The United States is on pace to eclipse last year’s surge in measles cases, and public health experts say the virus is becoming increasingly difficult to contain as outbreaks spread beyond isolated pockets of unvaccinated residents into broader communities.
The trend has already reached the nation’s capital. Last month, D.C. health officials investigated a confirmed measles case after an infected District resident visited multiple public locations while contagious, including Washington Dulles International Airport and Mary’s Center’s Adams Morgan clinic, prompting an effort to identify anyone who may have been exposed.
As of this week, the Centers for Disease Control and Prevention had confirmed 2,170 measles cases this year in 41 jurisdictions, including the District of Columbia. The total already approaches the 2,289 cases reported during all of 2025. The CDC said 93% of this year’s infections have been associated with outbreaks, and 93% occurred in people who were unvaccinated or whose vaccination status was unknown.
Health officials and infectious disease specialists say the growing difficulty in extinguishing outbreaks stems from several factors. Declining childhood vaccination rates have created larger groups of susceptible people, international travel continues to reintroduce the virus into the United States, and local health departments face the labor-intensive task of tracing contacts and isolating exposed individuals before the virus spreads further.
Various reports suggest that many younger physicians have limited experience diagnosing measles because the disease had become so uncommon for decades.
The virus is among the most contagious infectious diseases known. According to D.C. Health, it spreads through the air when an infected person coughs, sneezes or breathes, and can remain in the air for up to two hours after that person leaves an area. About nine out of 10 people who are not immune will become infected if exposed.
District health officials said anyone who was present at the identified exposure sites during the specified times and is not immune should contact a healthcare provider or DC Health.
“People who develop symptoms should stay home, call ahead before seeking medical care, and avoid exposing others,” DC Health officials wrote on its website. “Those who have received two doses of a measles-containing vaccine or were born before 1957 are considered protected. Individuals who have received only one dose are encouraged to speak with their health care provider about completing the recommended two-dose series.”
The District enters the current outbreak with vaccination rates that compare favorably with many parts of the country, although public health officials say there is still room for improvement.
The International Vaccine Access Center at Johns Hopkins University reported that Washington’s measles, mumps and rubella vaccination coverage among kindergarten students improved during the 2024-25 school year and remains similar to the national average. The District also has a lower non-medical exemption rate than the national median. Even so, the report found MMR coverage remains below the Healthy People 2030 target of 95%, the level public health officials associate with strong community protection.
Nationally, CDC data show kindergarten MMR vaccination coverage has slipped from 95.2% during the 2019-20 school year to 92.5% in 2024-25, leaving an estimated 286,000 kindergartners without the level of protection needed to help prevent outbreaks from spreading.
Former CDC Chief Medical Officer Dr. Debra Houry said misinformation has complicated efforts to control the disease.
“We had children being hospitalized, we had children dying from measles,” Houry told CBS News. “We needed people to respond during a measles outbreak and get vaccinated if they weren’t.”
