Lymphatic filariasis in children: age dependent prevalence in an area of India endemic for Wuchereria bancrofti infection

Lymphatic filariasis has been considered as a disease of adults and most epidemiological surveys have excluded children. The prevalence of infection and clinical manifestations of the disease among children in the age group of 1-15 years was determined in a Wuchereria bancrofti endemic area. The 1383 children from the rural villages of a coastal district (Khurda), State of Orissa, India, were studied. The finger prick blood (50ìl) samples were collected between 20:30 and 23:30 hours for parasitological and immunological evaluation. At the same time clinical examination was also recorded. Circulating Filarial Antigen (CFA) status and antibody (IgG) to filarial antigen was also determined in the study population. The prevalence of asymptomatic microfilaraemic carriers (AS), acute disease (AC), hydrocele (Hyd) cases and cryptic infection (CFA +ve) were 9.9%, 14.6%, 3.8% and 17.1% respectively. It was observed that 45.4% of the children below 15 years of age were either infected or had clinical manifestations of the disease. IgG antibody positivity 75.4%, 84% and 95.8% were observed in 1-5 yr, 6-10 yr and 11-15 years age group respectively. The study suggested that asymptomatic infection and acute form of disease were common occurrence among the children and more than half of the children population were either infected or having clinical manifestations of the diseased by pre-adult stage (11-15 years of age) in the endemic area.