The UKHSA is coordinating with WHO and other partners after an Andes hantavirus cluster aboard the MV Hondius; one confirmed UK case has been reported and international investigations continue
The UK Health Security Agency (UKHSA) is working alongside the World Health Organization (WHO), the Foreign, Commonwealth and Development Office (FCDO), the Department of Health and Social Care (DHSC) and international public health partners in response to a cluster of severe respiratory illness linked to the cruise ship MV Hondius.
The cluster has been confirmed to involve Andes hantavirus (ANDV) in laboratory testing performed by the National Institute for Communicable Diseases, South Africa, and Geneva University Hospitals, Switzerland. This article summarizes the current UK position, the international context and the technical definitions used in the investigation.
Public updates on case counts associated with this incident are published daily: a case number update is posted at 9:30am and represents the situation as of 12:30pm the previous day. As of 12:30pm on 26 May 2026, there is one confirmed case of hantavirus in the United Kingdom linked to this outbreak.
The WHO continues to publish detailed international updates and risk assessments on its public pages.
What happened on the MV Hondius and the international response
In early May 2026, WHO was alerted to a cluster of severe respiratory illness aboard a cruise vessel carrying 147 passengers and crew from multiple countries. Initial laboratory testing on 2 May 2026 identified hantavirus infection, subsequently characterised as Andes hantavirus (ANDV). The voyage began in Ushuaia, Argentina on 1 April 2026 and included stops in Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island before anchoring off Cape Verde on 4 May 2026.
By 6 May 2026, international reporting indicated a total of 8 cases associated with this event: 3 laboratory-confirmed and 5 suspected, with 3 deaths. The index patient first developed symptoms on 6 April 2026 while still onboard and later died. A second individual who had travelled in South America with the index case disembarked and deteriorated clinically during a flight to Johannesburg, South Africa on 25 April 2026, subsequently dying.
Coordination and control measures
The outbreak is being managed through a coordinated international public health response that includes epidemiological investigations, patient isolation and clinical care, and when necessary, medical evacuation. WHO has assessed the overall risk to the global population as low based on available evidence. UKHSA continues to monitor and liaise with WHO and national authorities in affected countries to trace potential contacts and to inform clinicians and laboratories.
Clinical and laboratory definitions
Understanding how cases are classified helps interpret the reported numbers. In this incident, an outbreak confirmed case is defined as a person with laboratory confirmation of ANDV via reverse transcription polymerase chain reaction (RT-PCR) or serology testing. The term hantavirus refers to a family of viruses primarily carried by rodents and transmitted through their droppings, urine or saliva; most hantaviruses do not spread between people, but the Andes strain is known, in rare circumstances, to enable person-to-person transmission.
Laboratory characterisation for this cluster was completed by recognised reference laboratories, ensuring accuracy in identifying the virus as Andes hantavirus. Where available, both molecular testing (RT-PCR) and serological confirmation are used to classify cases as confirmed.
Data quality and reporting cadence
UKHSA states that reported figures are provisional. Data quality assurance is performed through manual checking, and counts may be revised up or down as new evidence emerges, clinical assessments evolve or additional microbiological characterisation is completed. Daily publication times are intended to provide a consistent snapshot of case numbers while investigations proceed.
Risk to the UK and advice for travellers
Although hantavirus infections originating from rodents do occur in the UK, there is currently no established risk of Andes hantavirus circulation within the country. UKHSA and WHO consider the probability of sustained spread in the UK to be low. Nevertheless, rare travel-associated cases could be seen among people returning from Argentina or Chile, and clinicians are asked to consider relevant travel history in patients with compatible symptoms.
For members of the public, the essential messages are: follow official travel and public health advice, seek medical care if you develop severe respiratory symptoms after travel to affected regions, and inform healthcare providers about any recent travel to South America or exposure to cruise ship outbreaks. For the latest official guidance and rolling updates, consult the UKHSA website and WHO situation reports.
