Napa, California – Another case of measles has been reported in the Bay Area as outbreaks of the highly contagious viral disease spread across the country.
Napa County health officials said this is the first confirmed case in the county since 2012.
what we know
The patient was confirmed to be a child who had not been vaccinated against measles. Health officials said the child became ill after traveling to South Carolina, which is dealing with a large outbreak.
From a numerical perspective
As of Wednesday, South Carolina reported 646 cases.
In California, the state Department of Health website says there have been two cases so far in 2026. It’s unclear whether that includes cases in Napa County, according to the latest data update on Monday.
In 2025, a total of 25 cases of measles were reported in three Bay Area counties, including one in the East Bay last month.
Contra Costa County health officials are reminding the public of possible exposure in the days leading up to Christmas at locations such as the store at Broadway Plaza Mall.
‘No public health threat’ to Napa County
Napa County officials said, “At this time, there is no public health threat to the general public.”
The county said it is working with the California Department of Public Health to track people who may have been exposed and ensure they are up to date on their MMR vaccinations.
Detected in waste water
Dig deeper
In Santa Clara County, public health officials announced Wednesday that the disease had been detected in wastewater samples.
Health officials detailed that the samples were collected from a Palo Alto sewer shed on Jan. 10, noting that the sewer shed contained waste from a small number of communities in northern Santa Clara County and San Mateo County.
The Santa Clara County Public Health Department stressed that the source was unknown and that samples tested over the next five days showed no further evidence in the water.
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“The investigation is ongoing and it is unknown at this time whether the measles detected in the wastewater is related to recent cases of measles among residents of other Bay Area counties,” the agency said.
Highly contagious
The respiratory illness is an airborne virus that spreads easily.
Health experts say the virus can linger in airspace or surfaces for up to two hours after an infected person leaves an area.
“Simply being in the same room with someone who has measles can lead to infection in someone who is not immune,” Napa County Public Health Officer Dr. Kristen Wu said in a news release.
The best line of defense, officials urge, is to get vaccinated.
“Napa County Public Health recommends that all unvaccinated individuals one year and older receive the measles vaccine to protect themselves and those around them,” the agency said.
record high
Last year, cases in the United States hit their highest levels in recent decades.
The Johns Hopkins University School of Public Health reported in July: “The number of reported measles cases in the United States has passed a milestone, and by 2025, the number of cases will reach the highest level since measles was declared eliminated in the United States in 2000 and the highest number of cases in more than three decades.”
It refers to the U.S. Measles Tracking System, Which, The latest data from the tracker shows there are 2,540 cases. This covers a period of approximately one year from January 1, 2025, to January 16, 2026.
Highly preventable
Measles is completely preventable.
“It is estimated that when 95% of a community is vaccinated, those people and others in the community are protected from measles,” Harvard Health Publishing wrote in an article published earlier this month.
The recent surge in cases can be attributed to a decline in childhood vaccinations.
“Nationally, measles vaccination rates among school-age children dropped from 95% in 2019 to 92% in 2023,” the publication said.
symptom
Symptoms of measles include a patchy rash that usually starts on the face and spreads down the body, as well as fever, cough, runny nose and red eyes.
Symptoms may appear 7 to 21 days after exposure.
A person is contagious from four days before the rash appears to four days after the rash appears, with the rash appearing as day 0.
The Centers for Disease Control and Prevention urges people who think they have measles to contact their health care provider immediately.
“Measles is more than just a little rash. Measles can be dangerous, especially for babies and young children,” the CDC says.
If unsure about vaccination status, experts recommend consulting your healthcare provider.
“The MMR vaccine is safe and highly effective and provides lifelong immunity after two doses,” Napa County health officials emphasized.
