An American man who contracted the coronavirus while a passenger on the Diamond Princess cruise ship has warned that the virus hits 'hard and fast' after he rapidly fell ill on his flight home to the United States.

Carl Goldman, 66, left the U.S. in January for a 16-day cruise around eastern Asia with his wife Jeri Seratti-Goldman, joining the cruise that has seen six coronavirus deaths.

He finally returned to the U.S. on February 17 and had to be brought to hospital by stretcher after falling ill with the coronavirus, despite walking onto the plane an apparently healthy man.

Goldman said that the virus, which has now claimed almost 3,000 lives globally, struck him out of nowhere causing a high fever after he displayed no symptoms at all during the two weeks he spent in quarantine in Japan.

The couple is now at a bio-containment facility at the University of Nebraska Medical Center in Omaha where Carl is still testing positive for the disease.

Carl Goldman on a stretcher being taken to Nebraska after he contracted the coronavirus

Carl Goldman, pictured with his wife Jeri, was a passenger on the Diamond Princess cruise ship. Six people have died and over 700 were diagnosed with the coronavirus from the ship

A bus arrives near the cruise ship Diamond Princess which was placed in quarantine after dozens of passengers tested positive for coronavirus, may others were diagnosed after release

'I had a bit of a cough, but I chalked it up to the dry air in the cabin,' he said of his flight back to the U.S. as he was evacuated from Japan.

Goldman said that exhausted from departing the ship, he fell asleep but woke up feeling that he had a fever.

'When I woke up about two hours later, I knew I had a high fever,' he told ABC News.

'My wife touched me and she knew I was burning up. I went up to the military doctors, they took my temperature and immediately put me in a quarantine area.'

Goldman added that the coronavirus 'hits very, very fast' and that a person 'can go for days feeling fine' despite having the illness.

'We could have been exposing so many people to the virus not knowing we had it,' he said.

The cruise ship was first warned of the onboard outbreak on January 17 when a passenger who had disembarked a few days earlier tested positive.

It quickly turned back to Yokohama in Japan where the entire ship was kept in quarantine for two weeks.

Goldman and his wife left the quarantine believing that they had avoided contracting the disease until Carl took ill.

Over 700 other passengers have been diagnosed with confirmed cases, six of whom died.

Jeri Goldman continues to test negative for the virus, despite sharing a room with her husband during the ship's quarantine.

Carl Goldman claims that the virus is no worse than a cold or flu and his symptoms were 'mild'

Carl Goldman, far right, and his wife Jeri Seratti-Goldman, below him, with another couple aboard the Diamond Princess cruise ship where Carl contracted the coronavirus

Goldman already lives a fit and healthy lifestyle having gone skiing for his 60th birthday

Although falling in the older age range which evidence shows places Carl Goldman at higher risk of both contracting the virus and it proving to be fatal, the disease has not worked to slow him down.

The 66-year-old posts online from his confinement about trying to beat his steps each day, continuing the active lifestyle which saw him go skiing to celebrate his 60th birthday as he warns that exercising is the way to remain healthy.

While the virus appeared to hit him from out of nowhere, he described his other symptoms as 'mild' and that he felt worse when he contracted bronchitis.

'I am in my late 60s, and the sickest I've ever been was when I had bronchitis several years ago. That laid me out on my back for a few days,' Goldman wrote in an op-ed for the Washington Post.

'This has been much easier: no chills, no body aches. I breathe easily, and I don't have a stuffy nose. My chest feels tight, and I have coughing spells. If I were at home with similar symptoms, I probably would have gone to work as usual.'

When the couple landed back in California, they and 11 other infected evacuees were flown immediately to the center in Nebraska but Goldman was already showing signs of improvement by the time he reached Omaha.

'The good news is my fever broke by the time I came to the hospital. I had a little fever, mild fever the first day. And then over a night ago, I had a little fever as well, that just came for about an hour and then disappeared,' he said.

While he is still testing positive for the virus, he told NPR that all he has is a 'little cough still'.

'My voice is a bit raspy, and I'm a little fatigued, but that may be also because of the jet lag and the travel and everything else on top of it,' he said.

'It doesn't feel any different than recuperating from a regular cold.'

A picture taken by Jeri Seratti-Goldman as the couple arrived back in the United States

Bus carrying the passengers from the quarantined Diamond Princess cruise ship leave the port

Goldman also warned that there is no need to panic about the virus as it will have less of an impact than the flu.

'I think just have a thermometer... don't panic with this, and realize that this is going to be less of an impact in terms of deaths than the flu is each season,' Carl told Fox News when asked for advice.

He adds that he seems to have been given 'gallons and gallons' of Gatorade while in quarantine which has helped to ward off any dehydration.

Goldman has been keeping an on-going journal of his experience via the website for the radio station he owns, offering some tips to beat off any symptoms.

'The advice I relay in all my interviews is to purchase a good digital thermometer for each person at home, drink warm fluids, put fresh ginger in warm water, and exercise,' he writes.

'All will push body temperatures up. It appears the coronavirus, COVID-19, like the flu bug, does better in cold environments. It doesn't like the heat.

'My wife also wisely advises to refrain from our typical California greeting of hugs and kisses. We should segue to the Japanese custom of a simple bow.'

The couple, who have been married for 29 years, are both still separated in quarantine but are able to call each other from their separate cells. They haven't seen each other face-to-face in almost two weeks despite being in the same building.

'The time has passed more quickly than I would've expected. With my laptop, I get as much work done as I can, remotely. I catch up with friends. I take walks around my room, trying to take a thousand more steps each day. I also watch the news,' Goldman writes.

'It's surreal to see everyone panic - news conferences, the stock market falling, school closures - about a disease I have. It does seem likely that coronavirus will spread in the U.S., but it won't help anybody if we all panic.

'I have been relatively fortunate: At least six Diamond Princess passengers have died from the virus, of the around 705 passengers who caught it. But coronavirus doesn't have to be a horrible calamity,' he added.

'If you told me when I left home in January that I wouldn't be back until March - that, instead, I would be confined for more than 24 days because I'd catch a novel virus at the center of what could become a pandemic - that would have completely freaked me out. But now that it's happening, I'm just taking it one day at a time.'

A top Japanese government adviser has now claimed that the quarantine on board the Diamond Princess cruise ship may have been flawed, allowing for further transmission of the disease to other passengers and staff.

'We suspected some of the cruise staff may have already been infected, but ... they had to operate the cruise ship itself, they had to see the passengers, they had to deliver the meals,' said Dr. Norio Ohmagari, the director of the Disease Control and Prevention Center at the government-funded National Center for Global Health and Medicine.

'So that may have caused some close contact with the cruise ship workers and also the passengers.'