As temperatures warm and people begin spending more time outdoors, the risk of getting bit by a disease-carrying tick increases.
Beth Gilliam, coordinator of an Illinois program called I-Tick, doesn't mean to alarm people, but there are 10 times as many tick-borne cases reported in Illinois today as there were in 1990. That is, if there were 20 then, today there are 200.
The numbers are similar in Iowa, she added. The two most common are Lyme disease and Rocky Mountain spotted fever.
Why the increase?
"That's the magic question," Gilliam said. Are ticks moving into areas where they haven't lived before? Is vegetation changing, thereby creating more favorable habitat? Are new tick-borne pathogens being discovered?
To gather data that might help provide answers, Gilliam is coordinating a University of Illinois Extension program in which people throughout the state — specifically those who spend time outside — are being asked to participate in a tick surveillance program.
Gilliam will conduct a training session for volunteers at 2 p.m. Tuesday at the Milan Extension office, 321 W. 2nd Ave.
Participants will be asked to keep a record for five days during a two-week period about the ticks they find on themselves, and to collect and return those ticks to the Milan office. The ticks and data will be sent to the University of Illinois for evaluation and to become part of the state record.
The Quad-City region is a good place for surveillance because ticks are "pretty heavily" established in the area that includes Rock Island, Henry, Mercer and Whiteside counties, Gilliam said.
She hopes to get about 1,000 participants statewide.
Ticks also are established in the Quad-City area of eastern Iowa, and a lyme disease surveillance program was founded in 1990 at Iowa State University, Ames, to respond to growing concern about the disease.
Not every tick one encounters carries pathogens, Gilliam noted. And even if a a tick carries a particular pathogen, that does not mean a person will become infected or sick. But it pays for people to be wary.
What are the diseases they carry and how common are they?
The two most common are Lyme, named after Old Lyme, Connecticut, where some of the first cases in the United States were documented, and Rocky Mountain spotted fever.
In Iowa, there were 254 cases of Lyme disease and 17 cases of Rocky Mountain spotted fever reported in 2017, according to the Iowa Department of Public Health.
Of those, 14 of the Lyme disease cases were from Scott County. No reports of Rocky Mountain spotted fever were filed for Scott County.
In Illinois, there were 237 cases of Lyme disease and 68 cases of Rocky Mountain spotted fever reported in 2016, the latest year for which numbers are available, according to the Illinois Department of Public Health.
No cases of either disease were reported in Rock Island County, according to the state health department.
Lyme: Typical symptoms include fever, headache, fatigue, and a characteristic skin rash that can look like a bull's eye. If left untreated, infection can spread to joints, the heart, and the nervous system. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics, according to the Centers for Disease Control, or CDC.
Rocky Mountain spotted fever: Most people who get sick with Rocky Mountain spotted fever will have a fever, headache, and rash. The disease can be deadly if not treated early with the right antibiotic, according to the CDC.