We report 2 cases of babesiosis in immunocompetent patients in France. A severe influenza-like disease developed in both patients 2 weeks after they had been bitten by ticks. Diagnosis was obtained from blood smears, and Babesia divergens was identified by PCR in 1 case. Babesiosis in Europe occurs in healthy patients, not only in splenectomized patients.
Babesiosis, a tick-borne infectious disease that occurs worldwide, is caused by species of Babesia, an intraerythrocytic parasite (1). Babesia spp. parasites infect wild and domesticated animals and may cause a malaria-like syndrome.
The first human case was described in 1957 in a splenectomized Yugoslavian farmer who died (2). More than 100 Babesia species infect animals, but human infection has been associated with only a few species, mainly B. microti and B. divergens (1–3). B. microti parasites are transmitted by Ixodes scapularis ticks and infect rodents. Since 1957, these parasites have caused hundreds of human babesiosis cases in the United States, the most affected country. Infections are found mainly in healthy persons and manifest as asymptomatic or mild to moderate illness; severe disease, even in immunocompromised or elderly patients, is seldom reported (2,3). B. divergens parasites are endemic to Europe; they are transmitted by I. ricinus ticks and infect bovines (4). In Europe, the disease is rare in humans; ≈40 cases have been reported (2,3,5–7). These cases are almost exclusively severe in immunocompromised patients, especially those whose spleens have been removed (2,3,8). B. divergensparasites are responsible for >70% of these cases (2,8), although the disease is not always confirmed by molecular-based methods.
References
Homer MJ, Persing DH. Human babesiosis. In: Goodman JL, Dennis DT, Sonenshine DE, editors. Tick-borne diseases of humans. Washington: ASM Press; 2005. p. 343–60.
Vannier E, Krause PJ. Update on babesiosis. Interdiscip Perspect Infect Dis. 2009;9845–68.
Gelfand JA, Vannier E. Babesia species. In: Mandell GL, Bennett JE, Dolin R, editors. Principles and practice of infectious diseases, 7th ed, Philadelphia: Elsevier; 2010. p. 3539–45.
L'Hostis M, Dumon H, Dorchies B, Boisdron F, Gorenflot A. Large scale survey of bovine babesiosis due to Babesia divergens in France. Vet Rec. 1995;136:36–8. PubMed DOI
Hunfeld KP, Hildebrandt A, Gray JS. Babesiosis: recent insights into an ancient disease. Int J Parasitol. 2008;38:1219–37. PubMed DOI
Zintl A, Mulcahy G, Skerret HE, Taylor SM, Gray JS. Babesia divergens, a bovine blood parasite of veterinary and zoonotic importance. Clin Microbiol Rev. 2003;16:622–36. PubMed DOI
Gorenflot A, Moubri K, Precigout E, Carcy B, Schetters TP. Human babesiosis. Ann Trop Med Parasitol. 1998;92:489–501.
Meliani P, Khatibi S, Randazzo S, Gorenflot A, Marchou B. Human babesiosis. Med Mal Infect. 2006;36:499–504. PubMed DO
