Infections

• US measles cases climbed to 1,671 as of April 6, 2026, with 96 new infections reported in the past week, the vast majority in Utah according to the CDC weekly update. • All but 10 cases are linked to 32 states and New York City, with 94% associated with 17 outbreaks including one new outbreak of three or more related cases. • The number of affected states increased by one this week, highlighting ongoing transmission risks amid declining vaccination rates.

• The US measles caseload climbed to 1,671 infections with nearly 100 new cases reported in the past week, according to the CDC's weekly update, with the vast majority occurring in Utah. • Utah recorded 73 new measles cases this week and 142 new cases over the past three weeks, bringing the state's 2026 total to 362 cases compared with 197 for all of 2025. • The outbreak spans 32 states and New York City, with 94% of confirmed cases linked to one of 17 outbreaks; Arizona has 71 total cases, Florida has 129, and Texas has 175 cases.

A major measles outbreak in South Carolina is slowing, with nearly 1,000 total cases reported and new infections dropping to about 10 per week from a peak of 200 in mid-January. Health officials note a consistent downward trend over several weeks amid vaccination efforts. The decline matters as it signals potential containment in the largest U.S. outbreak this year, reducing risks to unvaccinated communities. Monitoring continues to prevent resurgence as cases stabilize.