Zoonotic diseases are spread from animals to man. They can be caused by viruses, bacteria, fungus or parasites About Zoonotic Diseases | One Health | CDC. Examples are rabies, Ebola, Avian Influenza, the plague, Leptospirosis, Listeria, Salmonella, Campylobacter, E. coli, histoplasmosis and toxoplasmosis. Some, like rabies, can have a very high mortality rate while others may show little or no illness (considered sub-clinical).

Infections caused by bacteria like Campylobacter, Salmonella and E. coli can be contracted through direct contact with the animal or indirectly through eating contaminated food or water. Foodborne illnesses are very common. In 2019 it was estimated that close to 10 million people in the United States (US) were diagnosed with a foodborne illness, with more than 53,000 people hospitalized and over 900 deaths Report: Illnesses from contaminated food increased in 2024, severe cases doubled | CIDRAP. The exact number of illnesses is underrepresented because many people choose not to seek medical care. The overall number of foodborne illnesses in the US increased 25% in 2023 compared to the previous year. Hospitalizations have also increased during this time by over 47% and deaths by 50%. These increases have been attributed to major outbreaks in multiple states, and an increased gap between initial illnesses occurring and the recall of the offending food(s), therefore increasing the chances of additional illness. Close to 17% of outbreaks are attributed to homemade food. The CDC defines an outbreak as two or more people. 

Zoonotic diseases caused by direct contact with animals, such as Avian Influenza are also on the increase. There are several reasons for the increase of new and reemerging zoonotic diseases. Urban sprawl has long been thought to influence new and reemerging zoonotic diseases. Urban sprawl envelopes wildlife habitats causing increased interaction with humans. As humans develop land, wildlife continue to move into urban areas having nowhere else to go. This allows new diseases such as Avian Influenza to ‘jump’ (process referred to as reassortment) from wildlife to humans, and reemerging diseases like leptospirosis to increase in both humans and domestic animals. Changes in temperature and precipitation are additional reasons for increases in zoonotic diseases. Global temperatures have increased 1.7⁰F since 1890 World of Change: Global Temperatures. This increase in temperature doesn’t sound like a lot, but this is a significant amount of heat energy at land, ocean, the atmosphere and frozen areas on the globe Climate change: global temperature | NOAA Climate.gov. In Kentucky both temperature and precipitation have changed significantly. Between 1985 and 2019 (in five-year increments), the average temperature and precipitation was 55.4⁰F/40.3” and 57.7⁰F/56.3” respectively. These changes favor microorganisms, warming temperatures help many bacteria and viruses adapt, proliferate and potentially become more virulent. 

There has also been an increase in natural disasters such as flooding, tornadoes and hurricanes in the US, which can destroy the environment. The destruction of farms, whether they are used for growing crops or grazing, can be devastating for food security and the destruction of family farms. Destruction to the environment cost losses of over $20 billion dollars to farmers in 2024 alone (Hurricanes, Heat and Hardship: Counting 2024’s Crop Losses | Market Intel | American Farm Bureau Federation). In Kentucky between 1980-2024 there were 92 confirmed weather disaster events and between 2021-2024 these disasters cost over $3 billion each of those 4 years Billion-Dollar Weather and Climate Disasters | Kentucky Summary | National Centers for Environmental Information (NCEI). These events included severe storms, droughts, flooding, winter storms and 5 tropical cyclone events. The destruction by these events can destroy ecological niches and have a ripple effect on crops, animals and ultimately humans. The destruction of people’s homes, sometimes more than once in a short period of time, causes an increase in migration of people moving to safer areas. The migration of people also increases the movement of viruses and bacteria which move with them and their animals, creating diseases in areas where they had not previously been seen. This exposes people and animals to new infections. Both bacteria and viruses adapt to new environments very quickly, allowing them to spread unabated. 

There are several things’ people can do to decrease their risk of becoming ill from a zoonotic disease: 

• The number one thing is to wash your hands with soap and water for at least 20 seconds
  • after touching animals, their feed or waste
  • before/after preparing food
  • going to the bathroom
  • caring for someone who is sick

 This list isn’t exhaustive but is an excellent way to think about what you are touching prior to touching your face or eating food

• Properly cook your food and clean everything before and after contact with raw food products such as meats and eggs
• Avoid contact with insects who may contaminate food or water such as flies
• Don’t drink unpasteurized milk or water contaminated with feces