Welcome to the seventh edition of FOI Clinical. Each week, I'll send you a briefing on outbreak news. When something urgent breaks, you'll get an alert the same day.
In this edition
Measles - Seasonal respiratory illness update - Mpox in Missouri - Hantavirus pulmonary syndrome in New York - Leptospirosis in Ohio, territories - Meningitis in the UK
National interest
Measles
As of March 19, 2026, there have been 1,487 confirmed cases of measles this year. Thirty-two states have reported cases. The largest case totals are in South Carolina, Utah, Florida, and Texas.
Several notable outbreaks are underway. The list below is not comprehensive, but rather a selection of prominent active clusters worth keeping in mind.
- South Carolina: As of March 24, there have been 997 confirmed cases in a multi-county outbreak. There have been no new cases reported since the last edition of FOI Clinical.
- Arizona/Utah: The outbreak in Utah is growing quickly. There have been 486 confirmed cases, an increase of 38 from last week. All local health departments in the state have reported cases, with the majority of cases reported in Southwest Utah (n = 233), Utah County (n = 78), Salt Lake County (n = 53), and Central Utah (n = 36). The virus is present in wastewater samples around the state, confirming active community spread. Exposed locations are listed here. The outbreak in Arizona is growing more slowly; there have been 2 new cases reported in the last week, raising the total for the outbreak to 280.