Welcome to the latest 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: World Cup preparedness - Mpox - Legionellosis update - Cyclosporiasis: seasonal watch - Coccidioidomycosis update - Hantavirus: MV Hondius ship evacuation and new cases
National interest
Measles
CDC has confirmed 1,842 cases as of May 7, with 25 outbreaks across 39 jurisdictions and 93% of cases outbreak-associated. The combined January 2025–May 2026 total is now 4,130 cases across 47 jurisdictions, meaning nearly every state has seen cases or outbreaks. Ninety-two percent of patients are unvaccinated or of unknown vaccination status; 6% have been hospitalized (96 patients). Three deaths have been reported, all in 2025.
State updates
- New York: 11 confirmed cases. 6 in New York City and 5 in the rest of the state. Recent public exposures include a case linked to a Hell's Kitchen restaurant and a separate case in an unvaccinated child in Nassau County.
- Utah: 466 confirmed cases in 2026 (441 in 2026, 197 in 2025) as of May 5. Although the outbreak remains active, the number of new cases has slowed in recent weeks.
- Texas: 181 cases as of late April; the state has not published updated data in several weeks.
- California: 48 confirmed cases year to date. No new reported cases in May 2026.
FIFA World Cup preparedness
With Seattle hosting six FIFA World Cup matches in June and expecting approximately 750,000 visitors, health officials are preparing for increased measles risk. Washington state has reported 43 confirmed cases in 2026, more than triple the 12 cases in all of 2025, with cases in nine counties and evidence of undetected community spread. UW Medicine's virology lab is expanding measles testing capacity, and Public Health; Seattle & King County has held pop-up MMR vaccination clinics. The Pan American Health Organization has flagged the World Cup as a mass gathering risk.
Legionellosis update
Legionella was detected through routine internal monitoring at Kaiser Permanente Santa Clara in May 2026, with multiple cases confirmed and an investigation ongoing. This follows the significant national spike flagged in Issue 13; 61 cases as of the last reporting week, the highest single-week count of the year at nearly double the seasonal baseline.
Cyclosporiasis: seasonal watch
The cyclosporiasis season is entering its typical May–August peak, driven by imported fresh produce. The accelerating signal from Issue 13 (most recent reporting week: 6 cases, 3.0x the 4-week average) puts this on the watchlist as the season unfolds. Clinicians should consider Cyclospora in patients presenting with prolonged watery diarrhea and a history of consuming fresh berries, basil, cilantro, or mesclun lettuce.
Regional interest
Coccidioidomycosis update
No change to the trajectory from Issue 13: 3,258 cases year-to-date (roughly one-third of last year's pace), with California accounting for 81% of national cases. Cases continue to appear in states where cocci doesn't typically circulate — Alabama (10), Kentucky (10), Maryland (15), Michigan (16), and Minnesota (11) — most likely linked to travel exposure.
International interest
Hantavirus — MV Hondius: ship evacuation and new cases
The MV Hondius outbreak advanced on two fronts this week: the ship completed its evacuation in Tenerife, and new cases emerged among dispersed passengers.
Ship arrives in Tenerife
The MV Hondius arrived off Tenerife at approximately 05:30 local time on May 10 and anchored offshore. Disembarkation, managed by Spanish health authorities and WHO under strict infection control protocols, began immediately. Ninety-four of the 147 people on board disembarked on the first day, with seven evacuation flights departing by late evening to six European countries and Canada. All passengers were evacuated by May 11. The ship departed Tenerife for Rotterdam with 25 crew and 2 medical staff, expected to arrive May 17.
Case count: 8 → 11
Three new confirmed cases emerged post-disembarkation, bringing the total to 11 cases (9 confirmed, 2 probable) and 3 deaths (unchanged):
- French woman: Developed symptoms during the evacuation flight from Tenerife to Paris on May 10. Tested positive May 11. French Health Minister Stéphanie Rist described her condition as critical and deteriorating. France has imposed the strictest quarantine of any EU country: 42 days for all evacuated passengers.
- American man: Tested positive May 11 despite being asymptomatic at evacuation. He is receiving care in an isolation facility.
- Spanish man: PCR-positive on arrival at the Gómez Ulla Central Defence Hospital in Madrid. Currently asymptomatic and in good condition. The other 13 Spanish evacuees tested negative.
U.S. repatriation
Eighteen Americans (17 passengers plus 1 dual British-U.S. citizen) were evacuated from Tenerife on a U.S. government medical repatriation flight to Offutt Air Force Base, then transferred to medical facilities:
- UNMC, Omaha (16 patients): 15 asymptomatic passengers in the National Quarantine Unit; 1 PCR-positive asymptomatic patient in the Biocontainment Unit, described as "doing well."
- Emory University Hospital, Atlanta (2 patients): 1 symptomatic patient in the Serious Communicable Diseases Unit who has since tested negative for hantavirus; 1 asymptomatic close contact (the two are a couple).
HHS has recommended a 42-day quarantine for all evacuated passengers, though it is not mandatory. The medical director stated patients could be released earlier if they remain asymptomatic throughout.
Other repatriations
- United Kingdom: 22 individuals evacuated to Arrowe Park Hospital, Wirral, for 72 hours, then 45-day home isolation under UKHSA monitoring.
- Canada: 4 nationals isolated in Victoria, BC, for a minimum of 21 days.
- France: 5 passengers evacuated; 1 positive (see above); 4 tested negative. Twenty-two contact cases identified, including 8 French nationals who shared the Airlink flight from Saint Helena.
- South Africa: 62 potential contacts identified; 42 located and all tested negative.
Resolved: KLM flight attendant tests negative
The KLM flight attendant from Haarlem who was hospitalized at Amsterdam UMC after contact with the infected Dutch woman on KLM Flight 592 tested negative for hantavirus on May 8 (both PCR and serology). Two other passengers who reported symptoms also tested negative. RIVM stated: "The chance that people in the Netherlands will get sick because of this situation is very small."
Official risk assessments
- CDC: Issued Health Alert Network advisory HAN-00528. Classified the outbreak as a Level 3 emergency response. Risk to U.S. public health: extremely low.
- WHO: Director-General Tedros stated: "This is not another COVID" and "people shouldn't be scared." WHO deployed an expert on board and shipped 2,500 diagnostic kits from Argentina. Global risk: low.
- ECDC: Risk to EU/EEA general population: very low. The Andes virus rodent reservoir does not exist in Europe.
All three agencies warned that additional cases remain possible due to the up-to-8-week incubation period, with 42 days being the most common quarantine recommendation.
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