Can the Public Help Detect Emerging Tick-Borne Disease Risks?

Illinois residents submitted 740 ticks from 54 counties
Ticks were encountered during 11 months of the year
Community surveillance identified Lyme bacteria and other pathogens

Public-health officials cannot collect ticks from every yard, park, trail, farm, or neighborhood. Yet those are the places where people and animals actually encounter them. A tick removed from a person or dog may therefore provide information that would be difficult to obtain through conventional field surveys alone.

A 2026 study from Illinois illustrates the potential value of public participation. Between 2018 and 2023, residents and community organizations submitted 740 ticks from 54 counties to a passive surveillance program. Researchers identified eight tick species and tested a subset for multiple pathogens. The findings documented Lyme bacteria, Borrelia miyamotoi, Anaplasma phagocytophilum, several spotted fever group Rickettsia, and two coinfected blacklegged ticks.

The study does not establish an individual person’s probability of becoming ill. It does show how community submissions can complement systematic tick collection, identify unusual encounters, and help determine where more intensive surveillance may be needed.

What is public tick surveillance?

Public tick surveillance is a form of passive surveillance. Instead of researchers systematically collecting ticks from selected sites, members of the public, veterinarians, clinicians, park employees, hunters, or other participants submit ticks they have encountered.

Depending on the program, researchers may identify the tick’s species and life stage, record where and when it was encountered, document whether it was attached to a person or animal, and test selected specimens for pathogens. Travel history is also important. A tick submitted in one county may have been acquired during a trip elsewhere.

Active surveillance takes a different approach. Trained teams may drag or flag cloth over vegetation, use traps, or collect ticks from animals at predetermined locations. Because the methods and sampling areas are defined in advance, active surveillance is better suited to estimating tick density, comparing locations, and tracking changes over time.

The two approaches answer different questions. Active surveillance asks what ticks are present in a systematically sampled environment. Passive surveillance shows which ticks people and animals are actually finding and submitting. Used together, they can provide a more complete picture.

What did Illinois residents help researchers find?

The Illinois program received 740 ticks collected between 2018 and 2023. Submissions came from 54 counties and included eight species. The most common were American dog ticks, blacklegged ticks, lone star ticks, and winter ticks.

Most submitted ticks were adults. That does not necessarily mean adults posed the greatest risk. Adults are larger and easier to see than nymphs or larvae, making them more likely to be noticed, removed, and submitted. A passive program therefore reflects both tick activity and human detection behavior.

The most commonly reported hosts were humans, deer, and dogs. Humans accounted for 33.1% of submissions for which host information was recorded, deer for 16.1%, and dogs for 15.8%. More than one-quarter of submissions did not identify a host.

Researchers also found less commonly encountered species. A groundhog tick was reported attached to a person. Groundhog ticks are associated with the transmission cycle of Powassan virus, although the study did not report that this particular tick carried Powassan virus. The importance of the observation is that a community submission detected an unusual human–tick encounter that environmental dragging might not have captured.

Were pathogens found in the submitted ticks?

Researchers obtained pathogen results for 169 ticks in 161 individual or pooled samples after excluding specimens with unclear locations or reported recent travel. This represented approximately 22.5% of all submitted ticks.

Among 85 adult blacklegged ticks tested, an estimated 14% carried Borrelia burgdorferi, the principal cause of Lyme disease in the United States. Borrelia miyamotoi, which can cause hard tick relapsing fever, was detected in an estimated 4.7%, while Anaplasma phagocytophilum was detected in an estimated 1.2%.

Two blacklegged ticks carried more than one pathogen. One was positive for B. burgdorferi and B. miyamotoi; another was positive for B. burgdorferi and A. phagocytophilum. These findings reinforce that a single tick may carry more than one organism, although detection in a tick does not establish that transmission to a person occurred.

The study also detected several spotted fever group Rickettsia species in other ticks. The researchers emphasized that the ability of some of these organisms to cause human illness remains unclear. A positive molecular result should not automatically be interpreted as evidence of a recognized human disease.

Is there really an 11-month tick season?

Ticks were submitted during 11 months of the year, with February the only month without a reported specimen. The largest number arrived in May and June, followed by another peak in October and November. Blacklegged ticks had the broadest seasonal range and were submitted during eight months.

These findings do not mean that tick activity or the probability of a bite was equal throughout those 11 months. Submission counts are influenced by weather, outdoor activity, tick biology, public awareness, and whether someone notices and submits a tick. Nevertheless, the study shows why tick exposure should not automatically be dismissed merely because it occurred outside the traditional spring and summer season.

A patient evaluating a possible exposure should consider the season without using it as an absolute exclusion. The location and activity also matter. As discussed in why travel history matters in Lyme disease, a weekend trip, visit to a park, time around a wooded property, or exposure involving a pet may be relevant even when no tick bite was recognized at the time.

How can the public identify risks that conventional surveillance misses?

Systematic field collection is essential, but it is resource intensive. Investigators must choose the counties, properties, habitats, and dates that will be sampled. A program may generate high-quality information from selected locations while leaving other areas unsampled.

Public submissions can cast a wider geographic net at relatively low cost. They may help researchers:

• Document a tick species in a county where it had not previously been recognized.
• Detect invasive or expanding tick species.
• Identify ticks that are actually biting people or domestic animals.
• Recognize seasonal activity outside the expected peak months.
• Find uncommon tick–host encounters.
• Screen for emerging or less frequently tested pathogens.
• Identify locations that warrant targeted active surveillance.

This role may be especially important near the edge of a tick’s known geographic range. Surveillance maps are built from collected evidence. An apparent absence on a map may sometimes mean that an area has not been sampled adequately rather than that the tick is truly absent.

Community participation can help generate an early signal, but investigators still need systematic follow-up. A cluster of public submissions may justify active collection to determine whether a tick population is established, how abundant it is, and whether pathogens are circulating locally.

Why do dogs and other animals matter to human tick surveillance?

Dogs move through grass, brush, leaf litter, yards, and trail edges where ticks seek hosts. They may bring an attached or crawling tick into closer contact with household members. In the Illinois study, blacklegged ticks and lone star ticks were commonly submitted after being detected on dogs.

A tick found on a dog does not prove that anyone in the household was exposed or infected. It may, however, demonstrate that a human-biting tick species is active in an environment shared by the dog and its owners. Veterinary observations can therefore supplement human and environmental surveillance.

People should check pets after outdoor activity and follow veterinary guidance on tick prevention. They should also check themselves rather than assuming that the pet was the only possible host.

What can public tick surveillance not tell us?

Passive surveillance has important limitations. People who know about a submission program are more likely to participate. Some counties may submit many ticks because of effective outreach, while another county with similar tick activity may submit few. Larger adults are more likely to be noticed than small nymphs. Damaged specimens may be difficult to identify or test. The exact exposure location may also be uncertain.

For these reasons, the 14% prevalence of B. burgdorferi among tested adult blacklegged ticks should not be presented as the percentage of all Illinois ticks carrying Lyme bacteria. Only a subset of submitted ticks was tested, and those specimens were not obtained through uniform random sampling across the state.

Nor does a positive tick test diagnose a patient. A tick may carry an organism without transmitting it. Conversely, a negative result may create false reassurance if the submitted tick was not the only bite or if testing was incomplete. According to the CDC, treatment decisions should not be based on commercial testing of an individual tick.

Clinical evaluation instead considers the tick species when known, attachment and feeding, exposure location, timing, symptoms, examination findings, and appropriate patient testing. Anyone who develops fever, an expanding rash, severe headache, facial weakness, palpitations, unusual joint swelling, or other concerning symptoms after possible tick exposure should contact a clinician. The absence of a remembered bite does not by itself exclude tick-borne illness.

Could community surveillance change clinical awareness?

Clinicians use geography as one part of estimating the likelihood of a tick-borne illness. That is reasonable, but geographic risk is not static. Tick populations and pathogens can expand, travel can complicate the exposure history, and surveillance may lag behind changes occurring locally.

A community program can help identify signals that deserve further investigation. If systematic follow-up confirms an emerging risk, public-health agencies can update educational materials, alert clinicians, direct prevention programs, and improve surveillance in the affected area.

The finding should not lead clinicians to diagnose every nonspecific symptom as a tick-borne infection. It should encourage a more accurate question: Is the patient’s exposure genuinely plausible based on the latest available evidence rather than an outdated assumption about where a tick or pathogen can occur?

How can someone participate responsibly?

Submission programs differ by state, county, university, or health department. Before mailing a specimen, individuals should locate an established program and follow its instructions. Useful information may include the date, likely exposure location, host, whether the tick was attached, estimated attachment duration, recent travel, and a photograph.

Removing the tick promptly remains more important than preserving it perfectly. Use fine-tipped tweezers to grasp the tick close to the skin and pull upward with steady pressure. Do not delay removal while searching for a container or identification service. After removal, clean the bite area and hands.

Public participation is most valuable when the submitted information is accurate. If the exposure location is uncertain or recent travel occurred, that should be reported rather than assigning the tick to the submitter’s home county.

Frequently Asked Questions

What is public tick surveillance?

Public tick surveillance is a passive system in which residents, veterinarians, clinicians, or community organizations submit ticks they encounter. Researchers may identify the species, record where and when it was found, and test selected specimens for pathogens.

Can a tick submitted by one person reveal an emerging local risk?

One submission can provide an early signal, particularly if the species or pathogen was not previously recognized in the area. It usually cannot establish local population size or disease risk by itself. Targeted, systematic surveillance is needed for confirmation.

Does a positive tick test mean that the person was infected?

No. Detecting a pathogen in a tick does not prove that it was transmitted. Treatment decisions should be based on the exposure history, clinical findings, symptoms, and appropriate patient testing rather than the tick result alone.

Does a negative tick test rule out a tick-borne infection?

No. Testing may not include every relevant pathogen, the specimen may be unsuitable, or another unnoticed tick may have caused the exposure. A person who becomes ill after a possible bite should seek medical evaluation rather than rely on a negative tick result.

Were ticks submitted during 11 months of the year?

Yes. In the Illinois study, ticks were submitted during every month except February, with peaks during May–June and October–November. This does not mean that tick activity or the probability of a bite was equal throughout those 11 months.

Clinical Takeaway

Public tick submissions cannot replace systematic field collection or diagnose an individual patient. Their value lies in extending the reach of surveillance and identifying patterns, species, pathogens, seasons, or host encounters that merit closer investigation.

For clinicians, surveillance findings should refine—not dictate—the assessment of exposure. For patients, participation can contribute useful public-health information, but a tick test should not substitute for clinical evaluation after symptoms develop.

When communities, researchers, veterinarians, clinicians, and public-health agencies share reliable information, emerging tick-borne risks may be recognized earlier than any one group could detect alone.

Related Articles

Is Lyme Disease Moving Farther South?
What Are the Bad Signs After a Tick Bite?

References

1. Tuten, H. C., Jones, L. E., Promee, J., Kim, C. H., & Stone, C. M. Community-engaged passive tick surveillance highlights the diversity of ticks and tick-borne pathogens in Illinois. PLOS ONE. 2026;21(8):e0355935.
2. Eisen, R. J., & Paddock, C. D. Tick and tickborne pathogen surveillance as a public health tool in the United States. Emerging Infectious Diseases. 2020;26(4):662–668.
3. Foster, E., Maes, S. A., Holcomb, K. M., & Eisen, R. J. Prevalence of five human pathogens in host-seeking Ixodes scapularis and Ixodes pacificus by region, state, and county in the contiguous United States generated through national tick surveillance. Ticks and Tick-borne Diseases. 2023;14(6):102250.
4. Centers for Disease Control and Prevention. What to do after a tick bite. CDC. 2026.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention