SAN RAFAEL (CBS SF) — Prompted by a spike in coronavirus cases locally, Marin County announced Friday it will delay the reopening of some businesses that had been told they could restart operations on July 29.

As of Thursday the county had recorded 54 new cases — its highest single-day number since the pandemic began. As well, Marin County has a pandemic-high number of COVID-19 patients in hospital, 12, with five of those in intensive care.

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With more than 500 inmates found to be infected during the past two weeks, San Quentin State Prison is compounding the surge in cases. A number of critically-ill prisoners have been transferred to local hospitals. More than 75 prison staff, some of whom are county residents, have been infected.

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“Since the beginning of our reopening process in early May, Marin Public Health has committed to moving at a sequential rate, guided by local COVID-19 data and our progress indicators,” said Dr. Matt Willis, Marin County public health officer. “We’re seeing patterns we need to pay attention to. We’re not closing anything down. We’re just slowing the pace in response to the data,” Willis added.

The move by Marin County officials mirrors similar pauses being made elsewhere in the Bay Area. On Friday, San Francisco Mayor London Breed announced that the planned next step in businesses reopening scheduled for June 29 would be delayed.

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Officials in Contra Costa and Santa Clara counties were similarly reassessing plans for reopening after ending up on the state’s watch list for counties showing an increasing spread of coronavirus cases.