SANTA CLARA (CBS SF) — A surge of new Santa Clara County COVID-19 cases over the weekend has triggered a plea from local health officials to adhere to social distancing requirements and always wear face coverings.

Currently, the county is in the moderate Orange Tier of California’s COVID-19 monitoring scale, but the recent surge is threatening to slide Santa Clara back down into the Red Tier, forcing some business restrictions to be re-imposed.

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Health officials said there were 358 new COVID-19 cases reported on Sunday, which was second only to the record of 385 new cases reported on July 15.

Nearly all the new cases were from test samples collected in the past week, officials said. About half of those coming in the past three days.

The all  important seven-day average of new cases last week was between 131 and 139, accelerating after a slow climb that started in mid-October. In addition, the number of hospitalizations on Sunday was up by nearly 10 percent.

“This surge in COVID-19 cases is not what we want to see going into the fall and winter holiday season,” said Dr. Sara Cody, Health Officer and Director of Public Health for the County of Santa Clara. “New cases and resulting hospitalizations are increasing locally, regionally, as well as statewide and across the country and the world. These trends serve as a stark reminder that COVID-19 is all around us.”

Cody compared the situation in Santa Clara County to the increased wildfire danger the Bay Area faces during fire season, saying there’s a lot of dry tinder, and all it takes is one spark or hot ember to start and out-of-control blaze.

“You can see that over October, we began to drift up. And we’ve been tracking that drift up and we’ve been talking about that drift up,” said Cody. “But what’s happened in the last week, it is no longer a drift. Our cases are surging up.”

At a morning news conference, Cody said the surge could not be traced to a specific ‘super spreader’ event.

“We don’t have a clear signals of particular groups or sub-populations or clear super spreader events that would explain this surge,” she said. “We are actively investigating to understand whether there may be such events.”

The hardest hit have been young adults age 18-34 years old,  particularly those in the 25-29. Figures show East San Jose and Gilroy have a disproportionately high number of cases.

Dr. Cody also warned residents not to succumb to what she called “pandemic fatigue.”

“What we mean by pandemic fatigue is that all of us has been worrying about COVID for a very long time. We’re wearing masks, we’re watching hands, we’re not seeing friends, we’re not seeing family,” said Cody. “And it takes an extraordinary amount of effort to keep it up, and people are tired. We’re here today to say we hear you, we understand you’re tired and you still have to keep it up.”

Cooler temperatures and inclement weather that come with fall and winter mean people will be inclined to engage in more indoor activities, which are riskier than outdoor activities

Indoor dining, gathering in private homes with people outside of one’s household, and becoming complacent with “pandemic fatigue,” all elevate the risk of COVID-19 transmission.

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“Everyone appreciates the additional options that come from being in a less-restrictive tier,” Board of Supervisors President Cindy Chavez said. “But we all need to be mindful that being in that tier doesn’t mean some activities do not come with certain risk, and that risk is greatly magnified if businesses and customers do not follow the rules in place to help keep them safe.”

Chavez acknowledged the sacrifices that officials were asking county residents to make, especially with the holidays looming.

“I know we’re asking a lot, and I know people are tired. But here’s the thing: We’re only going to get this through this one way, and that is it. We’re working really hard and we’re working really hard together,” said Chavez. “We recognize that this is not something that any one of us can do alone, but we’re asking everybody in our community to dig in a little more dig in a little longer and get us across the finish line.”

San Jose residents KPIX 5 spoke with understood the need to dial back Thanksgiving celebrations.

“It’s tough, because we have a tradition of seeing everyone in Thanksgiving,” said San Jose’s Connor Watson. “But I think having that peace of mind knowing that they’re going to be more safe, it’ll minimize the risk. It will be better for us.”

San Jose resident Steven Dotson agreed.

“Cancel Thanksgiving. It’s not worth it,” said Dotson. “Thanksgiving is important to family and friends and they’re going to get together no matter what and think they’re safe. But we’ll see the surge after the holidays like we have every time there was a holiday.”

Local officials also were ramping up efforts to respond to complaints of non-compliance of local COVID-19 business restrictions.

By far the most complaints received involve the food service industry, and indoor dining continues to be one of the highest-risk activities currently allowed due to the fact patrons must remove their face covering to eat.

County officials are urging citizens to eat only at restaurants that feature an orange check that shows they are following proper COVID guidelines.

Residents who see any violations in the county are asked to report them to

Code enforcement officials said the county has received 1,850 reports of violations, responding to 1,300 calls and complaints so far. Officials have issued 79 violation notices and levied $600,000 dollars in fines.

Formal enforcement is used for serious, repeat and willful violations and typically only when a business has refused to comply after being given an opportunity to do so. Fines start at $250 and increase to $5,000 for each violation and may double for multi-day violations.

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Kiet Do contributed to this report.