Maryland officials on Sunday reported more than 2,000 new cases of the novel coronavirus and 19 deaths as the state’s governor expressed deep concern that despite warnings from leading health experts, people may let their guards down during the upcoming holiday.

Speaking on CNN’s “State of the Union,” Gov. Larry Hogan (R) said he’s fearful that unintentionally reckless choices during the Thanksgiving holiday could accelerate an already rapid rise in coronavirus cases.

“We’re pretty worried about it,” Hogan said, reminding the public: “We’re in the worst part of this crisis.”

Hogan said data on past infection sources shows that family gatherings can be spreader events.

“Our contact tracing shows that family gatherings [are] the No. 1 transmission event,” he said. “It’s just because you feel so comfortable. You take off your mask, you’re spending time with people who you love and care about. You don’t feel like you’re unsafe. You’re not going into a bar or somewhere. When you let your guard down, that’s when it transfers.”

In the past week, daily reported counts of new cases in the United States spiked nearly 14 percent, according to data tracked by The Washington Post.

Through 5 p.m. Sunday, 4,475 new coronavirus cases were reported in the District, Maryland and Virginia, bringing the total number of cases in the region to more than 420,000.

Health officials in the District reported 190 cases, up from Saturday, when officials reported 153 cases. No new deaths were reported in the District on Sunday. In Virginia, officials reported 2,117 cases Sunday but no deaths.

Officials nationwide expressed concern that cases and deaths could spike over the long Thanksgiving holiday weekend.

On Thursday, the Centers for Disease Control and Prevention, in its first press briefing in months, urged Americans to stay home this Thanksgiving because of the risks posed by travel.

“Right now, as we’re seeing exponential growth in cases and the opportunity to translocate disease or infection from one part of the country to another, leads to our recommendation to avoid travel at this time,” said Henry Walke, incident manager for the CDC’s covid-19 response.

A recent survey by AAA Mid-Atlantic found that the vast majority of residents in the national capital region are staying home. The survey, which was conducted before the CDC’s recommendation against travel, found that 83 percent of area residents said they would not be traveling for Thanksgiving. Of those, 65 percent cited concerns about the virus as a reason, and 93 percent said they perceived that traveling at this time poses a risk.

Even so, many are on the move. The Transportation Security Administration reported that it screened more than 1 million people Friday. It was only the second time since the pandemic began that more than a million people moved through airport security checkpoints. TSA reported screening more than 980,000 people on Saturday. The numbers could spike again this week; officials expect that more people will travel on Wednesday and then again on Sunday, which has traditionally been one of the busiest travel days.

The numbers are a fraction of a normal Thanksgiving week, but they still are worrisome to public health officials, who continue to sound alarms about people congregating at airports.

AAA Mid-Atlantic previously said it expected up to 50 million Americans to travel for Thanksgiving — a drop from the 55 million who traveled in 2019. But that number was based on mid-October economic forecast models, before the most recent nationwide surge in coronavirus cases, AAA noted.

“Given the recent surge in covid-19 and the strong urging of public health officials for everyone to stay home for the holiday, the Thanksgiving travel landscape continues to change,” said John Townsend, spokesman for AAA Mid-Atlantic.

In Maryland, Hogan is reminding residents to continue to wear masks, wash their hands and practice social distancing. The governor also has emphasized the importance of testing.

“As we battle this fall surge, one of the most important things you can do to protect your friends and family is to get tested for COVID-19. Marylanders can plan to be tested at one of more than 230 testing sites by visiting,” Hogan tweeted last week.

The CDC on Saturday also recommended that people who plan to fly internationally get tested before their flights and again when they return from their travels. Even if their post-travel test is negative, the agency recommended that people stay home for seven days.

Closer to home, in a video message tweeted by the Montgomery County Department of Health and Human Services, Lisa Moholt, an ICU nurse at Holy Cross Hospital, also urged people to continue to wear their masks and practice good hygiene and social distancing.

“I cannot tell you how many hands I’ve held as they’ve crossed over, how many families — I’ve witnessed their grief firsthand,” Moholt said, in the message recorded in front of Holy Cross Germantown Hospital. “Stay safe so you can continue to celebrate with your loved ones in the new year.”