The San Francisco Department of Public Health provides daily updates each morning. We will do the same.
Update, 5:10 p.m. Sorry for the delay, but we did get an explanation of the big one-day 122 jump in cases. “We have switched to a new data tracking system and there was a one-day bump as some of the lab data is now reported more quickly,” said Veronica Vien, from the Department of Public Health. “It should return to normal tomorrow.”
10:09 a.m.
The most recent numbers from the Health Department show 122 new confirmed cases, and 3 new deaths as of yesterday.
In absolute terms, that’s the largest number of daily new cases ever reported in San Francisco. As a percentage increase over the previous day’s figure, it clocks in at 6 percent. We have had other daily percent increase numbers that have matched that — most recently, on May 4 and April 22 — but all other instances of higher percentage increases were more than a month ago. It’s just a single daily datapoint, though, and far too early to know if it indicates a trend.
Moreover, we don’t yet know why the jump occurred, but we are asking the Department of Public Health and will update you on what we discover.
The jump may be a result of increased testing – albeit with problems – in vulnerable communities such as the Tenderloin and Bayview where officials know the incidence will be higher. But again, we will do our best to find out quickly where the new cases are coming from.
On Thursday we looked at the state’s reopening metrics concerning hospitalizations and found San Francisco on an excellent downward trend. That continues today with a drop in the total hospitalizations to 56.
Another state metric — one revised from an earlier, more stringent guideline — calls for counties, over 14-days, to have less than 25 COVID-positive cases per 100,000 residents or a testing positivity over the past 7 days of less than 8 percent.
In San Francisco, this works out to about 220 cases over 14 days or around 15 new cases a day. The earlier metric called for 88 cases or 6 cases a day over 14 days so the state has loosened this considerably.
We’re still not meeting the lower bar of 220 cases as we are well over 400 cases over the last two weeks. On the bright side, our testing positivity is well below 8 percent so the state would give us a pass on our higher cases.
On testing, we’re simply doing nowhere near our capacity of 5,800 tests a day. As we have reported, virtually any resident can get tested because the required symptoms have been vastly expanded. Especially if you are working with the public, go here to register for a test or call 311 if the site frustrates you.
And as we write today, efforts to expand testing have indeed frustrated residents at the city’s new mobile site in the Tenderloin.
Also on our site today, Dr. George Rutherford, a UCSF professor of epidemiology, said in Thursday’s Grand Rounds that, yes, the kids should return to school in the fall. Parents, on the other hand, are likely to have fewer bars to visit as the pandemic is killing them off.
Short of a vaccine or treatment, what will be most important for individuals in keeping the curve headed in the right direction? “We wear masks,” said Rutherford on Thursday, a mask mantra he began several weeks ago.
Rutherford, by the way, would choose masks over social distancing (if you put a gun to his head).
And, according to new guidelines by the Centers for Disease Control and Prevention, surfaces appear to be less of a problem, the Washington Post reported this morning.
Transmission is mostly person-to-person and masks especially prevent asymptomatic carriers from passing it on to someone else. Remember, in the Mission District study, 53 percent of the COVID-positive residents were asymptomatic.
Rutherford agreed about surfaces: He doesn’t worry about mail or bags at the supermarket, but he also expressed some caution on surfaces. They’re “not as worrisome as having somebody sneeze in your face. But I think you discount this at your peril.”
He offered a vision of the long vertical bar in the New York City subway. “I’d sure as hell wash my hands right after I touched it.” Ditto.
Enjoy the long weekend.
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Please note:
The embedded data tracker below will continue to be updated daily after this post is published.
There is a discrepancy between the total number of positive test results reported by the city and the total daily number of confirmed cases. The discrepancy comes from a delay in fully investigating positive test results. In doing so, health investigators find some duplicates and some are for people who live outside of the city, according to epidemiologists at the Department of Public Health. New cases are only added to the daily confirmed cases after an investigation is completed.
Also, there is also a discrepancy between the hospitalization data reported by the San Francisco Department of Public Health (SFDPH) and the county hospital data reported by the California Department of Public Health (CDPH). This is because SFDPH receives data from one additional hospital, San Francisco VA Health Care System, that is not required to report to CDPH. “SFDPH statistics will trend higher as long as this hospital has patients admitted as either COVID-19 positive or suspected COVID-19 positive.”
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Thank you for being the only news outlet to look into what caused today’s spike in cases.
We will review all of this over the weekend and yes, we are looking more deeply into the whole subject of masks. Thanks for the links, Lydia
The dataset shows 358 cases in last 14 days, with 177 cases from 5/8 to 5/14, and 181 cases from 5/15 to 5/21. So there has not been big spike, but the number of cases in a week has increased very slightly when we are looking for it to decrease week over week. Infections are ongoing, and with reopening, the infection rate would not likely decrease if no other actions are taken. Contact tracing might help to reduce infection rate as it did in South Korea, but would that depend on how well it is done here.
The new relaxed criteria of 25 cases per 100,000 in last 14 days as a metric for reopening works out to 224 cases in last 14 days for our city using the population number of 896,000 found on Google. So the 358 cases in last 14 days still does not meet the relaxed criteria.
Yes thank you. It was just a one day spike I was referring to and now, as you can see, DPH has offered a reason for the 1220 new cases. I suppose I used a population of 879,166 for SF. But thank you. Sounds like you are a whole lot better at these calculations than I am and I welcome your help.
The large number caught my attention. I downloaded the dataset which shows 14 cases on 5/21, 29 cases on 5/20, 49 cases on 5/19, 27 cases on 5/18, etc. which are different from the number of cases previously reported for those days. The dataset shows 2360 cases, 40 of which are deaths, so it appears the 2320 cases reported in SFDPH summary does not include deaths which are reported separately. I have not downloaded any previous dataset so I can’t compare for which dates the numbers were changed. That the numbers have changed is certain and is likely due to an audit of records. We have seen this occur in the numbers reported by other locales when there is suddenly a big spike in cases on one day. Most notably in Wuhan during middle of their outbreak, I also recall a big spike reported in Santa Clara cases (>200 cases in a day) back in March, but this spike no longer appears in Santa Clara data. Bottom line, the big increase was not just in one day, but appear to be adjustments to cases reported in previous days.
Yes you are exactly right as it turns out. We updated the story with the comment from DPH. Thank you, Lydia