A hantavirus outbreak aboard the Dutch flagged expedition cruise ship MV Hondius has brought renewed attention to a disease that many people have not heard about since the Four Corners outbreak in the United States during the 1990s. As of May 4, 2026, the World Health Organization reported seven cases linked to the ship, including two laboratory confirmed hantavirus infections and three deaths. In this article, you will find the latest information about the MV Hondius outbreak, along with relevant journalistic and academic context that offers a brief introduction to infectious disease epidemiology and outbreak investigation.
Hantavirus is primarily transmitted from rodents to humans through exposure to infected urine, saliva, or droppings. Public health officials often associate exposure with cleaning enclosed spaces affected by rodents, including cabins, sheds, and storage areas, where contaminated particles can become airborne and inhaled.
Symptoms often begin with fever, fatigue, headaches, muscle aches, nausea, vomiting, diarrhoea, and abdominal pain. In more severe cases, patients can rapidly develop respiratory distress, pneumonia, shock, and hantavirus pulmonary syndrome, a potentially fatal condition that affects the lungs and breathing.
Many people first heard about hantavirus after the 1993 Four Corners outbreak in the southwestern United States, particularly in New Mexico, Arizona, Colorado, and Utah. Investigators eventually linked the outbreak to infected deer mice carrying what later became known as Sin Nombre virus, the hantavirus most commonly associated with hantavirus pulmonary syndrome in North America.
Most hantavirus infections are linked to environmental exposure rather than direct transmission between people. However, a South American strain known as Andes virus has previously shown limited evidence of human to human transmission in community and healthcare settings involving prolonged close contact. Because the MV Hondius departed from Argentina, investigators are examining several possible routes of exposure while laboratory sequencing and epidemiological investigations continue.
According to the World Health Organization, the ship was carrying 147 people, including 88 passengers and 59 crew members representing 23 nationalities. The vessel departed Ushuaia, Argentina, on April 1 and was traveling across the South Atlantic with stops including Antarctica, South Georgia, Saint Helena, and Ascension Island.
The first known patient, identified as case 1, developed fever, headache, and mild diarrhea on April 6 while aboard the ship. The patient later developed respiratory distress and died on April 11.
Case 2, described as a close contact of case 1, developed gastrointestinal symptoms and disembarked at Saint Helena on April 24. Her condition worsened during a flight to Johannesburg, South Africa, on April 25, and she died the following day. PCR testing later confirmed hantavirus infection.
According to WHO, both case 1 and case 2 had travelled in South America, including Argentina, before boarding the vessel in Ushuaia.
Case 3 developed fever, shortness of breath, and pneumonia on April 24 and was later medically evacuated to South Africa, where PCR testing also confirmed hantavirus infection. Case 4 developed symptoms on April 28 and later died on May 2. Three additional suspected cases remain aboard the ship with fever and gastrointestinal symptoms.
The timeline has become one of the most important aspects of the investigation. Symptoms in case 1 appeared only five days after embarkation, which may suggest exposure before boarding or very early during the voyage. According to WHO, symptoms of hantavirus pulmonary syndrome generally appear between two and four weeks after exposure, although onset can occur as early as one week after infection.
At this stage, investigators have not confirmed whether the outbreak resulted from environmental exposure, onboard contamination involving rodents, wildlife exposure during excursions, or possible person to person transmission involving a South American hantavirus strain. Laboratory sequencing and epidemiological investigations are ongoing.
WHO currently assesses the global risk from the outbreak as low. Passengers and crew have been advised to practice physical distancing, remain in cabins where possible, monitor symptoms, and follow strict hygiene and environmental cleaning measures while investigations continue.
To follow the WHO updates click on the WHO fact sheet photo to the right. To know more on the history of Hantavirus including the CDC "We were there" series click on the related images. All the images in this article will open links to educational material. All images are used solely for educational purposes.
