United States measles cases reach highest annual level since 1991

measles outbreak vaccination rates public health dispute CDC Pennsylvania

The United States is experiencing a significant rise in measles cases, with 3,134 confirmed infections recorded as of September 2026. This figure represents the highest annual total since 1991, driven largely by declining childhood vaccination rates. According to the CDC, measles vaccination coverage among kindergartners has fallen to 92.4 percent, down from 95.2 percent in the 2019-2020 school year.

In Pennsylvania, a measles outbreak has sparked a political and public health dispute regarding the classification of fatalities. Lancaster County Coroner Stephen Diamantoni confirmed the death of a 6-week-old infant with Amish lethal microcephaly from measles. This follows a separate report from the Pennsylvania Department of Health regarding two 'measles-associated' deaths. The coroner has contested one of these classifications, stating that a newborn who tested positive for the virus actually died from a ruptured spleen.

The dispute has escalated to the federal level. Reports indicate that HHS Secretary Robert F. Kennedy Jr. directed the CDC to remove references to these Pennsylvania fatalities from its online tracker, questioning whether the virus was the definitive cause of death. This friction between state and federal officials comes amid broader concerns regarding public trust in vaccinations and shifting federal guidance on immunization schedules.

Entities

Centers for Disease Control and Prevention · Department of Health and Human Services · Erica Schwartz · Pennsylvania · Pennsylvania Department of Health · Robert F. Kennedy Jr. · Stephen Diamantoni

Claims

What the coverage asserts, and how many sources carry each claim.

[○ 1 SOURCE] The state uses the term 'measles-associated' when evidence of the virus is present but the official cause of death is under investigation. keyt.com
[● 2 SOURCES] The reported deaths are the first measles-associated deaths in Pennsylvania in 35 years. keyt.com
[○ 1 SOURCE] A measles outbreak in Pennsylvania has affected at least 36 counties, resulting in 577 infections and 98 hospitalizations.
[○ 1 SOURCE] The Pennsylvania Health Department reviews all reported measles cases to ensure they meet CDC case definitions. ca.news.yahoo.com
[● 3 SOURCES] HHS Secretary Robert F. Kennedy Jr. reportedly directed the CDC to remove references to two Pennsylvania measles fatalities from its online tracker. ca.news.yahoo.com · www.ntd.com · time.news
[DISPUTED] A 6-week-old infant girl with Amish lethal microcephaly died from measles in Lancaster County. keyt.com
[DISPUTED] A newborn who tested positive for measles died from a ruptured spleen rather than the virus. ca.news.yahoo.com · keyt.com
[● 5 SOURCES] The Lancaster County Coroner maintains that a newborn who tested positive for measles died from a ruptured spleen rather than the virus. ca.news.yahoo.com · keyt.com · kioncentralcoast.com · www.ntd.com · kvia.com
[DISPUTED] Lancaster County Coroner Stephen Diamantoni confirmed the death of a 6-week-old infant with Amish lethal microcephaly from measles. ca.news.yahoo.com · www.ntd.com · time.news
[● 2 SOURCES] The United States recorded 3,134 confirmed measles cases in 2026 as of September 5. d2l6fjvu7g4rze.cloudfront.net · myrepublica.nagariknetwork.com
[● 2 SOURCES] U.S. kindergartner measles vaccination coverage fell to 92.4 percent during the 2025-2026 school year. d2l6fjvu7g4rze.cloudfront.net · myrepublica.nagariknetwork.com
[● 2 SOURCES] The 2026 measles case total is the highest annual number recorded in the United States since 1991. d2l6fjvu7g4rze.cloudfront.net · myrepublica.nagariknetwork.com