Poor response to praziquantel after Schistosoma mansoni infection.

Schistosoma mansoni infection (SMI) is potentially serious and necessitates treatment. Praziquantel (PZQ), one dosage of 40 mg/kg; is currently the be st choice. Nevertheless some poor responses to this treatment have raised q uestions for a therapreutic modulation. Fourteen patients returning from th e Republic of Central Africa were seen in the division of infectious diseas e for a SMI, treated by PZQ (40 mg/kg) and followed up. After 8 months, 13 patients were seen again: five (38.5%) were cured (rectoscopy and systemati c biopsy normal), five (38.5%) were still presented with illness (pathologi cal rectoscopy and eggs in the biopsy) and three (23%) presented abnormal r ectoscopy with normal biopsy. PZQ failure at 40 mg/kg has recently been des cribed in more detail. Improvements in diagnostic testing, the importance o f the parasitemia, treatment inefficacy of immature eggs, and young age (i. e., low levels of acquired immunity) explain this failure. In this case, PZ Q must be increase to 60 mg/kg in two divided doses. (C) 1999 Elsevier, Par is.