After a four-week pandemic plateau, Kentucky reported a high number of coronavirus cases Tuesday, as well as an increasingly high share of residents testing positive for the virus in the last seven days.

It looked like the start of an Omicron-variant surge that much of the nation is already experiencing, but Gov. Andy Beshear cautioned that it could be linked to delayed testing and reporting over the Christmas holidays.

The increase in the positive-test rate has accelerated most days in the past week, and soared Tuesday to 12.61%, 0.81 percentage points above Monday’s seven-day rate.

Covid-19 hospitalizations are also on the rise, jumping 10.4% in the last week; most of that jump came from an 8.5% increase from Monday to Tuesday, perhaps reflecting diagnosis and treatment delayed by the holidays.

Hospitals reported 342 Covid-19 patients in intensive care units, down six from Monday; and 203 Covid-19 patients on mechanical ventilation, an increase of 16% in just one week.

Nine of the state’s 10 hospital-readiness regions reported using more than 80% of their intensive care unit capacity, with five of them above 90%.

The state’s daily infection rate is 50.99 cases per 100,000 residents. The New York Times ranks Kentucky’s infection rate 28th among states, a big jump from 42nd on Monday.

Again, Beshear encouraged Kentuckians to wear a mask when appropriate and to get a Covid-19 vaccine or booster to protect themselves, their loved ones and their communities.

“We have the tools we need, even to fight this new variant. We’ve just got to be willing to use them,” he said. “Take care of yourself. Take care of your neighbor.”

The state reported 23 more Covid-19 deaths, bringing its pandemic death toll to 12,097.

Other pandemic news this week: The Centers for Disease Control and Prevention has shortened the recommended time for isolation and quarantine in some cases.

For people who have tested positive for the virus, but are asymptomatic, the recommended time for isolation has been shortened to five days instead of 10, followed by five days of wearing a mask when around others.

“The change is motivated by science demonstrating that the majority of [Covid-19] transmission occurs early in the course of illness, generally in the 1-2 days prior to onset of symptoms and the 2-3 days after,” says a CDC news release.

For people who have been exposed to the virus, the new recommendations for those who are unvaccinated, or are six months out from getting their second Pfizer-BioNTech or Moderna shots or more than two months after the one-dose Johnson & Johnson shot, is to quarantine for five days, followed by five days of strict mask use.

“Alternatively, if a five-day quarantine is not feasible, it is imperative that an exposed person wear a well-fitting mask at all times when around others for 10 days after exposure,” says the release.