[Serological epidemiologic surveillance on filariasis by ELISA]

In 1984-1990 longitudinal or sectional serological surveillance on filariasis by ELISA with Brugia malayi adult antigen was carried out in 6 villages, Yuhang County, Zhejiang Province, where malayan filariasis had been under control. During that period the microfilaraemia rate of inhabitants had been declining continuously till nil, the positive rate and mean optical density (OD) value in ELISA for positive inhabitants concurrently declined year by year, especially for children under age of 10. By the 5th year after control both the positive rate and mean OD value were close to those of healthy persons living in nonendemic areas of filariasis, no positivity was found in children. In the meantime, ELISA was used to detect serum antibodies in members of a family who were infected with bancroftian filariasis and inhabitants living around them in 1990. Positive rate of ELISA was higher in these inhabitants (8.33%) than in healthy persons (2.53%), and positive ones were detected from children under age of 10. The results suggest that the detection of antifilarial antibody by using ELISA is an effective method for the surveillance of filariasis.