Officials in the Pacific Northwest state of Washington have declared a measles outbreak after at least 22 people, including 20 children, have become infected with the disease since Jan. 1.
"It's an outbreak because generally the way we define an outbreak is when you have more observed cases than expected cases. And generally with measles, the expected number is zero," Dr. Alan Melnick with Clark County Public Health told KOIN6 TV in Portland, Oregon, last week. "You know, we have a very effective vaccine for measles. Two shots are 97 percent effective. We really shouldn't be seeing measles."
The outbreak comes on the heels of the Centers for Disease Control and Prevention (CDC) releasing data for 2018 earlier this month. The CDC said the 349 reported cases in 26 states and the District of Columbia made 2018 the second worse year for measles since 2000, when the disease was eliminated in the U.S. It said 2014 was the worst year, with a reported 667 cases.
The report said some of the cases were related to unvaccinated people in Orthodox Jewish communities, as well as travelers who became infected after visiting Israel, Italy, France and Britain, where major outbreaks are occurring. According to the CDC, an outbreak is defined as three or more linked cases.
The report also said 81 of the 349 cases were in people who traveled to the United States from other countries.
Clark County officials said a person infected with measles attended a Portland Trail Blazers National Basketball Association (NBA) game last week in Portland, Oregon, and contagious people visited other venues, such as the Portland airport, and local hospitals, stores and restaurants. Clark County is about a half-hour from Portland, causing officials to worry the disease may spread across the two-state region.
Eighteen states, including Oregon and Washington, allow families to opt out of vaccines based on philosophical beliefs.
While considered eliminated in the U.S., measles is common in other parts of the world, specifically Europe, the Middle East, Asia and Africa, according to world health officials.
Measles is a highly contagious viral illness that was thought to have been eradicated in the United States in 2000. Its symptoms, which include fever, runny nose and a skin rash, appear about 10 to 14 days after exposure to the virus. The infection occurs in stages over a period of two to three weeks, the CDC reports.
Before the vaccine was introduced in 1963, the disease was blamed for an estimated 400 to 500 deaths and 48,000 hospitalizations each year, according to the CDC.