A 40-year-old woman in Jefferson County, Pennsylvania has died of complications from measles, according to the county’s coroner.

It marks the third vaccine-preventable, measles-linked death in the US this year. All three have occurred in Pennsylvania, which is experiencing an explosive outbreak that has caused over 670 cases and 124 hospitalizations across 37 counties. Prior to these deaths, Pennsylvania had not reported a measles death in 35 years.

In a news release dated September 12, Jefferson County Coroner Greg Furlong said the death in the woman was “a heartbreaking loss for the family and an unfortunate reminder that measles can be a serious and potentially life-threatening disease.”

The county’s chief deputy coroner, Jason Stiver, added that “this tragedy highlights that measles should not be taken lightly.”

“Many people associate measles with a childhood illness, but it can lead to severe complications in individuals of any age,” Stiver said. “Measles is highly contagious and can result in serious respiratory illness, hospitalization, and in rare cases like this, death.”

Preliminary death certificate

While the news release stated that no additional information about the case would be provided, the New York Times obtained a preliminary death certificate. It indicated the woman had several chronic medical conditions, including chronic obstructive pulmonary disease (COPD), and she required supplemental oxygen at all times. Her health status made her vulnerable to complications from measles.

The death certificate listed the immediate cause of death as respiratory failure “due to suspected measles.” Furlong told the Times that the woman’s measles case had yet to be confirmed by testing, but that she was unvaccinated and known to have been exposed to someone with measles. At the time of her death, she had many symptoms of measles, including the tell-tale rash, which often begins as red spots on the head or face, and spreads down the body.

The news release noted that the coroner’s office is working with the state health department, which has not yet added the death to the state’s official outbreak tally. The health department provided a statement to the Washington Post saying that it was aware of the case.