An out-of-state adult who tested positive for measles visited Sharp Memorial Hospital’s emergency room on Frost Street on March 11th.

SAN DIEGO — An adult who tested positive for measles visited Sharp Memorial Hospital’s emergency room on Frost Street in San Diego’s Birdland neighborhood on March 11, prompting county health officials to urge anyone present that day to take precautions.

The unvaccinated woman from out of state visited the ER on Wednesday with cold-like symptoms, according to Dr. Mark Beatty. Four days later, she developed a rash and tested positive for measles. County Public Health is working quickly to notify anyone who may have been exposed.

Dr. Beatty emphasized the severity of measles, saying, “It can be a serious, even life‑threatening infection, especially for children,” and stressed that, “This is the most infectious disease there is.”

Anyone present in the ER between 11 a.m. and 4:30 p.m. that day should contact County Public Health at 866-358-2966, unless already notified. County officials have identified and reached out to most individuals who were present during that window. “We have the names of every person who was in that ER during that period and have been reaching out. We’ve almost reached them all, but it’s always good to double‑check. You may have been a patient, but you might have come with someone else,” said Dr. Beatty.

Those without symptoms and with proof of vaccination face no restrictions. Others may need to quarantine for 14 days. County Public Health can test those without proof of vaccination. “If they have documentation they’ve been vaccinated, they don’t have to quarantine,” said Dr. Beatty.

Residents should watch for fever, cough, runny nose and red eyes, with a red rash typically appearing one to four days later. Measles can develop up to 21 days after exposure. “Most people develop symptoms by two weeks, so we’ll be on high alert for at least double the incubation period to make sure we’re in the clear,” said Dr. Beatty.

No measles cases have been reported in San Diego County this year. The county documented one case linked to international travel in the previous year. Statewide, 29 confirmed cases have been reported as of March 16. Nationally, 1,362 cases have been confirmed as of March 12.

Health officials attribute the resurgence of a virus once considered eliminated in the U.S. to declining vaccination rates. “Unfortunately, even in San Diego, vaccination rates among school‑age kids have been dropping over the past couple of years,” said Dr. Beatty.

With spring break travel underway, officials urge everyone to ensure they are vaccinated. “The lower those rates get, the greater the risk of a local outbreak like we’re seeing in other parts of the state,” said Dr. Beatty.