Babesiosis. Diagnostic pitfalls

A case of babesiosis complicated by quinine-induced hemolysis is described. A splenectomized woman contracted babesiosis after visiting an endemic area. The patient presented with high fevers and minimal hemolysis. While she was on treatment, the hemolysis increased. The increased hemolysis was initially attributed to babesiosis, but after additional evaluation quinine therapy was found to be the cause. In the setting of this brisk hemolysis, there was an increase in red blood cell inclusions. At first, the inclusions were thought to be Babesia, but iron stain demonstrated that many of the inclusions were hemolysis-induced Pappenheimer bodies. The role of the clinical laboratory in sorting out this confusing picture is presented.