Q fever is a common zoonosis, caused by Coxiella burnetii. Natural reservoirs include several domestic and wild animals, most of which show no signs of disease (although infection can cause abortions).
Tularaemia is a zoonosis (infection that could transmit from animals to humans), caused by the bacterium Francisella tularensis, capable of surviving for weeks at low temperatures in water, moist soil, hay, straw or animal carcasses.
Plague is caused by Yersinia pestis bacteria. Blood sucking fleas transmit the bacteria among animals, and various species of rodents can become infected. Human cases are most likely to occur when domestic rats are involved, as these live in close proximity to humans.
Smallpox is caused by variola virus, genus Orthopoxvirus. Other members of this genus that cause infection in humans are vaccinia virus, monkeypox virus, and cowpox virus. In 1980, the World Health Organization officially declared smallpox to be eradicated.
Nipah virus (NiV) is a member of the family Paramyxoviridae, genus Henipavirus. NiV was initially isolated and identified in 1999 during an outbreak of encephalitis and respiratory illness among pig farmers and people with close contact with pigs in Malaysia and Singapore.