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