Measles Cases Rising in California
This year, California has reported more measles cases than in all of 2024, which is concerning given the large national outbreak of this highly contagious disease. It’s an alarming shift; for many Americans, measles had almost become a forgotten health issue.
“Measles is completely preventable,” said Dr. Elizabeth Hudson, the regional chief of infectious diseases at Kaiser Permanente Southern California.
California’s uptick in measles cases is notable, yet it doesn’t compare to the significant outbreak that started in Texas and spread to neighboring states. Texas alone has reported around 750 cases, whereas neighboring New Mexico has seen 81, Kansas 80, North Dakota 28, and Montana 23. Michigan has logged 15 cases, while Ohio and Illinois have seen 10 each, and Arkansas and Indiana have reported eight.
Authorities indicate that the majority of the measles cases are among individuals who haven’t been vaccinated or whose vaccination status is unclear. The MMR vaccine, which also protects against mumps and rubella, has faced skepticism from anti-vaccine groups. Ironically, some of these individuals are now influencing U.S. policy on childhood immunizations.
According to the state Department of Public Health, California has reported 17 cases this year, up from just 15 last year. Doctors are now more alert, realizing that many haven’t encountered a measles case in years due to its rarity.
People might be surprised at how easily measles spreads and the severity of its symptoms. “This isn’t just a mild childhood ailment,” Dr. Erica Pan, the director of the California Department of Public Health, noted during a briefing for doctors.
Measles has a death rate ranging from one in 500 to one in 1,000 cases. Federal data shows that over 145 individuals have been hospitalized with measles this year, many requiring intensive care. “It can lead to very severe complications,” Pan cautioned, “often resulting in a serious pneumonia.”
Measles is among the most contagious viruses. A person can contract it simply by being in the same room as an infected individual, even up to two hours after they have left, as noted by the CDC. Most cases this year are linked to outbreaks in close-knit communities with low vaccination rates, particularly certain Mennonite communities that have experienced outbreaks starting last fall in Ontario, Canada, and spreading to Texas and New Mexico.
Interestingly, the CDC reports that about 95% of measles cases this year in the U.S. occurred in unvaccinated individuals or those with an unknown vaccination status. A significant portion, around 29%, of these cases were in children under five, and an additional 37% occurred in those aged 5 to 19.
In total, there have been 1,227 confirmed measles cases in the U.S. this year, a figure already approaching the highest totals in decades. The last time the numbers were this high was in 2019, with 1,274 cases reported, and the overall highest was 2,126 cases in 1992.
“These numbers could be an undercount,” Pan said, emphasizing that many individuals affected are hesitant to seek testing. This year has also seen three reported measles-related deaths, including two unvaccinated children in Texas. There was also an unvaccinated adult in New Mexico who did not seek medical care before passing away.
In Canada, there have been over 3,300 confirmed and suspected measles cases this year. Tragically, a premature infant in Ontario died after being infected with measles, with the mother being unvaccinated.
California is currently not seeing an active outbreak, which is a relief. Most measles cases in the state this year have involved travelers returning from overseas. Thankfully, California boasts a relatively high vaccination rate among kindergartners, with 96.2% being vaccinated, which, while slightly down from last year, remains above the levels prior to a significant outbreak in 2014-15.
To prevent further outbreaks, health experts aim for a 95% vaccination rate. However, some California counties fall short, with San Diego County at 94.8% and San Bernardino County at 93.5%.
Vulnerable situations exist where unvaccinated individuals may congregate, such as homeschooling groups or doctor’s offices. Past outbreaks have shown just how quickly measles can spread in these environments.
In 2024, Los Angeles County recorded four measles cases, but most were related to international travel or domestic areas where outbreaks are occurring. The local health department is advising that anyone potentially exposed should monitor for symptoms, which include fever, rash, and cough, and to reach out to healthcare providers beforehand to avoid exposing others.
Overall, health officials stress the importance of vaccination as the primary means of protection against measles, underscoring its safety record and effectiveness.
