Treatment of Schistosomiasis mansoni with Neostibosan. ∗

Twelve patients with ova of 5. mansoni in their stools were treated with the pentavalent antimonial drug, neostibosan (Winthrop). The patients were all males with ages ranging from 15 to 32 years. The drug was administered intravenously during a 2-week period of hospitalization. During the first 3 days, doses of 0.2, 0.6 and 0.9 respectively were usually given, and thereafter either 0.6 or 0.9 was generally injected every day until the end of hospitalization. All patients tolerated the drug well and no serious reactions were seen. A low grade fever and abdominal pain, headache, nausea or anorexia were observed in most of the patients.

The effect of the drug on the number of schistosome eggs passed in stools was carefully observed. Stool examinations were made daily before and during treatment and on as many daily specimens as possible for each follow-up examination. The technic used for the quantitative determination of eggs in feces has been described previously. 1

The effect of treatment on the schistosome J infections, as determined by the number of alive and dead schistosome ova in stools may be seen in Table I. Although the majority of the patients (9 out of 12 or 75%) had stools negative for live and dead ova one to 2 months after treatment, 8 out of 11 (73%) relapsed 3 and 4 months later. Three out of 11 patients, however, have remained negative throughout, for a period of 11 months.

Although the per cent of cases which has remained negative for ova of S. mansoni after treatment with neostibosan is small (3 out of 11 examined or 27.3%) there is evidence indicating that the drug has parasitotropic effects. This is also suggested by the fact than the egg count 11 months after treatment in 6 of the patients are appreciably lower than the counts before treatment. There is the possibility that in those patients in whom the infection was not eradicated insufficient drug was administered.