Shrestha Santosh Man, Shrestha Shobhana, Tsuda Fumio, Nishizawa Tsutomu, Gotanda Yuhko, Takeda Naokazu, Okamoto Hiroaki
Liver Foundation Nepal, Tripureswor, Kathmandu, Nepal.
J Med Virol. 2003 Feb;69(2):207-14. doi: 10.1002/jmv.10276.
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.
1997年，对在尼泊尔加德满都谷地一家城市医院就诊的154例连续性散发性急性肝炎患者进行了研究。4例患者（3%）检测到甲型肝炎病毒IgM抗体，4例患者（3%）检测到乙型肝炎核心IgM抗体，20例患者（13%）检测到乙型肝炎表面抗原，4例患者（3%）检测到丙型肝炎病毒RNA。分别在77例（50%）和48例（31%）患者中检测到戊型肝炎病毒（HEV）IgM抗体（抗-HEV IgM）和HEV RNA。因此，包括9例无抗-HEV IgM的HEV病毒血症患者在内，86例患者（56%）被诊断为戊型肝炎。53例患者（34%）的肝炎病因不明。所有48份HEV RNA阳性样本均被基因分型为1型，进一步亚型分析为1a型17例（35%）、1c型29例（60%）、1a和1c混合感染2例（4%）。观察到HEV亚型流行率存在季节差异。雨季前（1月至7月），同时发现1a型和1c型分离株：开放阅读框2的412核苷酸序列中的亚型内差异分别高达9.0%和1.7%。雨季（8月）仅发现1c型分离株（n = 17），同一性为99.5-100%；17例分离株中有13例序列相同，与7月底出现的3例分离株相同。这些结果表明，一种特定的HEV 1c株在雨季广泛传播，并与1997年8月加德满都谷地的一次小范围流行有关。
