WHO says hantavirus may have spread between cruise ship passengers as three deaths confirmed
The World Health Organization has said that two confirmed Andes hantavirus cases on board the cruise ship MV Hondius may represent person-to-person transmission between passengers, in what would be one of the most consequential documented chains of human-to-human spread for the strain in two decades. The outbreak emerged during a voyage that originally departed from Cape Town.
In a statement issued from Geneva, the WHO said three deaths have so far been linked to the outbreak, although only two of the cases have been laboratory-confirmed. Tracing of the roughly 1,300 passengers on the ship's manifest is ongoing, and 11 national health agencies have issued contact-tracing notices to their own citizens.
According to South Africa's health ministry, the two confirmed patients carry the genetic signature characteristic of the Andes strain. That strain is most often associated with the Patagonia region and is the only hantavirus known to be capable of human-to-human transmission. The U.S. Centres for Disease Control and Prevention (CDC) noted that Andes does not generally have a high transmission rate but can spread by respiratory droplets from patients showing pulmonary symptoms.
Most of the passengers on board are Australian, Dutch, British and South African nationals. The Netherlands' National Institute for Public Health (RIVM) reported that of three people evacuated from the Hondius for treatment in the Netherlands, two have been hospitalised, while the third presents symptoms more consistent with a non-hantavirus respiratory illness.
Details of the three deaths have not yet been fully released. South African health authorities have confirmed that those who died were citizens of Chile, Germany and the United Kingdom, all of whom had taken part in a Patagonian inland nature excursion before joining the ship. That information strengthens the working theory that the virus was contracted through rodent exposure outside the vessel, before any onboard transmission occurred.
Mike Ryan, executive director of the WHO's Health Emergencies Programme, said in a briefing: "This event is significant in reminding us of hantavirus's potential for person-to-person transmission, but it is too early to say that it represents a generalised threat to the public." He confirmed that monitoring of the ship and its passengers will continue over the coming three weeks.
Clinically, hantavirus pulmonary syndrome typically begins with influenza-like symptoms — fever, muscle aches and nausea — and can progress to respiratory failure within several days. According to CDC data, mortality with the Andes strain ranges from about 15 to 35 percent depending on how quickly intensive supportive care begins. There is no approved antiviral; treatment relies on respiratory support and fluid management.
The ship is currently sailing toward Las Palmas in the Canary Islands, where health authorities have said that quarantine protocols will be applied before docking. Passengers will be screened with thermal imaging on disembarkation and then placed under a 21-day symptom-monitoring programme.
The European Centre for Disease Prevention and Control (ECDC) has issued a notice to European health agencies. It recommends contact tracing of anyone who has been in contact with Hondius passengers within the past 20 days, and the inclusion of hantavirus serology in the workup of any patients presenting with respiratory symptoms.
The WHO has emphasised that the Andes strain's transmissibility remains limited, and the evidence does not support a wider public-health alert. The episode may, however, prompt cruise operators to review how respiratory pathogens move through closed ventilation systems on board large vessels; industry associations have not yet said whether they will revise standard operating procedures in light of the outbreak.