Chikungunya fever in travelers:: Clinical presentation and course

Background. An outbreak of chikungunya virus infection emerged in the southwest Indian Ocean islands in 2005, spread out to India, and resulted in an ongoing outbreak that has involved > 1.5 million patients, including travelers who have visited these areas. Methods. Our study investigated 69 travelers who developed signs and symptoms compatible with chikungunya fever after returning home from countries involved in the epidemic. Twenty cases of infection that were confirmed by serological analysis, polymerase chain reaction, and/or cell culture were investigated. Results. All patients experienced flulike symptoms with fever and joint pain. No serious complications were observed, but 69% of the patients had persistent arthralgia for > 2 months, and 13% had it for > 6 months. Viral RNA could be detected in blood samples using reverse-transcriptase polymerase chain reaction in 4 of 4 patients who presented to a health care facility during their first week of illness, and the virus was successfully isolated from blood samples obtained from 2 of these patients. Chikungunya virus-specific immunoglobulin M and/or immunoglobulin G antibodies were detected in all patients. However, initial testing of serum samples yielded negative results for 3 of 5 patients during the first week. Conclusions. Chikungunya fever must be considered in travelers who develop fever and arthritis after traveling to areas affected by an ongoing epidemic. Related arthritis mainly affects smaller joints and often persists for extended periods. Serological testing may have negative results during the first week of the disease; diagnosis using polymerase chain reaction appears to be more reliable during this time. Travelers to areas of epidemicity should be informed of the risk of infection and of adequate preventive measures, such as protection against mosquitos.