The effect of 7-8 years of vector control on the evolution of ocular onchocerciasis in West African savanna
Dadzie, K.Y.; Remme, J.; Rolland, A.; Thylefors, B.
Tropical Medicine and Parasitology Official Organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit 37(3): 263-270
1986
ISSN/ISBN: 0177-2392 PMID: 3787122 Document Number: 283275
The evolution of Onchocerca volvulus ocular infection was studies in a cohort of 1170 persons over 5 years of age in Burkina Faso, Ghana and Ivory Coast, who were examined before the start of and after 7-8 years of effective vector [Simulium] control in 12 originally hyperendemic villages in the central part of the Onchocerciasis Control Programme area. The proportion of the cohort which at the outset of vector control was free from ocular onchocerciasis or had an early or recent infection in the form of punctate keratitis only, remained largely free of or lost their signs of ocular infection resp. and only a very insignificant proportion acquired microfilariae in the eyes or developed a severe onchocercal eye lesion at the initial stage. The proportion of the cohort with a heavy ocular microfilarial load had a reduced risk of developing severe eye lesions and no risk of going blind. The proportion of the cohort with already existing severe eye lesions at the advanced stage remained largely unchanged and some lesions at the initial stage disappeared. Blindness occurred only in those who had severe eye lesions at the outset and was comparatively less than in areas of on-going transmission.