HUMAN BABESIOSIS

The first demonstrated case of human babesiosis in the world was repor ted in Europe, in 1957. Since then, a further 28 babesial infections i n man have been reported in Europe. Most (83%) of the infections were in asplenic individuals and most (76%) were with Babesia divergens, a cattle parasite. Parasitaemias varied from 1%-80% of red blood cells. The usual clinical manifestations of severe B. divergens infection wer e severe intravascular haemolysis with haemoglobinuria. The most effic ient treatment consisted of a massive blood-exchange transfusion, foll owed immediately by c:hemotherapy with clindamycin. Hundreds of cases of human infection with Babesia spp. have been reported in the U.S.A. Most cases were infected by ticks carrying the rodent parasite B. micr oti, bur other emerging Babesia spp. (currently known as WA(1), CA(1) and MO1) are increasingly involved. Several cases were the result of b lood transfusion. In terms of clinical manifestations, human infection s with B. microti varied widely, from asymptomatic infection to a seve re, rapidly fatal disease. Parasitaemia ranged between < 1% and 85%. T he splenectomized, the elderly, the immunocompromised and HIV-infected patients were predisposed to severe infection. Infections with B. mic roti often remained subclinical or asymptomatic and were only detected through serological surveys. The currently recommended treatment of s ymptomatic cases is quinine plus clindamycin. A few other cases of hum an babesial infection have been described in China, Egypt, Mexico, Sou th Africa and Taiwan.