NATURAL-HISTORY, TREND OF PREVALENCE AND SPECTRUM OF MANIFESTATIONS OF BANCROFTIAN FILARIAL DISEASE IN PONDICHERRY (SOUTH-INDIA)

The study examines the changes in the disease parameters of lymphatic filariasis over a period of time based on three surveys during 1957, 1 986 and 1992 in Pondicherry, South India. The overall prevalence of fi larial disease in the three surveys was 4.7, 6.7 and 9.9% respectively . It was significantly higher in males (1957:5.3%; 1986:13.7%; 1992:18 .8%) when compared to females (1957:3.8%; 1986:2.3%; 1992:2.7%) in all the three surveys (P<0.05). The overall prevalence of acute adenolymp hangitis declined from 1.0 in 1957 to 0.2 in 1986 and 0.04% in 1992. W hile the prevalence of hydrocele showed an increasing trend from 2.7 i n 1957 to 11.9 in 1986 and 17.3% in 1992, the prevalence of lymphoedem a (1.9 in 1957; 1.9 in 1986 and 1.8% in 1992) was stable over the same period. The prevalence of disease was relatively higher in all age gr oups of both male and female population in 1992 when compared either t o 1957 or 1986. Similarly a monotonic increase in the prevalence of hy drocele was observed in all age groups in 1992 when compared to previo us surveys. The implications of the changes in prevalence of the chron ic manifestations when compared to the changes in the acute manifestat ions over a period of 35 years are discussed.