Three Santa Rosa police officers and a Sonoma County sheriff’s deputy have tested positive for COVID-19 and are among the 34 cases of the viral disease reported so far in Sonoma County, law enforcement officials said Tuesday.

All four tested positive for coronavirus in the past week — including one whose test was confirmed Tuesday afternoon. They are in isolation, at least one at a local hospital, officials said. One of the three officers had “minimal” contact with the public recently and the others had no contact, while the deputy had recently returned from a vacation, officials said.

“Right now, our thoughts are with them as they recover,” Santa Rosa Police Chief Ray Navarro said during a news briefing Tuesday.

The recent cases emerged as health officials around California continued to warn of a coming surge in illnesses, as transmission of coronavirus involving those who are unprotected — and perhaps asymptomatic — continues.

In Sonoma County, officials are honing in on alternative sites that can be converted to house nonacute patients, once local hospitals reach capacity, Emergency Management Director Chris Godley said.

Godley said the county would need about 500 additional beds for a moderate-to-severe outbreak.

Sonoma County Health Officer Sundari Mase said she hoped that aggressive steps taken to curb the spread of the virus, including a shelter-in-place order issued last week and, more recently, closure of all parks in the county, might mitigate the surge.

She also said she spoke Tuesday with law enforcement chiefs and urged them to follow up on reports of “nonessential” businesses that had remained in operation in violation of the preventive order to “see if there is any need for them to gently nudge” those found out of compliance to align with new regulations and close.