To Stop A Killer

Anthrax, a disease caused by bacteria, kills wild animals around the world. To stop the pathogens from spreading, managers often try to keep scavengers such as jackals away from victims’ carcasses — for example, by burning the bodies or draping tarpaulins over them.

But such efforts may be misguided, scientists say in Applied and Environmental Microbiology. According to their study, scavengers do little to increase the spread of the disease.

The team came to this conclusion after conducting an experiment in Etosha National Park, Namibia. The researchers found seven zebras and one wildebeest that had been killed by anthrax and placed electrified cages around four of the animals to keep scavengers away. Since the popular belief is that scavengers increase bacterial spore production by opening the carcasses, the team measured spores in the nearby soil.

The density of spores around the scavenged carcasses wasn’t significantly higher than it was around the carcasses that were left alone, the study authors say. “We thus suggest that anthrax control measures aimed at deterring scavengers to prevent sporulation appear unwarranted,” they write. Roberta Kwok | 24 April 2013

Source: Bellan, S.E. et al. 2013. Effects of experimental exclusion of scavengers from anthrax-infected herbivore carcasses on Bacillus anthracis sporulation, survival and distribution. Applied and Environmental Microbiology doi: 10.1128/AEM.00181-13.

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