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Kim's Korner: The right angle on Zoonotic Diseases

By: Dr. Kimberly Vonnahme

Life is all around us. Spring is a beautiful time of year because we see new life: baby chicks, baby lambs, new leaves on the trees, and flowers emerging. But life also comes in a very simple form: microscopic organisms, or microbes. Microbes, are tiny living things that are found all around us and are too small to be seen by the naked eye. They live in water, soil, and in the air. The human body is home to millions of these microbes, too. While some microbes are important for our health, some microbes make us sick. 


“Wash your hands and say your prayers, because Jesus and germs are everywhere!” This saying hangs in the bathroom of my parent’s home in Iowa. With 18 grandchildren running around most Sunday afternoons, reminders to clean up to prevent the spread of yucky germs (i.e. microbes) that would make us sick is important (and continuous prayers are always a good thing).


One famous microbe these days is COVID-19. This new virus in our lives has really shaken things up, hasn’t it? Our new enemy is one that we cannot see. We are learning more each day about this virus. One of the current theories is that the spread of COVID-19 was initiated from wildlife markets in Wuhan, China. In that part of the world, people like to buy live animals, including bats, to have fresh food. These markets are often call wet markets. Because there are many different types of animals in such a tight location, disease transmission is very successful. 


Since COVID-19 is central to our way of life right now, what can we learn about zoonotic diseases? What other zoonotic diseases are around us? How do livestock producers limit their exposure to these diseases? How we can learn from livestock producers to better human interaction by some simple safety precautions?


First of all, what is a zoonotic disease? Zoonotic diseases are diseases that can be transmitted from animals to humans (and humans to animals is called reverse zoonosis). Transmission of these diseases is not new to our times. Zoonotic diseases have been around since the prehistoric hunter-gather times, when people and animals began to interact. We all have heard of these (even if we didn’t know they were called zoonotic diseases): such as salmonella (a bacteria transferred from pets, reptiles, and birds to humans), lyme disease (a bacteria that is transmitted from deer to ticks to humans), Ebola (a virus that was transmitted from bats to monkeys and humans), avian flu (a virus transmitted from birds to humans), and swine flu (a virus transmitted from pigs to humans). 


So since animals can carry these diseases and in some cases infect people, how do livestock producers control this? First of all, we vaccinate ourselves and we vaccinate our livestock. In the case of swine flu, our flu virus can also infect our pigs. So it is important that caregivers get the flu shot each year. Likewise, we vaccinate our pigs for the flu. Some pig flu viruses only can infect pigs. Other flu viruses can infect people (like H1N1, the swine flu). Because the flu virus mutates, scientists must continuously develop new vaccines to keep pace with the changing virus. 


Secondly, just as we are now experiencing that we need to clean more often, today’s livestock production systems have a great deal of biosecurity. How does that work? Farmers, veterinarians, and other animal caregivers should not wear boots that they have worn in one production system into another. The clothes that we wear on one farm should be laundered before it is worn onto another farm. In swine production, we oftentimes go the extra mile. When I visit sow farms (that is a place where the young piglets are born), I have to shower-in and shower-out. Yes—we have to take a complete shower (wash our hair, scrub under our nails, etc.), and dress in clothes (yes, even underwear!) that are only worn on that farm. These barns have their own “laundry rooms”—so these clothes never leave the farm. If I wanted to bring in some paperwork, or even my lunch, it has to be wiped down with disinfectant, or placed under UV light to kill any virus, bacteria, fungus, or other microbe that could put pigs at risk. Just so we do not carry any disease out of the barn, we shower out, too. If I were to visit another sow farm, I would have to wait 48 to 72 hours before I could shower-in to that facility. Cleanliness is key and it would probably surprise some people how incredibly neat these facilities are.  


When we talk about zoonotic diseases on the farm, we wash our hands often and lots of times there is a special place we clean up before we enter into our homes. Mudrooms are a must on any farm. Chore clothes are washed separately from other clothes. Proper foot gear, gloves, and clothing are worn to limit scrapes, cuts, and other injuries where these microbes can infect us. Also, when I go to the doctor when I am sick, I tell them that I work around livestock as some of my symptoms could be related to a disease they may not see in many other patients (as ~1% of the population are livestock animal caregivers).


Pets can also transmit diseases to their owners. Bites, scratches, and when we clean up after them also pose a risk if we are not careful. Some of the zoonotic diseases that pet-owners should be aware of is rabies, ring worm, and toxoplasmosis (i.e. pregnant women should not clean out the cat’s litter box).


As I write this, I do not want to alarm any current animal caregivers or pet owners, but it is important that we are educated people. Microbes (and Jesus) are everywhere!! Taking a little extra time to clean ourselves, our tools, and our surfaces, are necessary for keeping our livestock, pets, and ourselves safe. That being said, being exposed to small amounts of microbes early in life can be an advantage. Did you know the children that grow up on farms have a stronger immune system than those that do not? Also, scientists have reported that children that grow up on farms are less likely to be affected by respiratory allergies to things like pollen and mold than urban-dwelling peers.


I personally want to thank those individuals who continue to care for our food animals during this time of COVID-19. Their dedication to the health and safety of the animals, and us as consumers, is tireless and I am awed by their continued efforts.


For further information on zoonotic diseases on the farm, please see the link below:


Stay safe, wash your hands, and say your prayers—we will come out of this stronger, wiser, and value more of what is really important!


I hope you come back to Kim’s Korner, where you can find the right angle on animal science!

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