Molecular investigation of hepatitis E virus infection in patients with acute hepatitis in Kathmandu, Nepal.
One hundred fifty-four consecutive patients with sporadic acute hepatitis, who were seen at a city hospital in the Kathmandu valley of Nepal in 1997, were studied. IgM antibodies to hepatitis A virus were detected in four patients (3%), IgM antibodies to hepatitis B core in four patients (3%), hepatitis B surface antigen in 20 (13%), and hepatitis C virus RNA in four patients (3%). IgM antibodies to hepatitis E virus (HEV) (anti-HEV IgM) and HEV RNA were detected in 77 (50%) and 48 (31%), respectively. Consequently, 86 patients (56%) including nine HEV-viremic patients without anti-HEV IgM, were diagnosed with hepatitis E. The cause of hepatitis was not known in 53 patients (34%). All 48 HEV RNA-positive samples were genotyped as 1, and subtyped further as 1a in 17 (35%), 1c in 29 (60%), and mixed infection of 1a and 1c in 2 (4%). A seasonal difference in the prevalence of HEV subtypes was recognized. Before the rainy season (January to July), both 1a and 1c isolates were found: the intrasubtypic difference was up to 9.0% and 1.7%, respectively, in the 412-nucleotide sequence of open reading frame 2. During the rainy season (August), only 1c isolates (n = 17) with 99.5-100% identity were found; 13 of 17 isolates had the same sequence, being identical to the 3 isolates that emerged at the end of July. These results suggest that a particular HEV 1c strain spread widely during the rainy season and was implicated in a small epidemic in the Kathmandu valley in August 1997.
Shrestha
Santosh Man
SM
Liver Foundation Nepal, Tripureswor, Kathmandu, Nepal.
Shrestha
Shobhana
S
Tsuda
Fumio
F
Nishizawa
Tsutomu
T
Gotanda
Yuhko
Y
Takeda
Naokazu
N
Okamoto
Hiroaki
H
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D016752:Hepatitis E virus / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D006525:Hepatitis, Viral, Human / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009390:Nepal / Q000453:epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood; D012621:Seasons
D006508:Hepatitis Antibodies; D012367:RNA, Viral