River blindness eradicated in 13 districts

New data from the health ministry indicates river blindness has been eliminated in 13 districts, reducing the adult population most at risk of the skin and eye disease to about 1.8 million Ugandans.

Data presented at the 9^th session of the Uganda Onchocerciasis Elimination Expert Advisory Committee meeting at the Sheraton Kampala Hotel on Thursday, indicated the country "more than hit" the target to restrict the disease from 36 to less than 10 districts in mid-northern Uganda from 2007 to today.

"When we started active treatment of the disease (in 2007), over 36 districts in Uganda reported cases. However, these cases have been contained and active transmission limited to a few districts in mid-northern Uganda," assistant commissioner for health services in charge of neglected tropical diseases at the ministry's vector control division Dr. Edridah Muheki Tukamuhebwa said presenting the data.

She said total eradication of the disease vectored by an infected female blackfly had been registered in 13 districts. These include Kabarole, Kyenjojo, Buhweju, Rubirizi, Mitooma, Bushenyi and Mbale districts.

Other districts where the disease has been eliminated are Sironko, Bududa, Manafwa, Ibanda, Kamwenje and Moyo districts.

Dr. Edridah Muheki Tukamuhebwa said the target was to eliminate the disease out of Uganda by 2020.

"With the intensive river dosing and treatment of persons (in radius of the infested rivers) programme, we hope to contain the disease and be certified as River Blindness free by 2020," she said.

The remaining districts where the disease is still rife include Gulu, Lamwo, Kitgum, Pader, Oyam and parts of Nwoya and Moyo.  

River blindness or onchocerciasis is spread by an infected female blackfly, common in rapid flowing rivers and around forested areas.

The disease bears the name (River Blindness) because the fly that transmits the infection breeds in rapidly flowing streams and the infection can cause blindness.

Assistant commissioner Health Service, Edridah Mweheki Tukahebwa, and chairman of Uganda Onchocerciasis Elimination Expert Advisory Committee (UOEEAC) Tom Unnasch during the 9th session at Sheraton Hotel. Photo by Mary Kansiime

Latest research also linked parasites spread by the vector to the brain-attacking nodding syndrome.     

Persons with heavy onchocerciasis infections will usually have one or more of three conditions: skin rash (usually itchy), eye disease, or nodules under the skin.

In extreme cases, persons with the disease develop a ‘leopard or lizard skin' because of scars sustained from over scratching the itching skin. The disease causes blindness when the parasites get to the eyes.

The World Health Organization's (WHO) expert committee on onchocerciasis estimates that at least 25 million people are infected and 123 million people live in areas that put them at risk of infection.

About 300,000 people are blind because of the parasite and another 800,000 have visual impairment. Nearly 99% of infected persons live in Africa.

Dr. Anthony Mbonye, the acting director general of health services at the health ministry, said the parasitic worm (Onchocerca volvulus) that causes the skin disease can stay beneath a patient's skin for up to 17 years.

The disease symptoms are predominant in adults above 20 years when the parasites start to ‘bite'. Blindness, which is the disease's end stage, is common in persons above 40 years.

"That is when the parasites have ‘crawled' beneath the skin and reached the eyes," the doctor said.

The infection can be treated with a dose of mectin.

Dr. Tukamuhabwa said they were intensifying interventions in the mid-northern Uganda districts where transmissions of the disease are still ongoing.

"Because of the civil unrest (the region experienced in 1990's), we started massive treatment of rivers which contain the blackfly, especially the falls at Aruu, and persons around these rivers in 2009," she said.

However, there are also concerns about districts that share the Uganda Congo border, especially the districts of Kabale, Kisolo, Zombo and Arua.

No new cases have been reported in these districts but the ministry is hesitant to say they are free from the infection unless it crosschecked with neighboring Congo.

Kisoro district health officer Dr. Stephen Nsaniyumva said they were working with officers the other side of the border to eliminate disease.