The final bastion of river blindness in the Americas lies along the border of Brazil and Venezuela, where the nomadic Yanomami indigenous people reside in hard-to-reach, ring-shaped temporary communities in the Amazon rainforest called shaponos. In partnership with the respective national governments and indigenous health workers, Â鶹´«Ã½ supports the provision of health education and effective treatment to the Yanomami where they are.
(All photos courtesy of Oscar Noya Alarcón)
River blindness once was endemic in about a dozen discrete transmission zones scattered across a wide swath of Latin America, but, thanks to the efforts of the national programs together with the Â鶹´«Ã½’s Onchocerciasis Elimination Program for the Americas (OEPA), the disease has been eliminated in Colombia, Ecuador, Mexico, and Guatemala.
It remains now only among people who live in the Amazon rainforest. River blindness was introduced to the indigenous population by outsiders.
River blindness is spread by the bites of infected black flies that thrive near fast-moving water. The flies transmit tiny worms that mature under the infected person’s skin, causing intense itching, rashes, skin nodules, and skin discoloration. Embryonic parasites (microfilariae) produced by female worms can eventually migrate to the eyes, where they can cause vision impairment and, ultimately, blindness.
The drug Mectizan®, donated by Merck, is effective at killing the microfilariae, ending the itching and preventing blindness. Eliminating the microfilariae within the body prevents the flies from transmitting the disease from one person to another.
If enough people are treated, transmission can be eliminated throughout an entire population, halting the disease cycle.
The correct dose of Mectizan is based on the height of the recipient. Individuals are measured and then given the appropriate number of tablets. When surveys show that transmission in a population has fallen to essentially zero, treatment can safely be halted. then continues for at least three years to make sure the disease hasn’t come back.
An estimated 35,000 highly mobile indigenous people live in isolated communities along the Amazon River.
The Venezuelan and Brazilian health ministries at times take advantage of their rare contact with the Yanomami to also provide a range of standard vaccinations or other health services, including malaria or dental treatment, during the same visit.
Indigenous health agents are essential to the work, as they understand the language and culture and are thus able to explain the need for treatment and how it is accomplished. Just as important, these indigenous agents know the ways of the rainforest and are adept at finding and following paths that might be impossible for outsiders to use on their own.
The photos in this gallery were created by Dr. Oscar Noya Alarcón, a physician and pilot of the Onchocerciasis Elimination Program team in Venezuela who has to participate in restoration of abandoned jungle airstrips to improve access to the Yanomami. "I consider it to be a privilege and a luxury to be able to enter into contact with communities that are so isolated from the world at large and who have been able to preserve their culture and their way of life," he says.
Please sign up below for important news about the work of Â鶹´«Ã½ and special event invitations.
