The number of confirmed measles cases in the Pacific Northwest is growing as the infection spreads across what has been dubbed an anti-vaccination “hot spot” near Portland, Oregon.

As of Friday, public health officials had confirmed 30 cases of measles and nine suspected cases in southwest Washington, across the Columbia River from Portland.

The Clark County Washington Public Health Department said 26 of the confirmed cases were not immunized against measles. The other four cases had not verified patients’ immunization status.

{mosads}Twenty-one of the cases were in children under 10 years old. Officials reported that there are eight cases of measles in teenagers and one who is an adult.

Washington officials declared a public health emergency in the area earlier this week as measles spread throughout the Pacific Northwest community. Clark County is a “hot spot” for outbreaks because of the high rate of nonmedical vaccine exemptions, The Washington Post reported this week.

State data shows that roughly 7 percent of Clark County students in the 2017-2018 school year were deemed exempt from receiving mandatory vaccines upon enrolling in kindergarten, citing personal or religious reasons. Research points to an increase over the past decade in “philosophical-belief” vaccine exemptions in 12 out of the 18 states that allow such exemptions.

According to the Centers for Disease Control and Prevention (CDC), two doses of the vaccine for measles, mumps and rubella, commonly referred to as MMR, is about 97 percent effective at preventing the infection. 

Nearly 350 confirmed measles cases were reported last year across 26 states and the District of Columbia. The number represented the second highest since 2000, according to the CDC.