In a recent disease survey of the buffalo in the Mozambican Limpopo National Park (LNP) adjoining the Kruger National Park (KNP), the blood taken from one buffalo tested positive for bovine tuberculosis. However, when the buffalo's organs were examined, no trace of the disease could be found.
Tissue from the buffalo has been taken to Onderstepoort Veterinary Institute to be cultured for the bacteria that could cause bovine tuberculosis. This will determine if the blood test has given a false positive result. Veterinarians spent a week in late October trying to test as many of the Mozambican park's buffalo as possible for several diseases that are of concern to animal health authorities.?
These include bovine tuberculosis, theileriosis (corridor disease), brucellosis, trypanosomiasis (which causes nagana or sleeping sickness in humans), bartonellosis (a bacterial disease spread by biting flies) and rift valley fever, as well as foot and mouth disease.
The diseases are of concern not only because they can affect domestic cattle, but also because many of them have consequences for human health. A recent survey has revealed that there are about 150 buffalo resident in the LNP, living in much smaller herds than typically occur in Kruger.
Some BTB-free buffalo were reintroduced from Kruger, while about 100 other animals were already living in the park. Kruger's wildlife veterinary services, together with the Mozambican authorities, managed to test over a third of all the buffalo in the park for the diseases of concern.
According to Dr Carlos Lopes Pereira, from the Mozambican national directorate of the veterinary authority, the buffalo herds resident in the Mozambican park do not have contact with Kruger buffalo, but their disease status was only known from a pilot study carried out in 2004. The current disease survey was intended to tell with a high level of confidence whether or not bovine tuberculosis had crept into the park.
?The preliminary results demonstrate that the resident herds of the LNP were not infected with bovine tuberculosis until recently or (in case we have a true positive) became infected very recently.? As one of the herds in the south of the park is in close contact with cattle and people, finding bovine tuberculosis would be of concern.
To eradicate bovine TB in cattle, the animals with the disease are slaughtered immediately. Humans can also contract bovine TB, especially if their immune system is compromised. Dr Pereira says that they intend to monitor the herds that do not have contact with Kruger buffalo every second year to check their disease status.
The testing of buffalo is also of interest to Kruger authorities, as diseases such as trypanosomiasis are not present in Kruger due to a lack of the flies that spread the disease. Finding it in Mozambican buffalo would then alert Kruger authorities to the potential of the disease entering the park.