Title: Hunting and logging linked to emerging infectious diseases
Abstract: A “synergy” between hunting of wild vertebrates and contemporary logging practices in tropical forests could be responsible for the emergence of new infectious diseases, says ecologist Nathan Wolfe (Johns Hopkins School of Public Health, Baltimore, MD, USA). “The commercialisation of hunting and dramatic increases in tropical logging, complete with new trucks and access roads, allow local disease outbreaks to have potentially global consequences”, he warns. Wolfe and colleagues reviewed risk behaviours and disease transmission in highly biodiverse lowland tropical forests. The strongest associations were for hunting–linked to transmission of Ebola virus and monkeypox–and wildlife necropsy–linked to transmission of Ebola virus and listeriosis. “The difference is that when wildlife necropsy is performed appropriately, people use protective measures. We don't know much about indigenous protection, but hunters still are less likely to be taking precautions, plus the frequency of hunting is much higher, making it a much greater risk”, says Wolfe. Other behaviours associated with disease transmission included butchering and other forms of meat processing (anthrax, Ebola), keeping pets (salmonella), and ecotourism (measles, Loa loa, cutaneous leishmaniasis). Combined with the transportation infrastructure provided by logging companies, rapid urban growth, and substantial geographic mobility, these activities represent “the ideal recipe for microbial emergence”, conclude the researchers (Global Change Hum Health 2000; 1: 10–25). “Hunting is as old as humankind, and disease transmission associated with hunting is equally old. But diseases which, in the past, would have gone extinct in some small rural group, now have the capacity to spread through cities and international airports to all parts of the world”, stresses Wolfe, who works in Cameroon. Studies are underway to identify the specific mechanisms of transmission with a view towards predicting, controlling, and preventing disease emergence, he notes. But Wolfe reminds that disease transmission is a two-way street. “There are quite a few endangered primate populations in isolated regions, and their risk of disease from humans involved in activities such as ecotourism is substantial”, he warns.