The term used to describe the transmission of disease from animals to humans is Zoonoses and it has a fascinating history.The best know diseases are rabies, anthrax, tuberculosis, plague, yellow fever, influenza, and certain zoonotic parasitic diseases. The most famous plague, also called the Black Death, was caused by the fleas being carried by black rats. In 1346 the plague entered Constantinople and by December 1348 London. By the end of the outbreak “The death toll throughout Europe was at least 25 million out of a total population of 40 million. (In warmer months and in southern Europe, at this time, there was at least one family of black rats per household and an estimated average of three fleas per rat.)” http://uhaweb.hartford.edu/bugl/histepi.htm#plague

Another transmitted disease is Yellow Fever. Yellow Fever is caused when a mosquito bites a human after it has bitten an infected monkey. Located in Western Africa this disease became know as “White Man's Grave” after killing colonists by the hundreds. http://www.cbwinfo.com/Biological/Pathogens/YFV.html

The diseases continue to infect humans as we move closer to wildlife areas. Between 2000 and 2005 and estimated 50 million people where infected with zoonotic diseases causing the death of an estimated 78,000 people. “For instance there has been a global resurgence in the Dengue virus – which is transmitted between monkeys in the jungle by the mosquitoes that feed on them. The cycle can move into nearby urban areas where it can then be transmitted from person to person by mosquitoes” says Dr Jonathan Heeney, Chair of the Department of Virology at the Biomedical Primate Research Centre in the Netherlands. http://www.innovations-report.de/html/berichte/medizin_gesundheit/bericht-73607.html

The rise of zoonoses as even produced an article “Zoonoses Likely to be Used in Bioterrorism” by C. Patrick Ryan in Public Health Reports, May-June 2008.