The autopsy of a woman from the state of Washington has revealed that her death was due to measles. In a statement released by the Washington State Department of Health, the agency confirmed that the patient, who died in the spring in Clallam County, had an undetected measles infection. Her actual condition was only revealed in the autopsy. Her official death has been ruled as "pneumonia due to measles."

The agency further stated that the woman had been at the county health facility during the time another person who exhibited measles rashes was getting treatment. "The woman had several other health conditions and was on medications that contributed to a suppressed immune system. She didn't have some of the common symptoms of measles such as a rash, so the infection wasn't discovered until after her death," the statement said.

Her identity was not released by the health agency.

"This should have been a preventable death, and I think her death is a tragedy," remarked Dr. Mark Schleiss of the Division of Infectious Diseases and Immunology at the University of Minnesota, according to Forbes. "Measles is a disease we know we can control with effective immunizations. For this to happen is really unfortunate and unnecessary."

"We know that Washington State is a state with one of the highest percentages of religious and philosophical exemptions for vaccines in the country," the doctor added. "It seems a reasonable conclusion that this death occurred because of inadequate immunization levels, but more epidemiological investigation will have to take place to find out."

The woman's case is the 11th reported case of measles in Washington this year, according to the Washington Post.

Meanwhile, as the U.S. has effectively eliminated measles since 2000, the disease has been making a comeback, particularly because many adults prefer to keep their children unvaccinated. The Center for Disease Control and Prevention said that there have been 178 people from 24 states that were reported as having measles since the start of 2015. At least a two-thirds of those cases come from the outbreak in California, the CDC report stated.

The news comes as California Gov. Jerry Brown signed the law regulating school vaccinations, with parents strictly disallowed to claim they cannot adhere to it due to personal beliefs.