An investigation by experts showed there have been no new cases in the area. Since the two stories appeared in July, Sightsavers has been working with the Kaduna State Ministry of Health, the Federal Ministry of Health, National Eye Centre and Nigerian Institute of Trypanosomiasis and Onchocerciasis to investigate their validity.
A survey covering epidemiological, entomological and ophthalmological investigations was conducted. Teams of surveyors used standard methodologies such as Rapid Assessment of Blindness (RAAB) examinations and skin snip samples to check communities for the disease. Surveyors also carried out a search for black flies, which transmit the disease, and their larvae along river banks in the communities and laboratory examinations of the flies for presence of Onchocerca volvulus, which causes the disease.
The results of the survey showed an absence of adult black fly in the communities, and the analysis of the skin snip tests were negative for the disease, proving that river blindness isn’t present in these communities.
The ophthalmologic investigation showed that 2.5 per cent of the 315 people examined were blind. It was found that three of the eight blind people were blind as a result of optic atrophy attributable to river blindness, but all three people were above 50 years of age, thereby indicating that these are not new cases of river blindness.
Sightsavers Nigeria Country Director Sunday Isiyaku said: “The absence of infected black fly as well microfilaria in the population disproves the possibility of active disease transmission. The result of the survey therefore invalidates claims made in the media stories about the possibility of fresh infection in the population or a possible outbreak of the disease.”
The billionth treatment was administered on Thursday 16 November to a seven-year-old girl named Dorcas, who was at risk of NTDs in Kaduna State, Nigeria.
Two more areas and more than a million people in the country have met the World Health Organization criteria for elimination of the disease.