UPDATE: The outbreak continues to grow. Click here for the latest developments.

A measles outbreak in Clark County has grown to 14 confirmed cases with three more suspected, and people who visited some 20 locations in Vancouver and Portland might have been exposed.

The confirmed cases include 12 children under 10 years old, and the remaining two are under 18. At least 13 of the 14 victims were not immunized against the disease, a highly contagious viral illness spread through the air when an infected person coughs or sneezes. (The final patient’s immunization status was uncertain.)

While contagious, the patients have visited schools, churches and medical facilities, as well as the Portland International Airport and busy retailers like the Northeast Portland Costco and Ikea stores. (A full list of locations and dates appears at the end of this post.)

One of the confirmed Clark County measles patients has been hospitalized, as was another suspected patient.

Measles cases usually begin with a runny nose, cough, red eyes and sore throat, followed by a rash that spreads over the entire body. But infected people can be contagious before they show any symptoms, and up to four days before and after the rash appears.

The disease can be deadly. Even when it’s not, complications can include ear infections or diarrhea, along with more severe health issues like pneumonia, encephalitis (brain swelling) or total hearing loss. Measles is dangerous for pregnant woman as well and can lead to miscarriages, premature births or babies with low-birth-weights.

This child shows a classic day-4 rash with measles. (CDC/NIP/ Barbara Rice)

Officials say anyone who has been exposed and believes they have measles symptoms should call their healthcare provider before visiting a medical office to avoid exposing others.

The illness can be prevented with the MMR vaccine, which also protects against mumps and rubella. The Centers for Disease Control and prevention recommends children get two doses of MMR vaccine, starting with the first dose at 12 through 15 months of age and the second dose at 4 through 6 years of age.

Clark County health officials say people might have been exposed at the following locations:

Health care facilities:

Magnolia Family Clinic, 2207 NE Broadway, Suite 200, Portland from 11:30 am to 3 pm Tuesday, Jan. 8.

The Vancouver Clinic, 700 NE 87th Ave., Vancouver 3:30 to 7 pm Friday, Jan. 11. 10:45 am to 1:30 pm Saturday Jan. 12. 4:30 to 7:30 pm Sunday, Jan. 13. 9:30 am to 1 pm Monday, Jan. 14.

Kaiser Cascade Park, 12607 SE Mill Plain Blvd., Vancouver from 1 to 8:30 pm Saturday, Jan. 12.

Randall Children's Hospital at Legacy Emanuel Emergency Department, 2801 N Gantenbein Ave., Portland from 11:30 am to 2 pm Saturday, Jan. 12.

PeaceHealth Southwest Medical Center Emergency Department, 400 NE Mother Joseph Pl., Vancouver 10 pm Saturday, Jan. 12 to 4 am Sunday, Jan. 13. 12:30 to 8:30 pm Sunday, Jan. 13.

Legacy Salmon Creek Medical Center , 2211 NE 139th St., Vancouver 8:30 pm Saturday, Jan. 12 to 1 am Sunday, Jan. 13.



Schools:

Cornerstone Christian Academy, 10818 NE 117th Ave., Vancouver on Friday, Jan. 4

Vancouver Home Connection, 301 S. Lieser Road, Vancouver on Monday, Jan. 7; Tuesday, Jan. 8; and Friday, Jan. 11.

Hearthwood Elementary School, 801 NE Hearthwood Blvd., Vancouver on Monday, Jan. 7; Tuesday, Jan. 8; and Wednesday, Jan. 9.

Image Elementary School, 4400 NE 122nd Ave., Vancouver on Tuesday, Jan. 8 and Wednesday, Jan. 9.

Eisenhower Elementary School, 9201 NW Ninth Ave., Vancouver on Tuesday, Jan. 8 and Wednesday, Jan. 9.

Other locations:

Church of Christ Savior, 3612 F St., Vancouver from 9:30 am to noon Sunday, Jan. 6 and 6 to 11:30 pm Sunday, Jan. 6.

Church of Truth , 7250 NE 41st St., Vancouver from 11 am to 4:30 pm Sunday, Jan. 6.

Portland International Airport , 7000 NE Airport Way, Portland from 10:45 am to 3:45 pm on Monday, Jan. 7. More specifically, anyone who spent time in Concourse D and the Delta Sky Lounge during that time period.

Costco , 4849 NE 138th Ave., Portland from 1 to 5:30 pm Tuesday, Jan. 8.

Amazon Lockers , 1131 SW Jefferson St., Portland from 3:30 pm to 7 pm Thursday, Jan. 10.

Rejuvenation , 1100 SE Grand Ave., Portland from 3:30 to 7:30 pm Thursday, Jan. 10.

Pho Green Papaya , 13215 SE Mill Plain Blvd., Vancouver from 7:30 to 10:30 pm Thursday, Jan. 10.

Chuck's Produce , 13215 SE Mill Plain Blvd., Vancouver from 8 to 11:45 pm Thursday, Jan. 10 and 2:30 to 5:30 pm Friday, Jan. 11.

IKEA, 10280 NE Cascades Parkway, Portland from 4:30 to 8:30 pm Friday, Jan. 11.

-- Elliot Njus

enjus@oregonian.com; 503-294-5034; @enjus

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