SACRAMENTO, Calif. >> The first California county to backpedal on its reopening plan wasn’t one of the urban areas that agitated to reopen or a coastal area where beaches draw crowds but a remote outpost that didn’t have a single known coronavirus case until last week.

All it took was a single infection that spread to four other people before Lassen County, home to 30,000 people living in pine-covered mountains and the high desert of Northern California, temporarily rescinded reopening orders. Dining at restaurants, in-store shopping, hair cuts and religious services are now barred for at least seven days.

Some businesses had to shut down after rehiring staff, sanitizing equipment and training workers on hygiene.

The county on the Nevada border had not reported a coronavirus case until May 22, when a resident who had traveled outside the county and became ill and tested positive, said Barbara Longo, the county health and social services director.

A small team of 11 nurses and other health department employees went to work over the holiday weekend to try to track down everyone who had been in contact with the infected person and get them tested, leading to all the additional cases, including the spouse of the initial patient.

Several more people who had come into contact with the initial person infected were also under orders to stay home for two weeks, the incubation period for COVID-19, even if they tested negative.

On Tuesday evening, the county notified businesses that had been allowed to reopen two weeks earlier that they would have to return to offering takeout food or curbside pickup.

“We were fully aware of the risk that the virus could come to our community from people visiting people living in infected areas outside of our county or people visiting our county,” Dr. Kenneth Korver, the county’s public health officer, wrote in a public health order. “Unfortunately, this did happen and we now have a serious problem.”

Kim Adair, a bartender at Lassen Ale Works Boardroom, said the step backward was a bummer but they were still brewing and selling curbside growlers, bottles of beer, and food.

“We were only open for a week then we got shut,” Adair said. “This is a happy place for everyone to come visit. Everybody was itching. But we’ve never done this before in our lifetime so everything is a learning curve right now.”

As of Wednesday afternoon, the county had only five cases — all spread within the community from the person initially infected.

Before the first case turned up, the county had made a push for more widespread testing, despite reluctance by residents. A radio station in town had taken an informal survey and found more than nine out of 10 listeners said they wouldn’t get tested, Longo said.

Longo said she wanted to dispel rumors floating around that the only reason there were no cases was because no one wanted to get tested due to fears that would lead to a longer shutdown.

After prevailing upon the state to agree to provide 20,000 tests, the county nearly doubled testing over three days by setting up a drive-thru site at Lassen Community College. Of the roughly 425 tested there last week, none came back positive, though about half those results are still pending. The three state prisons in the area have had no known cases.

The county began reopening businesses May 11 under state guidance that sets limits of fewer than one case per 10,000 residents in the past two weeks. Lassen County exceeded that limit with more than three cases. It has not had any deaths or hospitalizations.

Many of California’s rural, northern counties have seen few coronavirus cases, and they were among the first to receive approval from the state to begin reopening businesses. Forty-seven of the state’s 58 counties, including Lassen, have now been given state approval to move more quickly into reopening. They can get that approval based on hospitalizations, positive test rates or total case loads, but they must submit plans explaining how they would respond if an outbreak occurred.

While Lassen is now the first county to revoke its attestation to the state that it can safely reopen, it’s not alone in applying the brakes on the return toward a so-called normal.

Humboldt County on California’s North Coast was one of the first counties to get approval to open restaurants and is now taking a more cautious approach after a spike in cases and its first two deaths. Sonoma County said on Wednesday it would slow its reopening after a recent surge in cases.

Los Angeles County, which has more than half the statewide death toll from COVID-19, is awaiting word on its request to move ahead.

San Francisco, which had taken a more cautious approach, said today it would allow outdoor dining and indoor shopping, religious services and sporting events without spectators as of June 15 and give barbershops and hair salons permission to reopen in mid July. It also said it would require masks or face coverings outside the house — even during exercise.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, and death.