There has yet to be much hard evidence of where people are contracting COVID-19 in San Francisco. And, despite staffing up with contact tracers, public health departments have yet to say much of anything definitive to guide the public other than "stay home."

San Francisco has 244 people working on contact tracing every time a new positive case of the coronavirus pops up in the city — but with that now happening about 100 times per day, or more, the task is obviously a huge one. And, as Heather Knight notes in her latest Chronicle column, "Many people who test positive for the virus in San Francisco aren’t sure how they got it, and the city’s contact tracing team often can’t help them figure it out."

The surge we're seeing in SF may not be quite as extreme as elsewhere in the state or country, but its timing may still be telling. A number of San Franciscans likely returned to work in offices in October as cases were declining — and others likely began getting looser about dinner parties. Some blame has been put on Halloween parties — with younger people especially unable to resist the urge to gather indoors at costumed house parties. And we can't discount the fact that the surge started appearing in late October about three weeks after indoor dining began being allowed in the city at limited capacity.

Many pundits and experts, including several quoted by the Chronicle, blame indoor house parties and other social gatherings for the current surge locally — and that may be the case.

But a New York Times piece published today quotes epidemiologists as being far from certain what kinds of gatherings are driving the spread of the virus at the macro level. One figure cited, via contact tracing data in Colorado, suggests that out of 10,000 cases with decent tracing data, about 450 cases came out of bars, restaurants, casinos and bowling alleys, and just 81 came out of small social gatherings, while 4,000 were traced to correctional institutions, 3,300 were traced to colleges, and 2,400 were traced to nursing facilities.

Knight spoke to one restaurant server in San Francisco who recently tested COVID-positive, 24-year-old Becca Camping who works at the Michael Mina- and Ayesha Curry-owned International Smoke. She says she did no socializing and only left her apartment to go grocery shopping when she was not working, but during the latter part of the month of October, when the restaurant restarted indoor dining, she was working five dinner shifts a week. And she says that while she was masked, she was serving tables where people were often unmasked through their entire meals.

"You can do everything right and wear a mask and not go out, and you can still get it," Camping tells the Chronicle.

So far, none of Camping's coworkers have tested positive for the virus, and she remains isolated in her apartment with some unpleasant but non-severe symptoms.

San Francisco decided to pause indoor dining effective November 14, in the hope that this will help the city to once again flatten the curve — and it's possible that a move into the state's "Purple" tier this week will cause more businesses to be ordered closed, including indoor gyms and movie theaters.

The Chronicle notes that between October 21 and November 10, the city has been able to see a particular demographic shift in COVID-19 infections — with an increasing proportion of white people getting the disease. While the Mission and Bayview neighborhoods were the hardest hit through the last eight months, recent weeks have shown similar rates of infection between the Marina and the Tenderloin, and the percentage of infections among 18- to 30-year-olds has risen as well.

Chances are it's the combination of everyone's behaviors loosening, on top of rules changing about dining, etc., that is to blame for the surge we're now seeing. Pandemic fatigue is real, and by mid-October, people were starting to let their guard down, no doubt. And it may be telling that we haven't seen any significant outbreaks tied to SF restaurants, especially during the six weeks in which indoor dining was allowed.

Stay vigilant! Keep your Thanksgivings small or not at all!

Previously: San Francisco Likely Slipping Into 'Purple' Tier Next Week, Curfew to Follow

Photo: Marcus Urbenz