Measles cases worldwide have practically doubled. Half of this year’s cases were reported in the WHO European region

About one in 20 children with measles will develop pneumonia, and others may develop a dangerous swelling of the brain called encephalitis. Up to three in every 1,000 children who are infected with measles may die from respiratory and neurological complications

The number of measles cases worldwide nearly doubled between 2022 and 2023, researchers say, posing a challenge to efforts to achieve and maintain eradication status in many countries.

There were 171,153 cases worldwide in 2022, according to Patrick O’Connor of the World Health Organization, who released the new data at the recent ESCMID Global Congress in Barcelona. Provisional data indicates 321,582 cases in 2023 and more than 94,000 so far in 2024, although the number is likely to be much higher.

Almost half of this year’s cases occurred in the WHO European Region, with the highest incidence in Azerbaijan, Kyrgyzstan and Yemen.

The US has already had 128 measles cases reported in 20 regions this year, according to the US Centers for Disease Control and Prevention. This is the highest number since 2019.

Measles was declared eradicated in the US in 2000, “meaning there is no measles spreading in the country and new cases are only found when someone contracts measles abroad and returns,” explains the CDC. However, the rapid increase in the number of cases this year poses a threat to the disease’s eradication status, the CDC stresses.

Measles is a highly contagious airborne disease. It can cause serious health consequences or death, especially in young, unvaccinated children.

General symptoms may include fever, cough, runny nose, watery eyes, and a red, blotchy rash. About one in five unvaccinated people in the U.S. who gets measles will be hospitalized, according to the CDC. About one in 20 children with measles will develop pneumonia, and others may develop a dangerous swelling of the brain called encephalitis. Up to three in every 1,000 children who become infected with measles may die from respiratory and neurological complications.

It can also lead to “immune amnesia,” a condition that increases the risk of other infections for weeks or years.

The WHO official recalled that measles vaccination prevented around 57 million deaths between 2000 and 2022.

In the US, the CDC recommends that children receive the first dose of the vaccine that protects against measles, mumps and rubella (MMR) between 12 and 15 months of age. Children receive a second dose between 4 and 6 years of age.

The vaccine is considered highly effective. One dose is 93% effective against measles, and two doses are 97% effective. Vaccinated people can still get sick, but this doesn’t happen often and it’s usually a milder infection.

The U.S. has set a 95% vaccination goal, but coverage among children attending kindergarten has fallen below that in recent years. As of the 2022-23 school year, only 93.1% of U.S. kindergartners had completed their MMR vaccine series, leaving about 250,000 at risk.

Measles is “one crisis among many crises”, warned O’Connor in his presentation, with around 45% of outbreaks in fragile and conflict-affected countries.

“Over the past 20 years, there has been significant progress toward eliminating measles and rubella. To solidify and maintain these gains, we need to ensure high, uniform, and equitable routine immunization coverage, as well as robust outreach and rapid response to outbreaks.”