Four things farmers and the public need to know about anthrax

Carcass of a buffalo.

Recently, the Kenya Wildlife Service (KWS) reported that 10 buffaloes succumbed to anthrax in the Lake Nakuru National Park. This put Kenyan farmers and the public at large on a high alert as it was feared that the disease may spread to animals and humans outside the park.

Their concerns are genuine given that the disease can easily spread to neighbouring human settlements through scavengers or displaced soil particles harbouring anthrax spores.

The Directorate of Veterinary Services has already mobilised a team to work with other stakeholders to ensure the disease doesn’t spread from source.  

What is anthrax?

Anthrax is an infectious bacterial disease that affects herbivorous animals. The disease is spread through ingestion or inhalation of anthrax spores from contaminated soils by an animal. Anthrax manifests in three different forms; namely gastrointestinal, cutaneous and pulmonary forms.

The gastro-intestinal form is caused by ingestion of anthrax bacteria or spores. The cutaneous form is contracted through wounds on the skin and is common in people who frequently get in contact with animals and animal products. Pulmonary form of the disease also mainly affects people through inhalation of spores.

Clinical signs of anthrax

Cattle and sheep will die suddenly (within 2 or 3 hours of being apparently normal). Some animals will show high temperature, have difficulty in breathing, collapse and convulse before death. The most characteristic sign of anthrax is the oozing of blood from all body openings of the carcass –nose, mouth and anal openings.

This is because unlike in other cases where blood clots after death in anthrax blood doesn’t clot.  But sometimes this doesn’t happen and should not be solely relied on in cases where the animal dies suddenly. Anthrax carcasses also lack rigor mortis and fail to stiffen as is common in dead animals.

Transmission

Infection in animals occurs through ingestion of contaminated pastures and soils. This is common when animals graze close to the ground as it happens after prolonged drought when pastures are scanty and animals end up ingesting soils. Abrasive forage can cause injuries to the mouth parts and create pathways for the entry of bacteria into the blood stream effectively causing anthrax. The spores can remain buried in soils for years and can be brought to surface through road and dam constructions, deep tilling, soil erosion and flooding. The spores can also be inhaled. 

Prevention

Although there are antibiotics that are effective against anthrax; the disease kills so quickly before any treatment is instituted. Consult your vet for vaccination against anthrax.

The Kenya Veterinary Vaccines Production Institute (KEVEVAPI) distributes a vaccine against anthrax which is marketed as Blanthrax and retails at Sh1000 per 50 doses vial. It is also available in agrovets that stock veterinary vaccines and confers 12 months’ immunity.

What should the public do to contain its spread?

Farmers should report any sudden death of their livestock immediately to the nearest veterinary authority. They should never attempt to open or slaughter animals that die on the farm for human consumption. It is the action of opening anthrax carcasses that causes contamination of the environment with anthrax causing bacterial spores. The public should never eat any uninspected meat and should only buy their meat from designated meat outlets.

Prevent scavengers from anthrax carcasses. Incineration is the recommended method of disposal of anthrax carcasses. Where this is not practical deep burial 6-8 feet of carcasses covered with copious amounts of quick lime can also be done. But this should never be done in flood prone areas.  

(Dr Njagi is the Director of Veterinary Services and Kenya’s Chief Veterinary Officer)