CDC Tracker: 2026 Tick-Bite ER Visits Hit Their Highest Point Since 2017

CDC maintains a national tracker of emergency department visits specifically coded for tick bites, updated weekly throughout the year. As of April 19, 2026, that tracker showed a rate of 85 tick-bite-related ER visits per 100,000 people — more than double what's typically expected at that point in the season, and the highest level recorded for that time of year since 2017. For a few weeks in early spring, 2026 looked like it might be heading toward a genuinely exceptional tick season.

Why spring numbers don't tell the whole story

By the time more complete data came in, the picture moderated. A later report put the nationwide rate at 65 tick-bite-related ER visits per 100,000 people, up from 47 per 100,000 during the same point the previous year — still a meaningful increase, but a smaller one than the April snapshot implied, and CDC data of this kind is explicitly described as preliminary and subject to revision as more records are processed. By June, the comparison had narrowed further: that month saw 112 tick-related ER visits per 100,000 people, against 110 per 100,000 during the same period in 2025 — essentially flat year-over-year once the season was in full swing, a notably different picture than the dramatic spring spike suggested.

Why the rise isn't purely about more ticks

Coverage of the tracker data has specifically noted that part of the increase reflects factors beyond tick population size or activity. Greater public awareness of tick-borne illness generally pushes more people to seek care after a bite that they might previously have ignored, inflating ER visit counts independent of how many ticks are actually out there. A 2022 change to the official Lyme disease case-definition criteria has also been cited as a contributing factor to rising case and visit numbers in recent years, meaning some of the year-over-year increase reflects how cases get counted rather than a change in the underlying biological reality.

The bigger surveillance gap behind these numbers

ER visit tracking captures only a slice of the actual disease burden. A CDC-authored study published in Emerging Infectious Diseases in 2021 (Kugeler et al.), based on commercial insurance claims covering more than 25 million privately insured Americans under 65, estimated that approximately 476,000 people are diagnosed and treated for Lyme disease in the US each year. That figure is dramatically larger than the number that shows up through traditional public health surveillance — only about 30,000 to 40,000 cases get reported through that system annually, with the 2022 case-definition change pushing the reported count up to roughly 63,000 that year. CDC itself notes the insurance-claims estimate likely includes some patients who were treated for suspected Lyme disease but weren't actually infected, so it shouldn't be read as a precise case count — but the scale of the gap between it and formally reported cases illustrates just how much tick-borne illness activity sits outside standard surveillance entirely.

• CDC's tick-bite ER visit tracker showed 85 visits per 100,000 people as of April 19, 2026 — the highest level for that time of year since 2017.
• By a later report, the nationwide rate stood at 65 per 100,000, up from 47 per 100,000 the prior year; by June, the rate (112 per 100,000) was roughly flat compared to June 2025 (110 per 100,000).
• Part of the year-over-year rise reflects increased public awareness and a 2022 change to Lyme disease case-definition criteria, not purely tick population changes.
• A CDC-authored 2021 study estimated roughly 476,000 Americans are diagnosed and treated for Lyme disease annually — far more than the 30,000-40,000 cases captured through standard surveillance each year.
• Early-season spikes in tick-bite data don't necessarily predict how the full season plays out, as the gap between April's and June's year-over-year comparisons shows.

Whatever the exact year-over-year trend turns out to be, tick exposure risk around a home is something worth addressing directly rather than waiting on national tracking data. A free Sevacorp inspection can help identify the overgrown vegetation, leaf litter, and brush conditions that support tick activity close to where people and pets actually spend time outdoors.

• Sources:
• Journal of Urgent Care Medicine (JUCM) — "Visits for Tick Bites Rising Earlier Than Expected" — https://www.jucm.com/visits-for-tick-bites-rising-earlier-than-expected/
• U.S. CDC — "How Many People Get Lyme Disease?" — https://www.cdc.gov/lyme/stats/humancases.html
• Kugeler, K.J. et al. (2021) — "Estimating the Frequency of Lyme Disease Diagnoses, United States, 2010–2018" — Emerging Infectious Diseases (CDC) — https://wwwnc.cdc.gov/eid/article/27/2/pdfs/20-2731.pdf
• Office of U.S. Senator Susan Collins — "CDC Publishes New Data Showing Estimated 476,000 Americans Are Diagnosed With Lyme Disease Each Year" — https://www.collins.senate.gov/newsroom/cdc-publishes-new-data-showing-estimated-476000-americans-are-diagnosed-lyme-disease-each