Experts Explain Why Hantavirus Spread Now – And What's Next for the Cruise Passengers

When news broke of a deadly hantavirus outbreak aboard the cruise ship MV Hondius, the images were uncomfortably familiar – a deadly virus moving through the tight confines of an international cruise ship, and officials racing to trace contacts across multiple countries.

The Dutch-flagged ship left Ushuaia, Argentina, on 1 April and has since been linked to at least ten confirmed or suspected cases, including three fatalities, with passengers now in isolation across the US, Canada, and Europe.

Passengers are evacuated by small boat from the MV Hondius in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain. | Source: Getty Images

But health experts say the similarities to COVID-19 largely end there.

'Memories That None of Us Have Fully Put to Rest'

The emotional response was almost automatic. A cruise ship, close quarters, shared dining rooms, and passengers unable to leave. For anyone who lived through 2020, the setting felt like a rerun of something deeply unsettling.

But even as comparisons to COVID-19 spread online, global health officials insisted the similarities were largely superficial.

“This is not another COVID-19,” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said.

A passenger carries their belongings in a plastic bag to a waiting bus after being evacuated from the MV Hondius after docking in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain. | Source: Getty Images

In an unusually direct move, World Health Organisation Director-General Dr. Tedros Adhanom Ghebreyesus posted an open letter to the people of Tenerife, where the MV Hondius was due to dock. "I know you are worried," he wrote:

The Biology That Changes Everything

The comparison to COVID is understandable. The fear is not irrational, but the science tells a very different story.

Experts say that once you look past the headlines, the biology of hantavirus is fundamentally different from the virus that brought the world to a standstill five years ago.

CBS News medical correspondent Dr. Céline Gounder offered a vivid analogy. COVID-19, when it first appeared, was like dry forest in high winds — conditions ripe for a wildfire. Hantavirus, she said, is more like "a wet log in a stone fireplace." It smoulders, it does not explode.

Health workers in protective gears transfer patients with an ambulance after three suspected cases of hantavirus is evacuated from a ship in Praia, Cape Verde, on May 6, 2026. | Source: Getty Images

The difference starts with how the virus behaves inside the human body.

A central reason for that is where the virus takes hold in the body. Unlike COVID, which targets the upper respiratory tract and spreads easily through the air, hantavirus infects deep inside the lungs.

That makes it significantly harder to cough or breathe out enough of the virus to infect another person. Transmission requires prolonged physical contact with someone who is already showing symptoms.

The first passengers from the MV Hondius depart for Tenerife Airport, escorted by a member of Spainâs External Health Service, after disembarking at Granadilla Port in Tenerife, Canary Islands, on May 10, 2026. | Source: Getty Images

That alone dramatically limits the virus’s ability to spread widely.

The Andes virus strain involved in the MV Hondius outbreak is found in South America and is the only known strain capable of spreading between humans.

It has been found in areas where the Dutch couple at the centre of the outbreak had travelled before boarding the ship. The husband fell ill first and passed away several weeks before his wife.

Passengers carry their belongings in plastic bags after being evacuated from the MV Hondius after docking in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain. | Source: Getty Images

At a WHO briefing on 7 May, Maria Van Kerkhove, the organisation's director of epidemic and pandemic preparedness and prevention, was direct. The virus spreads "very, very differently" from COVID and influenza:

Admiral Brian Christine of the US Department of Health and Human Services reinforced that message at a briefing in Nebraska.

Medical teams and officials prepare for passengers to arrive after the MV Hondius docked in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain. | Source: Getty Images

Officials say the Andes strain is difficult to transmit and generally requires extended close contact with someone already showing symptoms. Still, authorities have treated the outbreak with caution from the outset.

A Quiet Crisis Building Before the Ship Set Sail

The outbreak aboard the MV Hondius may have captured international attention, but the warning signs had been building for months. Behind it lies a broader trend building quietly across South America. And that trend began long before the ship ever left port.

Cruise ship MV Hondius stationary off the port of Praia, the capital of Cape Verde, on May 4, 2026. | Source: Getty Images

Hantavirus cases in Argentina have almost doubled in the past year. The current season, which began in June 2025, has already seen 101 confirmed cases compared with just 57 during the same period the year before.

The country has recorded 32 fatalities, one of the highest lethality rates in recent years, and a rise of ten percentage points from the prior year.

Experts are pointing to climate change and habitat destruction as significant contributing factors. The virus is typically linked to rural and peri-urban environments and spreads through contact with the urine or faeces of infected rodents.

Health personnel returning from the cruise ship MV Hondius, are seen at the port of Praia, the capital of Cape Verde, as individuals wearing hazmat suits are helped into an ambulance on May 6, 2026. | Source: Getty Images

As temperatures shift and ecosystems are disrupted, those rodents are increasingly moving into new territories.

Eduardo López, an infectious disease specialist who advised the Argentine government during the Covid-19 pandemic, explained that the long-tailed mouse, the main carrier of the virus in Argentina and Chile, is proving highly adaptable to environmental changes.

That adaptability is creating more opportunities for human exposure.

A person in a hazmat suit is escorted to a ambulance from a medical aircraft allegedly carrying some of the passengers from the cruise ship MV Hondius believed to be infected with hantavirus, at Schiphol airport near Amsterdam on May 6, 2026. | Source: Getty Images

Roberto Debbag, vice president of the Latin American Society of Vaccinology, pointed to forest fires as another driver, pushing both humans and wildlife into unfamiliar areas. He said:

Argentine authorities are currently tracing the route taken by the Dutch couple, who crossed into Chile and Uruguay on several occasions before boarding the MV Hondius.

Passengers being disembarked from the MV Hondius and head by coach to the airport at Granadilla Port in Tenerife, Canary Islands, Spain on May 10, 2026. | Source: Getty Images

The exact origin of their infection remains unknown.

One Woman's Account of How Fast It Takes Hold

For anyone trying to understand what this illness actually does to a body, Jennifer Benewiat's account leaves little to the imagination. The Kansas woman survived hantavirus in 2010 and has spoken publicly about her experience as concern over the current outbreak has grown.

Jennifer Benewiat shares her experience with hantavirus 16 years ago | Source: YouTube/FoxNewsClips

She first noticed something was wrong during a drive home from a Christmas dinner with her father. She recalled to Fox & Friends:

Within days, she was struggling to breathe and was put on a ventilator. Her heart stopped three times in ten days. Doctors had initially missed a lung X-ray that would have revealed her lungs were already filled with fluid.

Benewiat’s account shows how quickly hantavirus symptoms can become life-threatening, which helps explain why health officials are continuing to closely monitor exposed passengers.

What Happens Now for the MV Hondius Passengers

Eighteen American passengers were flown back to the US on a government-chartered aircraft and are being monitored at the National Quarantine Unit at the University of Nebraska Medical Center.

Passengers carry their belongings in plastic bags after being evacuated from the MV Hondius after docking in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain. | Source: Getty Images

One has tested positive.

Another has mild symptoms.

Both travelled in biocontainment units on the flight.

Seven Canadian passengers are self-isolating in British Columbia and Ontario for a minimum of 21 days, with monitoring that could extend to 42 days depending on whether symptoms emerge. Canadian officials say none have shown signs of infection so far.

Aerial view shows health personnel assisting patients onto a boat from the cruise ship MV Hondius, while stationary off the port of Praia, the capital of Cape Verde, on May 6, 2026. | Source: Getty Images

The CDC recommends a 42-day monitoring period from the last known exposure, with immediate self-isolation if a fever or any other symptoms develop. Former FDA Commissioner Scott Gottlieb said over the weekend that those exposed during the outbreak are "nearing the end of the transmission window."

Health officials say the outbreak appears contained, and experts continue to stress that the risk to the wider public remains extremely low.

Passengers being evacuated from the MV Hondius after docking in the Granadilla Port on May 10, 2026 in Tenerife, part of the Canary Islands, Spain | Source: Getty Images

But investigators are still trying to determine exactly where the Dutch couple first encountered the virus — a reminder that even rare diseases can become global concerns in an age of constant international travel.

For many passengers and observers, however, the Hantavirus outbreak has already exposed something else entirely: how quickly the world still snaps back into pandemic mode whenever disease crosses borders.