Hantavirus Outbreak

Hantavirus Outbreak

Update #3 16/05/2026

As of 13th May, a total of 11 cases has been identified, including eight laboratory-confirmed cases, one inconclusive case, and two probable cases. Among these, three deaths have been reported, comprising two confirmed deaths and one probable death.

Since the publication of the previous Disease Outbreak News on 11th May, two new confirmed cases and one inconclusive case have been detected among passengers. The newly confirmed cases include one individual from France who developed symptoms during repatriation, and one individual from Spain who tested positive upon arrival after repatriation but remains asymptomatic and clinically stable.

The inconclusive case involves an individual send back to the United States of America who is currently asymptomatic. Laboratory testing produced mixed results, with one positive and one negative result from two separate laboratories, and repeat testing is underway. The individual was tested because of high-risk exposure to confirmed cases onboard the vessel. All laboratory-confirmed cases have tested positive for Andes virus (ANDV) infection.

Based on the information currently available, the leading hypothesis is that the index case acquired the infection before boarding the cruise ship through exposure on land. Investigations are ongoing, in coordination with authorities in Argentina and Chile, to determine the likely source and circumstances of exposure associated with the outbreak. Current findings indicate that subsequent human-to-human transmission likely occurred onboard the vessel. Preliminary genetic sequencing analysis further supports this, as viral sequences obtained from different cases were found to be highly similar or nearly identical.

The outbreak response is being coordinated internationally and includes comprehensive epidemiological investigations, isolation and clinical management of cases, medical evacuations, laboratory testing, as well as international contact tracing, quarantine, and monitoring measures. Recommendations may be revised as further epidemiological, laboratory, and genetic sequencing information becomes available.

On 10th May, the ship arrived in the Canary Islands, Spain, where passenger getting off embarked. Passengers and most crew members were subsequently sent back to their home countries or transit destinations through specially arranged non-commercial flights, and its partners during the landing process. The vessel departed the Canary Islands on 11th May and is currently en route to the Netherlands. Twenty-five crew members remain onboard, accompanied by two Dutch healthcare professionals responsible for ongoing health monitoring and provision of medical care if required.

Update #2 11/05/2026

Occurrence Update

On 2 May 2026, a cluster of severe respiratory illness among passengers aboard a cruise ship was reported. At the time of reporting, the ship operator indicated that 147 passengers and crew members remained onboard, while 34 individuals had already disembarked during the voyage.

Since the previous Disease Outbreak News update published on 4 May 2026, three additional suspected cases have been laboratory-confirmed, and one new confirmed case has also been identified. As of 8 May 2026, a total of eight cases, including three deaths, have been reported, resulting in a case fatality ratio (CFR) of 38%. Among these, six cases have been laboratory-confirmed as hantavirus infections, all identified as Andes virus (ANDV).

Based on the currently available information, the overall risk to the global population remains low, while the risk to passengers and crew members aboard the vessel is considered moderate. The situation will continue to be closely monitored.

Case Distribution

Table 1. Distribution of reported Andes hantavirus cases by case status and outcome, as of 8 May 2026

Two medical evacuation flights departing from Cabo Verde transported two symptomatic laboratory-confirmed patients and one previously suspected case to the Netherlands on 6 and 7 May 2026.

As of 8 May 2026, four patients remain hospitalized. One patient is receiving intensive care treatment in Johannesburg, South Africa, while two patients are admitted separating hospitals in the Netherlands, and another patient is hospitalized in Zurich, Switzerland. The previously suspected case was subsequently transferred to Germany for further evaluation. Laboratory investigations, including both PCR and serological testing, returned negative results for Andes virus (ANDV). Consequently, the individual is no longer classified as a confirmed or suspected case.

Further investigations into the potential exposure of the first case and the source of the outbreak are ongoing in collaboration with authorities in Argentina and Chile. The outbreak is being managed through a coordinated international response, including in-depth epidemiological investigations, case isolation and clinical management, medical evacuations, laboratory testing and international contact tracing and monitoring.

The Swiss Federal Office of Public Health (FOPH) has confirmed that a passenger who travelled on the first leg of the voyage has tested positive for hantavirus and is currently being treated at the University Hospital Zurich.

Hantavirus infection has no specific cure, so treatment focuses on supportive care. Patients are usually hospitalised early for close monitoring.

Update #1 04/05/2026

Occurrence Update

On 2 May 2026, the World Health Organization received notification from the National International Health Regulations (2005) (IHR) Focal Point of the United Kingdom regarding a cluster of severe acute respiratory illness reported on a Dutch-flagged cruise ship. The cluster initially included two fatalities and one critically ill passenger. Laboratory testing conducted in South Africa on the same day confirmed hantavirus infection in the critically ill patient, who was admitted to an intensive care unit (ICU).

On 3 May 2026, an additional death was reported, while three more suspected cases remained onboard the vessel. By 4 May 2026, a total of seven cases had been identified, comprising two laboratory-confirmed cases and five suspected cases, including three deaths overall.

The cruise ship departed from Ushuaia on 1 April 2026 and navigated through the South Atlantic region, with scheduled stops at several remote and environmentally sensitive locations, including mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island. However, the extent of exposure or interaction between passengers and local wildlife during the voyage, or prior to embarkation in Ushuaia, remains unclear.

The vessel was carrying a total of 147 individuals, including 88 passengers and 59 crew members, representing 23 different nationalities. As of 4 May 2026, the ship was anchored off the coast of Cabo Verde.