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Babesiosis
Classification & external resources

ICD-10	B60.0
ICD-9	088.82
DiseasesDB	1200

Babesiosis is a rare malaria-like parasitic disease caused by protozoan parasites of the genus Babesia.

Contents 1 Epidemiology 2 Pathophysiology 3 Diagnosis 4 Treatment 5 References 6 External links

Babesiosis is a vector-borne illness usually transmitted by ticks. (Babesia microti uses the same tick vector, Ixodes scapularis, as Lyme disease does.) In babesia-endemic areas, the organism can also be transmitted by blood transfusion.

Infection with Babesia parasites can be asymptomatic or cause a mild non-specific illness, and therefore many cases go unnoticed. Most diagnosed cases occur in the very young, very old, or persons with underlying medical conditions (such as immunodeficiency). 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.

Babesia parasites reproduce in red blood cells, where they can be seen as cross-shaped inclusions (4 merozoites asexually budding but attached together forming a structure looking like a "Maltese Cross") and cause hemolytic anemia, quite similar to malaria.

Note that unlike the Plasmodium parasites that cause malaria, Babesia species lack an exo-erythrotic phase, so the liver is usually not affected.

Babesiosis can be diagnosed by direct examination of the blood (see photo), with serology, or with PCR-based tests. Other laboratory findings include decreased numbers of red blood cells and platelets on complete blood count.

Most cases of babesiosis resolve without any specific treatment. For ill patients, treatment is usually a two-drug regimen. The traditional regimen of quinine and clindamycin is often poorly tolerated; recent evidence suggests that a regimen of atovaquone and azithromycin can be equally effective ^[1].

• Herwaldt BL, Persing DH, Précigout EA, et al. A fatal case of babesiosis in Missouri: Identification of another piroplasm that infect humans. Ann Intern Med 1996;124:643-65.
• Pershing DH, Herwaldt BL, Glaser C, et al. Infection with a Babesia-like organism in northern California. N Engl J Med 1995;332:298-303.

1. ^ Krause P, Lepore T, Sikand V, Gadbaw J, Burke G, Telford S, Brassard P, Pearl D, Azlanzadeh J, Christianson D, McGrath D, Spielman A (2000). "Atovaquone and azithromycin for the treatment of babesiosis". N Engl J Med 343 (20): 1454-8. PMID 11078770. 

• http://www.dpd.cdc.gov/dpdx/HTML/Babesiosis.htm - Public domain source from which the first version of this article was derived.