A randomized, double-blind, placebo-controlled study with diethylcarbamazine for the treatment of hydrocoele in an area of Tanzania endemic for lymphatic filariasis

Hydrocoele is common in men in Wuchereria bancrofti-endemic areas, the trea tment for which is currently surgical intervention. Two community studies h ave recently suggested that the antifilarial drug diethylcarbamazine (DEC) may have a beneficial effect of reducing the size of hydrocoeles of filaria l origin. To test this hypothesis, a double-blind, placebo-controlled study was carried out in 1998 and 1999 in an area of northeastern Tanzania where microfilaria (mf) carrier rates and hydrocoele prevalence rates were known to be high. Ninety-eight adult male volunteers (aged greater than or equal to 15 years) with chronic hydrocoele received DEC 300 mg per day for 12 da ys (49 patients), or placebo (49 patients). Circumferential and ultrasonogr aphic measurements of the scrotum, and a serum sample for measuring W. banc rofti antigen, were obtained at the onset and after 3, 6 and 12 months. Scr otal size and hydrocoele fluid volume indices were calculated. No statistic ally significant differences in volumetric measurements between the DEC and placebo groups were found at any of the follow-ups. Separate analyses divi ding patients by antigen status, hydrocoele size or presence of thickening of the scrotal skins gave similar results. Geometric mean intensity of W. b ancrofti antigen was significantly lower in the DEC group than in the place bo group (P = 0.008), indicating that lack of compliance was not a signific ant factor. Two months into the treatment trial, mass treatment with monthl y low-dose DEC was given to the rest of the community. We conclude that DEC is not effective in reducing the size of hydrocoele of filarial origin. In terventions to replace or supplement hydrocoelectomy should be investigated .