Welcome to the thirty-second 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.
Measles: four deaths in Pennsylvania – Rabies: CDC advisory on post-exposure prophylaxis – Cyclosporiasis season updates – Salmonella: broccoli sprouts – Seasonal respiratory viruses – Dengue: Florida – Legionnaires’ disease: South Bronx – Eastern equine encephalitis in Michigan and Wisconsin – Ebola: DRC
National interest
Measles: four deaths in Pennsylvania, none in the national count
Pennsylvania has now confirmed four measles-associated deaths in 2026. CDC’s national count still lists none.
The Pennsylvania Department of Health announced two more measles-associated deaths on September 15, in addition to the two deaths in Lancaster County infants that were reported on August 25. All four were unvaccinated, and neither infant was old enough for immunization. The state says it confirmed each through investigation with the relevant county coroner’s offices by assessing clinical evidence of infection, laboratory testing, and exclusion of unrelated causes.
The four deaths:
- A male neonate in Lancaster County, born August 14 to a mother with active measles. The infant died shortly after delivery. Measles virus was detected in postmortem lung tissue. The immediate cause of death was splenic rupture.
- A six-week-old infant in Lancaster County who died August 18. The infant had Amish lethal microcephaly and was receiving palliative care; the coroner subsequently concluded measles was the cause of death.
- A 40-year-old woman in Jefferson County who died September 12. She lived with chronic obstructive pulmonary disease and asthma and was dependent on supplemental oxygen. She declined testing while alive; a nasal swab taken at death returned positive. Her husband had symptoms consistent with measles but was never tested, and has recovered.
- An 18-year-old in Mifflin County, whose cause of death was determined to be acute disseminated encephalomyelitis (ADEM). ADEM is a rare post-infectious inflammatory attack on the myelin of the brain and spinal cord, occurring days to weeks after measles in roughly 1 in 1,000 cases.
Why federal and state reporting disagree
CDC has changed the data source it uses to count measles deaths, moving from state reports submitted through the National Notifiable Diseases Surveillance System to death records held by the National Center for Health Statistics. The agency’s measles page, updated September 11, states that the National Center for Health Statistics "does not currently have any death records from 2026 that indicate measles is the underlying cause." The 2026 death count is shown as an asterisk; the 2025 column shows three.
"CDC will report measles deaths if and when the National Center for Health Statistics reports measles as the underlying cause of death," a Department of Health and Human Services spokesperson told The Guardian.
Epidemiologists quoted by CIDRAP called the change confusing, noting that vital statistics are designed to track long-term mortality trends rather than individual infectious disease cases. Death certificates are filed, coded and released on a timescale of months. Pennsylvania has submitted its measles-associated death case definition to CDC and the Council of State and Territorial Epidemiologists, which are developing a standardized national definition.
CDC reported 3,294 confirmed cases nationally as of September 10, with 38 outbreaks this year and 95% of cases outbreak-associated (3,123 of 3,294).
State updates
- Pennsylvania: The state has reported 693 cases as of September 14, including 99 new cases in one week, across 38 counties. Of the cases, 133 have been hospitalized and fewer than 1% were in people recorded as fully vaccinated. The dashboard still lists two deaths; the two announced on September 15 will likely be added to the tally at the next update.
- Wisconsin: The state has reported 163 cases as of September 11, of which 162 were unvaccinated. The outbreak is concentrated in Lafayette, Iowa and Grant counties, and measles virus has now been detected in wastewater from treatment facilities in all three.
- Georgia: The state has confirmed 16 cases this year as of September 11, including a cluster of ten linked to a metro Atlanta daycare.
Rabies: CDC warns on post-exposure prophylaxis as exposures rise
CDC issued a Health Alert Network (HAN) advisory on September 10 warning of an increase in human rabies exposures and errors in administering post-exposure prophylaxis.