Public Health Officials Announce Progress in Elimination of Transmission of the Tropical Disease River Blindness

Whitehouse Station, N.J., U.S.A. and Oaxaca, Mexico – Public health officials gathering at the 18th Inter-American Conference on Onchocerciasis (IACO) in Oaxaca, Mexico, announced that transmission of the tropical disease onchocerciasis (also known as river blindness) has been halted in areas covering 31 percent of the population in Latin America formerly at risk of contracting the disease.

Health officials confirmed that in Oaxaca, Mexico and Huehuetenango, Guatemala, onchocerciasis transmission has been interrupted due to the effectiveness of treatment with MECTIZAN(R) (ivermectin). This raises the total population no longer in need of treatment with MECTIZAN to 157,446, or 31 percent of the 510,947 people in the Americas considered at risk for the disease.

This accomplishment follows an historic resolution passed on Oct. 7, 2008, by the Pan American Health Organization (PAHO) calling for the interruption of onchocerciasis transmission throughout the Americas by the year 2012.

"The continued success towards elimination of onchocerciasis in the Americas signals improved health for hundreds of thousands of people," said Dr. Mauricio Sauerbrey, director of the Onchocerciasis Elimination Program of the Americas (OEPA). "The recent commitment by PAHO to interrupt transmission of the disease by 2012 will galvanize the resolve of all the partners involved with this landmark initiative in public health."

According to Juan Arredondo Jimenez, head of the National Center of Disease Surveillance and Control of the Mexican Ministry of Health, "In Mexico there were only three affected areas: one in Oaxaca and two in Chiapas. In Oaxaca, with some 45,000 people, there are no more cases of blindness due to this disease and transmission has been interrupted. Therefore, OEPA recommends stopping treatment in 2009, followed by epidemiological surveillance through 2011. This follows the program's success in North Chiapas, leaving only South Chiapas for further treatment and, hopefully, elimination of the disease very soon as well."

Onchocerciasis, a leading cause of preventable blindness worldwide, is transmitted through the bite of black flies and can cause intense itching, disfiguring dermatitis, eye lesions and over time, blindness. It is hyper-endemic in 34 countries, primarily in sub-Saharan Africa and isolated areas of the Americas and Yemen. In October 1987, Merck announced it would donate MECTIZAN – the only well-tolerated drug known to halt the development of onchocerciasis – to all who need it for as long as necessary until onchocerciasis is eliminated as a public health problem.

Announcements Give Hope to Other Countries

The Ministries of Health of Mexico and Guatemala made today's announcement based on epidemiological studies conducted by their national onchocerciasis program and OEPA, a program of the Carter Center, which showed that onchocerciasis infection levels had been maintained at a level low enough to effectively break the cycle of transmission. The program attributed the results to the strategy of twice annual mass treatment with MECTIZAN. Based on these findings, experts from the Program Coordinating Committee of OEPA recommended that treatment with MECTIZAN should be suspended in Oaxaca, Mexico and Huehuetenango, Guatemala.

"In 2007, Colombia became the first country in the world to interrupt onchocerciasis transmission on a country-wide basis. Today's announcement continues the expectation that onchocerciasis can be eliminated by 2012 from all affected countries in the Americas," said Dr. Adrian Hopkins, director of the MECTIZAN Donation Program.

Since 1989, more than 8 million treatments with MECTIZAN have been approved for distribution in Latin America by community health workers and non-governmental organizations. Treatment programs currently exist in Brazil, Ecuador, Guatemala, Mexico and Venezuela. Partners in the MECTIZAN Donation Program in Latin America include Merck & Co., Inc., OEPA, The Carter Center, Lions Clubs International Foundation, The Bill & Melinda Gates Foundation, the WHO/PAHO and Ministries of Health of the affected countries.

About the MECTIZAN Donation Program

To date, the MECTIZAN Donation Program has approved more than 600 million treatments for onchocerciasis to 33 countries in Africa, Latin America and Yemen and donated more than 2 billion MECTIZAN tablets, at a market value of US$3 billion. The program currently reaches more than 80 million people each year for the treatment of onchocerciasis; an estimated 40 million treatments of MECTIZAN are also approved each year for lymphatic filariasis through Merck's work with the Global Alliance to Eliminate Lymphatic Filariasis. To ensure the appropriate infrastructure, distribution and support for the donation, Merck established in 1988 the MECTIZAN Donation Program, working through a unique, multisectoral partnership, involving the WHO, the World Bank, UNICEF, ministries of health, non-governmental development organizations and local communities. The MECTIZAN Donation Program Secretariat is housed at the Taskforce for Child Survival and Development in Atlanta, Ga., U.S.A. For more information, visit www.mectizan.org.

About OEPA

The Onchocerciasis Elimination Program of the Americas (OEPA) is the technical and coordinating body of a multinational, multi-agency coalition working to end illness and transmission of onchocerciasis in Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela. The Carter Center is the sponsoring agency for OEPA, whose partnership includes the ministries of health of the six affected countries in Latin America, PAHO, the Centers for Disease Control and Prevention, academic institutions and independent organizations. For more information, visit www.oepa.net.

About Merck

Merck & Co., Inc. is a global research-driven pharmaceutical company dedicated to putting patients first. Established in 1891, Merck discovers, develops, manufactures and markets vaccines and medicines to address unmet medical needs. The Company devotes extensive efforts to increase access to medicines through far-reaching programs that not only donate Merck medicines but help deliver them to the people who need them. Merck also publishes unbiased health information as a not-for-profit service. For more information, visit www.merck.com.

Forward-Looking Statement

This press release contains "forward-looking statements" as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements are based on management's current expectations and involve risks and uncertainties, which may cause results to differ materially from those set forth in the statements. The forward-looking statements may include statements regarding product development, product potential or financial performance. No forward-looking statement can be guaranteed, and actual results may differ materially from those projected. Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, or otherwise. Forward-looking statements in this press release should be evaluated together with the many uncertainties that affect Merck's business, particularly those mentioned in the risk factors and cautionary statements in Item 1A of Merck's Form 10-K for the year ended Dec. 31, 2007, and in its periodic reports on Form 10-Q and Form 8-K, which the Company incorporates by reference.

For more information please contact:

Amy Rose
Merck & Co., Inc.
(908) 423-6537