Temporal and spatial distribution of cattle anthrax outbreaks in Zimbabwe between 1967 and 2006
This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to identify risk areas in Zimbabwe. The data were extracted from the monthly and annual reports of the Division of Livestock Production and Veterinary Services for the period 1967 to 2006. The data were analyzed in relation to temporal and spatial factors. The hot-dry season was found to be significantly (X 2 = 847.8, P < 0.001) associated with the occurrence of anthrax in cattle, and the disease was found to be approximately three times more likely to occur during this season compared to other seasons. Anthrax outbreaks demonstrated a gradual temporal increase from an annual mean of three outbreaks for the 5-year period (1967–1971) to 42 for the 5-year period (2002–2006). Similarly, the data demonstrated a spatial increase in the number of districts affected by anthrax between 1967 and 2006, with 12 districts affected for the 10-year period (1967–1976) that expanded to 42 districts for the 10-year period (1997–2006). The majority of outbreaks (83.7%) were recorded in rural areas, and 11 districts were found to be at a higher risk than others. There is need to develop differential vaccination strategy, other control strategies and preventive recommendations to reduce anthrax in high-risk districts. In the medium- to low-risk districts, maintenance of effective surveillance systems and improvement of awareness is very important to detect and contain outbreaks early.
KeywordsAnthrax Cattle Distribution Outbreaks Spatial Temporal Zimbabwe
The authors are grateful to the Department of Veterinary Technical Services, Dr Donora of the Department of Veterinary Field Services for allowing access to anthrax records.
- Blackburn, J.K., McNyset, K.M., Curtis, A. and Hugh-Jones, M.E., 2007. Modeling the geographic distribution of Bacillus anthracis, the causative agent of anthrax disease, for the contiguous United States using predictive ecologic niche modeling, American Journal of Tropical Medicine and Hygiene, 77, 1103–1110.PubMedGoogle Scholar
- De Vos, V., 1990. The ecology of anthrax in Kruger National Park, South Africa, Salisbury Medical Bulletin, 68 (special supplement), 19–23.Google Scholar
- Dohoo, I., Martin, W., Stryhn, H. Veterinary Epidemiologic Research: AVC Inc., Charlottetown, Prince Edward Island, 2003.Google Scholar
- Dragon, D.C. and Rennie, R.P., 1995. The ecology of anthrax spores: tough but not invincible, Canadian Veterinary Journal, 36, 295–301.Google Scholar
- Johnson, R., 2005. Epizootiology and ecology of anthrax. In: United States Department of Agriculture, Center for Emerging Infections, Centers for Disease Control, Veterinary Services Report.Google Scholar
- Kobuch, W. E., Davies, J., Fleischer, K., Isaacson, M. and Turnbull, P. C. B., 1990. A clinical and epidemiological study of 621 patients with anthrax in western Zimbabwe, Proceedings of the international workshop on anthrax, Salisbury Medical Bulletin, 68(supplement), 34–38.Google Scholar
- Nass, M., 1992. Anthrax epizootic in Zimbabwe 1978–1980: due to deliberate spread?, PSR Quarterly 2, 198–209.Google Scholar
- OIE., 1997. OIE Animal Health and Disease Control Report 1997. Office International Des Epizooties, Paris, France.Google Scholar
- Pugh, A.O. and Davies, J.C.A., 1990. Human anthrax in Zimbabwe, Salisbury Medical Bulletin, 68 (special supplement), 32–33.Google Scholar
- Starr, J.R., 1988. Weather, climate and animal performance, Technical Note No. 190, World Meteorological Organization, Geneva, Switzerland.Google Scholar
- Stein, C.D., 1945. The history and distribution of anthrax in livestock in the United States, Veterinary Medicine (Praha), 40, 340–349.Google Scholar
- Stein, C.D. and van Ness, G.B., 1955. A ten year survey of anthrax in livestock with special reference to outbreaks in 1954, Veterinary Medicine (Praha), 50, 579–590.Google Scholar
- WHO, 2005. Guidelines for the Surveillance and Control of anthrax in humans and animals, Emerging and Communicable Disease Surveillance, Control. http://www.who.int/emc.
- Turnbull, P.C.B., Hudson, R.A., Ward, M.J., Jones, M.N., Quinn, C.P., Finnie, N.J., Duggleby, C.J., Kramer, J.M. and Melling, J., 1990. Bacillus anthracis but not always anthrax, Journal of Applied Bacteriology, 72, 21–28.Google Scholar
- Turner, M., 1980. Anthrax in humans in Zimbabwe, Central African Journal of Medicine, 26, 291–298.Google Scholar