A regional initiative launched in the 1990s to eliminate onchocerciasis (river blindness) in the Americas has substantially reduced the prevalence of the disease in recent years, as evidenced by a 31% decrease in the number of individuals requiring mass drug administration in six endemic countries. Results were reported today at the 58th annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH).
The reported progress reflects the success of the Onchocerciasis Elimination Program for the Americas (OEPA), which promotes health education and twice-yearly administration of the deworming drug Mectizan® (ivermectin) to more than 85% of the eligible population of endemic communities in six countries. The OEPA was formed in response to a 1991 Pan American Health Organization (PAHO) resolution to stop blindness from onchocerciasis in the Americas by 2007 (later augmented to stop transmission by 2012).
The Carter Center in Atlanta, GA is the sponsoring agency for the Guatemala-based OEPA, a partnership that includes the six endemic countries, Lions Clubs Foundation International, the U.S. Centers for Disease Control and Prevention (CDC), the PAHO (the American regional office of the World Health Organization), and the Bill & Melinda Gates Foundation. Merck & Co., Inc. contributes greatly to the program's achievements by donating supplies of Mectizan for as long as is necessary to eliminate river blindness as a public health problem.
"OEPA is a true success story made possible by the combined efforts of governments, industry, and untold numbers of local people doing field work in extremely difficult conditions," said Frank O. Richards, MD, who directs the River Blindness Program of The Carter Center. "However, we cannot rest on our laurels. Critical work remains to be done to reach our goal of interrupting onchocerciasis transmission in the Americas by 2012."
Onchocerciasis, the world's second leading infectious cause of blindness, is a parasitic disease caused by a roundworm called Onchocerca volvulus. It is transmitted to humans by the bites of tiny black flies that breed in rapidly flowing rivers and streams. The worm enters the body through the skin, under which it matures and reproduces. The offspring, known as microfilariae, migrate under the skin and cause intense itching. Movement of the microfilariae to the eyes can result in worsening vision and blindness. The World Health Organization (WHO) estimates that approximately half a million people worldwide have been blinded by onchocerciasis.
"Opportunities to eliminate any tropical disease, especially on a regional level, are rare and infrequent. The progress reported today by the OEPA is a real milestone," said Thomas Wellems, MD, PhD, president of ASTMH. "Onchocerciasis is a major obstacle to economic growth in many countries, particularly in Africa because it often results in arable land being abandoned out of fear of infestation. By ridding countries of this and other diseases, we will see the world economy improve. Health advances are the foundation for increased prosperity."