Human babesiosis

Hundreds of cases have been reported in the United States, but only 29 cases in Europe. The cattle parasite, B. divergens, was responsible for most cases in Europe; asplenic individuals were the highest risk group. In severe B. divergens infections, clinical manifestations were characterized by a severe intravascular haemolysis and the most efficient treatment consisted of a massive blood exchange transfusion and immediate subsequent chemotherapy by clindamycin. Mortality rate was high (42% of the splenectomized). In the United States, most cases were caused by the rodent parasite B. microti. Clinically human B. microti infection varied widely from an asymptomatic infection to a severe disease (mortality: 5%). Splenectomized, elderly, immunocompromised and HIV infected patients were predisposed to severe infection. The currently recommanded treatment of symptomatic cases was quinine plus clindamycin, A few other cases of human babesial infection have been described in China, Egypt, Mexico, South Africa and Taiwan.