River blindness may soon be a thing of the past in East Africa.
Scientists believe a long-term community drug treatment in Abu Hamed, Sudan has eradicated this parasitic disease, which causes severe skin problems and in some cases, total blindness.
Abu Hamed is the world’s northernmost location of onchocerciasis, also known as river blindness. In 1998, residents of this Nile River town began a community-directed treatment program of ivermectin, a medication that stems the infestation of worms.
In 2012, treatment was halted after scientists found that following eight years of annual treatment and six years of semi-annual treatment, there was no evidence of the disease or its transmission around Abu Hamed.
Dr. Tarig Higazi, who was born and raised in Sudan, is a professor at Ohio University and lead author for the study. His team studied three primary onchocerciasis-endemic areas in Sudan and South Sudan
Higazi said that the findings from northern Sudan are significant.
“And we now prove that the disease is not transmitted. So there’s no more treatment in northern Sudan,” he said. “And hopefully, in a couple of years, we’ll be able to prove that the disease has been eliminated.”
The disease will be officially declared eliminated in Abu Hamed after three years of mandatory post-treatment surveillance are complete, in accordance with World Health Organization guidelines.
Higazi said that this is the first time river blindness appears to have been completely eliminated in a large remote area – with over 100,000 people at risk in Abu Hamed.
“It is very isolated, it’s far away from any other endemic areas, it’s in the middle of the Sahara Desert, basically, meaning that it’s only confined to the River Nile,” he said.
Onchocerciasis is transmitted by black flies that breed in fast-moving waterways. The flies serve as disease vectors, so when they bite humans, they deposit larvae under the skin that develop into adult worms.
As the worms grow under the skin, they cause severe itching and discomfort. In South Sudan, Higazi said, the disease more closely resembles the West African strain, where blindness occurs.
But, not everyone with river blindness goes blind.
Higazi asserted that in Sudan, for example, people do not usually lose their eyesight from the disease. Instead, they may suffer from what locals call sowda
, meaning that the limb appears completely black.
“And the interesting thing about the disease is that it was not a blinding disease. So, you barely see any blind people,” he said. “But, the skin reactions, there are very severe skin reactions, but basically there is no blindness.”
Scientists from the Carter Center
, a U.S.-based NGO focused on health, human rights, and democracy initiatives, and the U.S. Centers for Disease Control and Prevention
attribute the global progress in eliminating the disease to ivermectin, the de-worming medication.
Experts like Dr. Mark Eberhard, a senior microbiologist with the CDC’s Division of Parasitic Diseases and Malaria, said that this medicine – all on its own, is a bit of a miracle worker.
“Just to clarify and be really clear, that when given long enough, often enough and to a high percentage of the population, ivermectin can not only control the disease, but you can interrupt transmission,” he said.
According to the Carter Center, river blindness in Africa accounts for more than 99 percent of cases worldwide.
And within Africa, the World Bank estimates that more than 102 million people are at risk of the disease.