SAN FRANCISCO (CBS SF) — Officials with the San Francisco Department of Public Health on Tuesday issued a notification regarding possible measles exposure from a contagious person who spent time in the city last week.

ALSO READ: Amid Measles Outbreaks, California May Toughen Immunization Rules

READ MORE: FDA Clears Johnson & Johnson's Single-Dose COVID-19 Vaccine for Immediate Use

While officials emphasized that there was a low risk to the public and is no outbreak, they noted that people without immunity could possibly develop measles if exposed at one of several locations that the contagious individual visited between April 1 and April 3.

Below is a list of the different places the contagious person might have exposed people to measles.

Monday, April 1

6.56 a.m. – 8:13 a.m. — Caltrain train 319 northbound. First car of train (car 116)
8:45 a.m. – 9:15 a.m. — Caltrain train 232 southbound. Last car of train (car 116)
8 a.m. – 10 a.m. — Hayes Valley Bakeworks at 525 Golden Gate Avenue
9:15 a.m. – 9:45 a.m. — SF Muni Bus #47
8:30 a.m. – 7 p.m. — Federal Building at 450 Golden Gate Avenue

Tuesday, April 2

8 a.m. – 7:30 p.m. — Federal Building at 450 Golden Gate Avenue
8 a.m. – 9:30 a.m. — Johnny Doughnuts at 392 Fulton Street
8 a.m. – 10 a.m. — Hayes Valley Bakeworks at 525 Golden Gate Avenue
6:30 p.m. – 8 p.m. — Double Decker Restaurant at 465 Grove Street

Wednesday, April 3

8 a.m. – 10 a.m. — Hayes Valley Bakeworks at 525 Golden Gate Avenue
8:30 a.m. – 3:30 p.m. — Federal Building at 450 Golden Gate Avenue
3 p.m. – 4:30 p.m. — Caltrain station, 700 4th Street
3:34 p.m. – 5:10 p.m. — Caltrain train 258 southbound. Second car from the back (car 3861)
5:32 p.m. – 6:15 p.m. — Caltrain train 279 northbound. Second car from the front (car 3861)

San Francisco benefits from high rates of vaccination against measles, with most residents having received the measles vaccine (“MMR”) as children to gain immunity. However, unvaccinated children, unvaccinated adults born in 1957 or later and those with severely weakened immune systems are advised to review the list of above locations.

READ MORE: Sacramento Doctor Appears in Virtual Traffic Court While Performing Surgery

“It can sort of hang in the air for up to an hour after someone has been in the space,” Dr. Julie Stoltey of the San Francisco Department of Public Health told KPIX 5. “It can cause pneumonia in up to 1 in 20 children. More rarely, people can develop encephalitis as a complication of measles, which is a brain infection and it can be deadly.”

Anyone susceptible to measles who was present at any of the specific sites at the times listed should monitor their health for symptoms of illness. Symptoms can develop between 7 and 21 days after the date of exposure. Common symptoms of measles include fever, cough, runny nose, and red eyes, followed by a red rash that starts on the head or face.

This reported case does not have any known link to any other confirmed cases of the measles in California, health officials said. They said it was not known how the person — a Santa Clara County resident — was infected. The public health departments in San Francisco and Santa Clara are working together to ensure the safety of the infected person and residents and visitors of both counties.

Officials said the infected individual was not hospitalized and has been recovering at home. Further information will not be released to protect the person’s medical privacy.

Regular Caltrain commuters KPIX 5 spoke with expressed their concerns about the measles exposure on the train.

“That’s not right. A lot of people take the train. I take the train everyday and you never know who’s sitting next to you,” said Caltrain rider Art Cristerna. “People coughing, people sneezing and you assume it’s a cold and it’s not a big deal.”

“It’s just shocking that other people still aren’t vaccinated and taking public transportation. I guess taking Ubers isn’t too much different though,” said Caltrain commuter Elissa Flandro.

News of the exposure comes as communities in the Bay Area and across the country grapple with measles outbreaks. Last week, officials at the University of California, Davis Medical Center in Sacramento warned 200 people that they may have been exposed to measles in March.

Last month, Santa Clara County health officials issued three separate alerts on potential measles exposures, including from a tourist who possibly exposed thousands of people by visiting multiple landmarks, restaurants and malls.

MORE NEWS: San Francisco Police Return Stolen Puppy to Richmond Family

Also last month, Alameda County health officials warned patrons of a barbecue restaurant in Livermore of being possibly exposed to the disease.