In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan.


Babesiosis is an infectious disease caused by intraerythrocytic, tick-borne protozoa of the Babesia species.

In the USA and Europe, the organism Babesia is transmitted following the bite of ticks. Babesia primarily infects animals and humans are only opportunistic hosts. The parasite is also referred to as piroplasms because of its 'pear-shape' that is seen within the infected erythrocytes. In the USA, infection by babesia is rare and only limited to certain geographical regions. Most individuals exhibit no symptoms but certain patients may exhibit high morbidity and mortality. Overall, the disease chiefly affects patients who are splenic, immunocompromised or the elderly.

Babesiosis is not easy to diagnose and a high index of suspicion is required, especially in endemic regions. Treatment is recommended for patients regardless of symptoms to prevent progression and transmission of the disease.

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