Parasitological and clinical studies of Wuchereria bancrofti and Mansonella ozzardi in Coastal North Trinidad, West Indies.

A parasitological and clinical survey of Wuchereria bancrofti and Mansonella ozzardi was conducted in Blanchisseuse an isolated rural community of 650 people in coastal north Trinidad. W. bancrofti microfilariae were found in 15% of the resident population and the prevalence was higher in males (19%) than in females (12%). Microfilaraemias were undetected in children under 5 years of age but 12% of children and adolescents between 5 and 19 years of age were positive. Microfilaraemias were most common in males aged 40-59 years (34%) and in females in the same age group (21%). Whereas geometric mean microfilaria densities were generally higher in females than in males under 40 years old in the older age groups the pattern was reversed the difference being especially pronounced in the over 60s. There were more than 2 times as many males with M. ozzardi microfilariae (35%) than there were females (15%). The prevalence was low in children and young adults but increased with age thereafter. In the older age groups microfilaria densities followed a similar trend. Genital signs compatible with lymphatic filarial disease were seen in 29% of males; these included hydrocoele (15%) and elephantiasis of the scrotum (1%). Most signs were seen in persons over 50 years of age. 6% of females had lymphoedema of the leg(s) and in 4 cases (2.3%) this had progressed to elephantiasis. A positive association was found between M. ozzardi microfilaraemia and clinical history of articular pain. The findings suggest that both filarial species are of some public health significance in at least 1 rural area of Trinidad and they provide a basis for the development of a lymphatic filariasis control strategy in the community. (authors modified)