A six-week-old infant has died of measles, the Lancaster County coroner said, increasing scrutiny of the state's expanding outbreak as reported cases approach 400. Coroner Stephen Diamantoni confirmed the finding to multiple news outlets and said the child had a condition described as Amish lethal microcephaly. Medical experts note children with that condition typically survive only five to six months and are more vulnerable to respiratory infections.

State health officials have not confirmed whether this infant is one of two Lancaster County residents described last week as having died in “measles-associated” cases. The first of those fatalities was recorded on 14 August and involved a newborn whose mother had measles and transmitted the virus. In that earlier case the coroner listed a ruptured spleen as the immediate cause, while measles appeared on the death certificate and the parents said they believed measles was responsible.

Pennsylvania’s official tally stands at nearly 400 measles cases across 28 counties, with almost half concentrated in southern Lancaster County. Most reported infections affect adults aged 18 to 49, and public health officials caution that reported counts typically understate the true number of infections because of testing and reporting gaps.

The recent fatalities have sharpened a public dispute between governor Josh Shapiro and the administration’s health secretary, Robert F Kennedy Jr. Some commentators on the right questioned whether the deaths were caused by measles after officials used the phrase “measles-associated.” Kennedy accused the governor’s team of staging the announcement and wrote on social media, “The performance was a replay of the Democrats’ Covid playbook: fear-mongering, misinformation, finger-pointing, and the weaponization of infectious disease fears for political gain.”

Federal health officials were not including the two recent measles-associated deaths in their official counts as of Monday. Former CDC leaders Debra Houry and Demetre Daskalakis criticised the politicisation of outbreaks and urged clearer public information and easier access to vaccination, writing, “Chicken noodle soup and vitamin A are not substitutes for vaccination.”

State investigators and public health authorities continue to review the deaths and the outbreak. Officials have not resolved whether the newly reported infant death corresponds to the previously announced measles-associated fatalities, and case totals are likely to be adjusted as inquiries and confirmations proceed.