The tick season in Missouri is getting longer and more severe, according to researchers in Missouri and Illinois.
Ticks survive best in warm, wet climates. As seasons become warmer due to climate change, more ticks survive, thrive and multiply, latching onto animals and humans and spreading diseases including Lyme disease and Heartland virus, they said.
New tick species also are moving into the central Midwest, carrying new viruses or bacteria with them that can infect humans, pets and livestock.
鈥淓ven though we are already seeing these changes 鈥t鈥檚 such a slow-progressing thing we don鈥檛 feel it right away,鈥� said Ram Raghavan, a University of Missouri epidemiologist who recently completed a three-year field study of ticks in Pittsburg, Kansas, near Joplin.
Raghavan and a former graduate student wanted to paint a comprehensive picture of what kind of ticks were present in the area, how many there were and when they were most active. They ultimately collected and catalogued nearly 16,000 ticks. The findings were in the scientific journal Plos One.
Following ticks for three years allowed them to determine when people and animals were most at risk of bites. The ticks were active from early March through November, he said.
鈥淭he seasons are extending on both sides,鈥� Raghavan said. 鈥淵ou can expect to see ticks active all the way through Thanksgiving on one side, and ticks are becoming active much sooner.鈥�
The study 鈥渉elps us create a baseline understanding of the current situation from a public health perspective,鈥� he said. 鈥淣ow we have meaningful, relevant data to look back on for comparisons to see if certain trends continue in the future.鈥�
The data will be helpful at a time when tick-borne diseases are on the rise, both regionally and nationally, Raghavan said. There in the United States in 2019, according to the Centers for Disease Control and Prevention. That鈥檚 more than twice the number reported in 2004.
The researchers found the Lone Star Tick was most common in the Kansas area, where they did their field studies. More than 80% of the ticks they captured were Lone Star ticks.
Lone Star ticks have been steadily making their way north, said Catherine Santanello, a professor of Pharmaceutical Sciences at the University of Southern Illinois-Edwardsville who studies diseases transmitted by bugs.
鈥淚t used to be found just in the southeast: Florida, Georgia, etc.,鈥� Santanello said. 鈥淚f you look up its range, even 40 years ago versus now, it鈥檚 much more northerly. Basically that鈥檚 in part because the temperature is increasing.鈥�
The Lone Star ticks carry a newly discovered disease: Missourians have begun, which causes diarrhea, muscle aches and fever. In some cases, the virus is fatal.
But ticks aren鈥檛 the only ones moving. People and animals are beginning to move into previously wild areas, she said. They鈥檙e hiking and camping in the woods but also building homes and living in undeveloped areas.
鈥淎 lot of it is truly attributed to the fact we鈥檙e kind of encroaching on the area of deer, coyotes,鈥� Santanello said. 鈥淲e鈥檙e getting close to them, which causes us to get bitten more.鈥�
She expects other disease-carrying critters, like the Chagas disease-causing Kissing Bug in Central America, to make their way to Missouri in the next few decades.
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Correction: A previous version of this story misspelled the name of the Kansas town near where the ticks were collected.
