title: Prevalence of antibodies to Japanese encephalitis virus among pigs in Bali and East Java, Indonesia, 2008.
abstract: Japanese encephalitis virus (JEV) is a fatal disease in Asia. Pigs are considered to be the effective amplifying host for JEV in the peridomestic environment. Bali Island and Java Island in Indonesia provide a model to assess the effect of pigs on JEV transmission, since the pig density is nearly 100-fold higher in Bali than Java, while the geographic and climatologic environments are equivalent in these areas. We surveyed antibodies to JEV among 123 pigs in Mengwi (Bali) and 96 pigs in Tulungagung (East Java) in 2008 by the hemagglutination-inhibition (HAI) test. Overall prevalences were 49% in Bali and 6% in Java, with a significant difference between them (P < 0.001). Monthly infection rates estimated from age-dependent antibody prevalences were 11% in Bali and 2% in Java. In addition, 2-mercaptoethanol-sensitive antibodies were found only from Bali samples. Further, the average HAI antibody titer obtained from positive samples was significantly higher in Bali (1:52) than Java (1:10; P < 0.001). These results indicated that JEV transmission in nature is more active in Bali than East Java.
authors.affiliation: Indonesia-Japan Collaborative Research Center for Emerging and Re-Emerging Infectious Diseases, Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamanaka
authors.forename: Kris Cahyo
authors.initials: KC
authors.lastname: Mulyatno
authors.forename: Helen
authors.initials: H
authors.lastname: Susilowati
authors.forename: Eryk
authors.initials: E
authors.lastname: Hendrianto
authors.forename: Takako
authors.initials: T
authors.lastname: Utsumi
authors.forename: Mochamad
authors.initials: M
authors.lastname: Amin
authors.forename: Maria Inge
authors.initials: MI
authors.lastname: Lusida
authors.forename: Soegeng
authors.initials: S
authors.lastname: Soegijanto
authors.forename: Eiji
authors.initials: E
authors.lastname: Konishi
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000453:epidemiology / Q000662:veterinary*; D006385:Hemagglutination Inhibition Tests; D007214:Indonesia / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology*
chemical_list: D000914:Antibodies, Viral