by: Jaylene Matias

The spread of diseases occurs through mosquito and tick bites, and contact with animals, fungi, and water, but did you know that climate change affects how easily these diseases are spread through different geographic regions? Milder winters, warmer summers, and fewer days of frost make it easier for infectious diseases to expand and spread into new geographic areas and infect more people. Lyme disease, West Nile virus, and Valley fever are all examples of infectious diseases that are currently increasing in cases and spreading to new areas of the United States.

Climate change has caused the temperature to increase and that means that we have shorter winters and spring comes early. The warmer temperature gives mosquitoes and ticks the opportunity to reproduce and spread diseases rapidly. According to the CDC, between 2004 and 2018, there were a total of 760,000 illnesses reported from mosquito, tick, and flea bites in the United States. During that time period, nine new germs spread by mosquitoes were discovered. In 2012, because of the mild winter and hot summer, there was an outbreak of the West Nile virus in the United States. The virus resulted in 5,600 illnesses and 286 deaths.

Contact with Animals

Contact with animals also causes diseases to spread. Climate change has forced some animals to leave their natural habitats for new ones. This change has increased contact between animals and humans, which has increased the potential spread of zoonotic diseases (e.g., rabies, Alaskapox, Ebola, Lassa, Rift Valley fever, and monkeypox.) Zoonotic diseases can be very deadly, and as temperatures rise, the risk of these diseases being imported into the United States increases substantially.


Fungi do not survive in colder temperatures. Rising global temperatures mean more opportunities for fungus to survive and thrive. Valley fever is an infection that is caused by a fungus that lives in the soil in hot and dry areas. This particular fungus can be very severe and result in death. The change in environmental temperatures causes new fungal diseases to materialize and become more adapted to surviving in humans. With climate change comes the risk of natural disasters like hurricanes and floods, which allows mold to grow in someone’s home. Mold in your home can be extremely dangerous and cause deadly infections in both the lungs and the brain


Climate change will likely have devastating effects on freshwater and marine environments. Algal blooms, the rapid growth of algae in lakes, rivers, oceans, and bays, can become more harmful and frequent. This endangers not only our health when we eat contaminated seafood, but algal blooms can also endanger the lives of pets and harm livestock, wildlife, and the environment. Does research indicate that antibiotics are present in algal blooms? and the antibiotic residues can sometimes remain in the environment (such as in waterways and soils) for a very long time.