Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T10:37:08.136Z Has data issue: false hasContentIssue false

A study of African swine fever virus infected ticks (Ornithodoros moubata) collected from three villages in the ASF enzootic area of Malawi following an outbreak of the disease in domestic pigs

Published online by Cambridge University Press:  15 May 2009

J. M. Haresnape
Affiliation:
Central Veterinary Laboratory, P.O. Box 527, Lilongwe, Malawi
P. J. Wilkinson
Affiliation:
Pirbright Laboratory, AFRC Institute for Animal Health, Pirbright, Woking, Surrey
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A detailed study was made in 1983–5 in three villages in Mehinji district in the African swine fever (ASF) enzootic area of Malawi, following an outbreak of ASF which affected all three villages.

Ticks of the Ornithodoros moubata complex were collected from both pig sties and houses shortly after the outbreak, and approximately 24% contained ASF virus. The proportion of ticks infected did not differ significantly in the three villages, or more surprisingly in different types of premises, and was equivalent in all stages of ticks. The proportion infected decreased with the passage of time, but infected ticks were still present in all three villages 8 months after the outbreak,some with high titres of virus.

The proportion of seropositive pigs in the three villages approached 100% following the outbreak, with many apparently healthy pigs being seropositive. It is suggested that Malawian isolates of ASF virus may be less virulent in African than European breeds of domestic pig.

Type
Special Article
Copyright
Copyright © Cambridge University Press 1989

References

REFERENCES

Gardner, M. J. & Altman, D. G. (1986). Confidence intervals rather than P values: estimation rather than hypothesis testing. British Medical Journal 292, 746750.CrossRefGoogle Scholar
Haresnape, J. M. (1984). African swine fever in Malawi. Tropical Animal Health and Production 16, 123125.CrossRefGoogle ScholarPubMed
Haresnape, J. M., Lungu, S. A. M. & Mamu, F. D. (1985). A four-year survey of African swine fever in Malawi. Journal of Hygiene 95, 309323.CrossRefGoogle ScholarPubMed
Haresnape, J. M., Lungu, S. A. M. & Mamu, F. D. (1987). An updated survey of African swine fever in Malawi. Epidemiology and Infection 99, 723732.CrossRefGoogle ScholarPubMed
Haresnape, J. M. & Mamu, F. D. (1986). The distribution of ticks of the Ornithodoros moubata complex (Ixodoidea: Argasidae) in Malawi, and its relation to African swine fever epizootiology. Journal of Hygiene 96, 535544.CrossRefGoogle ScholarPubMed
Haresnape, J. M., Wilkinson, P. J. & Mellor, P. (1988). Isolation of African swine fever virus from ticks of the Ornithodoris moubata complex (Ixodoidea: Argasidae) collected within the African swine fever enzootic area of Malawi. Epidemiology and Infection 101, 173185.CrossRefGoogle ScholarPubMed
Plowright, W., Parker, J. & Pierce, M. A. (1969). The epizootiology of African swine fever in Africa. Veterinary Record 85, 668674.Google Scholar
Plowright, W., Perry, C. T., Pierce, M. A. & Parker, J. (1970). Experimental infection of the Argasid tick. Ornithodoros moubata porcinus, with African swine fever virus. Archiv für die gesamte Virusforschung 31, 3350.CrossRefGoogle ScholarPubMed
Schlafer, D. H., Mebus, C. A. & McVicar, J. W. (1984). African swine fever in neonatal pigs: passively acquired protection from colostrum or serum of recovered pigs. American Journal of Veterinary Research 45, 13671372.Google ScholarPubMed
Schlafer, D. H., McVicar, J. W. & Mebus, C. A. (1984). African swine fever convalescent sows: Subsequent pregnancy and the effect of colostral antibody on challenge inoculation of their pigs. American Journal of Veterinary Research 45, 13611366.Google ScholarPubMed
Stuchbery, H. M. (1949). Report of the Veterinary Department for the year ended 31st December 1948. Nyasaland Protectorate. Printed by the Government Printer, Zomba. Nyasaland.Google Scholar
Thomson, G., Gainaru, M., Lewis, A., Biggs, H., Neville, E., Van der Pypekamp, H., Gerber, L., Esterhuysen, J., Bengis, R., Bezuidenhout, D. & Condy, J. (1983). The relationship between African swine fever virus, the warthog and Ornithodoros species in Southern Africa. In African Swine Fever, CEC/FAO Research Seminar, Sardinia, 1981 (ed. Wilkinson, P. J.), pp. 85100. CEC Publication EUR 8466EN.Google Scholar
Turnbull, D. O. (1932). Report of the Veterinary Department for the year ended 31st December 1931. Nyasaland Protectorate. Printed by the Government Printer, Zomba. Nyasaland.Google Scholar
Turnbull, D. O. (1933). Report of the Veterinary Department for the year ended 31st December 1932. Nyasaland Protectorate. Printed by the Government Printer, Zomba. Nyasaland.Google Scholar
Wilkinson, P. J. (1984). The persistence of African swine fever in Africa and the Mediterranean. Preventive Veterinary Medicine 2, 7182.CrossRefGoogle Scholar