Key facts
- Pennsylvania has reported a fourth death associated with measles, the state's worst outbreak in over three decades.
- The Trump administration changed its method for counting measles deaths, now using National Center for Health Statistics (NCHS) data.
- The CDC is no longer using the National Notifiable Diseases Surveillance System (NNDSS) for measles death tracking.
- The NCHS data currently lists no measles deaths nationally for 2026.
- Robert F. Kennedy Jr., HHS secretary, has previously questioned earlier measles death counts and has not commented on the latest death.
Pennsylvania health officials have reported a fourth death associated with measles, marking the state's most severe outbreak of the disease in over three decades and the worst nationally since 1992. The Trump administration has altered its methodology for tracking measles deaths, shifting to data from the National Center for Health Statistics (NCHS) for mortality trend analysis, a move described as 'puzzling' by former CDC chief medical officer Debra Houry. Previously, the CDC relied on the National Notifiable Diseases Surveillance System (NNDSS). The NCHS system is not designed to confirm individual cases but rather to analyze long-term mortality trends, and currently lists no measles deaths nationally for 2026. Robert F. Kennedy Jr., the HHS secretary, has not commented on the latest death and previously questioned the attribution of earlier deaths to measles. Pennsylvania has recorded 676 confirmed measles cases, with outbreaks centered in agricultural areas. The measles, mumps, and rubella (MMR) vaccine prevents 97% of measles cases, but vaccination rates have declined.