Everything Idaho Needs to Know About Highly Contagious, Deadly Disease Confirmed in 18 States

Idaho has survived “Fools Spring” and the “Spring of Deception.” That means another one of Idaho’s unique seasons, “The Pollening,” is right around the corner. Seasonal allergies are circulating along with lingering respiratory illnesses like influenza and RSV. However, there’s one serious and deadly infection that Idahoans should stay vigilant of. 

Dangerous Infection Confirmed in 18 States in 2025; What Idahoans Should Know

According to the CDC measles was considered “eliminated” in the United States back in 2000, but the illness is starting to rear its ugly head again. Last year, there were 285 measles cases reported across 33 different jurisdictions including Idaho. 

Almost three months into 2025, the number of cases has jumped to 378 cases resulting in at least one death in a non vaccinated school aged child in Texas. A second death of an unvaccinated adult in New Mexico is under investigation after the deceased tested positive for the highly contagious disease. These are the first measles related deaths in the United States in a decade. 

While there has not been a case reported in the Gem State this year, there have been cases reported in nearby Washington State. Cases have also been reported in California, Texas (250+ this year,) and Florida which were all listed as Top 10 Travel Destinations for Idahoans during Spring Break 2025. 

How Dangerous Are Measles?

The CDC says that symptoms of measles can include high fever, cough, runny nose, red watery eyes, a raised rash beginning near the hairline and spreading down the neck, torso, arms, legs and feet. The rash may be accompanied by a fever of up to 104 degrees. 

Serious complications can include hospitalization, pneumonia or swelling of the brain which could lead to convulsions leaving a child deaf or with an intellectual disability. The CDC estimates that one to three of every 1,000 children who contract the measles will die because of respiratory or neurologic complications the virus creates. 

Why Measles Should Matter in Idaho

While Treasure Valley schools just returned to class after Spring Break, other areas of the state are kicking off spring break now. Measles is often contracted while traveling and as we mentioned, several top destinations for Idaho travelers. 

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According to a release from Southwest District Health, the measles virus can linger up to two hours in the air after an infected person has left the area. They go on to explain that the virus is so contagious that 90% of people who were near someone with the virus who have no immunity will also get sick. Those with an infection may be contagious up to four days before and after the rash appears. 

The Measles-Mumps-Rubella vaccine played a large role in the “elimination” of the disease back in the year 2000 and is considered 97% effective after two doses. On its information page about measles, the CDC showed that during the 2023-2024 school year, Idaho has the lowest MMR vaccination rate in the country at 79.6%. 

If you recently traveled to an area with an active outbreak, these are the symptoms to watch out for.