A recent measles scare involving five Tuolumne County residents has public health officials concerned about the potential for an outbreak in the county.

Dr. Bob Bernstein, the county health officer, addressed the county Board of Supervisors at a public meeting on Tuesday about the five people who were exposed to an airline attendant infected with the vaccine-preventable disease while on a domestic U.S. flight.

Bernstein, who was limited to three minutes to speak during time set aside for public comments at the start of the meeting, said that all five agreed to self-quarantine and wear surgical masks while being tested for measles immunity and infection.

“All five were determined to have been protected by immunization and were not infected,” he said. “Thus, a potential outbreak of measles in Tuolumne County was averted — for now.”

Bernstein declined to provide specific details about the people who were exposed and dates it occurred to protect their identities and prevent them from being subject to scrutiny.

A total of 880 cases of measles have been confirmed in 24 U.S. states between Jan. 1 and May 17, which the Centers for Disease Control and Prevention say is the worst outbreak in the country since 1994.

About 74 percent of the cases were reported in children under 18, 13 percent in infants under 12 months, and 88 percent were associated with “close-knit communities” or other settings, such as schools, Bernstein said.

Though there have been no confirmed cases of measles in Tuolumne County during the nationwide outbreak, one unvaccinated school-age girl in neighboring Calaveras County was diagnosed with the disease in April after traveling overseas.

Of particular concern for Bernstein is the fact that the county generally lags behind the 90 to 95 percent vaccination rate needed to achieve “herd immunity,” meaning the level of coverage needed to protect the entire population.

Data for 2017-18 from the California Department of Public Health showed that 536 of 620 kindergartners, about 87 percent, in the county had all of the state-required vaccinations to enter school.

The state average was 95 percent for the same period. State law requires students entering California schools to be vaccinated, though there are medical exemptions.

The same data also showed that the number of enrolled kindergartners in Tuolumne County who had received the measles vaccine was 565 of 620, or about 91 percent.

Information about immunization provided by Bernstein stated that large outbreaks can occur when vaccinations are not equally distributed and clustered in certain groups, such as schools in the county, even if the rate for the overall population is high.

Bernstein said measles is no at “harmless childhood disease” in his experience practicing medicine in the United States and overseas in Asia and Africa.

“It’s a highly contagious, potentially life threatening disease,” he said.

According to the CDC, symptoms of measles typically appear within two weeks of contracting the disease and can include high fever, cough, runny nose, and red, watery eyes. A rash breaks out after another three to five days.

Complications from measles can include pneumonia, swelling in the brain that can lead to deafness or intellectual disabilities in children, and death, the CDC says.

The CDC says about one out of four people who get measles will become hospitalized, one out of every 20 children gets pneumonia, and one or two of every 1,000 children will get swelling in the brain or die from neurologic complications.

“We have the ability to protect our children and the community, especially those who cannot get vaccinated because they’re too young or have weakened immune systems,” Bernstein said.

Contact Alex MacLean at amaclean@uniondemocrat.com or (209) 588-4530.