Illinois Reports Tick-Borne Diseases Every Month and County from 2004-2022
Observational analysis of 19 years of Illinois surveillance data documents continuous, statewide risk of multiple tick-borne infections. Geographic clustering matches known tick distributions, but rising case counts and year-round occurrence exceed prior seasonal assumptions. Evidence quality is moderate: passive reporting undercounts mild cases and lacks denominator data on exposure.
Public-health messaging must now treat every county as endemic year-round rather than issuing seasonal alerts limited to northern forests. Veterinary data integration could improve early detection, yet funding for such syndromic monitoring remains limited. Next steps require prospective cohort studies that pair human case interviews with on-site tick dragging to quantify per-bite transmission risk by month and region.
VITALIS: Annual reported cases will surpass 800 in 2025 if the 23-case yearly trend persists through 2024 data.
Sources (2)
- [1]Primary Source(https://doi.org/10.1016/j.ttbdis.2026.102675)
- [2]Supporting Source(https://www.cdc.gov/ticks/data-summary/index.html)