Chicago continues to grapple with the prevalence of mosquitoes and ticks during the hot and humid summer season
Rising Mosquito and Tick Activity Pose Health Risks in Chicago and Illinois
Chicago, IL - The hot, wet weather that has been plaguing the Chicago area this summer is not just causing discomfort, but it's also creating ideal conditions for mosquitoes and ticks to thrive. As a result, the risk of contracting West Nile virus and Lyme disease is currently high in Cook County [1][3].
Marissa Sulek, a reporter for News Chicago, has been covering this issue extensively. Sulek, who joined the team in January 2025, previously worked as a general assignment reporter in Nashville at WSMV [2].
According to Dr. Katrine Wallace, an epidemiologist at the University of Illinois Chicago School of Public Health, there is a common denominator for the increase in ticks and mosquitoes - the hot, wet weather and changing temperatures that create ideal conditions for these pests to thrive longer and more intensely year-over-year [3].
In Cook County, nearly every city, village, and town has detected West Nile virus [1]. About 60% of mosquito samples are testing positive for the virus, a higher rate than previous years [1][4]. So far, 3 human West Nile cases have been confirmed in Illinois this year, though the actual number may be higher due to underreporting and delayed symptom onset (up to two weeks post-bite) [1][4].
The increase in mosquito populations testing positive for West Nile virus is causing concern, as the virus can be harmful to humans. Symptoms of West Nile Virus may not show until two weeks after the bite, and these numbers could increase in the coming weeks [1].
Lyme disease and tick-borne illnesses are also on the rise. Emergency room visits for tick bites have reached the highest level in eight years, correlating with a rise in Lyme disease cases reported by CDC data [1][2]. Deer ticks, which transmit Lyme disease and other pathogens like Powassan virus, have expanded their active season due to warmer temperatures extending into late fall through early spring [1][2][3].
To combat this, doctors are urging people to protect themselves. They recommend using bug repellents containing DEET or proven alternatives, removing or draining standing water around homes, repairing torn window screens, limiting outdoor activities during dawn and dusk, wearing long sleeves and pants, and checking for ticks after outdoor activities in grassy or wooded areas [1][5]. Public health campaigns are ongoing to raise awareness and promote these protective measures [1][5].
Despite the risks, it's important to note that cicadas, specifically scissor-grinder cicadas, are present in Chicago between July and early October. However, unlike cicadas, mosquitoes are not harmless [3].
In summary, persistent hot, wet weather and climate changes are driving higher mosquito and tick activity in Chicago and Illinois in 2025. This has caused increased risks of West Nile virus and Lyme disease, prompting public health authorities to emphasize prevention and early detection measures.
References:
[1] Sulek, M. (2025, July 23). Mosquitoes, ticks, and the risks they pose in Chicago and Illinois. News Chicago. Retrieved from https://www.newschicago.com/mosquitoes-ticks-risks-chicago-illinois/
[2] News Chicago. (2025, July 23). Marissa Sulek joins News Chicago as a reporter. Retrieved from https://www.newschicago.com/marissa-sulek-joins-news-chicago/
[3] Wallace, K. (2025, July 23). Interview with Dr. Katrine Wallace, epidemiologist at the University of Illinois Chicago School of Public Health. News Chicago. Retrieved from https://www.newschicago.com/interview-dr-katrine-wallace/
[4] Illinois Department of Public Health. (2025, July 23). West Nile virus in Illinois. Retrieved from https://www.idph.state.il.us/dph/diseases/westnile/
[5] Chicago Department of Public Health. (2025, July 23). Mosquito and tick prevention measures. Retrieved from https://www.chicago.gov/city/en/sites/health/home/mosquito-and-tick-prevention-measures.html
- The news of rising mosquito and tick activity in Chicago and Illinois has caused concern for public health.
- Marissa Sulek, a reporter at News Chicago, is continuously covering this issue, focusing on the health risks posed by these pests.
- Dr. Katrine Wallace, an epidemiologist at the University of Illinois Chicago School of Public Health, attributes the increase in mosquitoes and ticks to the hot, wet weather and changing temperatures.
- West Nile virus is currently prevalent in nearly every city, village, and town in Cook County, with 60% of mosquito samples testing positive for the virus.
- Three human West Nile cases have been confirmed in Illinois this year, while the actual number may be higher due to underreporting and delayed symptom onset.
- Lyme disease and other tick-borne illnesses are also on the rise, with emergency room visits for tick bites at an eight-year high.
- Ticks, such as deer ticks, have expanded their active season due to warmer temperatures, posing a greater threat to humans.
- To combat these health risks, doctors urge people to take preventive measures like using DEET-based bug repellents, draining standing water, and checking for ticks after outdoor activities.
- Public health campaigns are ongoing to raise awareness and promote protective measures against mosquitoes and ticks.
- Cicadas may be present in Chicago between July and early October, but unlike cicadas, mosquitoes pose a health risk due to their increased presence and the potential for West Nile virus.
- Climate change, contributing to hot, wet weather, is driving higher mosquito and tick activity in Chicago and Illinois.
- This increased activity has led to higher risks of West Nile virus and Lyme disease.
- Apart from health and wellness, this issue affects other aspects of life, including personal finance, lifestyle, and environmental science, as residents may need to allocate resources for protective measures and adapt their activities to reduce exposure to mosquitoes and ticks.
