With pressure heating up from residents, San Mateo County officials began reporting COVID-19 cases by ZIP code Thursday to provide a more granular picture of how the disease has spread throughout the community.
Public health officials and politicians had previously been reluctant to show this level of data, fearing it would lead residents to underestimate the magnitude of the coronavirus, county Supervisor Dave Pine said.
Given that testing is still inadequate and many infected people display no symptoms, he said, the number of reported cases represents only a segment of what’s likely a much larger total.
“The issue was discussed internally for weeks,” Pine said, adding that county leaders value transparency, but they were worried people might draw the false conclusion that the number of infections is “quite low” if they saw a small number reported in their own neighborhood.
But arguments against releasing the information by ZIP codes lost ground as the virus escalated in San Mateo County. It’s now logged 1,197 cases and 51 deaths.
ZIP code data show the highest number of infections — 159 — in greater Daly City, or the 94015 area.
Supervisor David Canepa, whose district includes Daly City, said he was shocked when he saw the numbers.
“It just blew me away,” he said. “This is an absolute game changer.”
He hopes that more precise data will show the county where to steer resources and ramp up testing to avoid the racial and class disparities that are popping up throughout the country.
Daly City is a mostly working-class area with a diverse population, including large Burmese, Filipino and Brazilian communities, Canepa said.
The county’s small towns, such as Pescadero and Moss Beach, report the lowest number of cases, with less than 10 each.
San Francisco and Alameda counties already release ZIP code data, while Santa Clara and Contra Costa counties break down cases by city. Marin County has mapped out cases by geographic region.
Rachel Swan is a San Francisco Chronicle staff writer. Email: rswan@sfchronicle.com Twitter: @rachelswan
