The Andes Hantavirus: How a Rare "Person-to-Person" Strain Turned a Luxury Cruise into a Global Health Race

CAPE VERDE — A rare and lethal respiratory virus has turned a nature expedition into a global public health emergency. As of May 6, 2026, the World Health Organization (WHO) has confirmed that at least eight people associated with the MV Hondius cruise ship have fallen ill with the Andes strain of hantavirus, a pathogen notable for its unique ability to spread directly between humans.

The outbreak has already claimed three lives. The victims include a Dutch couple and a German national, while several others remain in critical condition. One British passenger was medically evacuated to South Africa, where he remains on a ventilator, though doctors report his condition is slowly improving.

The Mystery of the "Andes" Strain

Most hantaviruses found in the United States, such as the Sin Nombre virus, are considered "dead-end" infections. This means a human can contract the virus from rodent droppings or urine, but they cannot pass it to another person. The Andes strain, primarily found in Argentina and Chile, is the terrifying exception.

"There is very limited experience handling this virus," says Dr. Gustavo Palacios, a microbiologist at the Icahn School of Medicine at Mount Sinai. Palacios, who helped investigate a similar 2018 outbreak in Epuyen, Argentina, that killed 11 people, warns that the Andes strain is particularly deceptive.

While the virus typically requires close proximity to spread, researchers have found that it can be transmitted during incredibly brief social interactions—such as crossing paths in a hallway—if the encounter happens during the patient's peak infectious window.

Short Window, Long Wait

Experts have identified two major challenges in containing the current cruise ship cluster:

• The 24-Hour Window: A person is most infectious on the exact day they develop a fever. Because the symptoms start as a general "flu-like" feeling, many patients may be out in public during their most contagious moments.

• The 45-Day Incubation: Unlike the common cold or COVID-19, hantavirus has a long incubation period. It can take up to six weeks for a person to show symptoms after exposure, making contact tracing for passengers who have already disembarked and flown home a monumental task.

On Wednesday, Swiss authorities confirmed that a passenger who flew home to Zurich after leaving the ship has tested positive, sparking immediate contact tracing efforts for everyone on that individual's commercial flights.

From Ground Zero to Global Ports

The MV Hondius departed from Ushuaia, Argentina, in early April, carrying many avid birdwatchers who had spent time in South American agricultural regions before boarding. In these areas, the virus is carried by the long-tailed pygmy rice rat.

While the WHO maintains that the overall risk to the general public remains low, the agency has classified hantaviruses as "priority pathogens" due to their high mortality rate, which can reach 40 percent.

The tragedy hits home for many Americans following the high-profile death of Betsy Arakawa, wife of actor Gene Hackman, who passed away from a hantavirus infection in 2025. Health officials urge anyone who has recently traveled to South America or been in contact with rodents to seek immediate medical attention if they experience sudden fever, deep muscle aches, or shortness of breath.

For now, the MV Hondius remains anchored off the coast of West Africa as international teams coordinate the safe evacuation and isolation of the remaining passengers.

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