Survey on the clinical trial results achieved in Brazil comparing praziquantel and oxamniquine in the treatment of mansoni schistosomiasis

A random, double-blind, parallel group clinical trial program was carried out to compare praziquantel, a recently developed anti-helmintic drug, and oxamniquine, an already established agent for treating mansoni schistosomiasis. Both drugs were administered orally as a single dose, on the average, praziquantel 55 mg/kg and oxamniquine 16 mg/kg BWT. The diagnosis and the parasitological follow-up lasting for a minimum of six months, were based on stool examinations according to Kato/Katz technique. A patient was considered cured if all results were negative and if he had performed at least three post-treatment controls, each one comprising three stool examinations. The finding of a single S. mansoni egg in any stool examination indicated, a therapeutical failure. A total of 267, cases were treated with praziquantel and 272 with oxamniquine. The two groups were homogeneous in regard to patients, age, clinical form of the disease, risk of reinfection and worm burden, relevant factors in the therapeutical response. The incidence and severity of untoward, effects were similar in both groups but abdominal distress and diarrhoea were more frequently reported under praziquantel and dizzines under oxamniquine (p < 0.05). In the former group a marked urticariform reaction was observed whereas in the latter one patient presented convulsion. The laboratory work-up. failed to disclose any significant alteration although the AST, ALT and y-GT mean values revealed a tendence to increase on the 7th day after oxamniquine intake. The overall parasitological cure rates were 75.5% (139/ 184) with praziquantel and 69.8% (134/192) with oxamniquine (p > 0.05). Amongst the noncured aptients a reduction of 88.6% and 74.6% in the mean number of eggs/g of feces Was seen following the treatment with praziquantel and oxamniquine, respectively (p < 0.05). In conclusion, in spite of their different chemical, pharmacological and toxicological profiles as well as mechanisms-of-action, inclusively praziquantel already had proved to be 100% active against S. mansoni strains resistant to oxamniquine, both drugs showed comparable tolerance and therapeutical efficacy.

A multivariate analysis of the relationship between work ability and S. japonicum infection in Dongting Lake Region, in China

A cross-sectional case-control study on the association between the reduced work ability and S. japonicum infection was carried out in a moderate endemic area for schistosomiasis japonica in the southern part of Dongting lake in China. A total of 120 cases with reduced work ability and 240 controls paired to the case by age, sex, occupation and without reduced work ability, participated in the study. The mean age for individuals was 37.6 years old (21-60), the ratio of male: female was 60:40, the prevalence of S. japonicum in the individuals was 28.3%. The results obtained in this study showed that the infection of S. japonicum in case and control groups was 49.2% (59/120) and 17.9% (43/240), respectively. Odds ratio for reduced work ability among those who had schistosomiasis was 4.34 (95%), confidence interval was 2.58-7.34, and among those who had S. japonicum infection (egg per gram > 100) was up to 12.67 (95%), confidence interval was 3.64-46.39. After odds ratio was adjusted by multiple logistic regression, it was confirmed that heavier intensity of S. japonicum infection and splenomegaly due to S. japonicum infection were the main risk factors for reduced work ability in the population studied.