Beware anthrax outbreaks rise during rainy season

Friday March 30 2018

Sheep on a farm in Nyandarua. Always clean and disinfect clothes and foot-ware that come into contact with contaminated soil and livestock to protect your animals from anthrax infection. PHOTO | FILE | NATION MEDIA GROUP


Anthrax is a zoonotic disease that primarily affects animals, mostly ruminants but can also cause diseases in human.

Anthrax is caused by spore-producing bacteria called Bacillas antharcis found in the soil. The disease is highly fatal due to the extreme potent toxins produced by the bacteria. It can occur anywhere in the world except the antarctica.

Frequent outbreaks occur in some areas (endemic areas), while in others outbreaks occur only sporadically due to factors like rains, deep tilling of soil and overgrazing.

These factors make resistant spores in the soil, from previous outbreaks, to be brought to the surface and cause infection of animals as they graze.

The current heavy rains in most parts of Kenya may cause sporadic outbreaks of anthrax, and so we should look out for cases of sudden death in livestock particularly the ruminants.

The disease is highly contagious and may spread through injuries in the mouth caused by abrasive forages that allow the bacteria to enter the blood stream as the animals ingest the spores while grazing.


Humans and carnivores get exposed through ingestion of infected meat, inhalation of spores and skin contact with contaminated carcasses.

There are three forms of anthrax that pose serious threat to public health:

1. Gastrointestinal forms that occur when spores from contaminated meat are ingested by people or animals including dogs.

2. Cutaneous form that is seen mostly in exposed humans, as skin ulcers with dark centres.

3. Pulmonary forms that occur when bacteria is inhaled if a carcass is opened, or when working on hides or wool from anthrax infected animals.

Clinical signs of anthrax in livestock

The disease causes sudden death with little indication that the animal was sick. Shortly before the animal dies, there are signs of trembling, fever, difficulty in breathing, collapsing and convulsion.

Bleeding from all natural orifices: mouth, nose, ears and anus; the blood does not clot and neither does the carcass undergo rigour mortis (stiffening).


Once you notice the signs, call a veterinarian immediately as early treatment with bacteriocidal antibiotics is effective. All in contact animals should be treated.

• A vaccine against anthrax in animals is available in the market.

• Clean and disinfect clothes and foot-ware that come into contact with contaminated soil and livestock.

• Carcasses from suspect cases of sudden death must not be opened as exposure to oxygen will allow the bacteria to form spores that cause spread of disease pulmonary form of the disease.

• Properly dispose carcasses where an outbreak has occurred to prevent the spread of anthrax. All carcasses should be disposed off preferably by incineration (burning) or by deep burial with quick lime.

• Quarantine the areas that have anthrax outbreaks until the storm is over and then vaccinate all the susceptible animals against anthrax.

• Always report to veterinary authorities all cases of sudden death that occur in the farm.

In conclusion, it is important to note that regular vaccination, early detection of outbreaks, quarantine of affected premises/farms, destruction of diseased animals and formites and implementation of appropriate sanitary procedures at abattoirs and dairy factories will ensure the safety of products of animal origin intended for human consumption.

At no time should dead animals be eaten by humans.

Dr Muchibi is the animal health manager at Elgon Kenya Ltd.