Measles cases are on the rise across the United States and around the world, prompting health officials in Hawaii to urge residents to stay vigilant. The highly contagious viral illness, which was declared eliminated in the U.S. in 2000, has been making a troubling comeback as vaccination rates decline.
The state Department of Health warns that the state remains at risk for a travel-related measles case, which could lead to an outbreak due to the virus’ extreme contagiousness and suboptimal vaccination coverage.
Measles cases in the U.S. have surged in recent years. In 2023 the Centers for Disease Control and Prevention reported 59 cases nationwide, but that number spiked to 285 in 2024. As of March 13 there have already been 301 confirmed cases across 15 states.
Internationally, the World Health Organization reported 10.3 million measles cases worldwide in 2023. The highly infectious nature of the virus means even a single case brought into Hawaii could rapidly spread within the community.
An infected person can transmit measles up to four days before and after symptoms appear, and the virus can linger in the air for up to two hours after an infected person leaves an enclosed space. The CDC estimates that if a person has measles, 9 out of 10 nearby people who are not immune will become infected.
“As a doctor and governor, I want to be clear: measles is a serious, highly contagious disease, and cases are rising worldwide. It spreads fast, causes severe complications, and puts our keiki, kupuna, pregnant women, and those with weakened immune systems at risk,” Gov. Josh Green said in a statement. “Prevention is the best cure, and a measles outbreak is preventable. The best protection is vaccination. Two doses of the MMR vaccine are 97% effective in preventing infection and stopping the spread. Measles was once eliminated in the U.S., but low vaccination rates are bringing it back. We can’t let that happen here in Hawaii.”
For communities to be protected from a measles outbreak, at least 95% of the population must be vaccinated. Hawaii’s measles, mumps and rubella — or MMR — vaccination rate for kindergartners was 90% during the 2023-2024 school year, below the national average of 93%.
Some areas, including schools on Maui, Kauai and Hawaii Island, have even lower vaccination rates, some below 75%, making these communities especially vulnerable.
To compare, Gaines County, Texas — where a major outbreak has taken hold — has a vaccination rate of 82%. Health officials warn that an outbreak in Hawaii, particularly on a neighbor island, would place a significant strain on the health care system, as no hospitals outside of Oahu have pediatric intensive care units.
Measles is not just a rash and fever — it can lead to severe and sometimes fatal complications, according to the CDC. Symptoms usually begin seven to 14 days after exposure, with a high fever often accompanied by a cough; red, watery eyes; and a runny nose. A red rash follows a few days later, spreading from the face and upper neck to the rest of the body.
“Some people think of measles as just a little rash and fever that clear up in a few days,” the CDC wrote on its website. “But measles can cause serious health complications, especially in children younger than 5 years old.”
About 1 in 5 unvaccinated people who contract measles require hospitalization due to complications such as pneumonia. Other potential complications include ear infections that can lead to hearing loss, encephalitis or brain swelling, and, in severe cases, death. Pregnant people who contract measles face an increased risk of miscarriage, stillbirth and low birth weight.
With cases rising in the U.S., including an expanding outbreak in Texas and New Mexico, the DOH issued a medical advisory to health care providers on March 11. The advisory emphasizes identifying and reporting cases and ensuring that all patients, especially those planning international travel, are up to date on their MMR vaccinations.
The DOH also reminds residents that if they suspect they have measles, they should call ahead before visiting a clinic to prevent further spread.
Health officials continue to stress the importance of vaccination.
The CDC states that the best way to protect against measles “is with the measles, mumps, and rubella (MMR) vaccine. MMR is safe and effective.” Two doses of the MMR vaccine are about 97% effective at preventing measles, while a single dose is about 93% effective. The vaccine not only protects individuals, but also helps prevent communitywide outbreaks.
Measles was once eliminated in the United States, but low vaccination rates have allowed the virus to return. Every year, cases are brought into the country by unvaccinated travelers who contract measles abroad.
The DOH urges all Hawaii residents, particularly parents, to ensure their children are fully immunized.
“High vaccination rates not only protect vaccinated individuals but also safeguard the broader community,” the department said in a release.
