An outbreak of hantavirus has been reported on the Dutch-flagged cruise ship MV Hondius, anchored off the coast of Cape Verde in the Atlantic Ocean. This virus can result in severe illness in humans, with a mortality rate of up to 50%.

So far, seven individuals have been infected, with three fatalities confirmed.

Understanding Hantavirus

Hantaviruses are a category of viruses carried by rodents known to cause severe illnesses in humans. Infection typically occurs through exposure to infected rodents or their urine, feces, or saliva.

Different hantaviruses cause various clinical syndromes across the globe. In the Americas, they can lead to a severe illness known as hantavirus cardiopulmonary syndrome (HCPS), which has a fatality rate of about 50%. In Europe and Asia, they primarily cause hemorrhagic fever with renal syndrome (HFRS), affecting kidneys and blood vessels.

It is estimated that there are 10,000 to over 100,000 hantavirus infections annually worldwide, with the highest rates in Asia and Europe.

The specific strain of hantavirus affecting those on board the ship remains unidentified. “There are multiple species, at least 24, that can be harmful to humans,” says Adam Taylor, a researcher at Lancaster University, UK. “Until we determine which strains are involved, we cannot fully understand the situation.”

Where Was the Ship Located?

The World Health Organization (WHO) has been notified of this outbreak. On May 2, a statement announced an outbreak of severe acute respiratory illness onboard the MV Hondius, including two fatalities and one critically ill passenger.

The cruise departed from Ushuaia, Argentina, on April 1, 2026, and traveled across the South Atlantic, with stops including Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, St. Helena, and Ascension Island. WHO identified the Argentine port as a focal point for investigations into the outbreak due to the presence of the Andes virus, known for limited person-to-person transmission in South America.

A total of 147 individuals from 23 nationalities were onboard, consisting of 88 passengers and 59 crew members. The extent of contact with local wildlife during the voyage remains unclear, as per WHO’s statement.

What Are the Symptoms of Hantavirus?

Initial symptoms may include fever, muscle aches, headaches, and gastrointestinal issues. Some patients may develop respiratory complications. Diagnosis typically involves specialized blood tests.

How Does Hantavirus Spread?

The primary route of infection is contact with infected rodents, particularly through inhalation of virus particles from contaminated rodent droppings, urine, or saliva.

“For this reason, investigations often focus on potential exposure to rodent-contaminated areas,” stated Roger Hewson from the London School of Hygiene and Tropical Medicine. “Hantaviruses are not generally believed to be easily transmissible between humans.”

While rarer, infection may also occur through rodent bites. High-risk activities include cleaning poorly ventilated spaces, farming, and sleeping in rodent-infested environments. According to WHO, human-to-human transmission has only been recorded for the Andes virus in the Americas, occurring with close and prolonged contact, mainly among family and intimate partners, particularly during the early stages of the disease.

Current Outlook on the Infection Spread

According to Taylor, there is no need for panic. “Transmission of hantaviruses usually requires contact with animal products, not person-to-person contact,” he emphasized. “While precautions are in place on board, they are just that—precautions.”

Hewson added that it’s crucial not to make assumptions based on the cruise ship context. “Infection confirmation among passengers does not clarify whether the exposure occurred on the ship, prior to embarkation, during shore excursions, or through common environmental contact,” he remarked. “Therefore, public health surveillance, lab confirmations, and possible virus sequencing are vital.”