of central Africa. Viruses and other pathogens develop and mutate in animals there, then jump into the human population. Africans tend to live in very close proximity to both domestic and wild animals, so transmission to humans is almost guaranteed.

Africa's climate is also a factor. The warm, humid environment of central Africa allows viruses and bacteria to remain viable for longer outside of animal and human hosts. Poor response by health care professionals, terrible sanitation, sexual promiscuity within the indigenous populations, and many other factors also contribute.