Anxieties over anthrax

Outbreaks of anthrax have become an annual occurrence in Zambia. Since 1990 when the disease was identified in Western Zambia, hundreds of animals and people have died. A large-scale vaccination campaign was started in the same year and has continued on an annual basis. However, reports from veterinary field staff suggest that farmers' reluctance to vaccinate has hindered control of the disease.

Farmers are told to rest their oxen for two weeks after vaccination and therefore some refuse to vaccinate their animals during the rainy season because that is when they need draught power. Some farmers, especially in areas where there has been no experience of the disease, fear that anthrax could be spread via the vaccine. The haphazard nature of vaccination has resulted in the disease becoming more widespread during recent years.

A recent study conducted by the Zambian Department of Veterinary and Tsetse Control Services suggests that farmers' knowledge of the disease is very limited, even in areas where it has been prevalent for many years. The majority of farmers are able to identify the disease only by the enlarged spleen and are unable to recognize it from an unopened carcass. The result is that vaccines meant for diseases other than anthrax are often used. There have also been complaints from farmers about the effectiveness of the anthrax vaccine because, in many instances, animals have died in the weeks or months following vaccination.

Anthrax, which is caused by the spore-forming bacterium Bacillus anthracis most commonly occurs in warm-blooded animals but the spores, if inhaled or ingested in contaminated soil, food or water, are known to infect humans. It is unlikely that spread of the disease occurs from direct person-to-person contact but spores are resistant to most disinfectants and can remain viable in the soil for up to ten years. The Zambian report states that some farmers find it difficult to accept that a disease which kills cattle can also be infectious to humans, which has resulted in farmers and their families becoming infected after handling or eating meat from an infected animal. Death occurs in 25-60% of those who contract intestinal anthrax particularly as antibiotics, such as penicillin, are only effective if treatment is sought at an early stage.

Despite a massive campaign launched by the Zambian government on the importance of vaccination, erratic supply of anthrax vaccine has rendered control strategies ineffective because in most cases cattle are only vaccinated in the middle of an outbreak, when some animals are already infected.

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