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Welcome to the thirty-fourth 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
Influenza: an early signal in the Pacific states – Measles: CDC's count reaches two deaths – Hepatitis A: imported frozen clams – E. coli: raw-milk cheese – Candida endophthalmitis after cataract surgery – Covid-19 – National surveillance, week 37 – Dengue: three Florida counties declare emergencies – Flea-borne typhus: Los Angeles – Ebola: DRC
National interest
Influenza — an early signal in the Pacific states
Influenza is off to an early start in Pacific states. Already, test positivity in the Pacific census division is at 6.9% and rising quickly. Other regions of the country are not seeing much activity yet; the Mountain division is next highest at 3.0% test positivity. Other regions are all below 2%: 1.4% in New England, 1.6% in the Mid-Atlantic and under 1% in the South Atlantic.
State by state: Alaska's influenza A positivity has climbed for several weeks and is now similar to levels recorded last December, with emergency department visits for influenza at 1.8%. Washington is at 8.4% in CDC data, with ED visits at 0.9% against the state's own activity threshold of 1.4%, and children under five are most affected. Hawaii is at 6.3%, with ED visits up from 1% to 1.4%. California reads 5% on the state dashboard and 8.5% in CDC clinical laboratory data, with the Bay Area at 7%. Oregon’s activity is somewhat lower than its neighbors but still elevated compared to the off season.
So far, H1N1 is predominating. Nationally, 96 specimens were subtyped at public health laboratories in week 37. Of those, 91 were A(H1N1)pdm09 and five were H3N2. This is a change from last winter, when H3N2 was most common. Ninety-six specimens is too few to establish a change in the dominant subtype, but it’s notable given the early season.
Clinical note: Consider encouraging patients to get vaccinated as soon as possible, rather than waiting until later in the season, particularly in the Western region. CDC recommends everyone six months and older should be vaccinated annually, ideally by the end of October, and vaccination should continue as long as flu is circulating.
Measles — CDC's death count reaches two, Pennsylvania passes 900 cases
CDC's measles page, updated September 25, now lists two measles deaths in 2026. It listed one a week ago and none the week before that. The 2025 column still shows three deaths. Separately, Pennsylvania has confirmed five measles-associated death, an increase of one since last week.
State updates:
- Pennsylvania: the state dashboard reported 943 cases on September 30, including 119 in the preceding seven days; 176 people have been hospitalized. In its September 25 statewide update, the health department put the count at 890 across 39 counties, with four deaths and four cases in vaccinated people. State health staff have given more than 5,300 MMR doses at 165 pop-up clinics since the outbreak began in late April.
- Wisconsin: state health services confirmed 214 cases statewide as of September 29, up from 171 a week earlier. The southwest outbreak in Grant, Iowa, Lafayette and Vernon counties account for 202 confirmed and six probable. Marathon County now has three cases and Chippewa one, all linked to out-of-state travel and not to the southwest outbreak.
- Illinois: the state reported 23 confirmed cases this year on September 25, 16 of them in an outbreak in Douglas and Moultrie counties among people unvaccinated or of unknown vaccination status. Separate cases in Kane and Madison counties are not outbreak-linked.