Barely more than a week into the new year, the California Department of Public Health confirmed its first measles case of 2026.
The diagnosis came from San Mateo County, where an unvaccinated adult likely contracted the virus from recent international travel, according to Preston Merchant, a San Mateo County Health spokesperson.
Measles is one of the most infectious viruses in the world, and can remain in the air for two hours after an infected person leaves, according to the CDPH. Although the U.S. announced it had eliminated measles in 2000, meaning there had been no reported infections of the disease in 12 months, measles have since returned.
Last year, the U.S. reported about 2,000 cases, the highest reported count since 1992, according to CDC data.
“Right now, our best strategy to avoid spread is contact tracing, so reaching out to everybody that came in contact with this person,” Merchant said. “So far, they have no reported symptoms. We’re assuming that this is the first [California] measles case of the year.”
San Mateo County also reported an unvaccinated child’s death from influenza this week.
Across the country, measles outbreaks are spreading. Today, the South Carolina State Department of Public Health confirmed the state’s outbreak had reached 310 cases. The number has been steadily rising since an initial infection in July spread across the state and is now reported to be connected with infections in North Carolina and Washington.
Similarly to San Mateo’s case, the first reported infection in South Carolina came from an unvaccinated person who was exposed to measles while traveling internationally.
At the border of Utah and Arizona, a separate measles outbreak has reached 390 cases, stemming from schools and pediatric centers, according to the Utah Department of Health and Human Services.
Canada, another long-standing “measles-free” nation, lost ground in its battle with measles in November. The Public Health Agency of Canada announced that the nation is battling a “large, multi-jurisdictional” measles outbreak that began in October 2024.
If American measles cases follow last year’s pattern, the United States is facing losing its measles elimination status next.
For a country to lose measles-free status, reported outbreaks must be of the same locally spread strain, as was the case in Canada. As many cases in the United States were initially connected to international travel, the U.S. has been able to hold on to the status. However, as outbreaks with American-origin cases continue, this pattern could lead the Pan American Health Organization to change the country’s status.
In the first year of the Trump administration, officials led by Health Secretary Robert F. Kennedy Jr. have promoted lowering vaccine mandates and reducing funding for health research.
In December, Trump’s presidential memorandum led to this week’s reduced recommended childhood vaccines; in June, Kennedy fired an entire CDC vaccine advisory committee, replacing members with multiple vaccine skeptics.
Experts are concerned that recent debates over vaccine mandates in the White House will shake the public’s confidence in the effectiveness of vaccines.
“Viruses and bacteria that were under control are being set free on our most vulnerable,” Dr. James Alwine, a virologist and member of the nonprofit advocacy group Defend Public Health, said to The Times.
According to the CDPH, the measles vaccine provides 97% protection against measles in two doses.
Common symptoms of measles include cough, runny nose, pink eye and rash. The virus is spread through breathing, coughing or talking, according to the CDPH.
Measles often leads to hospitalization and, for some, can be fatal.
