A Hantavirus Outbreak at Sea, and the Challenges of Dealing with Spreading Infections on Board Cruise Ships
MV Hondius, a “purpose-built vessel for polar expedition cruising”, departed the Argentinian port of Ushuaia, the southernmost city in the world, on 1 April 2026, carrying 88 passengers and 59 crew members from 23 countries. What was meant for many to be the cruise of a lifetime, as they sailed through the spectacular wildernesses of the South Atlantic, soon turned into unmitigated tragedy as several people fell ill between 6 and 28 April. A 70-year-old Dutch national became the first passenger to die on the ship on 11 April. His 69-year-old wife was flown on 24 April from St Helena to Johannesburg, where she succumbed two days later. Both victims tested positive for hantavirus. A British national was evacuated on 27 April for intensive care treatment in Johannesburg. A German passenger died on the ship on May 2- the day the outbreak was notified to the WHO. The following day, MV Hondius was anchored off the coast of Cabo Verde. As of 4 May, according to the WHO, a total of two laboratory- confirmed and five suspected cases of hantavirus had been identified on board MV the ship. The seriously- ill ship’s doctor, a Dutch national, was flown to the Canary Islands on 5 May. Meanwhile, passengers have been allowed off the ship at Cabo Verde, which lacks the “necessary capabilities” to process them.
MV Hondius, which sails under the Dutch flag and offers four-star accommodation for up to 170 passengers, is operated by the highly-rated Oceanwide Expeditions, a cruise line company based in Vlissingen in the Netherlands. In response to the outbreak, all passengers have been confined to their cabins, awaiting further instructions. The Spanish government initially agreed to receive the vessel at the Canary Islands, about a thousand miles northeast of Cape Verde, where public health officials would screen, treat, and transfer passengers as necessary. Since then, the regional government of the Canary Islands, which is led by political opponents of Spain’s Socialist central cabinet, has stepped in, citing public safety concerns, and refused permission to let the ship enter its waters.
Hantaviruses can be found all over the world. These viruses are carried by rodents, such as mice or rats, and transmitted to humans by their urine, saliva, faeces (droppings), and nesting materials. Humans can be infected when they inhale contaminated air, or through the skin via bites, scratches, or pre-existing cuts. Rodent-to-human transmission usually occurs in rural areas, such as farms, fields, and forests, where rodents coexist with people. Human-to-human transmission is rare, requires close and prolonged contact, and has been reported with previous outbreaks of Andes virus-a species of hantavirus that is endemic to Argentina and Chile. The precise source of the present cluster of infections has yet to be identified, and no rodents have been identified on board the MV Hondius.
Hantavirus infection initially presents with non-specific flu-like symptoms of fever, fatigue, muscle pain, headache, dizziness, nausea, abdominal pain, vomiting, and diarrhoea. Symptoms usually develop anywhere between one and eight weeks after hantavirus exposure and can vary in severity. Some of those infected can develop more severe disease, and even die from their illness. Two specific syndromes can develop over time: hantavirus pulmonary syndrome (HPS), which manifests as cough and shortness of breath and can damage the lungs, and haemorrhagic fever with renal syndrome (HFRS), which can lead to kidney failure. Acute infections can be diagnosed by testing for antibodies to hantavirus. No preventative vaccine or specific approved anti-viral treatment is available. Supportive care, including rest, hydration, and management of symptoms, forms the mainstay of treatment.
The current hantavirus outbreak brings into focus the problems of treating outbreaks of infectious diseases at sea. The concept of quarantine was indeed developed in medieval times to isolate passengers arriving by ship from plague-infected areas. By itself, the isolation and benign neglect of potentially infected passengers is no longer enough to satisfy the more exacting standards of today. The logistics of how best to detect, investigate, isolate, manage, and control the spread of infections that emerge aboard ships, especially the mega-cruise liners of today, can be most challenging. Liaison with the closest competent onshore authorities can be affected by political considerations and by varying public health regulations. The current hantavirus outbreak highlights some of the difficulties in dealing with infections on board ship and should hopefully guide future global policy-making on this matter. Luckily, the hantavirus is not highly contagious, and the wider public is not required to restrict travel, trade, or other activities that involve human-to-human contact. Meanwhile, the crew and passengers of MV Hondius await the implementation of more joined-up thinking from onshore authorities, just as their immediate fate hangs in the balance.
Ashis Banerjee