Summer is in full swing, bringing hordes of Californians together for parties, concerts and blockbuster movies.
But where the masses flock, Covid follows. Viral levels are slowly rising in California, according to new data from WastewaterSCAN, a program that tracks pathogens in municipal sewage treatment plants.
San Francisco’s wastewater shows the state’s largest summertime spike in Covid, surpassing all other California plants in late July.
The San Francisco Department of Public Health said it monitors wastewater data to help keep track of trends and confirm local case numbers.
“While data from the Sewer Coronavirus Alert Network indicates an increase, Covid-19 rates remain much lower than previous years,” a DPH spokesperson said. “Currently, we do not expect more serious illness or hospitalizations for people who are up to date on their vaccinations.”
Still, Covid is spreading across the state and not just in the Bay Area. In late July, sewer plants in Los Angeles County and elsewhere in Southern California recorded spikes of their own.
The increase appears to be driven by the “XBB” Covid variant – called “Arcturus” by some—which was first discovered in San Francisco’s wastewater in January, according to WastewaterSCAN. Public health experts told KQED it was set to become the dominant tribe in the Bay Area this summer.
Other California municipal sewers showing significant increases in Covid include those in Palo Alto, San Bernardino, San Rafael, Sausalito, Half Moon Bay, Lancaster, Los Banos, Riverside and Turlock.
While Covid is on the rise, current cases remain below the rates seen during the winter flu season. In some areas –such as Alameda County– The Covid levels in waste water do not appear to be increasing significantly.
However, not every county in California screens its wastewater for Covid and other pathogens. WastewaterSCAN partners with 58 sewer facilities throughout the state, but notably no jurisdictions north of Sacramento participate in the program.
“U.S. Covid-19 rates remain near historic lows after seven months of steady declines,” CDC spokeswoman Kathleen Conley said. San Francisco Chronicle in a statement. “The United States has seen increases in Covid-19 over the past three summers, so it is not surprising to see an increase.”
“We continue to encourage all San Franciscans to stay safe by staying up-to-date on their vaccinations, having a supply of testing kits, keeping masks on hand during times of high community spread or when extra precautions are needed, by how to reach a doctor (especially to get Paxlovid treatment if you test positive for Covid-19), says a DPH spokesperson.
Check out these charts from WastewaterSCAN to see where Covid is rising in California.