Measles

Measles is a very contagious rash illness caused by a virus. Common complications from measles include ear infections and diarrhea. Measles can cause severe illness and serious health complications, especially in children younger than age 5 years, adults older than age 20 years, pregnant women, and people with immune system problems. These complications include:

• Pneumonia
• Brain swelling, which could lead to permanent brain damage
• Death
• Subacute sclerosing panencephalitis (SSPE): a very rare progressive, disabling, and deadly brain disorder that results from a measles virus infection acquired earlier in life. SSPE generally develops 7 to 10 years after a person has measles, even though the persons seems to have fully recovered from the illness.

Current Events

Measles in the United States

Measles is a highly contagious viral disease that can cause severe health complications, especially in young children, pregnant women, and individuals with weakened immune systems. While the United States achieved near-elimination of measles in the year 2000 through widespread vaccination efforts, recent years have seen an increase in measles cases, primarily due to lapses in vaccination coverage and international travel.

In recent years, there have been cases of measles across the United States. These cases have been linked to lower vaccination rates in certain communities, as well as travel to regions where measles is still common. According to the Centers for Disease Control and Prevention (CDC), most of the measles cases reported in the U.S. are among unvaccinated individuals.

In 2024, the U.S. reported 285 measles cases across 33 jurisdictions, with 16 outbreaks affecting 69% of cases. The majority of cases were in children under 5 (42%) and unvaccinated or unknown vaccination status (89%). Hospitalizations occurred in 40% of cases, with the highest rates among children under 5 (52%) and adults 20+ (39%).

As of November 25, 2025, the U.S. reported 1,798 measles cases, with 92% of cases among unvaccinated or unknown vaccination status individuals. The age distribution was in children under 5 years (26%), between 5-19 years (40%), 20+ years (33%), and age unknown (12 cases, 1%).

Hospitalizations occurred in 12% of cases, with 21% of children under 5 years hospitalized, between 5-19 years (6%), 20+ years (11%), and age unknown (0%). There were 3 deaths associated with measles: two confirmed cases were both from Texas in school-aged children and who were not vaccinated and had no known underlying conditions, and one case in New Mexico with an unvaccinated individual who did not seek medical care before passing. For more information, visit Texas Health and Human Services and New Mexico Health’s webpage for their respective cases. You can also visit CDC’s Newsrooms for current events on measles in the United States.

Measles in Hawaii 2025

Maui

The first-ever wastewater detection of the virus for Maui County. The virus detected is the naturally occurring type that spreads person to person, not the weakened form used in vaccines. No suspected measles cases have been identified on Maui.

The DOH issued a medical advisory to healthcare providers statewide with information on how to test for measles and current vaccination recommendations.

Subsequent samples are currently being tested. Each week, municipal wastewater samples across Maui and other locations across the Hawaiian Islands are routinely sent for testing to identify infectious diseases including measles that maybe present in the community.

Kaua’i

The Department of Health was notified on the result on October 20, 2025, of the sample collected on September 24, 2025, at a site in East Kaua’i County. The presence of measles virus in wastewater does not confirm a clinical case or community spread. Instead, it serves as a reliable indicator to be alert for possible measles cases.

So far, no suspected measles cases in 2025 have been identified on Kaua’i as of November 28, 2025. No subsequent wastewater detections have been reported on Kaua’i since September 24, 2025.

Oahu

As of April 22, 2025, two laboratory confirmed cases of measles have been identified, one in a school-age child and a second in adult member of the child’s family. Both individuals had returned from international travel just prior to diagnosis and recovered at home.

DOH issued news releases to inform the public of potential exposure to measles at various locations on Oahu.

HDOH investigated the case, worked to identify those who might have been exposed and steps for preventing the spread of disease by reaching out directly to individuals who had known contact with the confirmed and suspected case. As of April 14, 2025, HDOH had identified 92 individuals who were exposed to one or both cases of measles and had successfully contacted 88 of them. Most of these individuals have either been vaccinated or have other proof of immunity. Those without evidence of immunity have been advised to isolate at home and are being actively monitored.

At this time, Oahu is the only island in the state with confirmed cases in 2025.

Why is this a public health concern in Hawaii?

Measles is highly contagious and can lead to severe complications, such as pneumonia, brain inflammation, and death, especially in young children and those with weakened immune systems. It spreads quickly, even before symptoms appear, and outbreaks can occur in communities with low vaccination rates.

If one person has it, up to 9 out of 10 people nearby will become infected if they are not protected. It spreads through direct contact with an infected person or through the air when an infected person coughs or sneezes. An infected person can spread measles to others from four days before developing the rash through four days afterward. The virus can remain in the air for up to two hours after an infected person has left the room.

While preventable through vaccination, measles remains a serious risk, highlighting the importance of maintaining high vaccination coverage to protect vulnerable populations and prevent widespread outbreaks.