Babesia

The economically most important genus of the protozoan family Babesiidae; characterized by multiplication in host red blood cells to form pairs and tetrads; it causes babesiosis (piroplasmosis) in most types of domestic animals, and two species cause disease in splenectomized or normal people; vectors are ixodid or argasid ticks. [V. Babès]

- B. divergens the cause of bovine babesiosis in western and central Europe; vector tick is Ixodes ricinus; it has caused human babesiosis in splenectomized individuals in Europe; also found in reindeer.

- B. microti a malarialike protozoan naturally parasitizing certain rodents (Peromyscus and Microtus spp.) in North America; a number of human cases have been reported in the U.S. The local tick vector is Ixodes scapularis, whose numbers and infection levels have greatly increased in recent years with the increase in the deer population, which serves as an abundant blood source for I. scapularis. SEE ALSO: Borrelia burgdorferi.

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ba·be·sia bə-'bē-zh(ē-)ə n

1) cap the type genus of the family Babesiidae

2) any of the sporozoans of the genus Babesia or sometimes the family Babesiidae that are parasitic in mammalian red blood cells (as in Texas fever) and are transmitted by the bite of a tick called also piroplasm V. Babès see BABES-ERNST GRANULE

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Ba·be·sia (bə-beґze-ə) [V. Babeş] a genus of protozoa of the order Piroplasmida, occurring as single or paired parasites within the erythrocytes of various vertebrates, causing babesiosis and other diseases; they are transmitted by ticks, in which a sexual multiplicative cycle occurs.

Babesia; some erythrocytes contain multiple parasites, and in one the organisms are arranged in a characteristic Maltese cross shape (arrow).