Epidemiology

Hantavirus cardiopulmonary syndrome (HCPS), also known as hantavirus pulmonary syndrome (HPS), is a zoonotic viral respiratory disease caused by hantaviruses of the Orthohantavirus genus, Hantaviridae family, and Bunyavirales order. Over 20 viral species have been identified within this genus.

Hantaviruses are associated with two distinct clinical syndromes in humans:

Hantavirus Pulmonary Syndrome (HPS): Predominantly reported in the Americas.

Hemorrhagic Fever with Renal Syndrome (HFRS): Reported mainly in Europe and Asia.

Human hantavirus infection is primarily acquired through contact with the urine, feces, or saliva of infected rodents, or by touching contaminated surfaces. Exposure typically occurs during activities such as cleaning rodent-infested buildings, although it can also happen during routine activities in highly infested areas. Human cases are most commonly reported in rural areas—such as forests, fields, and farms—where rodents are present and exposure opportunities are higher.

Symptoms and Progression
Hantavirus pulmonary syndrome (HPS) is characterized by headache, dizziness, chills, fever, myalgia, and gastrointestinal symptoms (such as nausea, vomiting, diarrhea, and abdominal pain), followed by sudden respiratory failure and hypotension. Symptoms generally appear 1 to 6 weeks after initial exposure to the virus. However, they can emerge as early as the first week and up to eight weeks post-exposure.

Global Incidence
Hantavirus infections are relatively uncommon worldwide:

The Americas: In 2025, eight countries reported HPS, with 229 cases and 59 deaths, resulting in a case fatality rate of 25.7%. [2] HPS is not reported in other parts of the world.

Europe: In 2023, 1,885 hantavirus infections causing HFRS were reported (0.4 per 100,000), marking the lowest rate observed between 2019 and 2023. [3]

East Asia: Particularly in China and the Republic of Korea, HFRS continues to record thousands of cases annually, although incidence has decreased in recent decades.

The overall case fatality rate for hantavirus pulmonary syndrome (HPS) can reach up to 50%. Although there are no approved treatments or vaccines for hantavirus infections, early supportive care and immediate transfer to a facility with a fully equipped ICU can improve survival rates.

Environmental and ecological factors affecting rodent populations can influence the seasonal trends of the disease. Since the reservoirs for hantavirus are wild rodents, transmission can occur when people come into contact with rodent habitats.

Human-to-Human Transmission
Although uncommon, limited human-to-human transmission of HPS caused by the Andes virus has been reported in community settings involving close and prolonged contact. Secondary infections among healthcare workers have been documented in healthcare facilities, though they remain rare. Secondary transmission appears more likely during the early phase of the disease when the virus is most transmissible. Currently, limited evidence is available due to the rarity of hantavirus outbreaks linked to human-to-human transmission.

Situation Description

On May 2, 2026, the WHO received notification from the National IHR Focal Point (NFP) of the United Kingdom of Great Britain and Northern Ireland (hereinafter the UK) regarding an outbreak of severe acute respiratory illness, including two deaths and one passenger in critical condition, aboard the Dutch-flagged cruise ship MV Hondius.

On May 8, two additional confirmed cases and one inconclusive case were reported among the passengers:

France: One confirmed case who developed symptoms during repatriation.

Spain: One confirmed case tested upon arrival after repatriation, currently well and asymptomatic.

United States: One inconclusive case. The individual was repatriated, is currently asymptomatic, and had inconclusive laboratory results (one positive and one negative from two different labs). Retesting is underway. The sample was collected due to high-risk exposure to confirmed cases onboard.

All laboratory-confirmed cases involve ANDV (Andes virus) infection, and all were passengers aboard the MV Hondius.

Ongoing Investigation
Based on currently available information, the working hypothesis is that the first case acquired the infection prior to boarding the cruise through onshore exposure. Investigations are underway to elucidate the potential exposure circumstances and the source of the outbreak, in collaboration with authorities in Argentina and Chile. Current evidence suggests subsequent person-to-person transmission aboard the ship. This is also supported by a preliminary sequence analysis, which shows a close, nearly identical sequence across different cases. [1]

The outbreak is being managed through a coordinated international response, including in-depth epidemiological investigations, case isolation and clinical management, medical evacuations, laboratory testing, international contact tracing, quarantine, and monitoring. Recommendations may be updated as new epidemiological and laboratory evidence, including genetic sequencing data, becomes available.

Contact Tracing and Disembarkation
Follow-up and tracing of all hantavirus case contacts linked to the cruise ship are ongoing. This includes passengers who disembarked in:

St. Helena, UK (April 24)

Praia, Cape Verde (May 6)

Tenerife, Spain (May 10 and 11)

Passengers who traveled on flights where they may have been exposed to later-confirmed cases have been identified and contacted. Contacts are being monitored by local health authorities in their respective countries.

On May 10, the ship arrived in the Canary Islands, Spain, where disembarkation began. Passengers and the majority of the crew were repatriated to their respective countries of residence or transit hubs via specially arranged non-commercial flights, with WHO and its partners supporting the process. The ship left the Canary Islands on May 11 and is currently sailing toward the Netherlands with 25 crew members on board, alongside two Dutch healthcare workers to conduct health monitoring and provide necessary medical care.