Five unvaccinated members of the same household in Canyon County contracted measles recently after traveling out of state, regional health officials say.

Earlier this month, Southwest District Health warned parents of students in Vallivue middle and high schools that their children could’ve been exposed to measles. But the health district hasn’t publicly announced the measles cases in a news release because officials say they were able to contact everybody who may have been exposed.

“Since the exposures were just restricted to the school, we were able to notify everybody that were exposed,” health district epidemiologist Lekshmi Venugopal told the Idaho Capital Sun in an interview Friday.

Southwest District Health spokesperson Monique Evancic also said the health district is hopeful that the infections will stay contained to the household.

“We want to, especially post-COVID, be mindful of, like, fear mongering,” she said in an interview.

Idaho has at least 7 measles cases this year

So far this year, Idaho has reported 7 measles cases, according to the Idaho Department of Health and Welfare’s infectious disease data dashboard. Last year, during the U.S.’s worst outbreak of measles in decades, Idaho reported 13 cases.

Regional health officials are classifying the measles cases reported in Canyon County as “probable” because people were diagnosed based on their symptoms, and they didn’t do laboratory testing. Officials say the family has voluntarily quarantined at home.

In a statement, Evancic said the health district doesn’t know any other students or staff in the Vallivue School District who have measles symptoms. She said the health district alerted local health care providers that measles is in the area. But Venugopal said she does not believe measles is spreading within the southwest Idaho community, and that the five cases in Canyon County are no longer infectious.

Idaho has the lowest rate of kindergartners — nearly four out of every five — who are reportedly up to date on their measles vaccine, according to Centers for Disease Control and Prevention data.

Southwest District Health notes that’s well under the 95 percent vaccination rate that prevents outbreaks from spreading. But Venugopal said the schools where there could be exposure had around 95 percent vaccination status.

“The main public health concern right now is low vaccination coverage, which increases the risk of measles spreading in schools and the community,” Evancic told the Idaho Capital Sun.

Here’s what Southwest District Health has said about the measles cases in Canyon County:

• Two children in the household attended school in the Vallivue School District this month while infectious with measles. One attended Vallivue Middle School on Jan. 9. Another attended Vallivue High School on Jan. 20. Both children did not have symptoms at the time.
• Parents should monitor their children for measles symptoms, which can surface up to 21 days after they were exposed.
• Venugopal said the other three cases in the household did not cause public exposure.

What to know about measles

Vaccination is the best way to prevent measles, which is highly contagious and usually leads to hospitalization for one in five children younger than 5 years old who are infected.

Measles is highly contagious but rare. Up to 90 percent of non-immune people in contact with an infected person can become infected. The virus can live in the air up to two hours after someone infected leaves.

Symptoms typically appear seven to 14 days after exposure and include high fever, cough, runny nose, red eyes, and a distinctive rash, the CDC says. While many recover without problems, measles can lead to serious complications, especially in very young children and people with weakened immune systems.

The virus’s serious complications can include pneumonia, encephalitis (an inflammation of the brain) and, in rare cases, death.

People with measles symptoms should not enter health care settings without calling ahead, and they should contact their health care providers. People exposed to measles should monitor for symptoms for 21 days after exposure.

There is no antiviral treatment for measles, according to the CDC.