An American doctor stranded on a cruise ship infested with hantavirus said the luxury vacation descended into panic amid the deadly outbreak.

Dr Stephen Kornfeld boarded the MV Hondius cruise ship in Argentina last month expecting the trip of a lifetime but his plans were upended when a Dutch couple were struck down with the virus. 

Health officials believe they contracted the disease on a birdwatching trip to an Argentinian landfill. The 70-year-old husband was the first passenger to die from the virus on April 11 before his wife also succumbed on April 24. 

Kornfeld told CNN that he 'fell into the role of becoming the ship doctor' after the onboard medic was also sickened by the virus.

So far at least eight passengers have been identified with the infection, including three people who have died. 

Kornfeld is among 17 Americans stuck on board with 129 other passengers as it makes its way to the Spanish island of Tenerife.

His situation has led his local Oregon Congresswoman Janelle Bynum to call for his immediate repatriation to the US.

The doctor explained how he took action when the first man fell ill and the situation rapidly deteriorated as 'over 12 to 24 hours, it became clear there were a number of people sick and they were getting sicker.' 

He said passengers were showing 'a lot of confusion, a lot of weakness' and panic set in as the rat-borne hantavirus, which has a mortality rate of approximately 40 percent, tore through the ship. 

Kornfeld explained the ship's doctor and two more people became seriously ill within a day and were showing 'a lot of fever, fatigue, flushing, some gastrointestinal issues, some shortness of breath.' 

'The fear with hantavirus is you can go from seriously ill to critically ill very quickly,' he said. 

His local representative Bynum revealed she has been in contact with Kornfeld as she slammed the Trump administration for 'abandoning' US citizens on board. 

Bynum said in a statement on Friday that after speaking with Kornfeld and hearing of the other US citizens left on the ship, she feels they have been let down by the government in their time of need.

'They have no guidance and no support to ensure their safe return home,' she said. 

Bynum criticized officials for a lack of urgency in solving the crisis or deploying health officials to support the passengers. 

'This outbreak was first publicly reported at least four days ago,' she wrote in an open letter to US Secretary of State Marco Rubio and Centers for Disease Control and Prevention Acting Director Jay Bhattacharya.

'Despite the severity of the situation, my office has seen no evidence of a sufficient federal response to protect the Americans on board or to ensure their safe return home.' 

In a video posted to X, Bynum added that she shared her letter to pressure the White House into making a 'real plan to get the Americans home safely and healthy.'

The hantavirus outbreak has sparked panic among health officials over the potential for the deadly virus to spread, after it emerged that dozens of passengers were allowed off the ship without being informed of the risks. 

Following the deaths of the Dutch couple last month, a German woman died from the virus on May 2. 

At least two more victims are in critical condition in hospitals in South Africa and Switzerland, and health officials are monitoring dozens more people who left the ship or may have come in contact with the infected across the globe. 

Hantavirus can have an incubation period of over a month before patients begin showing symptoms, leading to fears that infection rates could skyrocket if the virus is not monitored effectively. 

Kornfeld said he is relieved that those already showing symptoms were able to get off the ship and are receiving treatment, saying that hantavirus can be a catastrophic virus if it gets out of control.

'What happens with hantavirus, ultimate survivability is really dependent on your ability to get critical care at the right time. On the boat, that would not be possible,' he said. 

Amid claims that the cruise ship failed to contain the deadly virus before letting passengers disembark, Turkish vlogger Ruhi Cenet shared footage of captain Jan Dobrogowski reassuring passengers after the first Dutch man died. 

The captain was seen in footage holding a briefing with passengers to share the news that the man had died on April 11, but he said that the death was due to 'natural causes' and there was no threat to others.

'Tragic as it is, it was due to natural causes, we believe,' Dobrogowski said. 'And also whatever health issues he was struggling with, I’m told by the doctor, were not infectious, so the ship is safe when it comes to that.

'The ship is safe. This gentleman, unfortunately, succumbed to natural causes. And like I say, we do what we can in order to continue in a safe and dignified way.'

Cenet slammed the captain for failing to realize the gravity of the situation.

'It turns out we were not well informed,' he told NBC News. 

In response to Cenet's video, the ship's operator, Oceanwide Expeditions, said it was 'aware' of the announcement. 'We want to provide clarity on this video,' the company said.

At the time the captain spoke to passengers, the firm said: 'The cause of death of this individual was unknown.'

'No other symptomatic individuals were present on board. At the time of the announcement, no evidence of a virus or contagion was present on the vessel. The case was believed to be isolated following medical review.'

The company added that 'proper procedure was followed in informing all guests and crew aboard MV Hondius.

'Health and safety and maritime standards regarding the proper management and reporting of a death while at sea were followed.'