SEATTLE -- A Clallam County woman died this spring due to a measles infection, the Washington state Department of Health said Thursday. It's the first reported measles-related death in the U.S. since 2003 and the first in the state of Washington since the 1990s.

The infection wasn't discovered until an autopsy. The official cause of death was pneumonia due to measles.

DOH spokesman Donn Moyer said the woman was likely exposed at a local medical facility during a recent outbreak in Clallam County. She was there at the same time as a person who later developed a rash and was contagious for measles.

Officials say the woman had the D9 strain of the measles, which is common in southeast Asia and is the same strain connected to the Clallam County outbreak.

County health officials say this is not the same strain that was the cause of the measles outbreak at Disneyland.

The woman was dealing with other health conditions and was on medications that weakened her immune system. Moyer said she did not exhibit some of the common symptoms of measles so the infection was not discovered until after she died. They did not say whether she was vaccinated.

Moyer says the woman was moved to the University of Washington Medical Center in Seattle, where she died. He says officials are withholding her age to protect her identity, but she wasn't elderly.

Moyer it's possible to develop measles within three weeks of exposure. Since more than three weeks have passed since the last active measles case in Washington state there is no risk for anyone who had contact with one of those known measles patients.

The Department of Health says this is a reminder to the public to get the measles, mumps, and rubella vaccine (MMR) before they catch it. Moyer says measles is highly contagious and can be caught just by walking into a room where someone with the disease has been in the past couple of hours.

"People with compromised immune systems often cannot be vaccinated against measles. Even when vaccinated, they may not have a good immune response when exposed to disease; they may be especially vulnerable to disease outbreaks," wrote DOH spokesman Donn Moyer in a statement.

Moyer says children should get two doses of MMR vaccine – the first between 12-15 months and the second at 4-6 years old. Adults born after 1956 should have at least one measles vaccination while some may need two.

Measles symptoms:

  • Fever
  • Runny nose
  • Cough
  • Rash all over the body
  • People can spread measles before they show symptoms

When do symptoms appear?

  • 7 to 21 days after exposure: mild to moderate fever, cough, runny nose, red eyes, and sore throat.
  • 2 to 4 days after symptoms begin: tiny white spots may appear inside the mouth.
  • 3 to 5 days after symptoms begin: a red or reddish-brown raised rash that feels like sandpaper appears, usually beginning on the face. The rash rapidly spreads down the neck, upper arms, and chest. Later, it spreads over the back, abdomen, the rest of the arms, thighs, legs, and feet. When the rash appears, a person's fever may spike to more than 104 degrees Fahrenheit.
  • Symptoms usually last seven to 10 days.