Examples of Zoonotic Diseases and How They Spread

Every year, it seems like there is a new disease that shows up. Part of this comes from contact with animals. Diseases that spread from animals to humans are called zoonotic diseases.

Zoonotic diseases can come from a variety of sources like bacteria, viruses, parasites and fungi. Additionally, the World Health Organization states 75% of all new pathogens in the last decade are zoonotic.

What are some examples of zoonotic diseases? You might be surprised by some of these.

Did you know that some common flu strains are actually zoonotic diseases? Since at least 61% of all human pathogens are zoonotic, according to the WHO, it makes sense. Explore a few examples of zoonotic diseases.

A large family of viruses, coronavirus is responsible for everything from the common cold to SARS (severe acute respiratory syndrome), including the newest strain COVID-19. The coronavirus crossed species to start infecting humans causing a world pandemic in 2020. These infections affect the respiratory system with symptoms like fever and cough. Severe infections can lead to pneumonia, other complications, and even death.

There is a reason that you give your dog or cat a rabies vaccine! That’s because they can transfer rabies to you. A virus transmitted by a bite, rabies affects the nervous system. While it can be treated, once clinical symptoms appear, it’s typically fatal.

Tick bites are more than just annoying. They can end badly, especially if the tick is carrying the bacteria Borrelia burgdorferi. Transferred during the bite of a blacklegged tick, Lyme disease includes symptoms like fever, headache and fatigue. While it can be treated with antibiotics in the early stages, Lyme disease might have lasting effects.

Reptiles and baby chicks are fun to play with, but it’s important to wash your hands after. This is because they carry Salmonella bacteria. If that Salmonella gets into your system, it can cause severe gastrointestinal symptoms and fever. While this is a mild infection most of the time, it can cause severe symptoms.

Pigs get the flu virus. And when they do, they can pass this flu on to humans. A common flu that passed to humans was H1N1. Passed through airborne respiratory droplets, this type of flu causes fever, cough and body aches. In certain individuals, it can lead to more serious infections. The 1918 flu pandemic was caused by the swine flu.

In addition to viruses and bacteria, parasites also transfer from animals to humans. One such parasite is giardiasis, which can be ingested through contaminated food and water. It’s excreted through feces, and can live for a long time in the soil. Dirt can then easily make it from your hands into your mouth causing giardiasis infections. Symptoms of giardiasis include diarrhea, nausea and weight loss.

A common skin infection caused by a fungus, ringworm can be easily transferred from animals to humans. Ringworm infections can affect the feet, scalp, groin or anywhere on the body. The symptoms are a raised lesion that looks like a circular worm. Hence, that’s why the infection is named ringworm.

People and animals interact all the time. For some, your pooch might be your best bed partner. Other people work with animals in agriculture. But how do these pathogens spread? There are a few major ways.

• Direct contact - This is when you come in direct contact to the pathogens through a bite or through touching animals. The pathogens are transferred to the human through bodily fluids like blood and saliva.
• Indirect contact - Pathogens can live for so long on a surface or in soil. If you touch that area and then touch your eyes, nose, mouth or an opening on your skin, you may introduce these pathogens into your body. Boom! You’ve been infected.
• Foodborne or waterborne - This is when the food or water you drink/eat is contaminated with the pathogen from an animal. For example, the pathogens could be transferred from animal feces in your garden to your vegetables and make you sick.
• Vector-borne - These are the zoonotic diseases that are transferred by a carrier or vector like mosquitoes and ticks.

When it comes to zoonotic diseases, it’s all about prevention. A few prevention tips include:

• Wash your hands often, especially after coming into contact with animals and dirt.
• Use bug sprays to keep ticks and mosquitoes away.
• Wash food well and cook it at the appropriate temperature.
• Avoid touching your mouth, nose and eyes.

When you think of a zoonotic disease, it might help you to remember the word “zoo.” Zoo will make you think of animals, which will help to remember that zoonotic diseases transfer from animals to humans. Now that you’ve learned a little about zoonotic diseases, you might explore the differences for a disease vs. a virus.