Overview
- The Wisconsin outbreak, which expanded Tuesday, has reached 36 confirmed and three probable cases after two new infections in Grant County linked to Lafayette and Iowa counties.
- Kentucky has recorded 19 confirmed cases in 2026, the most since 1991, with 15 cases confirmed over a four-day span in mid‑August across Christian, Owen, Todd, Trigg and Washington counties.
- State data show nearly all infected people in both states were unvaccinated, the majority are children 17 and under, and small numbers of patients have required hospitalization.
- Local and state health departments, backed by CDC support, are conducting case interviews, contact tracing and targeted vaccination outreach while Wisconsin officials say no public exposure locations have yet been identified.
- The outbreaks form part of a national resurgence — the CDC reported more than 2,566 U.S. cases as of Aug. 13 — and public health officials stress that two doses of the MMR vaccine are about 97% effective at preventing measles.