Anthrax kills wild chimpanzees in a tropical rainforest


Infectious disease has joined habitat loss and hunting as threats to the survival of the remaining wild populations of great apes. Nevertheless, relatively little is known about the causative agents1,2,3. We investigated an unusually high number of sudden deaths observed over nine months in three communities of wild chimpanzees (Pan troglodytes verus) in the Taï National Park, Ivory Coast. Here we report combined pathological, cytological and molecular investigations that identified Bacillus anthracis as the cause of death for at least six individuals. We show that anthrax can be found in wild non-human primates living in a tropical rainforest, a habitat not previously known to harbour B. anthracis. Anthrax is an acute disease that infects ruminants4,5, but other mammals, including humans, can be infected through contacting or inhaling high doses of spores or by consuming meat from infected animals6. Respiratory and gastrointestinal anthrax are characterized by rapid onset, fever, septicaemia and a high fatality rate without early antibiotic treatment6,7. Our results suggest that epidemic diseases represent substantial threats to wild ape populations, and through bushmeat consumption also pose a hazard to human health.

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Figure 1: Histological section of lung tissues of the chimpanzee Léo.


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We thank the Ivorian authorities for long-term support, especially the Ministry of the Environment and Forests as well as the Ministry of Research, the directorship of the Taï National Park, and the Swiss Research Center in Abidjan. We are grateful to P. Emmerich and H. Schmitz at the Bernhard-Nocht-Institut for VHF analyses. For technical support we thank S. Yumlu, T. Deschner, E. Normand, S. Pociuli, H. Emmel, and also U. Erikli for copy editing. This work was supported by the Robert Koch-Institut and the Max-Planck-Gesellschaft.

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Correspondence to Heinz Ellerbrok.

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The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Table 1

Characteristics of the chimpanzees analysed Supplementary Table 1 presents all chimpanzees that were analysed in this work with name, group age and sex. This list includes the date of death or disappearance, the observed symptoms and the results from anthrax diagnostics. (DOC 28 kb)

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Leendertz, F., Ellerbrok, H., Boesch, C. et al. Anthrax kills wild chimpanzees in a tropical rainforest. Nature 430, 451–452 (2004).

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