Infectious Disease Epidemiology Program

Zoonotic Diseases

Zoonotic diseases/infections are those which can be naturally transmissible from vertebrate animals to humans. Approximately 75% of recently emerging infectious diseases affecting humans are diseases of animal origin. Many factors like Environmental changes, human and animal demography, pathogen changes and changes in farming practice lead to the emergence of zoonotic diseases. Social and cultural factors such as food habits and religious beliefs play a role in the emergence of zoonotic diseases.

  • Rabies - Rabies is a viral disease of the central nervous system (brain and spinal cord) that is most often transmitted through the bite or scratch of a rabid animal. The vast majority of rabies cases occur in wild animals like raccoons, skunks, bats, and foxes. Domestic animals account for less than 10% of the reported rabies cases, with cats, cattle, and dogs most often reported rabid.Rabies in humans is very rare in the U.S., but is almost always fatal.
  • Brucellosis - Brucellosis is an infectious disease caused by the bacteria of the genus Brucella. These bacteria can cause disease in many different animals. Humans become infected by coming in contact with animals or animal products that are contaminated with these bacteria.
  • Ebola Virus Disease - Ebola Virus Disease is caused by infection with one of the Ebola virus strains. 
  • Q fever - Q fever is a zoonotic disease caused by Coxiella burnetii, a species of bacteria that is distributed globally. Q fever mainly affects cattle, sheep and goats and can be passed to humans primarily by inhalation of these organisms from air that contains airborne barnyard dust contaminated by dried placental material, birth fluids, and excreta of infected herd animals.
  • Hantavirus (Hantavirus Pulmonary Syndrome) - Hantavirus pulmonary syndrome (HPS) is a deadly disease from rodents. Humans can contract the disease when they come into contact with infected rodents or their urine and droppings.
  • Leptospirosis - Leptospirosis is a bacterial disease that affects humans and animals. In humans it causes a wide range of symptoms, and is confirmed by laboratory testing of a blood or urine sample.
  • Psittacosis – also known as parrot fever and ornithosis — is a bacterial infection of humans that can cause severe pneumonia and other serious health problems. Many different bird species can be infected with Chlamydia psittaci and spread the disease.
  • Trichinosis - Trichinosis, also called Trichinellosis, is caused by eating raw or undercooked meat of animals infected with the larvae of a species of worm called Trichinella. Infection occurs commonly in certain wild carnivorous (meat-eating) animals but may also occur in domestic pigs.
  • Tularemia - Tularemia is a potentially serious illness that occurs naturally in the United States. It is caused by the bacterium Francisella tularensis found in animals (especially rodents, rabbits, and hares).