10 to the 31st power of varieties of virus on the planet.
human viruses have animal origins [Rabies, Yellow Fever, Dengu ever, SARS, Ebola, Influenza, HIV...]
he talked about the transmission of the various viruses from the bush hunters thru the contact with the animals blood. he pointed out that it is not the responsibility of the hunter; rather of us all. their work is really interesting. he posits that they can actually monitor the new flow of viruses into the flow of the human population.
good talk. informative. good style.
http://faculty.jhsph.edu/default.cfm?faculty_id=763&grouped=false&searchText=&department_id=0&departmentName=Epidemiology
http://gvfi.org/