Concerns Rise Over Suspected Hantavirus Outbreak on Luxury Cruise Ship

Authorities suspect that hantavirus may have spread on a luxury cruise ship, resulting in three fatalities and raising new alarm over a disease that, while rare, has an alarmingly high mortality rate. The context of shifting climate conditions makes this situation particularly concerning.

Investigators are working to figure out what went wrong on the ship, which offers trips costing up to $28,845 for a 46-day voyage that includes visits to the Antarctica Peninsula and Tierra del Fuego at the southern tip of Argentina.

In addition to the three deceased passengers, a fourth was taken to a South African hospital for intensive care, and two crew members reported illness. The Dutch-flagged vessel stayed anchored off the coast of Cape Verde, roughly 400 miles from Senegal, rather than docking as originally planned.

Although hantavirus is not commonly found in the Americas, its grave case fatality makes it a significant public health issue, as noted by the World Health Organization. It appears more frequently in Asia and Europe, where various strains exist, and those strains have a lower mortality rate ranging from less than 1% to 15%.

Typically, hantavirus is transmitted through inhaling particles contaminated with the virus, often found in dried mouse urine, saliva, or droppings. There’s also the Andes virus strain that can spread from person to person, noted to have been transmitted in Thailand and Argentina.

What remains uncertain is which strain affected the ship. The first reported death occurred on April 11 while the vessel was traversing the Atlantic, and the cause could not be identified on board. The man’s body was taken ashore on April 24 when the ship docked at Saint Helena Island, approximately 1,100 miles off the African coast, with his wife accompanying the remains.

Sadly, the wife soon became unwell during the return journey and later passed away. The ship operator learned of her death on April 27. Both individuals were Dutch nationals. On the same day, another passenger from the UK became seriously ill and was evacuated to South Africa, where it was confirmed he had hantavirus.

A German passenger also died aboard the ship this past Saturday, and the ship operator announced on Monday that two crew members, one British and one Dutch, exhibited acute respiratory symptoms—one mild, the other severe—resulting in a need for immediate medical attention.

Dr. Peter Chin-Hong from UC San Francisco suggested that potential explanations for the suspected outbreak include rodents boarding the ship and potentially exposing passengers, or possibly even human-to-human transmission. “Could a crew member have inadvertently aerosolized contaminated rodent droppings during cleaning?” posed Dr. Elizabeth Hudson, a regional infectious diseases chief. “Was there a shore excursion that led to similar exposure?”

Given the rarity of hantavirus, its impact on the cruise industry remains speculative. COVID-19 had already severely hit this sector, but that was a pandemic characterized by rapid human-to-human spread. Investigators are keen to understand the transmission dynamics in this case.

The MV Hondius, operated by Oceanwide Expeditions—an eco-tour cruise line that focuses on Arctic and Antarctic voyages—has capacity for 170 passengers across 80 cabins. As of Monday, 148 individuals were aboard, including 17 from the U.S., and one deceased passenger still remained on the ship.

Sailing from Ushuaia, Argentina on March 20, the vessel made a round trip to the Antarctica Peninsula and was initially scheduled to return on April 1, after heading back to Cape Verde with stops at various Atlantic islands.

Hantavirus in the Americas tends to affect small blood vessels in the lungs, leading to leakage that severely impairs breathing. “It feels like drowning,” explained Dr. Chin-Hong. “Fluid fills the lungs, making it incredibly difficult to breathe.”

The virus, particularly in its American strains, commonly leads to a cardiopulmonary syndrome, affecting both heart and lung function, according to Dr. Gaby Frank from Johns Hopkins Special Pathogens Center. Notably, hantavirus can carry a case fatality rate as high as 50% in this region.

There are no vaccines or targeted antiviral treatments available for hantavirus at present. Medical professionals often utilize life-support machines to assist breathing, which is intensive and contributes to the high fatality rate, per Chin-Hong.

Some experts predict hantavirus could increasingly cause concern in the future, driven by climate change, which might support animal populations associated with such diseases. For instance, changes in rainfall could lead to growing rodent populations over time, which poses a risk for deeper outbreaks.

In the U.S., around 30 hantavirus cases are typically reported each year, a figure that has remained consistent. However, there seems to be increased media focus on the disease lately, as noted by Hudson.