Bolinas became the first community in the nation to test negative for Covid-19, researchers announced last week. Not a single infection was detected out of 1,845 tests performed on Bolinas residents, essential workers and West Marin first responders during the week of April 20.
The number of people tested accounts for more than 90 percent of the town’s population, so it is unlikely that more than a handful of people are infected, said Dr. Bryan Greenhouse, an infectious disease expert at the University of California, San Francisco.
“Even though it doesn’t necessarily mean you can rip off your mask and start partying, you should feel much more safe and comfortable in your environment,” Dr. Greenhouse said in a Zoom meeting on Saturday. “If people have had this fear that many of us have had, of ‘Am I going to be infected? Are these practices enough?,’ you can be a bit more reassured that yes, at least for this town at this time, those precautions seem to be working quite well.”
It’s a moment of cautious celebration for the town, whose residents organized to make a task that has challenged governments look easy. The public face of the project, venture capitalist Jyri Engestrom, said he has fielded inquiries from places as far away as Uganda, Finland and New Zealand as well as some 30 communities in California that are asking how to implement community testing. Mr. Engestrom and his associates will release a playbook for community self-testing in coming weeks.
Researchers are trying to get each participant to complete an online survey before releasing demographic data, and the team is confident their outreach was successful in bringing in harder-to-reach people. Testers spent the last day visiting those unable to leave their homes, and the drive-through site was accessible to anyone.
“One day, in one lane, we had a car, a man on a bicycle, a young man on a skateboard and a woman in her tennis shoes all lined up in a row, and I thought, ‘All right, we’ve taken down those barriers,’” Dr. Aenor Sawyer said.
The project was anchored by an initial $100,000 donation and over 150 smaller contributions, and hundreds of volunteers lent countless hours. “It was incredible to see all of the community volunteers that stepped up in all facets of getting the project completed,” fire chief George Krakauer said. “I feel personally honored to have been a part of the project.”
The results will inform Dr. Matt Willis, the public health officer for Marin County, as he makes decisions around the county’s Covid-19 response. He visited the site and applied some of the operational details to a new drive-through testing site the county established in the Canal neighborhood of San Rafael last week.
The results also reassured him that the early shelter order was a critical step, and that relatively isolated communities can avoid widespread infection despite their proximity to infection hotspots.
The testing in Bolinas was followed by U.C.S.F. testing of residents and workers in the densely populated Mission District of San Francisco. There, 62 of 2,959 participants tested positive, a 2.1 percent infection rate.
“It wasn’t that Bolinas was not at risk, it was that you did the right thing to prevent disease in the context of risk,” Dr. Willis said.
His biggest concern is that the results will give people a false sense of security. The fact that not many people are infected means that more people are susceptible, and essential workers will continue to travel into town. People should continue to practice physical distancing and adhere to the shelter order.
“We may have dodged one bullet, but there is a lot of marksmen still out there shooting, and there are many more bullets,” he said.
Because transmission is low or nonexistent, a second round of testing is not being planned.
Results for the antibody tests, which detect past infection, are expected later this month.