Brief Summary. On May 2, 2026 the World Health Organization (WHO) received notification of a cluster of severe respiratory illnesses aboard a Dutch-flagged expedition vessel. The ship, the MV Hondius, had departed Ushuaia, Argentina on April 1, 2026 with 149* individuals onboard (88 passengers, 61 crew members), making numerous stops as it sailed across the South Atlantic. Originally, three cases were reported to the WHO on May 2, including two deaths (Cases 1 & 2) and one critically ill passenger (Case 3). On that same day, the WHO reported that the third case, who remains hospitalized in intensive care in South Africa, tested positive for hantavirus infection. Since then, one additional death has been reported (Case 4), along with four other cases (Cases 5-8). Cases have reported respiratory and gastrointestinal symptoms and fever. At least four of the cases rapidly progressed to pneumonia, acute respiratory distress, and shock. Since the initial WHO alert, it has been reported that Cases 1 & 2 went on a bird watching trip in Argentina, Chile, and Uruguay prior to boarding the vessel. This included travel to areas known to have the species of rat capable of carrying the Andes hantavirus species. Investigations into the movement of the first two cases remain ongoing.

The WHO assesses the overall public health risk of the ongoing outbreak as “low.” Current response priorities include caring for the ill that remain hospitalized, keeping the remaining passengers onboard safe, and preventing any further spread of the virus. Medical assessments of passengers are ongoing by WHO experts, two physicians from the Netherlands, and an expert from the European Centre for Disease Prevention and Control (ECDC). No other passengers or staff are reported to be symptomatic at this time.The ship is currently sailing towards the Canary Islands, where passengers will disembark. It is expected to take 3-4 days to get to this destination. The WHO is developing guidance for the safe disembarkation of those onboard upon arrival to Spain and for their onward travel home. They have also informed twelve countries that have nationals who disembarked the vessel in St. Helena in late April (reportedly 30 passengers). Finally, contact tracing is ongoing for passengers on the flight taken by Case 2 from St. Helena, where they disembarked the ship, to Johannesburg, where the case later died.

*There are conflicting reports of the number of passengers onboard, with WHO reporting 147 and the ECDC reporting 149. Oceanwide Expeditions, the owner of the MV Hondius, reported 149 total passengers.