title: Prevalence of antibodies to hepatitis E virus among apparently healthy humans and pigs in Bali, Indonesia: Identification of a pig infected with a genotype 4 hepatitis E virus.
abstract: In Indonesia where hepatitis E virus (HEV) is believed to be highly endemic, only three outbreaks of HEV transmission have been documented to date in restricted areas (West Kalimantan and East Java). A total of 1,115 serum samples collected from apparently healthy individuals in Bali, Lombok, and Surabaya in Indonesia in 1996 where epidemic HEV transmissions have never been reported, were tested for IgG class antibodies to HEV (anti-HEV). In Bali, anti-HEV was detected in 20% (54/276) of the tested population, in remarkable contrast with 4% (17/446) in Lombok and 0.5% (2/393) in Surabaya. On the other hand, antibodies to hepatitis A virus were highly prevalent in all three regions (95% in Bali, 90% in Lombok, and 89% in Surabaya). Although the majority of the population in Indonesia is Moslem, Balinese people are mostly Hindu and have a habit of consuming pork. Therefore, serum samples were obtained from the 99 farm pigs in Bali and tested for anti-HEV and HEV RNA. The sera from 71 pigs (72%) were positive for anti-HEV and a 2-month-old pig had detectable HEV RNA. The swine HEV isolate recovered from the viremic pig was named SB66-Bali. The SB66-Bali isolate was most closely related to the genotype 4 isolates from China, India, Japan, and Taiwan, but shared only 82.6-90.0% identity in the common 241-412 nucleotides within open reading frame 2 (ORF2). These results indicate that a presumably indigenous HEV strain(s) is circulating in Bali, Indonesia and that HEV infection may occur via zoonosis even in developing countries.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Sanglah Hospital of Udayana University, Denpasar, Bali, Indonesia.
authors.forename: I Dewa Nyoman
authors.initials: ID
authors.lastname: Wibawa
authors.forename: David H
authors.initials: DH
authors.lastname: Muljono
authors.lastname: Mulyanto
authors.forename: I G A
authors.initials: IG
authors.lastname: Suryadarma
authors.forename: Fumio
authors.initials: F
authors.lastname: Tsuda
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishizawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000818:Animals; D001483:Base Sequence; D006508:Hepatitis Antibodies / Q000097:blood*; D016751:Hepatitis E / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007214:Indonesia / Q000453:epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D016036:Seroepidemiologic Studies; D034421:Sus scrofa / Q000821:virology*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000821:virology*; D015047:Zoonoses / Q000453:epidemiology / Q000821:virology
chemical_list: D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D012367:RNA, Viral