Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock
The aim of this study was to estimate the overall prevalence and herd/flock seroprevalence of the Leptospira serovars Ballum, Copenhageni and Tarassovi and the differences in prevalence between regions in New Zealand. The samples used in the study were 3,878 stored serum samples from beef cattle, de...
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| Formato: | H3 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Clinical Sciences (until 231231)
2016
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| _version_ | 1855571538031411200 |
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| author | Mannewald, Alice |
| author_browse | Mannewald, Alice |
| author_facet | Mannewald, Alice |
| author_sort | Mannewald, Alice |
| collection | Epsilon Archive for Student Projects |
| description | The aim of this study was to estimate the overall prevalence and herd/flock seroprevalence of the Leptospira serovars Ballum, Copenhageni and Tarassovi and the differences in prevalence between regions in New Zealand. The samples used in the study were 3,878 stored serum samples from beef cattle, deer and sheep. The samples came from 9 different regions and from both the North Island and the South Island. The samples were analysed by MAT (microscopic agglutination test) using the titre cut-off point 1:48. Seroprevalence in beef cattle were 13.7%, 14.7% and 18.0% for Ballum, Copenhageni and Tarassovi, respectively. In deer the corresponding figures were 6.6%, 15.5% and 3.6% and in sheep 10.5%, 16.7% and 14.0%. When a farm was regarded as positive as long as at least one positive animal was found, the prevalence of farms positive for Ballum was 76.0% and 88.4% for Copenhageni and 74.0% for Tarassovi. Two farms had no positive samples for any of the three serovars. The prevalence of the three serovars could also been seen to vary between the different regions, although there was a huge difference in number of samples from the regions. Ballum seemed to have a lower prevalence in the South Island than in the North Island. The origin of these serovars is unknown. Based on earlier findings, however, a working hypothesis for future studies is that domestic livestock may be infected through contact with infected wildlife species. As serovars Tarassovi and Ballum are not included in any of the vaccines registered in New Zealand, this study demonstrated that vaccination cannot fully protect farmers against exposure to Leptospira. |
| format | H3 |
| id | RepoSLU9534 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2016 |
| publishDateSort | 2016 |
| publisher | SLU/Dept. of Clinical Sciences (until 231231) |
| publisherStr | SLU/Dept. of Clinical Sciences (until 231231) |
| record_format | eprints |
| spelling | RepoSLU95342016-09-20T08:11:05Z Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock Prevalens av atypiska Leptospira serovarer i Nya Zeelands betesdjur Mannewald, Alice Leptospira leptospirosis prevalence pastoral livestock New Zealand atypical serovars The aim of this study was to estimate the overall prevalence and herd/flock seroprevalence of the Leptospira serovars Ballum, Copenhageni and Tarassovi and the differences in prevalence between regions in New Zealand. The samples used in the study were 3,878 stored serum samples from beef cattle, deer and sheep. The samples came from 9 different regions and from both the North Island and the South Island. The samples were analysed by MAT (microscopic agglutination test) using the titre cut-off point 1:48. Seroprevalence in beef cattle were 13.7%, 14.7% and 18.0% for Ballum, Copenhageni and Tarassovi, respectively. In deer the corresponding figures were 6.6%, 15.5% and 3.6% and in sheep 10.5%, 16.7% and 14.0%. When a farm was regarded as positive as long as at least one positive animal was found, the prevalence of farms positive for Ballum was 76.0% and 88.4% for Copenhageni and 74.0% for Tarassovi. Two farms had no positive samples for any of the three serovars. The prevalence of the three serovars could also been seen to vary between the different regions, although there was a huge difference in number of samples from the regions. Ballum seemed to have a lower prevalence in the South Island than in the North Island. The origin of these serovars is unknown. Based on earlier findings, however, a working hypothesis for future studies is that domestic livestock may be infected through contact with infected wildlife species. As serovars Tarassovi and Ballum are not included in any of the vaccines registered in New Zealand, this study demonstrated that vaccination cannot fully protect farmers against exposure to Leptospira. Målet med den här studien var att skatta den generella prevalensen och gårds-/flock prevalensen av Leptospira serovarerna Ballum, Copenhageni och Tarassovi och skillnaderna i prevalens mellan olika regioner i Nya Zeeland. Proverna som användes i studien bestod av 3,878 lagrade serum prover från nöt (köttdjur), hjort och får. Proverna kom från nio olika regioner och från både nordön och sydön. Proverna analyserades med hjälp av MAT (mikroskopiskt agglutinations test) och tröskelvärdet (titre cut-off point) som användes var 1:48. Prevalensen hos nöt var 13,7 %, 14,7 % och 18,0 % för respektive Ballum, Copenhageni och Tarassovi. Hos hjort var prevalensen 6,6 %, 15,5 % och 3,6 % och hos får låg den på 10,5 %, 16,7 % och 14,0 %. Med antagandet att en gård var positiv så länge det fanns minst ett positivt djur på gården så blev gårdsprevalensen för Ballum 76,0 % samt 88,4 % för Copenhageni och 74,0 % för Tarassovi. Två gårdar hade inga positiva prover för någon av de tre serovarerna. Prevalensen för dessa tre serovarer varierade mellan regionerna, dock så var det en stor skillnad i antalet prover från de olika regionerna. Ballum verkade ha en lägre prevalens på sydön än på nordön. Eftersom serovarerna Tarassovi och Ballum inte är inkluderad i något av vaccinerna som är registrerade i Nya Zeeland, så visar denna studie att vaccinering ej kan skydda bönderna fullt ut mot exponering av Leptospira. Var dessa serovarer har sitt ursprung ifrån är okänt, men baserat på tidigare studier kan man inför framtida studier arbeta efter hypotesen att domesticerade produktionsdjur kanske infekteras via kontakt med vilda djur som är infekterade. SLU/Dept. of Clinical Sciences (until 231231) 2016 H3 eng swe https://stud.epsilon.slu.se/9534/ |
| spellingShingle | Leptospira leptospirosis prevalence pastoral livestock New Zealand atypical serovars Mannewald, Alice Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title | Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title_full | Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title_fullStr | Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title_full_unstemmed | Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title_short | Prevalence of atypical Leptospira serovars in New Zealand’s pastoral livestock |
| title_sort | prevalence of atypical leptospira serovars in new zealand’s pastoral livestock |
| topic | Leptospira leptospirosis prevalence pastoral livestock New Zealand atypical serovars |