GUATEMALA CITY — On Monday, Sept. 26, The Pan American Health Organization (PAHO) declared Guatemala the fourth nation in the world to have eliminated onchocerciasis, commonly known as river blindness, after more than two decades of trying.
River blindness is an eye and skin disease transmitted to humans through repeated bites from infected black flies that breed near fast-flowing streams and rivers. The disease causes severe itching of the skin and eye lesions that can lead to visual impairment or irreversible blindness if left untreated.
People living in poverty are more susceptible to the disease, as are communities that depend economically on crops cultivated in fertile river valleys. In Guatemala, people living on coffee plantations were most at risk, as fast-flowing streams that provide irrigation became the primary breeding grounds for the infected flies. According to the Centers for Disease Control and Prevention (CDC), 231,467 Guatemalans were at risk for onchocerciasis, more than any other country in the Americas.
Guatemala’s eradication of river blindness is a huge achievement that required the collective efforts of health workers and volunteers, communities and the government. The country joined Colombia, Ecuador and Mexico, which became onchocerciasis-free between 2013 and 2015.
Efforts to combat river blindness in Guatemala were mainly contributed by The Onchocerciasis Elimination Program for the Americas (OEPA), a regional initiative launched in response to the 1991 resolution of PAHO to eliminate onchocerciasis transmission in the six endemic countries in the Americas: Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela.
OEPA is a partnership program that includes the six endemic countries, PAHO, Merck & Co., Inc., the CDC and international nongovernmental development organizations (INGDOs). The initiative aims to interrupt the transmission of onchocerciasis in the 13 foci, primary centers from which the disease developed and localized, by 2007. Before the launch of this initiative, Guatemala had the greatest number of foci out of all six countries.
Guatemala’s main strategy to eliminate this disease was the periodic mass administration of the drug Mectizan® (ivermectin), which was provided by the Mectizan Donation Program of pharmaceutical company Merck. The antiparasitic drug was delivered semiannually for up to 12 years and dosage was calibrated according to the height and weight of individual recipients. The country was able to administer the medicine to at least 85 percent of its eligible population.
The four transmission foci in Guatemala included 518 endemic communities. Along with mass distributing the drug ivermectin, many community health workers also dedicated numerous hours to educating endemic communities about the disease. Guatemala’s Santa Rosa and Escuintla foci were the first in the Americas to interrupt transmission of the disease in 2006 and 2007 respectively.
Rodolfo Robles, a Guatemalan physician and researcher, also played an imperative role in eliminating the disease. In 1915, Robles discovered the relationship between onchocerciasis and the visual impairments it causes. His discovery helped shed new light on the disease, and onchocerciasis is now known as “Robles disease” in his honor.
Although river blindness has been eliminated in 95 percent of the endemic regions so far, active transmission is still present in two foci, among Yanomami indigenous people in the remote border areas of Venezuela and Brazil, and in regions of Africa. However, the Carter Center and Merck are continuing to collaborate with other organizations to eliminate river blindness not only in the Americas but also worldwide.
– Kelly Yu