As millions of Americans head home after Thanksgiving, the coronavirus could be hitching a ride — threatening to plant seeds of infection across the country as the US on Sunday topped more than 100,000 new cases for the 27th consecutive day.

So far Sunday, the United States has reported 109,671 new cases and 731 deaths, according to Johns Hopkins University.

A surge of new travel-related infections could overwhelm hospitals already stretched to capacity.

Hospitalizations of Covid-19 patients reached a record high of 93,238 on Sunday, trumping Saturday’s record-breaking 91,635 figure, according to the Covid Tracking Project.

It is the third time there have been over 90,000 Americans hospitalized with Covid-19 — the first being Thursday with 90,481 before a drop to 89,834 Friday that could be attributed to inconsistencies in reporting over Thanksgiving.

“There’s no way that the hospitals can be fully prepared for what we’re currently facing,” emergency medicine physician Dr. Megan Ranney said.

“This is like a natural disaster occurring in all 50 states at the same time. There are not adequate beds. There are not adequate staff.

And because of the lack of national preparation, there are still not adequate supplies,” said Ranney, a CNN medical analyst and director of the Brown-Lifespan Center for Digital Health at Brown University.

“Here in Rhode Island, we are currently planning to open our field hospital on Tuesday because our hospitals are so full of sick Covid-19 patients. But not every state has that option,” she said.

“And even if you open a field hospital, if you have hundreds of staff who are sick — which is what many states across the country are currently facing — if you don’t have nurses and doctors and respiratory techs, even a field hospital isn’t going to save you. Our health care system is literally at the breaking point right now, thanks to Covid-19.”

Sunday is expected to be the busiest air travel day of the entire pandemic even though the Centers for Disease Control and Prevention recommended that Americans not travel for Thanksgiving.

Roughly 6 million travelers passed through security at US airports after the CDC’s travel warning in the week leading up to Thanksgiving.

But it will be weeks before anyone knows how much of a role Thanksgiving gatherings and travel play in new hospitalizations and deaths.

“When you look at people who are hospitalized today, they were infected two weeks ago, maybe more,” said Dr. Jonathan Reiner, a professor of medicine at George Washington University.

“And then it takes usually another week for folks to succumb to the illness.”

So infections picked up on Thanksgiving “are going to show up in three weeks and are going to show up in deaths over Christmas and New Year’s and are going to spread in every state,” Ranney said.

Statistics reported in the days after the holiday might show a relative dip in Covid-19 cases, followed by a surge due to a lag in government agencies’ reporting over the long weekend.

And given coronavirus’ lengthy incubation time and how long it takes an infected person to test positive, cases related to Thanksgiving are unlikely to show in public data until the first full week of December at the earliest.

Even before then, Covid-19 is killing Americans at a staggering rate. At least 1,189 new deaths were reported on Saturday alone, according to Johns Hopkins University.

More than 266,000 people in the US have died from Covid-19 since the pandemic began.

Health experts say anyone who gathered with people outside their household should take serious precautions in the coming days, especially young people who might be carrying and spreading coronavirus without any symptoms.

“If you’re young and you gathered, you need to be tested about five to 10 days later,” said Dr. Deborah Birx on CBS’s “Face the Nation” on Sunday. “You need to assume that you’re infected and not go near your grandparents and aunts and others without a mask.”

Birx, a member of the White House coronavirus task force, recommended those over age 65 get tested immediately if they develop any symptoms.

“If you’re over 65 or you have comorbidities and you gathered at Thanksgiving — if you develop any symptoms, you need to be tested immediately,” she said.

Many hospitals are on the brink of exceeding capacity, threatening reduced care for everyone — even those without coronavirus.

So officials around the country have reinstated or rolled back on restrictions. In Los Angeles County, a three-week stay-at-home order goes into effect on Monday.

“What I wish is that people would follow those stay-at-home orders,” said Ranney, the emergency medicine physician in Rhode Island.

“I can’t tell you how many patients I take care of who tell me, ‘Well, I just went to an indoor restaurant.’ Or, ‘I just went to a party with a few friends. I didn’t actually think I was going to catch Covid.’ So those stay-at-home orders are critical.”

The Los Angeles County stay-at-home order prohibits all public and private gatherings with people outside a single household.

“Residents are advised to stay home as much as possible and always wear a face covering over their nose and mouth when they are outside their household and around others,” the county’s public health department said.

The order is in effect through December 20. It does not apply to “faith based services and protests, which are constitutionally protected rights,” the health department said.

Essential retail businesses will be limited to 35% occupancy, while the occupancy limit for nonessential retail operations, personal care services and libraries will be 20%, the county said.

“Even if you’re not feeling sick, the simple act of gathering with people outside your household puts everyone at risk,” county health director Barbara Ferrer said.

Ranney said it’s possible some schools and workplaces can operate safely if precautions are met.

“I think it’s really important that you keep safe workplaces and safe schools open,” she said.

“We know that in those structured settings, where people are masked, keeping a distance, having adequate ventilation, the spread of the virus is pretty low in those settings,” she said.

“I am hopeful that that type of order will be effective. And we’ve seen in France that it works,” Ranney said.

“I sure hope it will be (effective) in L.A., and I hope the rest of the country can follow suit. Because we need to do something, or — again — this virus is just going to just continue to grow out of control.”

California set a new pandemic record on Sunday with 7,415 Covid patients in its hospitals, according to data provided by the California Department of Health.

That eclipses the previous California hospitalization record of 7,170 people on July 21. (CNN)

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