Months after emerging from a fourth surge of the coronavirus outbreak, Louisiana again is seeing growing numbers of COVID-19 cases, and an infectious disease expert said Monday the state is entering another spike as the omicron variant of the virus spreads.

“We’ve been through it so many times that the telltale signs are all there,” said Dr. Catherine O’Neal, the chief medical officer of Our Lady of the Lake Regional Medical Center in Baton Rouge.

Data released Monday by the Louisiana Department of Health shows the number of new cases of the coronavirus illness reached more than 2,300 since Friday — and more than 4,800 over the past week. That’s more than double the amount of new cases from the prior week.

And the health department warned those numbers are expected to balloon as dozens of cases of the fast-spreading omicron variant have been confirmed in Louisiana. The largest number of cases so far has been in the New Orleans area, but probable cases of the variant have been detected in every region of the state, according to the health department.

“If omicron is not already the dominant strain circulating in Louisiana, we feel that it will be very soon,” State Epidemiologist Theresa Sokol said on a health department conference call with O’Neal and reporters.

The number of people hospitalized in Louisiana with COVID-19 remains low so far, with 265 patients, Sokol said. That continues to be among the lowest number of COVID-19 hospitalizations since March 2020 and well below the state’s peak of more than 3,000 in August. But the numbers have increased from below 200 just last week.

“We’re seeing over the past four days fairly substantial jumps each and every day,” Sokol said.

Hospitals are bracing for another uptick in coronavirus patients. O’Neal said Our Lady of the Lake is again requiring masks for all of its employees and is moving to virtual appointments when cases allow.

Gov. John Bel Edwards and his public health advisers continue to urge people around Louisiana to get immunized against the coronavirus illness and get booster shots if eligible, saying that’s the best way to lessen the impact of an infection. Of those currently hospitalized with COVID-19, 80% are unvaccinated, according to the state health department.

Sokol and O’Neal said people should get tested for COVID-19 before traveling or before going to a holiday gathering and then test again when they return home. They called on people to resume wearing face coverings at indoor public gatherings, even though Edwards has lifted the state’s mask mandate.

“We can help to at least dampen the surge. I think it’s coming and our community has to prepare for it, but how high it gets, how painful this gets for all of our families, it depends on our community,” O’Neal said.

Much remains unknown about omicron, including whether it causes more or less severe illness. Scientists say omicron spreads even easier than other coronavirus strains, including delta, and it has become the dominant version of the coronavirus in the U.S. Early studies suggest the vaccinated will need a booster shot for the best chance at preventing an omicron infection but even without the extra dose, vaccination still should offer strong protection against severe illness and death.

Louisiana has one of the nation’s lowest immunization rates against the coronavirus. More than 2.3 million people in the state are fully vaccinated, according to the health department, just under half of Louisiana’s total population. About 661,000 people have gotten booster doses, about 14% of the state’s residents.