Skip to main content
Public Health

SF Wastewater Data Shows Unprecedented Summer Covid Surge 

Written by David SjostedtPublished Jul. 15, 2022 • 2:08pm
Rowan Zoltar and Nurse practitioner Mawayidna Tombegou prepare covid testing kits for passerbys out of the City Health mobile testing van, which parked at 16th and Mission streets on Wednesday, May 25, 2022. The DPH program aims to test everyone, especially uninsured community members. | Camille Cohen/The Standard

English

Data collected from San Francisco’s toilet water shows that the recent Covid surge may have topped the city’s former record high, illustrating how the city’s official case counts no longer give a complete picture of how the virus is spreading.

The wastewater data shows a peak that gathered steam throughout May, exceeding highs not seen since the first surge of the Omicron variant in January 2022. Cases spiked again in late June, according to the data, likely reflecting a rise in the highly infectious Omicron BA.5 variant, which is good at evading immune defenses. 

The data demonstrates how official case counts increasingly paint a limited picture as more Covid patients stick with at-home testing. Testing data shows a seven-day average of over 400 new cases per day versus more than 2,300 at the peak of the January surge. But the wastewater data, collected by a team of researchers at Stanford and Emory Universities, suggests a current true case count that is considerably higher. Los Angeles County, meanwhile, is considering going back to an indoor mask mandate amid rising cases and hospitalizations.  

However, San Francisco's wastewater data also shows that the current surge could be on the downswing—at least on the west side of the city, which looks to be carrying a considerably higher viral load, according to calculations by Stanford researchers. 

See Also

“The higher concentrations in Oceanside vs Southeast suggests that, during the current Covid wave, the infection rates (number of infections divided by the number of people in the sewershed) are higher in the oceanside compared to southeast sewershed,” wrote Alexandria Boehm, a Stanford professor of civil and environmental engineering who helped develop the data, in an email. 

Despite the dramatic summer surge, current cases have fortunately not proven more lethal. Deaths in May and June numbered  29 and 26, respectively—far lower than the 165 people who died during the Omicron surge in January. People who are unvaccinated are catching Covid at more than twice the rate of unvaccinated residents, according to the San Francisco Department of Public Health.

English

David Sjostedt can be reached at [email protected]


‘Like a Piece of Luggage’: SF Sends Away More Foster Kids Than Any County in California

‘Like a Piece of Luggage’: SF Sends Away More Foster Kids Than Any County in California


Mask Up: Covid Is Back in the SF Bay Area

Mask Up: Covid Is Back in the SF Bay Area


San Francisco Victim Aged Under 65 Dies of Flu as Residents Urged To Get Vaccinated

San Francisco Victim Aged Under 65 Dies of Flu as Residents Urged To Get Vaccinated


Mayor Breed Personally Ordered Homeless Sweeps, Lawsuit Claims

Mayor Breed Personally Ordered Homeless Sweeps, Lawsuit Claims


300 Health Department Employees With Secret Side Gigs Come Forward After Scandal

300 Health Department Employees With Secret Side Gigs Come Forward After Scandal


Stay on top of what’s happening in your city

SF’s most important stories, delivered straight to your inbox



By clicking Subscribe you confirm you have read and agree to our Terms of Use and acknowledge our Privacy Policy