The great hope for schistosomiasis treatment began with the development of oxamniquine and praziquantel.
These drugs can be administered orally in a single dose and have a high curative power with minor side effects. In
this study, we carried out a field experiment involving a population of 3,782 people. The population was examined
at four localities in Minas Gerais within the valleys of the Doce and Jequitinhonha Rivers. In this cohort, there were
1,790 patients infected with Schistosoma mansoni
(47.3%) and we showed that only 1,403 (78.4%) could be treated
with oxamniquine in a single dose of 12.5-20 mg/kg orally. The other 387 (21.6%) were not treated during the first
stage because of contraindications (pregnancy or impeditive diseases), absences or refusals. It was observed that,
on average, 8.8-17% of the infected patients continued to excrete S. mansoni
eggs at the end of the 2nd month after
treatment and 30-32% of the cohort was infected by the end of the 24th month. In one of the areas that we followed-
up for a total of 30 years, the prevalence of the infection with S. mansoni
fell from 60.8-19.3% and the hepatosplenic
form of the disease dropped from 5.8-1.3%. We conclude that specific treatment of schistosomiasis reduces the
prevalence of infection in the short-term and the morbidity due to schistosomiasis in medium to long-term time frames,
but does not help to control disease transmission.