(bă-bē-zē-ō′sĭs)
[Pronunciation]

A rare, usually self-limited disease caused by an intraerythrocytic protozoan, Babesia microti, and perhaps other Babesia species.
The disease is transmitted by deer ticks, and occurs most often in New England in the U.S. It has also been reported elsewhere. Severe forms are most likely to occur in elderly people and in people without functioning spleens. Rarely, the infection is transmitted by blood transfusion from an asymptomatic carrier. The incubation period may last from weeks to months.

SYMPTOMS
Symptoms include fever, chills, headache, sweats, myalgia, arthralgia, and nausea and vomiting.

DIAGNOSIS
The diagnosis is suggested when a patient with an appropriate outdoor exposure presents with typical symptoms, plus hemolytic anemia. Thick and thin blood smears and other laboratory techniques (e.g., the polymerase chain reaction) may be used for definitive confirmation.

PREVENTION
The skin should be protected from tick exposure. Asplenic persons should avoid endemic areas. After possible exposure, removal of ticks or their nymphs may prevent infection.

TREATMENT
Drugs used include atovaquone and quinine plus clindamycin or azithromycin, both given orally. Asplenic patients may require exchange transfusion.