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Zoonotic diseases

Last updated: June 18, 2021

Summarytoggle arrow icon

Zoonotic diseases are infections that are transmitted from animals to humans. While animals may transmit infection directly (e.g., via saliva) or indirectly (e.g., via contaminated objects), they usually serve as hosts for a pathogen that is then transmitted to humans by a vector (e.g., ticks, fleas) or via contaminated water or food. Zoonoses are usually endemic to certain geographical regions; peaks in incidence often correlate with the life cycle of the transmitting vector. Some examples of zoonotic diseases in the US are zoonotic influenza, salmonellosis, West Nile virus, plague, coronavirus infection, rabies, brucellosis, and Lyme disease. Although these conditions differ in their exact presentation, symptomatic cases typically present with fever, flulike symptoms, and possibly skin rashes. In some cases of fulminant disease, there may be complications such as disseminated intravascular coagulation, shock, and organ failure. Most zoonoses are treated with antibiotics and respond well to treatment.

Definition

  • Zoonotic diseases are infections that are transmitted from animals to humans.

Epidemiology

  • About 6 out of 10 infectious diseases are zoonotic. [1]
  • Zoonotic diseases are usually endemic to a certain geographical region
  • Peaks in incidence often correlate with the life cycle of the transmitting vector.

Etiology

  • Transmission occurs via
    • Contact with an animal directly (e.g., saliva, feces) or indirectly (contaminated objects such as cages)
    • Vector-borne (e.g., fleas, ticks)
    • Foodborne
    • Waterborne
Etiology of common zoonotic diseases transmitted via animals
Disease More information

Farm animals

(e.g., cattle, sheep, goats)

Swine
Birds
Dromedary camels
Rodents
Dogs, raccoons, skunks, foxes, bats
Potentially bats
Fruit bats, monkeys

Prevention

  1. Zoonotic Diseases. https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html. Updated: July 14, 2017. Accessed: June 2, 2021.
  2. Herold G. Internal Medicine. Herold G ; 2014