Anthrax is a bacterial disease that affects wild and domestic animals, as well as humans. Although outbreaks have mostly been reported in arid ecosystems of the African savannahs, lethal anthrax-like cases in wild chimpanzees were reported in a rainforest habitat, and the causative agent was identified as Bacillus cereus biovar anthracis (Bcbva). Hoffmann, Zimmermann et al. investigated the epidemiology of Bcbva by analysing isolates retrieved from flies, and the bones and carcasses of animals that were collected at rainforest sites over three decades. Mortality levels were comparable to those of classic anthrax, whereas the host range was broader and a seasonal effect on incidence was not always evident. In addition, simulations showed that this pathogen has the potential to cause the decline and extinction of local chimpanzee populations. Understanding disease dynamics will aid infection control and contribute to wildlife conservation.