Mosquito-transmitted disease risk is increasing as the climate warms

Angela Weideman is the health director for the Chippewa County Department of Public Health.

Chippewa County was in the midst of the COVID-19 pandemic, with over 850 confirmed cases. So, when I delivered our health department update, few Wisconsinites were expecting a reported death to be from a mosquito-borne disease, instead of from COVID-19. The news rattled our community, as our economy is based largely on outdoor tourism, such as fishing, boating, and swimming.

When the woman, who was in her 60s, first reported symptoms, her doctors thought it was likely COVID-19. However, after she passed out a few times, it became clear that her case was growing increasingly serious, and more tests were ordered. The results were surprising, especially for early autumn in Wisconsin. She came back positive for Eastern Equine Encephalitis — a rare virus that can cause fever, chills, exhaustion, joint and muscle pain, headache, vomiting, diarrhea, seizures, behavioral changes, swelling in the brain, and coma. Her illness progressed rapidly and after going on a ventilator, she passed away, leaving behind a husband and stepdaughter.

Unfortunately, this was not the first phone call I received from a family who had lost a loved-one due to an illness transferred by mosquitoes in our county. My first case came in 2017. The family had lost their son to West Nile. He was a young man, healthy and with no chronic conditions, when suddenly he began experiencing unusual symptoms during hunting season. He ended up in Mayo Clinic on a ventilator before he passed away. The family’s sorrow from such an unexpected loss echoed in every word they spoke to me.

This case made me fearful for my own son who loves the outdoors. As the health director in our area, I see the risk of mosquitoes increasing as their active season creeps into October and early November. In these colder months, visitors, outdoor workers, and other community members are typically not thinking of mosquito protection. However, the climate is changing. As our county grows warmer and wetter, so, too, grows the risk of these diseases. When I try to inform others of the risk and the importance of reducing standing waters that can act as mosquito breeding grounds, most people look at me like I’m an alien. They tell me, “It is just a bug bite!” or “Mosquito-borne illnesses are only in Africa or somewhere else far-away.” But I know all too well that the risk is very real, and it is at our doorstep.

This story is excerpted from from Medical Alert! Climate Change is Harming Our Health in Wisconsin (pdf)

The views and opinions expressed in this interview are those of the authors and do not represent official policy or position of the University of Wisconsin-Madison or the Wisconsin Initiative on Climate Change Impacts.