Andes Virus Alert: UK Authorities Trace Cruise Ship Hantavirus Outbreak — What You Need to Know

UK health authorities are conducting an urgent, large-scale contact tracing operation following a confirmed outbreak of Andes hantavirus on a cruise ship that docked at the British Overseas Territory of St Helena earlier this month. Several passengers who disembarked at St Helena subsequently returned to the United Kingdom on commercial flights, triggering the investigation that is now involving the UK Health Security Agency (UKHSA), the WHO, and health services across multiple countries.

What Is the Andes Virus — and Why Is It Concerning?

The Andes hantavirus is a rodent-borne pathogen first identified in South America in the 1990s. It causes Hantavirus Pulmonary Syndrome (HPS), a severe respiratory illness with a fatality rate of between 25 and 40 percent in confirmed cases. What makes Andes uniquely alarming among hantaviruses is that it is the only strain for which there is documented evidence of human-to-human transmission — a characteristic that most other hantaviruses do not share.

There is currently no approved antiviral treatment and no vaccine. Supportive care in intensive care settings is the primary medical response. The WHO classifies Andes virus as a high-consequence pathogen requiring enhanced surveillance.

The Cruise Ship Outbreak: What Happened

The outbreak originated aboard a vessel operating in the South Atlantic. Cases among crew and passengers were identified in early May. St Helena — a British Overseas Territory with limited medical infrastructure — was among the ports of call. A number of passengers with potential exposure subsequently boarded repatriation and commercial flights back to the UK, to other European countries, and to the United States.

UKHSA has confirmed it is in contact with all identified passengers from the relevant voyage. The agency stated the current risk to the general UK public is assessed as low — but emphasised that the situation is being monitored closely given the virus's potential for person-to-person spread.

What the NHS Is Doing

NHS England has issued clinical guidance to GPs and emergency departments on Andes virus presentation — fever, muscle aches, and early respiratory symptoms that can rapidly progress to respiratory failure. The guidance asks clinicians to take a travel history for any patient presenting with unexplained severe respiratory illness in the coming weeks.

The response is a stress test for UK public health infrastructure. The NHS is already operating under significant pressure with waiting lists at record levels. The hantavirus situation requires a different kind of response — specialist infectious disease capacity rather than general throughput — but the underlying staffing and resource constraints are the same.

Current Risk Assessment

UKHSA's current position: the overall risk to the UK population remains low. The number of potentially exposed individuals is limited and identified. There is no evidence of community transmission in the UK. The agency is conducting enhanced monitoring and will update its risk assessment as the contact tracing operation concludes.

For the public: there is no cause for alarm. For clinicians: heightened awareness of the presentation and travel history questions is warranted. For public health officials: this is a reminder that high-consequence pathogens reach the UK through the same global travel networks that bring everything else.

Sources:
UK Health Security Agency (UKHSA) · WHO — Hantavirus Fact Sheet · Public Health England — Guidance