The impact of traveling to endemic areas on the spread of hepatitis E virus infection: epidemiological and molecular analyses.
Traveling to endemic areas carries a risk of hepatitis E virus (HEV) infection, but no molecular analysis to document sources of infection is available. Eighteen (38%) of 47 patients with acute non-A, non-B, non-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 reaction following reverse transcription. Only 1 (5%) of the 21 patients with acute hepatitis A was positive for HEV RNA. Travel to endemic areas (mostly to China; odds ratio, 22.2; 95% confidence interval, 4.7-105.8) and deeper jaundice (odds ratio, 5.2; 95% confidence interval, 1.01-27.2) were the only factors associated with HEV infection in multivariate analysis. The two HEV isolates from two patients who had traveled to China and the HEV isolate from a patient whose travel history was obscure formed a monophyletic group with the isolates from Guangzhou. The HEV isolates from our patients show a homology of 72% to 78% in nucleotide sequence with the Burma, Beijing, India, Pakistan, and Xiangjiang strains; a homology of 81% to 91% with the Guangzhou strains; and a homology of 76% with the Mexico strain. The close relationship between the Taiwan isolates and the Guangzhou strains was further supported by the short Kimura's two-parameter distances among them. In summary, HEV infection does occur in this area. Epidemiological and molecular analyses strongly indicate that most cases of HEV infection originated from travel to HEV-endemic areas.
Wu
J C
JC
Department of Medicine, Veterans General Hospital, National Yang-Ming University School of Medicine, Taipei, Taiwan.
Sheen
I J
IJ
Chiang
T Y
TY
Sheng
W Y
WY
Wang
Y J
YJ
Chan
C Y
CY
Lee
S D
SD
D000328:Adult; D000368:Aged; D001483:Base Sequence; D003001:Cloning, Molecular; D005260:Female; D016751:Hepatitis E / Q000635:transmission*; D016752:Hepatitis E virus / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D012307:Risk Factors; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014195:Travel
D012367:RNA, Viral