Welcome to the thirteenth edition of FOI Clinical. Each week, we'll send you a briefing on outbreak news. When something urgent breaks, you'll get an alert the same day.
In this edition
Measles - Mpox - Chikungunya update - Influenza season wrap-up - Legionnaires' disease: Wynn Las Vegas investigation - Cyclosporiasis - Coccidioidomycosis - Hantavirus cluster: MV Hondius cruise ship
National interest
Measles
CDC has confirmed 1,814 cases as of April 30, with 24 outbreaks and 93% of cases outbreak-associated.
- Utah: Now the state with the most active measles transmission in the country. The outbreak reached 638 cases as of May 5, up from 602 two weeks ago. Approximately 10% of confirmed cases are breakthrough infections in vaccinated individuals. New exposure sites continue to be identified across the state, including hospitals, grocery stores, and dance studios.
- Texas: 180 cases as of April 22, with the majority (75.6%) in Hudspeth County, likely concentrated in federal detention facilities.
Mpox
Mpox case counts remain elevated compared to last year, though the gap is gradually closing. As of the most recent reporting week, 501 cases have been reported year-to-date, compared to 312 cases at the same point in 2025, a roughly 60% increase. Nine cases were reported in week 16. The year-over-year difference has narrowed slightly over the past week.