Uganda is edging closer to eliminating river blindness from the country. The government announced this week that it eliminated the disease in four areas of focus in the country, leaving only two more areas with active transmission of the parasite.
“This is the largest number of human beings declared free of river blindness under the current guidelines ever,” said Frank Richards, director of the River Blindness Elimination Program at the Carter Center, in an interview with Humanosphere.
River blindness, also known as onchocerciasis, is caused by a parasite acquired through a black fly bite. It generally occurs in areas with swift rivers. People who are infected with the parasite experience symptoms including intense itching and eye damage. Permanent blindness occurs in some cases that go untreated. Killing off the parasite is the only way to protect people and stop transmission.
Achieving elimination in Uganda by the goal date of 2020 will require dealing with issues beyond the parasite. Areas in the border region with the Democratic Republic of the Congo have succeeded in stopping transmission for the moment, but it’s uncertain whether it will hold given the potential that it can spread cross-border.
“We have areas that have cross-border transmission, and that has been a challenge for us and many countries,” Moses Katabarwa, senior program epidemiologist for the River Blindness Elimination Program at the Carter Center, told Humanosphere. “The problem is because we relied on international solutions – like working with WHO in Geneva or regional offices. What seems to work is working with the local people in the country.”
Local solutions are emerging. Katabarwa is working with officials in the Congo to track and control the spread of river blindness. The recent success in Uganda means that 821,230 people are no longer at risk. But there is still more work to be done in the country. The two remaining focus areas where the parasite is actively transmitted are home to nearly 1.5 million people.
There are also some questions about areas previously determined to have eliminated river blindness. Victoria, for example, achieved elimination in the 1960s. The roughly 1 million people that live in the region are counted among those who are onchocerciasis-free, but Richards warns the area does not likely meet the new standards set out by the World Health Organization (WHO).
“Uganda’s accomplishment is evidence that total elimination of river blindness is possible in Africa,” said Anthony Mbyne, director health services with the Ugandan Ministry of Health, in a statement.
More than 99 percent of all onchocerciasis cases are currently found in Africa. It is still found in a few parts of Latin America. The Onchocerciasis Control Program launched by the WHO in the 1970s helped to significantly reduce cases in West Africa through insecticide spraying. More recently the program is focused on providing preventive treatment. It reached more than 112 million people in 22 African countries in 2014, covering about 65 percent of people affected globally.
The Carter Center and the pharmaceutical company Merck are working with other organizations and governments to end river blindness. The drug Ivermectin is distributed to people in areas where the parasite is still transmitted. It acts to prevent people from getting sick when infected and kills off the parasite so it does not spread to more people. More than 240 million treatments have been distributed as a result of the partnership with the Carter Center, and that is in addition to the work done through the WHO.
Community health workers are at the front lines of the fight. They are the people providing the drug and educating their communities about the disease and how to prevent it. So far, the plan is working. Colombia, Ecuador and Mexico were declared to have eliminated onchocerciasis in the past three years. Work is continuing in Brazil, Ethiopia, Guatemala, Nigeria, Sudan, Uganda and Venezuela to bring the number of global cases down to zero.
If all goes well, Guatemala will officially be declared to have eliminated the parasite in 2016. Uganda may follow four years later.
