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Definition

Babesiosis is an infection of red blood cells caused by the single-celled parasite, Babesia microti, which is spread to humans by a tick bite.

Description

Babesiosis is a rare, tick-transmitted disease that is caused most often by the single-celled parasite Babesia microti. By 1995, fewer than 500 cases of babesiosis had been reported in the United States. The disease occurs primarily in New England and New York, especially on the coastal islands. However, cases have occurred in other parts of the United States. Because of tick activity, the risk for babesiosis is highest during June and July.

Ticks are small, blood-sucking arachnids. Although some ticks carry disease-causing organisms, most do not. Babesia microti is spread to humans through the bite of the tick Ixodes scapularis (also called Ixodes dammini). Ixodes scapularis, called the "blacklegged...