Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta
Japanese encephalitis virus (JEV) is one of the leading causes of acute encephalitis in humans. The virus is spread by mosquitoes, mainly belonging to the Culex species. The main reservoirs are considered to be birds and pigs, with pigs constituting the most important reservoir in regard to human in...
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| Formato: | H2 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Clinical Sciences (until 231231)
2013
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| Materias: |
| _version_ | 1855570903307386880 |
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| author | Nilsson, Sylvia |
| author_browse | Nilsson, Sylvia |
| author_facet | Nilsson, Sylvia |
| author_sort | Nilsson, Sylvia |
| collection | Epsilon Archive for Student Projects |
| description | Japanese encephalitis virus (JEV) is one of the leading causes of acute encephalitis in humans. The virus is spread by mosquitoes, mainly belonging to the Culex species. The main reservoirs are considered to be birds and pigs, with pigs constituting the most important reservoir in regard to human infection. During the last few decades the production of pork has increased significantly in Vietnam. With 90% of pigs being kept in households owning 10 pigs or less, pigs are widely spread across most parts of the country. Due to the ongoing urbanization of Vietnam, the need for urban agriculture and animal husbandry has increased, resulting in an increasing amount of pigs/reservoirs being kept in urban environments. In the city of Can Tho, located in the Mekong delta, almost 100 % of the pigs have been found to be JEV positive, and vectors needed for transmission of JEV have been shown to be present in the urban areas of the city. The objectives of this study was to examine the seroprevalence of JEV in dogs and pigs in an endemic region, and to evaluate if dogs make suitable sentinels and could be used to evaluate the risk that JEV may pose to humans living in urban areas. To do this, blood samples were collected from dogs and pigs. A total number of 127 dog samples and 176 pig samples were collected from Can Tho city province and 65 samples were collected for comparative purposes from dogs originating from Ho Chi Minh City. The samples from Can Tho were divided into two equal parts. One part was frozen and sent to Sweden to be tested for JEV antibodies, using a competitive IgG ELISA. One part of the samples from Can Tho was also tested at Can Tho University using an in house HI-test. Due to denaturation as a result of high temperature inactivation of the sera, none of the samples that were sent to Sweden could be tested using the competitive IgG ELISA. The HI-results showed that 27 of the 127 dog samples and 159 of the 176 pig samples, all originating from Can Tho city province, had measurable antibody titres against JEV. Twenty three per cent of the dogs originating from the urban district of Ninh Kieu had measurable antibody titres against JEV. Although the seroprevalence was much higher among dogs mainly kept outdoors than dogs mainly kept indoors, it is notable that more than 16% of the dogs mainly kept indoors were also seropositive for JEV. These results indicate not only that JEV does pose a risk to people living in the urban areas of Can Tho city, but also that dogs may be good sentinels for human infection and can be used for evaluating the risk that JEV poses to humans living in urban areas. |
| format | H2 |
| id | RepoSLU5793 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2013 |
| publishDateSort | 2013 |
| publisher | SLU/Dept. of Clinical Sciences (until 231231) |
| publisherStr | SLU/Dept. of Clinical Sciences (until 231231) |
| record_format | eprints |
| spelling | RepoSLU57932013-07-02T09:49:44Z Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta Seroprevalens av Japanskt encefalitvirus hos grisar och hundar i Mekongdeltat Nilsson, Sylvia Flavivirus Pets Swine Antibodies Sentinels JEV Vietnam Japanese encephalitis virus (JEV) is one of the leading causes of acute encephalitis in humans. The virus is spread by mosquitoes, mainly belonging to the Culex species. The main reservoirs are considered to be birds and pigs, with pigs constituting the most important reservoir in regard to human infection. During the last few decades the production of pork has increased significantly in Vietnam. With 90% of pigs being kept in households owning 10 pigs or less, pigs are widely spread across most parts of the country. Due to the ongoing urbanization of Vietnam, the need for urban agriculture and animal husbandry has increased, resulting in an increasing amount of pigs/reservoirs being kept in urban environments. In the city of Can Tho, located in the Mekong delta, almost 100 % of the pigs have been found to be JEV positive, and vectors needed for transmission of JEV have been shown to be present in the urban areas of the city. The objectives of this study was to examine the seroprevalence of JEV in dogs and pigs in an endemic region, and to evaluate if dogs make suitable sentinels and could be used to evaluate the risk that JEV may pose to humans living in urban areas. To do this, blood samples were collected from dogs and pigs. A total number of 127 dog samples and 176 pig samples were collected from Can Tho city province and 65 samples were collected for comparative purposes from dogs originating from Ho Chi Minh City. The samples from Can Tho were divided into two equal parts. One part was frozen and sent to Sweden to be tested for JEV antibodies, using a competitive IgG ELISA. One part of the samples from Can Tho was also tested at Can Tho University using an in house HI-test. Due to denaturation as a result of high temperature inactivation of the sera, none of the samples that were sent to Sweden could be tested using the competitive IgG ELISA. The HI-results showed that 27 of the 127 dog samples and 159 of the 176 pig samples, all originating from Can Tho city province, had measurable antibody titres against JEV. Twenty three per cent of the dogs originating from the urban district of Ninh Kieu had measurable antibody titres against JEV. Although the seroprevalence was much higher among dogs mainly kept outdoors than dogs mainly kept indoors, it is notable that more than 16% of the dogs mainly kept indoors were also seropositive for JEV. These results indicate not only that JEV does pose a risk to people living in the urban areas of Can Tho city, but also that dogs may be good sentinels for human infection and can be used for evaluating the risk that JEV poses to humans living in urban areas. Japanskt encefalitvirus (JEV) är en av de främsta orsakerna till akut encefalit hos människor. Viruset sprids av myggor, framförallt myggor tillhörande arten Culex. De viktigaste reservoarerna är fåglar och grisar, där grisar utgör den viktigaste reservoaren i förhållande till humansmitta. Under de senaste årtiondena har produktionen av fläskkött i Vietnam ökat markant. Då mer än 90 % av grisarna hålls i hushåll med 10 grisar eller färre innebär detta att grisproduktionen är spridd över stora delar av landet. Till följd av den pågånde urbaniseringen av Vietnam har behovet av urbant jordbruk och djurhållning ökat, vilket har lett till en ökande andel grisar urbana miljöer. I Can Tho city, beläget i Mekongdeltat, har man funnit att nästan 100% av grisarna har antikroppar mot JEV samt att de vektorer som krävs för smittspridning förekommer i stadens urbana områden. Syftet med denna studie var att undersöka seroprevalensen av JEV hos hundar och grisar i en endemisk region, samt att utvärdera huruvida hundar är lämpliga som indikatordjur/sentineldjur och om de kan användas för att utvärdera den risk som JEV utgör för människor. För att undersöka detta samlades blodprover in från hundar och grisar. Totalt samlades 127 hundprover samt 176 grisprover in från Can Tho-regionen och i jämförande syfte samlades även 65 hundprover in från Ho Chi Minh City. Proverna från Can Tho delades upp i två lika delar och därefter frystes serumet. Ena halvan av varje prov skickades sedan till Sverige i syfte att testas för JEV-antikroppar med hjälp av en kompetetiv IgG-ELISA. Som resultat av högtemperatursbehandlingen, som gjordes för att inaktivera eventuella patogener i proverna, blev proverna som sändes till Sverige obrukbara och de kunde inte användas för en ELISA. Proverna från Can Tho testades på Can Tho universitetet med hjälp av deras egen HI-test. Resultaten från HI-testen visade att 27 hundprover och 159 grisprover var positiva för antikroppar mot JEV. Tjugotre procent av hundarna som härrörde från det urbana Ninh Kieu-distriktet hade mätbara antikroppstitrar mot JEV. Trots att seroprevalensen var signifikant högre bland hundar som till största delen hölls utomhus jämfört med hundar som till största delen hölls inomhus, så var en relativt hög andel av hundarna som hölls inomhus också seropositiva. Över 16% av hundarna i inomhusgruppen hade mätbara antikroppstitrar mot JEV. Resultaten tyder inte bara på att JEV utgör en risk för folk som lever i de urbana delarna av Can Tho city, utan också på att hundar möjligen kan användas såväl som sentineldjur som för att utvärdera den risk som JEV utgör för människor. SLU/Dept. of Clinical Sciences (until 231231) 2013 H2 eng swe https://stud.epsilon.slu.se/5793/ |
| spellingShingle | Flavivirus Pets Swine Antibodies Sentinels JEV Vietnam Nilsson, Sylvia Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title | Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title_full | Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title_fullStr | Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title_full_unstemmed | Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title_short | Seroprevalence of Japanese encephalitis virus in pigs and dogs in the Mekong Delta |
| title_sort | seroprevalence of japanese encephalitis virus in pigs and dogs in the mekong delta |
| topic | Flavivirus Pets Swine Antibodies Sentinels JEV Vietnam |