School and health officials in Spokane County are urging parents and staff members to update their immunization records as the threat of a measles outbreak spreading from southwest Washington continues to grow.

There may be up to 2,550 students in Spokane Public Schools susceptible to the highly contagious virus, based upon those who either haven’t provided documentation to become compliant or have successfully sought an exemption, according to Spokane Public Schools spokesman Brian Coddington.

Of those, more than 1,300 attend classes in public school buildings.

Potential exclusions could also reach into Kootenai County. Coeur d’Alene Public Schools has identified 1,200 students in their district who either don’t have adequate immunization records or who have received exemptions and would potentially be ordered home, said Nichole Piekarski, lead nurse for the school district.

Spokane Public Schools is holding an immunization clinic for its staff next Thursday and is continuing to notify the families of students who don’t have up-to-date vaccination records that they need to do so, or face orders to remain home if the virus shows up in their school.

“We made a big push in the fall, as we do every year, to get vaccination records updated,” Coddington said.

Officials in Clark County reported Friday the number of confirmed cases of the airborne virus had risen to 42, with all but five of the infections occuring in patients who hadn’t received a measles vaccination. One case involved a patient who had been vaccinated.

No cases have yet been reported in Spokane, but the disease is highly contagious and two cases in adults were reported in the county in 2015 after a 21-year absence.

Exclusions from class can be ordered by the Spokane Regional Health District if just one case of measles appears in a school, said spokeswoman Kim Papich. They last for the entirety of the incubation period for the disease, which is a couple of weeks for measles. One new case starts the cycle over again.

“We’re trying to be proactive this time around,” said Papich, referencing the outbreak of mumps two years ago that sent hundreds of students home for weeks in some cases. “One of the things we’re asking the districts is, ‘How do you ensure continuity of education for kids who are going to be excluded?’ ”

The health district has been working with school districts to notify students who have received exemptions from the vaccine for religious or philosophical reasons that they will be required to remain at home during a potential outbreak, Papich said. Health officials are hoping parents who requested an exemption because they couldn’t get to a doctor’s office in the summer will take their children to be vaccinated now and avoid child-care complications should the disease spread.

Students are considered noncompliant if they haven’t provided the district with required information about the dates of their vaccinations for diseases that include measles, mumps and rubella (the MMR vaccine), hepatitis, tetanus and other required vaccinations. Families may also apply for an exemption for philosophical or religious beliefs, but are warned at that time that if an outbreak occurs, their child may be ordered home from school until all traces of the disease are gone.

Families will begin to receive notifications next week that they need to update their immunization records if they aren’t complete, added Piekarski, of Coeur d’Alene schools. That would allow families to avoid their child being excluded from class if a measles outbreak were to occur and health officials gave an order to stay home.

Officials in the Central Valley School District also are gathering their immunization information and working with Spokane Regional Health District should the virus reach classrooms, said Marla Nunberg, communications director for the district. Nunberg said she couldn’t provide compliance numbers for the district Thursday.

The Washington Department of Health collects data from school districts on compliance and exemptions each year. Those numbers are broken down by vaccine type, including the MMR innoculation. Exemptions are granted to a greater number of students enrolled in private schools than public schools, according to that data, and exemptions in both types of schools in Spokane County (4.4 percent of students) outpaced those statewide (2.9 percent) during the 2017-2018 school year, the most recent year for which data is available.

Health officials are once again asking parents to vaccinate their children against the measles virus in a struggle that dates back decades. New infections declined throughout the 1980s as health care providers pushed for vaccinations of the disease that killed between 400 and 500 Americans each year, according to the Centers for Disease Control and Prevention. A spike in cases in 1989 prompted the CDC to recommend two rounds of the vaccine, one around the child’s first birthday and again when the child reaches ages 4 to 6.

Only 61 percent of children in Spokane County receive that second round on time, according to data from the Spokane Reigonal Health District.

The vaccine is not recommended for children younger than 12 months and pregnant women. However, the CDC reports that a treatment known as immunogloblin is available for those with compromised immune systems if exposed to the virus.

That treatment is typically only given after exposure, Papich said. Those with infants between 6 months and 12 months old can speak with their doctor about getting the full vaccine, but they’ll still need two treatments after that.

The most recent outbreak of measles was discovered in January in Clark County, prompting Gov. Jay Inslee to declare a state of emergency late last week. One case has been confirmed in King County. Three of every four patients identified is under the age of 10, according to Clark County Public Health.

Clark County officials have ordered students without documented immunizations to remain home at several elementary and middle schools where exposure may have occurred.

Two measles cases were reported in Spokane County in 2015, according to the Washington Department of Health, the most recent occurrence of the disease. One of those cases involved an adult who hadn’t been vaccinated, according to news reports. Before that, measles hadn’t been reported in Spokane County since 1994.