What are zoonotic diseases?

• A. Diseases exclusive to animals.
• B. Diseases that occur only in plants.
• C. Chronic diseases caused by lifestyle.
• D. Diseases that can spread from animals to humans.

Answer: (D)

Zoonotic diseases are diseases that can spread from animals to humans. They originate in animal hosts and can be caused by viruses, bacteria, parasites, or fungi. Transmission can happen through direct contact with an infected animal (such as bites or handling), via vectors like mosquitoes or ticks that carry pathogens from animals to people, through consumption of contaminated animal products, or through contact with environments contaminated by animal waste. This concept underpins why public health watches the animal-human-environment interface and uses a One Health approach. Examples include rabies from animal bites, Salmonella from contaminated food, and certain strains of influenza that move between birds, pigs, and humans. The other options don’t fit because diseases exclusive to animals wouldn’t infect humans, plants aren’t involved, and lifestyle-related chronic diseases aren’t transmitted between species.