Principles of Medicine in Africa

Anthrax is a widespread zoonosis transmitted from animals (mainly herbivores) to humans. Robert Koch discovered the transmission cycle at the end of the nineteenth century. Since then, anthrax has been successfully controlled in Europe and the USA, though interest in Bacillus anthracis has recently risen due to the danger of terrorist attacks using B. anthracis. Most cases in Africa are due to contact with infected animals, animal products or infested soil.

The problem in Africa

Anthrax is a common infection of animals, both domestic and wild, and sporadic outbreaks of human anthrax are reported in many parts of Africa. Clinicians practising especially in rural areas of Africa need to have a basic knowledge of the epidemiology and clinical picture of anthrax. Outbreaks have been reported from Zambia, Zimbabwe (Davies, 1982), Tanzania, Kenya and South Africa (WHO, 1994), Ghana (Opare et al., 2000), Burkina Faso (Coulibaly and Yameogo, 2000) and Guinea Bissau (De Ridders, 1994). In The Gambia, human anthrax is endemic, occurring every dry season in a specific region (Heyworth et al., 1975).

The organism

Anthrax is caused by Bacillus anthracis, a Gram-positive encapsulated, non-motile, aerobic bacterium that forms spores, which can survive in dry ground for many years and infect animals and humans (Turnbull, 1999; Spencer, 2003).