Q. What are Zoonotic Diseases?

The World Health Organization defines Zoonoses (Zoonosis, sing.) as "Those diseases and infections, which are naturally transmitted between vertebrate animals and man".

Mode of transmission: Faeces, urine, saliva, blood, milk, via aerosol, oral, contact with bedding or animals, etc.

Approximately 150 zoonotic diseases are known to exist. Wildlife serves as a reservoir for many diseases common to domestic animals and humans. Persons working with wildlife should be alert to the potential for disease transmission from animals. Generally, disease is more easily prevented than treated. Many zoonotic diseases are so common in nature, so rare in humans, or so mild in their symptoms, that wild animals pose a minimal health risk to people.

Zoonotic diseases include:

• Those, which can be transmitted directly from animals to humans (e.g. rabies).

• Diseases that can be acquired indirectly by humans through ingestion, inhalation or contact with infected animal products, soil, water, or other environmental surfaces which have been contaminated with animal waste or a dead animal (e.g. salmonellosis, leptospirosis, anthrax).
Campylobacter infection is mainly found in chicken meat. Listeriosis and E. coli gastroenteritis are two other common infections caused by zoonotic agents. All these will be discussed one by one.

• A disease, which has an animal reservoir, but requires a mosquito or other arthropod to transmit the disease to humans (e.g. St. Louis encephalitis, Rocky Mountain spotted fever).