Imported Chikungunya Infection, Italy

摘要

To the Editor: Chikungunya vi-rus (CHIKV) infection is a self-lim-iting illness characterized by fever, headache, weakness, rash, and arthral-gia. Some patients have prolonged weakness or arthralgia lasting several months. In 2006, several Indian Ocean states and India had an outbreak of CHIKV infection (1,2). During the epidemic's peak, some European and American travelers returning from these areas were infected (3–6).Because the foci of Aedes al-bopictus, 1 of the 2 main vectors of CHIKV, are now in Italy and many travelers visit CHIKV-epidemic ar-eas, surveillance for imported cases is mandatory in Italy (7). From July to September 2006, a total of 17 con-fi rmed cases of CHIKV infection were observed in travelers at 5 Gruppo di Interesse e Studio delle Patologie di Importazione (GISPI) centers (Italian network of Institutes of Infectious and Tropical Diseases). Serologic diagno-sis was performed with a hemagglu-tination-inhibition test and confi rmed by a plaque-reduction neutralization test (8). Demographic and epidemio-logic characteristics of these patients are reported in the Table.Cases were distributed through-out the year with a peak from March to May 2006 (n = 10). Nine patients (53%) were men. Median age was 43 years (range 31–66 years). Sev-eral reasons for travel were reported: tourism (64.6%), visits to relatives or friends (11.8%), business (11.8%), and missionary work (5.9%). One patient was a resident in the disease-epidemic area. The median exposure time in the CHIKV-endemic area for the 15 trav-elers was 15 days (range 9–93 days) (missionary and resident patients were excluded). The median delay before being seen at a clinic after return was 2 days (range 0–73 days). Only 7 pa-tients (41.2%) were hospitalized. The remainder were outpatients