The Centers for Disease Control and Prevention's April 30 release confirms the decade-high tick-bite emergency-room visit rate: 114 per 100,000 in the fourth week of April, up roughly 25 percent year-on-year and the highest April rate since 2017. [1] The same release carries the agency's first explicit 2026 Lyme-diagnosis projection above the long-running 476,000-treated-cases baseline — more than 500,000 — that the CDC has carried in its annual model for a decade.

The Sunday paper framed the structural drivers: mild winters across the Northeast and upper Midwest, booming white-footed mouse populations along the nymphal-tick reservoir, and the continuing northward and westward expansion of Ixodes scapularis into states without long-established surveillance. Northeastern University's April 30 explainer adds the granular reading: established blacklegged tick populations now confirmed in 49 states, and 30 ticks per day on average being submitted to Connecticut testing labs in the first weeks of April. [2]

The sibling story is alpha-gal syndrome — the red-meat allergy triggered by Lone Star tick bites — which the CDC now estimates affects roughly 450,000 Americans. [3] Alpha-gal cases are not in the Lyme projection because alpha-gal is not Lyme; the disease is mediated by a different tick and a different immunological pathway. The under-reporting is structural: alpha-gal does not show up on the standard tick-borne serology, and primary-care physicians outside the Southeast often miss the diagnosis on first presentation.

The Lyme half-million is the headline number. The alpha-gal sibling story is the one the surveillance system has not yet learned how to measure.

-- KENJI NAKAMURA, Tokyo