KwaZulu-Natal - A serious outbreak of the highly contagious wildlife disease anthrax has wiped out nearly 50 percent of the rare roan antelope population and scores of hippos in the Kruger National Park.
This is the eighth major outbreak of the disease since the early 1960s in the country’s flagship national park.
SA National Parks confirmed this week that 30 dead hippos had been found in the Letaba and Olifants rivers over the past two weeks. Post-mortem examination results from some of the carcasses suggested they were infected with the anthrax bacteria.
Two weeks ago, Environmental Affairs Minister Edna Molewa revealed that most of the roan antelope had been wiped out by anthrax in a protective breeding enclosure inside the park during August.
Responding to queries in Parliament, Molewa said that 45 roan antelope had died in the Capricorn breeding enclosure – leaving just 13 survivors in this camp, another 35 in the Nwaswishumbe breeding enclosure and an estimated 40 to 50 free-roaming animals.
SANParks said this week that the anthrax outbreak had begun in late August. Visitors were urged to report any sightings of dead hippos to the nearest camp, but not to touch the bodies.
“Anthrax is a highly infectious disease caused by the bacterium Bacillus anthracis. It is thought that the disease is spread mainly by vultures and blowflies,” said SANParks spokesman Reynold Thakhuli.
“Vultures are immune to anthrax and spread the disease by consuming contaminated meat from affected carcasses, and then defecating in water where they regularly drink or bath. The toxins released by the bacteria when they sporulate are also fatal to some species.”
Thakhuli said anthrax outbreaks were “a natural occurrence” in the north of the park, and occurred more or less every 10 years. The outbreaks seemed to be related to the end of dry cycles, while the disease seemed to be closely linked to population density. When certain species like kudu and hippo reached high densities, anthrax spread more rapidly.
“This is the only disease in Kruger National Park that needs to kill its host in order to propagate itself. In all the outbreaks before, the disease naturally dissipated when the rains started and when animal densities decreased, so it can be considered a ‘natural regulator’ of animal densities… The… rangers are monitoring the situation,” Thakhuli said.
During the previous outbreak, in the Nxanatseni region in 2010, it was estimated that 2 000 animals died. - The Mercury