Hantavirus outbreak in a cruise departing from Argentina

The World Health Organization has confirmed ten cases including three deaths of hantavirus infection on the Dutch cruise ship Hondius, which anchored in Cape Verde during the first days of May 2026. He had left on March 20 from Ushuaia, in the Argentina Tierra del Fuego. Its destination was the Canary Islands. Three weeks after leaving, a Dutch couple and a German tourist developed respiratory symptoms and died. A sick British passenger was disembarked in South Africa and is doing well in an intensive care unit. There were three other passengers with symptoms, although the infection did not worsen. All people in the ship were tested and isolated in quarantine. There were 59 crew members and 74 passengers.

Hantavirus is a single-stranded RNA virus, like the flu virus and the COVID-19 coronavirus. The genome has about 12,000 nucleotides and is divided into 3 fragments: large, medium, and small. There are two main variants. The Eurasian, which causes kidney failure, and the American, which causes a pulmonary syndrome. Mortality from hantavirus infection can be high, 30-35%. There are no antivirals or vaccines.

The incubation period is long, from 1 to 4 weeks. The initial symptoms are flu-like, with headache, fever, and dyspnea. It can evolve into respiratory distress and cardiovascular shock. Many symptomatic patients require care in intensive care units, with hydroelectrolyte and hemodynamic support. The diagnosis is molecular and serological.

Human infection by hantavirus is a zoonosis, that is, there is an animal reservoir, which are small mammals and rodents. The virus causes chronic infection in animals without symptoms. They become carriers and eliminate particles in the feces and urine. Inhalation of particles in aerosols when sweeping or in enclosed spaces results in hantavirus infection in humans by inhalation. Most cases are acquired in rural and forest areas. Cases of human-to-human transmission for hantaviruses of the Andes variant have only been demonstrated when there is close contact.

In Asia, an infection rate of 6% has been reported in rodents in Indonesia and Singapore (Guo et al., PLoS Negl Trop Dis 2026). In Europe, there are sporadic cases in Germany, Finland, and the Balkans. In Argentina, 50-100 human cases are reported each year. The outbreak of hantavirus in Yosemite Park in 2012 is famous, when a dozen visitors who slept in cabins were infected, and there were three deaths (Nuñez et al., Emerg Infect Dis 2014).

At Christmas 2018, there was an outbreak in Argentina of 34 confirmed cases of hantavirus in the province of Chubut, bordering Patagonia. Eleven patients died. The index case transmitted the virus to three other patients during mass social gatherings, and there was evidence of several “super-spreaders” (Martínez et al., N Engl J Med 2020). It is very likely that in the current outbreak of hantavirus on the cruise ship, the Dutch couple who died at the beginning had been infected on land before starting the marine expedition. The close coexistence on the ship with the rest of the passengers and crew members while visiting Antarctica for a month was the catalyst that allowed the spread of the virus.