Japanese Encephalitis Among Three U.S. Travelers Returning From Asia, 2003-2008

Japanese encephalitis virus, a mosquito-borne flavivirus, is a leading cause of encephalitis in Asia. The risk for Japanese encephalitis for most travelers is low, but varies by travel destination, duration, season, and activities. As part of routine surveillance and diagnostic testing, state health officials or clinicians send specimens from patients with unexplained encephalitis to CDC. To characterize the epidemiologic and clinical features of JE cases, CDC reviewed all laboratory-confirmed cases that occurred during 1992 to 2008. Here, a report that describes the three previously unpublished cases is presented. All were Asian immigrants or family members who traveled to Asia to live or to visit friends or relatives and had not been vaccinated for JE.