Sanparks Veterinary Wildlife Services and the state veterinary authority joined forces for 10 days this July to carry out a survey to determine the prevalence of bovine tuberculosis (BTB) in buffalo in the northern regions of Kruger National Park (KNP).They were accompanied by Mozambican vets who are studying Kruger's methodology in order to carry out a BTB survey on buffalo in the Limpopo National Park in Mozambique later in the year. The BTB study group decided at a meeting earlier this year to investigate the spread of the disease in northern Kruger, partly as a result of the death of two buffalo from advanced bovine TB just kilometres from the KNP's border with Zimbabwe last year.The BTB situation in the southern and central regions of Kruger is better understood due to more recent surveys and a large research project in the central region of Kruger. The last surveys for BTB took place in the northern regions of Kruger in 2003 and 2000. These revealed that less than 10 percent of the buffalo in the northern region and less than two percent in the far north were infected with the disease. In contrast, one in three buffalo in the south of the park have visible BTB growths in their organs, with more animals testing positive for the disease but not yet showing obvious symptoms.

According to Dr Lin-Mari de Klerk- Lorist, about 70 to 80 percent of the buffalo herds between the Limpopo River and Punda Maria will be tested for BTB in the current survey. The buffalo are located using information obtained during 2005's elephant and buffalo census. A selection of animals of all ages from each herd will be darted from a helicopter. Blood samples will be taken from the animals and they will be marked with a number for identification purposes.

One animal from each herd will also be fitted with a radio-collar so that the herd can be relocated. The blood samples will be tested for BTB in the laboratory, and cultures will be made from those samples that test positive.

Any animals that test positive will be euthanased, to see how far the disease had progressed within the buffalo. The results from the blood tests should all be in by the beginning of August, giving the vets some idea of how fast bovine tuberculosis is moving through the buffalo population in Kruger. Although more than ten species of animals have been found suffering from bovine tuberculosis in Kruger, the animals most commonly found suffering from advanced BTB are buffalo, lion, warthog and kudu.

By Melissa Wray