BUJUMBURA, January 13th (ABP) – Onchocerciasis, more commonly known as “river blindness,” is a parasitic disease classified as a neglected tropical disease. It is caused by the parasitic worm called “onchocerca volvulus,” according to Dr. Alexis Ndayisaba, an infectious disease specialist at Prince Regent Charles Hospital.
On Thursday, January 9, 2025, that infectious disease expert told a check by ABP that onchocerciasis is transmitted through repeated contact with infected simulis, occurring in fast-flowing rivers and streams, especially in isolated villages located near fertile lands where the population depends on agriculture.
He further stressed that this disease is prevalent in tropical areas, and that more than 99% of infected people live in 31 countries in sub-Saharan Africa, including Burundi, Rwanda, and the Democratic Republic of Congo. Dr. Ndayisaba said that the symptoms of this disease are due to microfilariae that move in subcutaneous tissues, causing violent inflammatory reactions when they die. He also added that infected people experience severe itching and skin lesions, and that they can also sometimes have eye lesions that can lead to visual impairment and irreversible blindness.
According to him, in most cases, nodules appear under the skin around the adult worms. Regarding diagnosis, infectiologist Ndayisaba explained that microfilariae are detected by microscopic examination of superficial skin biopsies, the cornea or the anterior chamber of the eye. Identification of adult worms in nodules is also done, as well as PCR (Polymerase Chain Reaction) to detect parasite DNA in samples. Ndayisaba also adds that slit lamp examination of the anterior chamber of the eye and cornea is also done when diagnosing this disease. In relation to the treatment of this disease, Dr. Ndayisaba says that the treatment of onchocerciasis involves ivermectin at least once a year for 10 to 15 years.
Expert Ndayisaba calls on the Burundian population in endemic areas to prevent onchocerciasis by administering ivermectin annually or biannually, and to fight against vectors (similis) by wearing protective clothing and using insect repellents. It should be noted that untreated onchocerciasis can lead to blindness.