Situation at a glance
This is the third Disease Outbreak News report on the Hantavirus cluster, following the notification to the World Health Organization (WHO) on 2 May 2026 of severe respiratory illness cases aboard MV Hondius, a cruise ship. Since the last DON was published on 8 May, two additional confirmed cases were reported from France and Spain. In addition, there is one inconclusive result for a case in the United States of America. All were passengers on the ship. As of 13 May, a total of 11 cases, including three deaths, have been reported (case fatality ratio 27%). Eight cases were laboratory-confirmed for Andes virus (ANDV) infection, two are probable, and one case remains inconclusive and undergoing further testing. Through the International Health Regulations (2005) (IHR) channels, National IHR Focal Points (NFPs) have all been informed and are supporting international contact tracing efforts. WHO has assessed the risk posed by this event to the global population as low and will continue to monitor the epidemiological situation and update the risk assessment as needed.
Description of the situation
On 2 May 2026, WHO received notification from the IHR NFP of the United Kingdom of Great Britain and Northern Ireland (hereafter referred to as the United Kingdom) regarding a cluster of severe acute respiratory illness, including two deaths and one critically ill passenger, aboard the Dutch-flagged cruise ship MV Hondius.
As of 13 May, a total of 11 cases (eight confirmed, one inconclusive and two probable cases), including three deaths (two confirmed and one probable), have been reported. Since the last Disease Outbreak News was published on 8 May, two additional confirmed cases and one inconclusive case have been reported among passengers. These are one confirmed case from France, who became symptomatic during repatriation, one confirmed case from Spain, tested upon arrival following repatriation but currently well and asymptomatic, and one case considered inconclusive. The latter was repatriated to the United States of America, is currently asymptomatic with inconclusive laboratory results (one positive and one negative result from two different laboratories), and is being retested. The individual was sampled due to high-risk exposure to confirmed cases on board. All laboratory-confirmed cases are confirmed for ANDV infection. All were passengers onboard the MV Hondius.
Based on currently available information, the working hypothesis is that the first case acquired the infection prior to boarding the cruise, through exposure on land. Investigations are ongoing to elucidate the potential circumstances of exposure and the source of the outbreak, in collaboration with authorities in Argentina and Chile. Current evidence suggests subsequent human-to-human transmission onboard the ship. This is also supported by a preliminary analysis of the sequences, which show a close, near-identical sequenced from different cases.
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, quarantining and monitoring. Recommendations may be updated as additional epidemiological and laboratory evidence, including genetic sequencing data, becomes available.
Follow-up and contact tracing for all contacts of Hantaviruscases linked to the cruise ship is ongoing.
This includes passengers who disembarked in Saint Helena, United Kingdom, on 24 April; Praia, Cabo Verde, on 6 May; and Tenerife, Spain, on 10 and 11 May. Passengers who travelled on flights who may have had exposure to subsequently confirmed cases have been identified and contacted. Contacts are being monitored by local health authorities in their respective countries.
On 10 May, the ship arrived in the Canary Islands, Spain, where disembarkation began. Passengers and most of the crew were repatriated from the Canary Islands to their respective residence countries or transit points via specially arranged non-commercial flights, with WHO and partners supporting the disembarkation process. The ship left the Canary Islands on 11 May and is sailing to the Netherlands, with 25 crew members remaining on board, along with two Dutch health and care workers to conduct their health monitoring and provide any healthcare that may be necessary.
Epidemiology
Hantavirus cardiopulmonary syndrome (HCPS), also known as Hantavirus pulmonary syndrome (HPS), is a zoonotic, viral respiratory disease caused by Hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Bunyavirales. More than 20 viral species have been identified within this genus.
Hantaviruses are associated with two major distinct clinical syndromes in humans: HPS predominantly reported in the Americas, and hemorrhagic fever with renal syndrome (HFRS), mainly reported in Europe and Asia. However, human-to-human transmission has only been reported for HPS associated with Andes virus infection. Andes virus is endemic in South America, with confirmed circulation and human cases reported primarily in Argentina and Chile, and additional cases and related strains identified in Uruguay, southern Brazil, and Paraguay.
Human Hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. Exposure typically occurs during activities such as cleaning buildings with rodent infestations, though it may also occur during routine activities in heavily infested areas. Human cases are most commonly reported in rural settings, such as forests, fields, and farms, where rodents are present, and opportunities for exposure are greater.
HPS is characterized by headache, dizziness, chills, fever, myalgia, and gastrointestinal symptoms, such as nausea, vomiting, diarrhoea, and abdominal pain, followed by sudden onset of respiratory distress and hypotension. Symptoms of HPS typically occur from 1-6 weeks after initial exposure to the virus. However, symptoms may appear as early as one week and as late as eight weeks following exposure.
Hantavirus infections are relatively uncommon globally. In 2025, in the Region of the Americas, eight countries reported HPS, 229 cases and 59 deaths with a CFR of 25.7%. HPS is not reported in other parts of the world. In the European Region, 1885 Hantavirus infections causing HFRS were reported in 2023 (0.4 per 100 000), marking the lowest rate observed between 2019 and 2023.
In East Asia, particularly China and the Republic of Korea, HFRS continues to record thousands of cases annually, although incidence has declined in recent decades.
The overall CFR for HPS can be as high as 50%. While there are no licensed treatment nor vaccines for Hantavirus infections, early supportive care and immediate referral to a facility with a complete ICU can improve survival.
Environmental and ecological factors affecting rodent populations can influence disease trends seasonally. Since Hantavirus reservoirs are sylvatic rodents, transmission can occur when people come into contact with rodent habitats.
Although uncommon, limited human‑to‑human transmission of HPS due to Andes virus has been reported in community settings involving close and prolonged contact. Secondary infections among healthcare workers have been previously documented in healthcare facilities, though remain rare. Secondary transmission appears most likely during the early phase of illness, when the virus is more transmissible. Currently, little evidence is available due to the scarcity of Hantavirusoutbreak related to human-to-human transmission.
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Source: World Health Organization – www.who.int
