Measles-carrying Caltrain commuter sparks public health warning

Santa Clara County resident traveled up and down the Peninsula, visited San Francisco

For the fourth time in less than two weeks, public health officials are warning the public of possible exposure to measles — this time involving a Santa Clara County resident who traveled to San Francisco via Caltrain, the San Francisco Department of Public Health said Tuesday.

The commuter, an adult contagious with measles while visiting San Francisco last week, was not hospitalized and is recovering at home, according to the San Francisco agency, which is working with the Santa Clara County Public Health Department to assist the measles-carrying individual and make sure residents and visitors from both counties are safe from the disease.

The Santa Clara County resident traveled on Caltrain during the morning commute on April 1 and evening rush hour on April 3.

On April 1, the individual sat in the first car (car 116) of northbound Caltrain train No. 319, where travelers were exposed to the virus sometime between 6:56-8:13 a.m. The train was then designated as southbound Caltrain train No. 232, where any travelers who boarded the same car (car 116) were exposed from roughly 8:45-9:15 a.m.

The individual stayed in San Francisco on April 2, spending a majority of the day at the Phillip Burton Federal Building in the city's Civic Center from 8 a.m. to 7:30 p.m. and visiting three eateries: Johnny Doughnuts from 8-9:30 a.m., Hayes Valley Bakeworks from 8-10 a.m. and Double Decker Restaurant from 6:30-8 p.m.

On the afternoon of April 3, the traveler visited the San Francisco Caltrain station at 700 Fourth St., where the public may have been exposed to measles sometime between 3-4:30 p.m.

The individual took southbound Caltrain train No. 258 that departed at 3:34 p.m. sitting in the second car from the back (car 3861), where exposure to measles ranged from 3:34-5:10 p.m. The train then transitioned to northbound service, Caltrain No. 279, where the exposure time in car 3861 ranged from 5:32-6:15 p.m.

While there is no outbreak and the public's risk of contracting the measles is low, San Francisco public health officials emphasized that people who aren't immune and visited the same places as the measles-carrying resident may develop the disease. Santa Clara County public health officials added that the measles virus can linger in the air a short time after the infected person has left a place.

Any child who hasn't received the measles vaccine, any adult born in 1957 or later without the vaccine or individuals with "severely weakened immune systems" should heed the warning, according to the public health department.

Most people are immune to the disease if they were given the measles vaccine as children, public health officials said.

Symptoms of the measles can appear seven to 21 days after exposure. They include fever, cough, runny nose and red eyes, which can lead to a red rash beginning on the head or face, according to public health officials. Anyone who experiences these conditions is advised to immediately contact their doctor.

The case doesn't appear to be related to others across the state. Public health agencies across the Bay Area have issued warnings of possible measles exposure since late March. In Santa Clara County, an international traveler visited 20 establishments, including six in the Palo Alto area, from March 16 through March 23. A second case was made public on March 29 involving a resident who contracted measles while traveling abroad. The two cases don't seem to be connected.

In Alameda County, patrons of Sauced BBQ & Spirits in Livermore may have been exposed to measles by a customer on March 23.

More information on the measles can be found at and

Editor's note: This story has been updated to clarify which Caltrain trains the individual with measles traveled and trains where passengers were exposed to the virus.

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2 people like this
Posted by Len
a resident of North Whisman
on Apr 10, 2019 at 2:34 pm

The person went to SF on the train, stayed there for 32 minutes and then came back in the same train car. Why would you go to SF and not even get off the train? Does measles cause behavior & judgement problems?

Like this comment
Posted by Measly
a resident of Willowgate
on Apr 10, 2019 at 2:54 pm

I had measles as a child, both the 3-day and 7-day varieties. Am I immune or do I need a vaccine?

6 people like this
Posted by Usual suspects
a resident of Old Mountain View
on Apr 10, 2019 at 3:14 pm

Why did he get off the train and get back on? Lots of reasons. Sick, had an emergency, had to meet someone briefly, a store was closed,

Why do people post such dumb comments ?

4 people like this
Posted by Kev
a resident of Blossom Valley
on Apr 10, 2019 at 3:20 pm


If you're concerned, you can ask your doctor to check your "antibody titer" which is used as a metric of how strongly your immune system will fight off the disease if you're exposed. The results will help indicate whether you would benefit from a booster vaccine.

In fact, anyone who hasn't received a vaccine in the relatively recent past may benefit from this same screen, just to know how well the immunity is holding up. Some folks don't form antibodies as readily as others and need more boosters than average to get full protection. Others (rarely) have immune systems that refuse to form lasting antibodies at all, making the person vulnerable to infection regardless of immunization. These folks would need to treat exposures to the disease as if they never received the vaccine in the first place, and that can be very important information to have.

4 people like this
Posted by Not a doctor but
a resident of Old Mountain View
on Apr 10, 2019 at 3:36 pm

The exposure period lasts longer that the actual time the person is in a particular location. So he may have been on the train for a short time, but the exposure was long enough for the train to reach the end of the line and start going back. I kind of don't think that he rode the train to SF and then almost immediately got on a train going back, as stated by the article. Anyone else want to pipe in?

2 people like this
Posted by Nature lover
a resident of Old Mountain View
on Apr 10, 2019 at 10:00 pm

@ Measly- If you've had the measles you're immune for life. You don't need a vaccine. That's one of the wonderful advantages of getting the measles as a child- it's a benign disease in childhood but dangerous for adults and babies and as an immune adult woman you pass the (temporary) immunity on to your baby. Voila- an active case of childhood measles protects the vulnerable. Mother Nature is amazing isn't she?

11 people like this
Posted by Not benign
a resident of Old Mountain View
on Apr 10, 2019 at 11:03 pm

Measles is not benign in childhood. Kids under five are most likely to have severe complications like pneumonia or encephalitis. 1-2 kids out of 1000 who get the measles will die. Getting measles isn’t an ironclad guarantee that you’re immune for life. You’re far less likely to get it if exposed again, but there’s still a chance.

3 people like this
Posted by Alan
a resident of Cuesta Park
on Apr 11, 2019 at 10:14 am

If you look at the full report of locations visited you can see that this person spent the day in SF:
Web Link

The problem is that measles is very contagious so anyone who traveled back in the same car was probably exposed. In fact, anyone who traveled in that car anytime afterwards for a day or so was probably exposed!

3 people like this
Posted by Nature lover
a resident of Old Mountain View
on Apr 11, 2019 at 2:25 pm

@ Not Benign - I don't know where you're getting your stats (if it's the CDC they have an administrative revolving door between themselves and Big Pharma so they regularly disseminate propaganda in efforts to preserve big pharma vaccine revenue) but you couldn't be further from the truth. Death from measles in healthy, first world kids is extremely rare (NOWHERE near 1-2/1000!) and kids are more likely to get encephalitis from the vaccine than from the measles (check out the stats from the vaccine injury court). Pneumonia is possible (but also uncommon) as a complication of the measles but it's also possible as a complication of the common cold and many other common viruses. I grew up in the pre-vaccine era and I and every child I knew had the measles. You're sick for a week then back to school. Done. And then you don't have to worry about getting it as an adult and you protect your babies. Now adults and babies are at risk.

Sorry, but further commenting on this topic has been closed.

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