Babesiosis epidemiology and demographics

Epidemiology
Babesiosis is a vector-borne illness usually transmitted by ticks. (Babesia microti uses the same tick vector, Ixodes scapularis, as Lyme disease does, and frequently occurs in conjunction with it.) In babesia-endemic areas, the organism can also be transmitted by blood transfusion. The disease exists mostly in Eastern Long-Island and its barrier island, Fire Island, and the islands off the coast of Massachusetts. It is sometimes called "The Malaria of The North East."

Babesiosis causes a disease very similar to Malaria. In mild cases, people may experience mild fevers and anemia. In more severe cases, fevers go up to 105 degrees with shaking chills, and anemia (hemolytic anemia) can become severe. Organ failure may follow including adult respiratory distress syndrome.

Infection with Babesia parasites can be asymptomatic or cause a mild non-specific illness, and therefore many cases go unnoticed. It may also cause severe disease. While most severe cases occur in the very young, very old, or persons with underlying medical conditions (such as immunodeficiency) and those without a spleen, they can occur in normal individuals. Indeed, both the incidence or all cases of babesiosis and severe cases are increasing rapidly. Some cases are identified when patients with another tick-borne illness are screened for babesiosis.

Little is known about the occurrence of Babesia species in malaria-endemic areas, where Babesia can easily be misdiagnosed as Plasmodium.