
The main strategy of APOC, of community-directed treatment with ivermectin (CDTI), has enabled the programme to reach, empower and bring relief to remote and under-served, onchocerciasis-endemic communities. With CDTI, geographical and therapeutic coverages have increased substantially, in most areas, to the levels required to eliminate onchocerciasis as a public-health problem.
March 2002
The challenges of community-directed treatment with ivermectin (CDTI) within the African Programme for Onchocerciasis Control (APOC)
Published by Annals Trop Med Parasitol. 2002: 96(Supp 1): S41-S58.
Authors: Amazigo U, Brieger W, Katabarwa M, Akogun O, Ntep M, Boatin B, N'Doyo J, Noma M, Sékétéli A.
The principal strategy adopted by the African Programme for Onchocerciasis Control (APOC), for the control of onchocerciasis in the 19 countries of Africa that now fall within the programme's remit, is that of community-directed treatment with ivermectin (CDTI). Halfway through its 12-year mandate, APOC has gathered enough information on the main challenges to guide its activities in Phase 2.
Jan. 1, 2002
Involvement and Performance of Women in Community-Directed Treatment With Ivermectin for Onchocerciasis Control in Rukungiri District, Uganda (PDF)
Published by Annals of Tropical Medicine & Parasitology, Vol. 95, No. 5, 485-494 (2001).
Authors: Katabarwa, M.N., Habomugisha, P., Ndyomugyenyi, R., and Agunyo, S.
The present study aimed: (1) to assess and improve the level of women's involvement in a strategy to control onchocerciasis by community-directed treatment with ivermectin (CDTI) in three parishes of Rukungiri District, Uganda; (2) to measure the performance of female community-directed health workers (CDHWs) in comparison with males; and (3) to identify culturally acceptable means of enchancing women's involvement in community-directed healthcare.
Jan. 1, 2002
Lymphatic Filariasis Elimination and Schistosomiasis Control in Combination with Onchocerciasis Control in Nigeria (PDF)
Published by American Journal of Tropical Medicine and Hygiene. 2002; 67(3):266-72.
Authors: Hopkins D.R., Eigege A., Miri E.S., Gontor, I., Ogah, G., Umaru, J., Gwomkudu, C.C., Mathai, W., Jinadu, M.Y., Amadiegwu, S., Oyenekan, O.K., Korve, K., Richards, F.O.
This paper describes a pilot initiative to incorporate lymphatic filariasis (LF) elimination and urinary schistosomiasis (SH) control into a mature onchocerciasis control program bsed on community-directed ivermectin treatment in central Nigeria. In the same districts having onchocerciasis we found LF (as determined by blood antigen testing in adult males) in 90% of 149 villages with a mean prevalence of 22.4% (range 0-67%). Similarly, SH, as a mean prevalence in school age children of 24.4% (range 0-87%). Health education and treatment interventions for SH resulted in 52,480 cumulative praziquantel treatments, and 159,555 combined onchocerciasis and LF treatments (with ivermectin and albendazole) as of the end of 2000. Treatments for onchocerciasis and LF were separated by at least 1 week from treatments for SH. There was no negative impact on the coverage of the onchocerciasis program by the addition of LF and SH activities.
Dec. 1, 2001
Control of Onchocerciasis Today: Status and Challenges
Published by Trends in Parasitology, 2001 doi:10.1016/S1471-4922(01)02112-2
Authors: Frank O. Richards Jr., Boakye Boatin, Mauricio Sauerbrey, and Azodoga Sékétéli.
The filarid parasite Onchocerca volvulus is the causative agent of human onchocerciasis (river blindness), an infection characterized by chronic skin and eye lesions. There are three regional programs currently dedicated to controlling onchocerciasis in the endemic areas of Africa and the Americas: the Onchocerciasis Control Programme of West Africa, the African Programme for Onchocerciasis Control and the Onchocerciasis Elimination Program for the Americas. All three programs use periodic mass treatment with the microfilaricidal drug ivermectin with differing strategic purposes and, as a result, face different challenges to reach their goals.
Dec. 1, 2001
The Carter Center's Assistance to River Blindness Control Programs: Establishing Treatment Objectives and Goals for Monitoring Ivermectin Delivery Systems on Two Continents (PDF)
Published by the American Journal of Tropical Medicine and Hygiene 2001; 65:108-14.
Authors: F. Richards, E. Miri, M. Katabarwa, A. Eyamba, M. Sauerbrey, G. Zea-Flores, K. Korve, W. Mathai, M. Homeida, I. Mueller, E. Hilyer, and D. Hopkins.
Periodic mass treatment with ivermectin in endemic communities prevents eye and dermal disease due to onchocerciasis. As part of an international global partnership to control onchocerciasis, The Carter Center's Global 2000 River Blindness Program (GRBP) assists the ministries of health in ten countries to distribute ivermectin (Mectizan®, donated by Merck & Co.). The GRBP priorities are to maximize ivermectin treatment coverage and related health education and training efforts, and to monitor progress through regular reporting of ivermectin treatments measured against annual treatment objectives and ultimate treatment goals (e.g., full coverage, which is defined as reaching all persons residing in at risk villages who are eligible for treatment). Since the GRBP began in 1996, more than 21.2 million ivermectin treatment encounters have been reported by assisted programs. In 1999, more than 6.6 million eligible persons at risk for onchocerciasis received treatment, which represented 96% of the 1999 annual treatment objective of 6.9 million, and 78% of the ultimate treatment goal in assisted areas.
Nov. 1, 2001
On the Road with President Carter: Targeting River Blindness
Published by The Carter Center
Author: President Carter
During November 2001, former President Jimmy Carter attended the 11th annual InterAmerican Conference on Onchocerciasis in Mexico City, which brought together high-level representatives from the six onchocerciasis- or river blindness-endemic countries in the Americas to discuss recent findings that, under certain conditions, it is feasible to eliminate river blindness in the Americas. Occurring mostly in Africa, the disease also threatens about 540,000 people in Mexico, Guatemala, Venezuela, Colombia, Ecuador, and Brazil.
May 1, 2001
Involvement of Women in Community-Directed Treatment With Ivermectin for the Control of Onchocerciasis in Rukungiri district, Uganda: a knowledge, attitude and practice study (PDF)
Published by Tropical Medicine & Parasitology, Vol. 95, No. 5, 485-494 (2001).
Authors: Katabarwa, M.N., Habomugisha, P., Ndyomugyenyi, R., and Agunyo, S. Published in Annals of
A study of knowledge, attitudes and practice was carried out in the Rukungiri district of Uganda, in order to investigate the involvement of women in community-directed treatment with ivermectin (CDTI), for the control of onchocerciasis. The data analysed came from interviews with 260 adult women (one from each of 260 randomly-selected households in 20 onchocerciasis-endemic communities), community informants, and participatory evaluation meetings (PEM) in eight communities. The women who had been treated with ivermectin in 1999 generally had more knowledge of the benefits of taking ivermectin, were more likely to have attended the elevant health-education sessions and were more involved in community decisions on the method of ivermectin distribution than the women who had not received ivermectin in that year. There were fewer female community-directed health workers (CDHW) than male CDHW in the communities investigated. The reasons for not attending health-education sessions, not participating in community meetings concerning the CDTI, and the reluctance of some women to serve as CDHW were investigated.
Feb. 1, 2001
Community-Directed Health (CDH) Workers Enhance the Performance and Sustainability of CDH Programmes: experience from ivermectin distribution in Uganda (PDF)
Published by Annals of Tropical Medicine & Parasitology, Vol. 95, No. 3, 275-286 (2001).
Authors: M.N. Katabarwa, F.O. Richards Jr.
The performance and `drop-out’ rates of ivermectin (Mectizan) distributors in the Ugandan programme for community-directed treatment with ivermectin (CDTI) were investigated and related to the manner in which the distributors were recruited. Distributors, from randomly selected communities endemic for onchocerciasis in seven of the 10 affected districts, were interviewed.
Jan. 1, 2000
In Rural Ugandan Communities the Traditional Kinship/Clan System is Vital to the Success and Sustainment of the African Programme for Onchocerciasis Control (PDF)
Published by Annals of Tropical Medicine and Parasitology 94, 485-495.
Authors: Katabarwa, N. M.; Richards, F.O. Jr.; and Ndyomugyenyi, R.
In rural Ugandan communities where onchocerciasis is meso- or hyper-endemic, conrol of the disease is now being carried out using a strategy of community-directed programmes for the annual distribution of ivermectin to all persons eligible to take the drug. For these programmes to achieve their annual target coverage of at least 90% of the population eligible to take ivermectin, and to continue to sustain themselves for 10-15 years or more, even after external donor funding ceases, it has been found essential to replace the initial community-based strategy, imposed from outside, by a community-directed strategy developed by the community members themselves. Furthermore, it is essential for success that full use be made of the traditional social system, which is very strong in all rural communities in Uganda. This system is based on patrilineal kinships and clans, governed by traditional law, and in it women play an important role. If this system is ignored or by-passed by governmnet health personnel or by the sponsors and promoters of the programme, the communities are likely to fail to reach their targets.
Nov. 27, 1999
Monetary incentives and community-directed health programmes in some less-developed countries
Published by Lancet. 1999: 354: 1909.
Authors: Katabarwa M, Mutabazi D, Richards F.
New campaigns on community-based treatment or control measures are being launched against several major endemic diseases in less-developed tropical countries.
August 1999
Rapid epidemiological mapping of onchocerciasis (REMO) in areas of Uganda where Simulium neavei sl is the vector
Published by East Africa Medical Journal. 1998: 76(8).
Authors: Katabarwa M, Onapa A, Nakileza B.
This study was undertaken to test whether rapid epidemiological mapping of onchocerciasis (REMO) was suitable for mapping of onchocerciasis in foci where Simulium neavei sl is the primary vector. Topographical maps of scale 1:250,000 were used in demarcating regions into ecotopographic divisions and zones in order to identify potential onchocerciasis endemic areas in Kabarole and Nebbi districts in Uganda.
Feb. 27, 1999
Ivermectin distribution for onchocerciasis in Africa.
Published by Lancet. 1999: 353: 757.
Authors: Katabarwa M, Mutabazi D, Richards F.
Ivermectin as a single oral dose annually prevents derma and ocular morbidity from onchocerciasis.1 The drug is preventive, not curative, and treatment may be required indefinitely in places where parasite transmission is not interrupted.
June 1, 1998
The Onchocerciasis Elimination Program for the Americas: A History of Partnership (PDF)
Published by the Pan American Journal of Public Health 3(6), 1998 and is reprinted with permission.
Authors: J. Blanks, F. Richards, F. Beltrán, R. Collins, E. Álvarez, G. Zea Flores, B. Bauler, R. Cedillos, M. Heisler, D. Brandling-Bennett, W. Baldwin, M. Bayona, R. Klein, and M. Jacox
The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan® (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal.
April 1998
Problems and perspectives of managing an onchocerciasis control programme
Published by Annals Trop Med Parasitol. 1998: 92: S121-128.
Authors: Miri E.
The onchocerciasis control programme in Plateau state (now Plateau and Nasarawa states), Nigeria, was one of the pioneering Mectizan-distribution projects in Nigeria. Although initiated under the River Blindness Foundation (RBF) in 1991, in collaboration with the Ministry of Health, it was absorbed into the Carter Center's Global 2000 River Blindness Programme (GRBP) in 1996.
Oct. 3, 1997
Dracunculiasis and Onchocerciasis: Sudan
Published by Wkly Epidemiol Rec. 1997: 72: 297-301.
Authors: Dr A. Tayeh
In March 1995, the Government of Sudan announced a cease-fire to permit acceleration of efforts to eradicate dracunculiasis, control onchocerciasis, and deal with certain other health problems.
Jan. 1, 1996
Community-Based Ivermectin Distributors: Onchocerciasis Control at the Village Level in Plateau State, Nigeria (PDF)
Published by Acta Tropica 1996; 61:137-44.
Authors: F. Richards, C. Gonzales-Peralta, E. Jallah, E. Miri.
The use of community residents as agents for distributing mass ivermectin therapy for onchocerciasis provides a component of community participation absent from mobile team delivery methods. Community-based distribution, however, presupposes preexisting human resources in the endemic villages capable of fulfilling the essential functions of an ivermectin distribution process: mobilizing and educating the population, dispensing the drug, maintaining records, and monitoring and treating adverse reactions Even when such human resources exist, the comunity workers must continue to receive tangible support from both external (government and donor agencies) and internal (community) sources.
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