Anaplasma phagocytophilum Infection in Ticks, China–Russia Border

immunocompromised patients, the endogenous autoinfection cycle may result in the overproduction and dissemination of larvae into intestinal and extraintestinal tissues, including the central nervous system, leading to the hyperinfection syndrome which can be lethal (5). Most cases (96%) occur in immigrants, but some have been described in patients with a history of travel, sometimes many years previously. S. stercoralis infections have been reported up to 65 years after initial exposure in veterans who served in Asia during World War II (4,6). Although our patient exhibited poor general condition, he likely did not experience hyperinfection syndrome because he was not immunosuppressed, and he completely recovered after receiving standard ivermectin treatment. That the patient was originally infected in the Canary Islands seems improbable, although a low level of transmission exists in rural and disadvantaged areas in continental Spain, Portugal, and Italy (7). We did not fi nd evidence of Strongyloides spp. transmission in the Canary Islands. In particular, the patient stayed in a high-status tourist hotel for a short period, and he never walked in bare feet. He was probably infected when he lived in Vietnam. This case highlights the importance of systematically considering chronic strongyloidiasis when seeking a diagnosis for persistent hypereosinophilia, even in patients with no underlying disease, and the value of systematically obtaining any history of travel in disease-endemic areas even if it occurred many years previously. The endogenous autoinfection cycle can possibly persist for a lifetime. In addition, systematic examination of stool samples should be carried out, and ivermectin should be given when an immunosuppressive drug is required in a patient who has a history of travel to, or residence in, an area to which strongyloidiasis is endemic. Virginie Prendki, Pierre Fenaux, Rémy Durand, Marc Thellier, and Olivier Bouchaud Author affi liations: Hôpital Jean Verdier, Bondy, France (V. Prendki); Hôpital Avicenne, Bobingy, France (P. Fenaux, R. Durand, O. Bouchaud); Université Léonard de Vinci, Bobigny (R. Durand, O. Bouchaud); and Hôpital La Pitié Salpêtrière, Paris, France (M. Theillier)