More than 40,000 people flooded US airports in the weekend after Trump's coronavirus travel ban, creating a host of public-health mistakes. Here they all are.

Some travellers said they waited up to seven hours to get screened by the Centers for Disease Control and Prevention (CDC) upon arrival to the US.

Some people were waiting for as long as seven hours at Chicago's O'Hare on Saturday night, The New York Times reported.

One passenger, Katherine Rogers, told CNN that she was traveling through Chicago's O'Hare International Airport on Saturday and, five hours into her wait to get screened, she was told she would still have to wait for an hour.

"No one seems prepared," she told CNN. "To take us off planes from all over the world and put us together for hours seems counterproductive."

This is the scene at O’Hare airport. The traveler who took the photo said it’s a 6-hour wait for bags then on to customs for 2-4 more of waiting in shoulder-to-shoulder crowds. Police are handing out water and disinfectant wipes. @fly2ohare #ord #coronavirus #COVID19 pic.twitter.com/UTx9E0nj1s

Illinois Governor J.B. Pritzker criticized the federal government for the delays and crowding, tweeting on Saturday that "the federal government needs to get its s@#t together."

"To the frustrated people trying to get home, I have spoken with the mayor and our Senators and we are working together to get the federal government to act to solve this," he tweeted.

"We will do everything within our power to get relief."

4.5 hours and I'm out of O'Hare. Putting us all together like this is a great way to spread some stuff. BTW, employees were just as miserable as everyone else but generally nice. pic.twitter.com/yBUq1CZGGN

This meant people couldn't follow the CDC's warning to stay at least six feet away from people who are sick and places where the virus could spread.

Source: CDC

JFK airport in New York City has turned into a #CoronaVirus breeding ground along side O'Hare in Chicago. Crowds waiting in a very long lines in close quarters with thousands of people to clear US Customs' useless enhanced #COVID19 screening measures.pic.twitter.com/fyr8fyT0vq

The CDC also recommended on Sunday — after many travellers had already been through the airport — that all gatherings and events with at least 50 people be postponed.

"Large events and mass gatherings can contribute to the spread of COVID-19 in the United States via travelers who attend these events and introduce the virus to new communities," the CDC said.

It gave examples of events like conferences, festivals, parades, concerts, sporting events, and weddings, but said the guidance does not apply to places like schools, institutes of higher learning, or businesses.

"Events of any size should only be continued if they can be carried out with adherence to guidelines for protecting vulnerable populations, hand hygiene, and social distancing. When feasible, organizers could modify events to be virtual," the CDC said.

Some 40,000 people had come to the US from Europe on Saturday alone, acting Homeland Security secretary Chad Wolf said.

Source: The Washington Post

Wolf added that the wait times were "unacceptable," and claimed the situation had improved as of Sunday.

He said the situation had improved as of Sunday, with the average wait time in 13 airports dropping to 30 minutes, according to The Washington Post.

It is not clear whether more efficient plans were put in place, or if the number passengers returning had fallen since the announcement of the ban.

The Department of Homeland Security did not immediately respond to Business Insider's request for comment.

Chicago Mayor Lori Lightfoot also said the waits were "unacceptable," and tweeted at Trump and the Customs and Border Protection: "Stop putting Americans in danger."

"The reactionary, poorly planned travel ban has left thousands of travelers at ORD forced into even greater health risk," Lightfoot tweeted.

"@realdonaldtrump and @CBP: no one has time for your incompetence. Fully staff our airport right now, and stop putting Americans in danger."

One passenger traveling through Washington Dulles International Airport said many people were coughing and sneezing in the crowds, and that there was no separation between people who had been diagnosed with the virus.

In an opinion piece published in The Washington Post, Cheryl Benard wrote: "There was no attempt to enable social distancing; we were packed closely together. Two giant queues of people — one for US citizens and green-card holders and one for foreign nationals — wound their way through the cavernous hall."

"I counted and came up with approximately 450 people in each section, for a total of just under a thousand. Many were coughing, sneezing and looking unwell."

Experts currently believe the virus is mostly spread from person to person, "between people who are in close contact with one another (within about 6 feet)" and "through respiratory droplets produced when an infected person coughs or sneezes," the CDC said.

"These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs," it added.

Another passenger said he was able to get through Dulles quickly with his family after saying they had not been to any of the countries on Trump's travel ban, even though lots of people on his flight had.

Mike McGowan, who flew from London, told The Washington Post that many people on his flight had come from other parts of Europe on which Trump had imposed a travel ban, and where coronavirus cases are high.

Corona Screening lines in Chicago airport. After 7 hrs of lines and a missed flight we r still in line trying to reschedule a flight for tomorrow. Lord please be with us 🙏🏼 pic.twitter.com/eY8KbBlWTl

Multiple passengers travelling through American airports said officials were not wearing masks or visibly using sanitizer, and said their health forms were not looked at.

Sanitizer could help stop the virus from spreading to agents if they touch an infected object.

The CDC says that "a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth."

The CDC has also said that people do not need to wear masks unless they are sick, and that masks should be prioritized for caregivers.

James Millward, a history professor at Georgetown University, tweeted on Sunday night: "NO screening of passengers from Europe this evening at Dulles tonight, apparently. I guess keeping hundreds of us packed together for two hours last night was just for show. TSA didn't even collect med forms passengers had filled out."

Seems like Trump's chaotic last-minute "screening" that caused chaos and endangered 1000s of Americans on Friday was cancelled by Saturday. None in Dulles, none in Houston, either? TSA didn't even collect my wife's medical form on her rtn fr Spain & UK Saturday night. https://t.co/sPJX2979x7

He also said that he was asked by a health worker if he had been exposed to someone with the "China flu."

Trump and some Republicans have been criticized for calling the coronavirus — which causes the COVID-19 illness — names like the "China flu."

While the virus originated in China, there are now more cases in the rest of the world rather than in the country.

Newly hired EMT guy asking questions and taking my temperature at Dulles airport asked “have you been exposed to anyone with the China Flu?”

Another passenger at Dulles said their temperature was not checked, there was no hand sanitizer, and passengers shared pens to fill in immigration forms.

The CDC has warned that the coronavirus could stay on various surfaces for hours, or even days.

Fahim Hayat told The Post: "I'm a clean freak. So there were a lot of things I would have thought about twice."

@Dulles_Airport @CDCgov @NIH @thepointsguy @GovernorVA just landed Dulles from Europe. No social distancing. We are in lines jammed together. Staff don’t have masks or gloves. pic.twitter.com/KOY1SlXLKb