BERKELEY, Calif. (BCN) - Berkeley health officials say a resident infected with the highly contagious measles virus visited the Berkeley Bowl Market on Oregon Street from 3 p.m. to 5 p.m. last Tuesday May seventh.
The infected adult is Alameda County's first confirmed measles case of the year.
Dr. Lisa Hernandez, the City of Berkeley Public Health officer says it wasn't until last Saturday that the person's physician realized the risk.
"That individual physician was very astute and she called me as soon as possible," said Dr. Hernandez.
Dr. Hernandez says the Berkeley Bowl store is safe now because the virus can only live outside the body for a few hours.
The store posted warning signs for customers, however, because Dr. Hernandez says it might take as long as three weeks before a person sees any symptoms surface.
"For someone who was potentially exposed at Berkeley Bowl, they should be checking for symptoms up to May 28th," said Dr. Hernandez.
Measles is a highly contagious virus that is transmitted through the air by coughing or sneezing. It infects about 90% of people who have not been vaccinated and inhale it.
"You're contagious before you even know that you have measles and the first signs of measles are common cold or flu symptoms," said Dr. Hernandez.
Measles symptoms include a cough, runny nose, red eyes, and high fever. Then, four days later, it's typically followed by the signature red rash that spreads from the head down the body.
Many older adults are immune because they had measles as children before the vaccine became common in 1963.
"I had measles when I was little," said Carol Salvin of Oakland, "Everybody did, seems like."
Doctors say everyone should check their vaccine records and get immunized if they haven't already.
"After 2 doses of the vaccine, you're 97% protected," said Dr. Hernandez.
Many Berkeley Bowl customers say they will be vigilant, but most say they were vaccinated and aren't too worried about measles exposure.
"I'm concerned for people who aren't vaccinated but I think because we are I'm not that worried about it," said Jessica Agus, who was there with her young daughter.
City of Berkeley Public Health staff are interviewing everyone who had extended contact with the infected resident. The city would not say whether the individual had been vaccinated, how the person got the virus or what other locations the person might have visited.
Anyone who might think they have measles symptoms should alert the doctor or medical facility about possible exposure before arriving so they can take steps to protect other patients and visitors.
The Centers for Disease Control said measles had been eliminated in the United States in the year 2000. Since then, however, there have been outbreaks, often from unvaccinated people who have picked up the disease from other countries.
So far in 2019, 23 states have confirmed cases of measles with a total of 839 infected people.
The Berkeley resident is the tenth confirmed measles case in the Bay Area so far this year.