A zoonotic disease is one that can be passed between humans and animals. Read this lesson to learn about the many zoonotic diseases out there that you could be passing along or even risk catching!
What is a Zoonotic Disease?
Zoonosis or a zoonotic disease is one that can be passed between humans and animals. Humans often consider themselves separate from the ‘wild world’ of animals, but we are actually just another species and part of the big biological picture.
Zoonotic diseases are so common, in fact, that the Centers For Disease Control And Prevention has estimated that roughly six of every ten infectious diseases qualify as zoonotic. Many can be fatal if left untreated.
How Do Zoonotic Diseases Spread?
Usually, some type of physical contact is required. This can be via contact with the animal itself, through contact with bodily fluids (such as blood, saliva, urine, or feces) or through contact with something that has been contaminated by the animal or its bodily fluids. So, a bite from an insect or tick can transmit disease to a human.
Interacting with animals at a state fair, a petting zoo, a farm, or a pet store can transmit disease. Even eating or drinking contaminated food or water can transmit disease.
Types of Zoonotic Diseases
Most zoonotic diseases are caused by bacteria, viruses, fungi, or parasites. You’re probably already familiar with a number of different zoonotic diseases, even if you didn’t know they were zoonotic!Many (but not all) bacterial infections are foodborne in nature and can cause fever, diarrhea, abdominal cramps, fatigue, nausea, and vomiting. Examples of bacterial zoonotic diseases include E. coli, salmonella, plague, Lyme disease, Q fever, anthrax, brucellosis, leptospirosis, relapsing fever, and tuberculosis. Salmonella has a 5-10% fatality rate and can spread through contact with chickens, ducks, turtles, and snakes.
You can come into contact with E. coli almost anywhere on an animal. Good hygiene, such as washing your hands after coming in contact with animals and keeping them away from your mouth, is key to preventing an E. coli infection. Lyme disease is spread through bacteria from infected ticks.
After spending time outside, particularly in late spring or early summer, it is crucial to check your body for ticks so you can possibly remove them before they bite.
Viral infections have recently made the news. Examples you may have heard of include rabies, avian influenza (aka ‘bird flu’), ebola, West Nile virus, and Rift Valley fever. There is no cure for rabies, and it has a 100% fatality rate if an infected person is not treated.
Rabies spreads most often through a bite from an infected animal, such as a dog, bat, monkey, skunk, raccoon, or fox (among others).Parasitic infections can cause stomach or gastrointestinal distress or problems in the brain, like headaches and seizures. Examples of parasitic zoonotic diseases include trichinosis, toxoplasmosis, trematodosis, giardiasis, malaria, and echinococcosis. Malaria is spread through parasites introduced by mosquito bites. The parasites live in the mosquito’s saliva and are then transmitted into the human blood stream via a bite.
Fungal zoonotic diseases most often cause superficial skin infections. These can cause redness, itching, scaling, and even hair loss. Examples include dermatophytosis (aka ringworm) and sporotrichosis. Ringworm can be transmitted via dogs, cats, cattle, and rodents.We don’t hear as much about diseases passed from humans to animals (called reverse zoonosis).
In some cases, humans can pass a disease to an animal which can then pass it right back to a human (the circle of life, huh). For example, it’s possible to give your beloved dog the Influenza A virus if you yourself are sick. All the more reason to keep your hands clean and your sneezes to yourself.
So what have we learned about zoonosis, or zoonotic diseases? Well, they are infectious diseases that can be transmitted between animals and humans, either from direct contact or through a contaminated vector. Infections can be caused by bacteria, viruses, fungi, or parasites, and there are many different examples of each of these.
It’s estimated that about six out of every ten infectious diseases are actually zoonotic. However, this isn’t a one-way street. Humans can actually transmit diseases to animals (called ‘reverse zoonosis’), even though we don’t hear much about cases like this. To be safe, you should be vigilant about washing your hands after being near animals and take care that your food and water come from safe, clean sources.Medical Disclaimer: The information on this site is for your information only and is not a substitute for professional medical advice.