US measles cases reach 4,588 as Pennsylvania reports rising infections.
Is it spreading to new areas?
Spread confirmed
As of 21 October 2026, DuPage County health officials reported the county's first measles case of 2026 following potential exposure at Chicago O'Hare International Airport.
Sources: CBS NewsKey figures
| Figure | Value | Basis | As of | Sources |
|---|---|---|---|---|
| US total confirmed cases Reported by the US CDC | 4,588 | Official | Sources: ReutersCIDRAP | |
| Pennsylvania total confirmed cases Reported by the Pennsylvania Department of Health | 1,317 | Press reports | Sources: ReutersU.S. News & World Report | |
| US measles-related deaths (CDC count) Confirmed by the US CDC for 2026 | 3 | Official | Sources: Fox NewsFox News 2 | |
| Pennsylvania measles-related deaths Reported by local news outlet FOX 29 Philadelphia | 6 | Unverified | Sources: FOX 29 Philadelphia | |
| Lancaster County total confirmed cases Reported by LNP | LancasterOnline | 452 | Unverified | Sources: LNP | LancasterOnline |
Who says what
| Who | Says | Date | Sources |
|---|---|---|---|
| US Centers for Disease Control and Prevention (CDC) | Reported 4,588 total US measles cases, confirmed three national deaths, and dispatched a disease investigator to Pennsylvania. | Sources: ReutersFox NewsCBS News | |
| Pennsylvania Department of Health | Reported 1,317 total state cases, issued health alerts regarding risks to pregnant women, and accepted federal assistance while asserting CDC death tracking undercounts state fatalities. | Sources: Reuters6abc PhiladelphiaThe Philadelphia Inquirer | |
| DuPage County Health Department | Confirmed the county's first measles case of 2026 associated with exposure at Chicago O'Hare International Airport. | Sources: CBS News |
Summary
As of 25 October 2026, measles cases in the United States have more than doubled compared to the previous year's total [bb5188f5401ccde7]. National cases reached 4,588 according to the CDC, with 178 additional cases reported in recent updates [ca767b2891a7f0ab, 3043ba7db7dc7b19].
In Pennsylvania, confirmed cases reached 1,317 as of 21 October, with 21 additional cases reported over a three-day period by 23 October [353a438a45236fce, 0efa9ad6022f065e]. Adults account for two-thirds of Pennsylvania's cases [8cde2f15ed295aba]. State health officials issued warnings regarding congenital measles risks and infection during pregnancy [31fd3f3fb85ec01d, 6c723c805964e16d].
Federal health officials confirmed a third US measles-related death in 2026 [42a8c4f249b5aec2], while local reporting noted a sixth death in Pennsylvania [4be25d996d8b2b6b]. The CDC dispatched a disease investigator to Pennsylvania to assist state health officials [a47fba87485e0c65].
Timeline
- CDC reported total national cases reached 4,410, while Pennsylvania reported over 1,200 cases and five state deaths.Sources: ReutersThe Philadelphia Inquirer
- CDC recognized a third US measles-related death, while local media reported a sixth death in Pennsylvania.Sources: Al JazeeraFOX 29 Philadelphia
- Pennsylvania Department of Health reported cases rose to 1,317 and warned of congenital measles risks, while DuPage County, Illinois reported its first case.Sources: ReutersThe HillCBS News
- Pennsylvania Department of Health issued a measles health alert for pregnant women as a CDC investigator was deployed to the state.Sources: 6abc PhiladelphiaCBS News
- CDC reported US measles cases reached 4,588, and Pennsylvania reported 21 new cases over three days.Sources: ReutersPennLive
Still unknown
- The reason for the discrepancy between Pennsylvania's reported state death toll and the CDC's official national death count.
- The timeline and reasons for CDC decisions regarding requests for faster or high-volume measles testing validation.
- The extent of transmission risks among adults, who represent two-thirds of Pennsylvania's confirmed cases.