River blindness in East Africa: gains and losses

Fifty year old Santina Apoto is a mother of five children and lives in a small village in the Kitgum district of Uganda. Her eyes are cloudy and seem permanently fixed on a distant point. Because of onchocerciasis, or river blindness, Apoto has been blind for over a decade now.

The flies that are to blame for the disease know no geographic boundaries—onchocerciasis elimination requires strong cross border collaborations to avoid transmission. The Democratic Republic of Congo (DRC), South Sudan, and Uganda are all making efforts to eliminate it. Uganda is the nearest to that goal and DRC is following suit. South Sudan is not yet on course.

Apoto says she started experiencing pain in her eyes in 2004. She visited Kitgum General Hospital for treatment in 2005 and was referred to Mulago National Referral Hospital in Uganda’s capital city, Kampala.

“I had no idea what the doctor meant when he gave me the diagnosis of river blindness—at first I thought it was the water we drink,” says Apoto. “I also suspected that someone had bewitched my eyes.”

River blindness is caused by Onchocerca volvulus, a filarial nematode worm that is transmitted by black flies that breed in fast moving rivers. These flies transmit juvenile worms, or microfilariae, into the host causing severe itching, skin lesions, impaired vision, and, eventually, blindness.

The World Health Organization says that onchocerciasis is the second major infectious cause of blindness in Africa, behind cataracts. The Global Burden of Disease Study estimated in 2017 that there were 20.9 million prevalent O volvulus infections worldwide; 14.6 …