Is Hantavirus Human-To-Human Transmissible?

News outlets and the media are flooded with reports on the ongoing hantavirus outbreak aboard a cruise ship in the Atlantic Ocean. As the story develops, concerns about human-to-human transmission of the virus are rising.

“While that is always concerning, it is not unheard of,” said Marilyn N. Bulloch, PharmD, BCPS, FCCM, SPP, associate clinical professor and director of strategic operations at the Harrison College of Pharmacy, Auburn University. “It has been documented for certain strains, even those found in the American continents. When this has occurred, it’s been with very close and prolonged contact—so the situation on the cruise ship is not as surprising as it would be in a regular community.”

The most recent update involves a passenger on the ship who was receiving treatment at a hospital in Zurich, Switzerland, after having received an email from the ship's operator about the situation. A British patient was being treated in South Africa and, although in serious condition, was reported to be improving. An additional 3 passengers were medically evacuated from the ship on Wednesday, May 6, 2026, and were being flown to the Netherlands.¹

Additionally, 26 passengers who may have been exposed to hantavirus disembarked on April 24, 2026—about 2 weeks before the formal reports were issued. Among these passengers were Americans who are now back in the US. Health officials are working to contact these individuals for testing and monitoring.²

The World Health Organization confirmed that the strain identified in the patients is the Andes strain, the only known human transmissible hantavirus. This strain is primarily found in Argentina and Chile and is particularly serious, with a fatality rate of approximately 40%. Contracting the Andes strain requires prolonged, close contact with infected individuals. The onset of symptoms can happen anywhere between 1 and 8 weeks.^3,4

There is no treatment for hantavirus pulmonary syndrome (HPS), the disease caused by hantavirus. HPS is associated with a wide array of symptoms and complications affecting the heart and lungs. As the disease progresses, symptom severity increases.⁴

“What may be surprising is just how long people are sick with this virus,” said Bulloch. “We’re sort of used to being sick with a virus for a week, maybe two. Not hantavirus. It’s months. Symptoms may not even appear for 8 weeks after exposure.”

According to Bulloch, fever typically presents within 1 to 7 days of infection, whereas hypotension, when it occurs, tends to emerge more rapidly—often within the first 3 days. Between days 2 and 6, patients may develop oliguria, followed paradoxically by polyuria around the second week.

A wide range of additional symptoms can arise, including gastrointestinal distress, headaches, cardiac complications, and cough. Recovery is generally prolonged, with many patients remaining in a convalescent state through months 3 to 6, often left physically weakened by the burden of the illness. Even beyond this period, shortness of breath may persist for up to 2 years.

In addition to a lack of treatments, there are no approved vaccines or preventive alternatives to sanitation and reduced exposure. The populations most affected are in more rural areas and those who work in agriculture or encounter rodent infestations in enclosed spaces, such as barns. Individuals with an increased risk of exposure should maintain proper sanitation methods regarding personal hygiene and potential contaminated areas.⁴

“They have studied potential treatments, including repurposed drugs like ribavirin or certain flu medicines like baloxavir,” explained Bulloch. “But monoclonal antibodies produced from convalescent patients seem to have shown the most benefit, at least toward hantavirus. They do have vaccines in development, but how ready they are for human testing remains uncertain.”

The MV Hondius cruise ship is set to dock at the Port of Granadilla in Tenerife, Canary Islands, where passengers will be allowed to debark. The Madrid military base will be responsible for managing quarantine for passengers with symptoms. Asymptomatic passengers are permitted to return to their countries of origin.³

REFERENCES

1. Roeloffs MW. Hantavirus-infected cruise ship: deadly Andes strain identified (latest updates). Forbes. May 6, 2026. Accessed May 6, 2026. https://www.forbes.com/sites/maryroeloffs/2026/05/06/hantavirus-infected-cruise-ship-deadly-andes-strain-identified-latest-updates/

2. Fiore K. Some hantavirus cruise passengers are back in the U.S. May 6, 2026. Accessed May 6, 2026. https://www.medpagetoday.com/special-reports/exclusives/121146

3. Peyton N, Meijer BH. Hantavirus-hit cruise ship evacuates 3 passengers, expected to head next to Spain. Reuters. May 6, 2026. Accessed May 6, 2026. https://www.reuters.com/business/healthcare-pharmaceuticals/two-cases-hantavirus-which-spreads-human-to-human-linked-ship-south-africa-says-2026-05-06/

4. Chen RX, Gong HY, Wang X, et al. Zoonotic Hantaviridae with global public health significance. Viruses. 2023;15(8):1705. doi:10.3390/v15081705