[Clonorchiasis in the People's Republic of Vietnam. 2. The clinico-parasitological examination of a focus and a trial of prazinquantel treatment].

Examinations of 1599 residents of a polyinvasion focus at a seaside province Ha Nam Nin, Vietnam, have revealed clonorchiasis in approximately 13.9% of the examinees; in subjects aged over 30 this value was 29.3%. Factors conducive to a lower incidence of clonorchiasis were detected, among them a moderate intensity of the invasion: the mean arithmetic was 1419 +/- 306 eggs/g, the mean geometric 673 egg/g, as shown by the Kato-Kats' technique. Analysis of five therapeutic schemes used in clonorchiasis, making use of chloxilin, medamin or praziquantel, has demonstrated a low efficacy of all of them. Praziquantel therapy in a daily dose of 25 mg/kg for 2 days was found the most effective (52%), being conducive to a reduction of the invasion intensity by at least 90%. Such therapy was associated with a high incidence of side effects (91.2%), this ruling out a higher dosage.