In an update on the anthrax update at Lake Nakuru National Park in Kenya from July, Dr Kisa J. Z. Juma Ngeiywa, CVO Director of Veterinary Services with the Ministry of Agriculture in Nairobi reported to the World Organisation for Animal Health that the outbreak is ongoing and the number of animals affected has increased.

Bacillus anthracis/CDC

Ngeiywa notes the number of dead Cape buffaloes due to anthrax in Lake Nakuru National Park has reached 300. The park has a buffalo population of 4,500.

In addition, a number of other animals have been affected to include rhinos, Rothschild giraffes, elands, impalas, warthogs and Thomson gazelles.

Officials report the source of the outbreak is contact with infected animal(s) at grazing/watering near the lake shore, watering holes and the fence line since mid-July.

Kenya has applied the following measures to help contain the outbreak: Movement control inside the country, disinfection / disinfestation, quarantine, surveillance outside containment and/or protection zone, official disposal of carcasses, by-products and waste and surveillance within containment and/or protection zone.

According to the Merck Veterinary Manual, Anthrax is a zoonotic disease caused by the sporeforming bacterium Bacillus anthracis. Anthrax is most common in wild and domestic herbivores (eg, cattle, sheep, goats, camels, antelopes) but can also be seen in humans exposed to tissue from infected animals, contaminated animal products or directly to B anthracis spores under certain conditions.


Depending on the route of infection, host factors, and potentially strain-specific factors, anthrax can have several different clinical presentations. In herbivores, anthrax commonly presents as an acute septicemia with a high fatality rate, often accompanied by hemorrhagic lymphadenitis.

B. anthracis spores can remain infective in soil for many years. During this time, they are a potential source of infection for grazing livestock. Grazing animals may become infected when they ingest sufficient quantities of these spores from the soil.In addition to direct transmission, biting flies may mechanically transmit B. anthracis spores from one animal to another.

People can get anthrax by handling contaminated animal or animal products, consuming undercooked meat of infected animals and more recently, intentional release of spores.

Robert Herriman is a microbiologist and the Editor-in-Chief of Outbreak News Today

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