Seroepidemiology of Hantaan virus infection in Taiwan

Abstract

In order to investigate the infection rate of Hantaan virus in Taiwan, a total of 6,536 human serum samples were collected from residents, selected by stratified random sampling, from 19 townships covering four different ethnic groups: Aborigines, Fukien Taiwanese, Hakka Taiwanese, and Mainland Chinese. Serum samples were screened for Hantaan virus antibodies by indirect immunofluorescence. The prototype Hantaan virus (76/118)-infected Vero E6 cells were used as the viral antigen for the antibody detection. Among 6,536 human serum samples, 403 (6.2%) samples had Hantaan virus antibodies. The seropositive rates for males and females were 6.1% and 6.2%, respectively. A higher seropositive rate was found among Aborigines on the Orchid Islets (11.5%) and Fukien Taiwanese on the Penghu Islets (11.6%), while the lowest rate was observed among Hakka Taiwanese in the south of Taiwan (2.5%). In comparing with different ethnic groups, the highest prevalence was found among Fukien Taiwanese (8.1%) and the lowest among Mainland Chinese (4.9%). Among the different geographical areas, the highest positive rate was found in western Taiwan (7.1%) and the lowest in southern Taiwan (5.4%). Hantaan virus antibodies were also detected in 22 of 548 (4.0%) rat serum samples. The highest seropositive rate was found in rat sera collected from the Orchid Islets (21.4%). None of the rat sera collected from Hsinchu, Miaoli, Changhua, Nantu, Yunlin, Chiayi, Tainan, and Penghu Counties were positive. Hantaan virus antibodies were found in rats: Rattus rattus (20%), Bandicota indica (9.0%), Rattus norvegicus (8.3%), Bandicota nemorivaga (6.3%), Rattus losea (4.2%), and Apodemus agrarius (1.6%). Hantaan virus antibodies were not detected in rat sera collected from species of Rattus coxinga, Rattus culturatus, Mus musculus, Mus caroli, Suncus murinus, and Apodemus semotus. The results show that the Hantaan or Hantaan-related virus exists and is distributed widely in both human and rats in Taiwan.

Hantavirus infection in Taiwan: The experience of a geographically unique area

“…Our finding that only SEO was prevalent in Taiwan and that no HTN could be identified was contradictory to a previous seroepidemiologic study by Kao et al [1996], in which 6.2% (403/6536) of human serum specimens randomly sampled from Taiwanese residents showed detectable HTN antibodies. The seroassay used in Kao's study was a relatively non-specific method, indirect immunofluorescence, used only the prototype HTN virus (76-118)-infected Vero E6 cells as the viral antigen.…”

“…Taiwan was alarmed by the identification of the first imported case of HFRS in April 1995. Subsequent seroepidemiologic investigation unexpectedly revealed prevalent distribution of this virus in rodent populations in Taiwan [Wu et al, 1996;Kao et al, 1996]. Despite this prevailing infection of hantavirus in rodents in Taiwan and despite the fact HFRS is frequently reported in countries around Taiwan, including China, Japan, Korea, and other southeastern Asian countries [Lee, 1996], one puzzling observation has yet to be explained: no local case of HFRS has been confirmed in Taiwan [Wu et al, 1996].…”

Seaport as a source of hantavirus: A study on isolated isles

“…This finding confirmed the results obtained by Chin et al (2000). Among the remote and offshore isles of Taiwan, the highest seroprevalence of hantavirus in the small mammals has been demonstrated on the Orchid Islets (21.4%) in southeast Taiwan (Kao et al 1996). However, only negative results were obtained after examination on 202 animals in another survey (Chin et al 2000).…”

“…In order to understand the seroprevalance in the human population, 6536 serum samples were collected and screened for Hantaan virus antibodies and 6.2% of the samples were positive for these antibodies. There was no significant difference in the seropositive rates by sex (Kao et al 1996). Moreover, antibodies against hantavirus have also been detected in certain high-risk groups.…”

First Detection of Bartonella spp. in Small Mammals from Rice Storage and Processing Facilities in Myanmar and Sri Lanka

“…The inevitable proximity of humans and rodents [46] is likely to increase the risk of transmission of zoonotic pathogens from rodents to humans. This is confirmed by high antibody titers of the Hantaan virus in rodents and in humans living in close contact with rodents in Thailand and Taiwan [47,48]. The commensal shrew S. murinus is a reservoir for Yersinia pestis and responsible for recent human plague outbreaks in Vietnam [49].…”