THE IMPACT OF TRAVELING TO ENDEMIC AREAS ON THE SPREAD OF HEPATITIS-EVIRUS-INFECTION - EPIDEMIOLOGIC AND MOLECULAR ANALYSES

Traveling to endemic areas carries a risk of hepatitis E virus (HEV) i nfection, but no molecular analysis to document sources of infection i s available. Eighteen (38%) of 47 patients with acute non-A, non-B, no n-C hepatitis were positive for antibody to HEV (anti-HEV), and 9 (50% ) of these were also positive for serum HEV RNA by polymerase chain re action following reverse transcription. Only 1 (5%) of the 21 patients with acute hepatitis A was positive for HEV RNA. Travel to endemic ar eas (mostly to China; odds ratio, 22.2; 95% confidence interval, 4.7-1 05.8) and deeper jaundice (odds ratio, 5.2; 95% confidence interval, 1 .01-27.2) were the only factors associated with HEV infection in multi variate analysis, The two HEV isolates from two patients who had trave led to China and the HEV isolate from a patient whose travel history w as obscure formed a monophyletic group with the isolates from Guangzho u, The HEV isolates from our patients show a homology of 72% to 78% in nucleotide sequence with the Burma, Beijing, India, Pakistan, and Xia ngjiang strains; a homology of 81% to 91% with the Guangzhou strains; and a homology of 76% with the Mexico strain, The close relationship b etween the Taiwan isolates and the Guangzhou strains was further suppo rted by the short Kimura's two-parameter distances among them. In summ ary, HEV infection does occur in this area. Epidemiological and molecu lar analyses strongly indicate that most cases of HEV infection origin ated from travel to HEV-endemic areas.