GLOBAL HEALTH SECURITYHantavirus at Sea: A Test for Global Health Security
Cruise ships can facilitate disease transmission because of close social interactions and shared environments. In the last two years, at least 4 major outbreaks have occurred on a cruise ship, including norovirus, Legionnaires disease, Salmonella and now hantavirus.
On May 2, 2026, the World Health Organization (WHO) received notification from the National International Health Regulations (IHR) Focal Point of the United Kingdom about an outbreak with respiratory symptoms aboard a cruise ship in the Atlantic. Although the cause of the outbreak was initially unknown, cases were later confirmed to involve the Andes strain of hantavirus. As of May 13, the WHO reported 11 total cases, including 9 confirmed and 2 probable cases. Three passengers succumbed to the disease, with the first death occurring on April 11. Of the three reported deaths, two were confirmed positive for hantavirus. Epidemiological investigations are underway to determine the source of exposure that led to the outbreak.
The cruise ship, the MV Hondius, operated by Oceanwide Expeditions, departed from the Argentine city of Ushuaia on April 1, 2026. Public awareness of the outbreak began on April 12, when a passenger released a video filmed during an onboard announcement regarding the death of an individual aboard the vessel the previous day, according to the operating company. The announcement triggered panic among passengers, prompting some individuals to disembark when the ship reached the island of Saint Helena in the south Atlantic. Those passengers subsequently travelled to several countries, including the United States, Canada, Turkey, New Zealand, Denmark, Sweden, Germany, the Netherlands, Saint Kitts and Nevis, Singapore, Switzerland, and the United Kingdom. At this point, the WHO had not yet been formally notified of the outbreak, raising concerns about whether exposed individuals may have already travelled internationally while incubating the virus. Health officials have since initiated contact tracing efforts to identify those who may have been in contact with these passengers as they returned to their home countries.
Hantavirus belongs to a family of viruses mainly spread by rodents. Transmission usually occurs when a person inhales aerosolized viral particles from rodent saliva, urine, or droppings. Hantaviruses generally cause two major syndromes: Hantavirus Pulmonary Syndrome (HPS), more commonly reported in Latin America and primarily affects the respiratory system, and Hemorrhagic Fever with Renal Syndrome (HFRS), more common in Europe and Asia and primarily affects the kidneys. The current outbreak involves HPS caused by the Andes strain of hantavirus. According to the U.S. Centers for Disease Control and Prevention (CDC), the Andes strain has an incubation period of 4 to 42 days.
Cruise ships can facilitate disease transmission because of close social interactions and shared environments. In the last two years, at least 4 major outbreaks have occurred on a cruise ship, including norovirus, Legionnaires disease, Salmonella and now hantavirus. Fortunately, the hantavirus has a relatively low basic reproduction number (R0), with limited person-to-person transmissibility and low pandemic potential. Following notification of the WHO, epidemiologists were dispatched to the cruise ship to investigate the outbreak while international contact tracing efforts continued for passengers who had previously disembarked.
