UKHSA Hantavirus Cruise Ship Outbreak Update

UKHSA continues to work with international health agencies and governments on the hantavirus outbreak linked to the MV Hondius cruise ship. The risk of wider transmission in the UK remains very low.

Japan has supplied favipiravir to support UK preparedness.
UKHSA has accepted delivery of favipiravir.
Some contacts linked to St Helena and Ascension Island have been brought to the UK for isolation and monitoring.
Arrowe Park is being used for monitoring selected asymptomatic contacts.
HCID units are involved where specialist assessment is needed.
The risk of wider transmission in the UK remains very low.

This page is for education only. Always follow UKHSA, NHS, and local infection control guidance.

Source: UKHSA / GOV.UK — Published 6 May 2026, last updated 18 May 2026

Read latest UKHSA update

Overview

Situation Summary

On 08 May 2026, the UK Health Security Agency (UKHSA) issued a national briefing note (BN2026/011) regarding an outbreak of Andes Hantavirus (ANDV) linked to the expedition cruise ship MV Hondius.

The vessel, operated by Oceanwide Expeditions, carried passengers and crew from multiple countries through South American and Antarctic waters. As of the alert date, eight suspected or confirmed cases of Hantavirus Cardiopulmonary Syndrome (HCPS) have been identified among passengers, with three deaths reported. Laboratory testing has confirmed five cases as Andes virus.

Twenty-two British nationals were on board. Repatriation arrangements are in progress, and UKHSA has classified this as a National Enhanced Incident.

Key Figures

Outbreak at a Glance

8 total cases: suspected or confirmed Hantavirus Cardiopulmonary Syndrome
5 laboratory-confirmed Andes virus (ANDV) infections
3 deaths reported as of 07 May 2026
Case fatality rate: 32–50% for HCPS (published literature)
22 British nationals among passengers on MV Hondius
Multi-country involvement: passengers from UK, Europe, and other nations
HCID classification: Andes virus is classified as an airborne High Consequence Infectious Disease in the UK

Pathogen

What is Andes Virus?

Andes virus (ANDV) is a hantavirus in the family Bunyaviridae, genus Orthohantavirus. It causes Hantavirus Cardiopulmonary Syndrome (HCPS), a severe and often fatal respiratory illness. ANDV is the only hantavirus with documented human-to-human transmission. It is classified as an airborne High Consequence Infectious Disease (HCID) in the UK.

First identified: Argentina, 1995
Primary reservoir: Oligoryzomys longicaudatus (long-tailed pygmy rice rat)
Endemic region: Southern Argentina and Chile (Patagonia)
No specific antiviral treatment exists. Management is supportive
No licensed vaccine is currently available

Clinical

Disease Progression

HCPS typically progresses through three clinical phases. Deterioration from the febrile prodrome to cardiopulmonary failure can be rapid.

Prodromal Phase

Days 1–5

Fever, myalgia, malaise
Headache, nausea, vomiting
Abdominal pain, diarrhoea
Symptoms resemble influenza

Cardiopulmonary Phase

Days 4–10

HCPS onset

Non-productive cough, tachypnoea
Progressive pulmonary oedema
Hypotension, cardiogenic shock
Rapid deterioration possible

Critical / Recovery

Days 7–14+

ARDS and multi-organ failure
ICU-level support often required
Survivors: diuresis phase, gradual recovery over weeks
Case fatality rate 32–50%

Incubation period: Usually 2–4 weeks, but it can extend to 40 days. Exposed people may develop symptoms weeks after exposure.

Transmission

How Andes Virus Spreads

Rodent-to-human (primary route)

Inhalation of aerosolised urine, droppings, or saliva from infected rodents
Direct contact with rodent excreta or nesting material
Rodent bites (less common)

Human-to-human

Andes virus is unique among hantaviruses. It is the only species with documented person-to-person transmission, observed among close household and healthcare contacts during the symptomatic and cardiopulmonary phases. This is a key reason for its HCID classification in the UK.

Close contact with a symptomatic case (especially during the cardiopulmonary phase)
Respiratory droplets and possibly aerosol-generating procedures
Healthcare settings pose a risk without appropriate infection prevention measures

Risk Groups

Who is at Risk?

Passengers and crew of MV Hondius: direct exposure to the outbreak setting
Household contacts of returning passengers during the incubation period
Healthcare workers who care for suspected or confirmed cases without appropriate PPE
Travellers to Patagonia and southern South America with rodent exposure risk
Laboratory workers handling specimens from suspected cases

The incubation period extends to 40 days, so British nationals who were on board should stay alert for symptoms and self-monitor as directed by UKHSA.

Guidance

What Exposed Individuals Should Do

If you were a passenger or crew member on MV Hondius, or have had close contact with someone who was, follow this guidance.

Self-monitor for symptoms (fever, myalgia, cough, breathlessness) for 40 days from last exposure
If symptomatic: contact NHS 111 or your GP by telephone first. Do not attend in person without prior arrangement
Inform healthcare providers of your travel history and potential Andes virus exposure
Follow UKHSA instructions. Local Health Protection Teams may contact you directly for follow-up
Do not donate blood, organs, or tissue during the monitoring period
Practise good respiratory hygiene and minimise close contact with vulnerable household members if unwell

Surveillance

Case Definitions

These case definitions follow UKHSA guidance for this outbreak investigation.

Category	Definition
Confirmed case	Clinically compatible illness with laboratory confirmation of Andes virus infection (PCR or serology: IgM/IgG with appropriate clinical and epidemiological context)
Probable case	Clinically compatible illness with epidemiological link to MV Hondius or a confirmed case, pending laboratory confirmation
Possible case / Person under investigation	Any person who was aboard MV Hondius (or close contact of a passenger/crew member) who develops a febrile illness with respiratory symptoms within 40 days of last potential exposure
Contact requiring follow-up	Any individual who had close contact (within 1 metre for a prolonged period or household-level contact) with a confirmed or probable case during the symptomatic period

Clinician Alert

Information for Emergency Clinicians

Be aware: Andes virus (ANDV) is classified as an airborne HCID in the UK. Suspected cases must be managed in accordance with HCID protocols. Contact your local Infectious Diseases / Microbiology team and UKHSA Health Protection Team immediately.

When to suspect Andes virus

Acute febrile illness with respiratory symptoms AND travel history to South America (especially Patagonia) or epidemiological link to MV Hondius
Rapid-onset non-cardiogenic pulmonary oedema / ARDS with thrombocytopaenia in a returned traveller
Unexplained febrile illness in a close contact of a confirmed or probable case

Key laboratory findings

Thrombocytopaenia: early and marked
Haemoconcentration (rising haematocrit)
Left shift with immunoblasts on blood film
Elevated LDH and lactate
Bilateral infiltrates on chest radiograph

Immediate actions

Isolate the patient: negative-pressure room if available; otherwise single room with closed door
Full HCID-level PPE: FFP3 mask, gown, gloves, eye protection
Notify immediately: local Infection Prevention team, Microbiology on call, and UKHSA Health Protection Team
Do not perform aerosol-generating procedures without full HCID precautions
Supportive care: early fluid resuscitation (with caution: risk of pulmonary oedema), oxygen, vasopressors, ECMO consideration for refractory cases
Specialist transfer: discuss with HCID network centres (Royal Free Hospital, Newcastle upon Tyne Hospitals)

References & Contact

UKHSA Contact and References

UKHSA Health Protection Teams

National: UKHSA Colindale — 0344 225 4524
Local HPTs: Contact your regional Health Protection Team for case notifications
Imported Fever Service: available 24/7 for clinical advice on returned travellers with suspected HCID. Call 0344 225 4524

Key references

UKHSA Briefing Note BN2026/011 — Andes Hantavirus, MV Hondius, 08 May 2026
UKHSA HCID guidance — airborne HCIDs, including Andes virus
Advisory Committee on Dangerous Pathogens (ACDP) — HCID classification
WHO Disease Outbreak News — Hantavirus
Martinez VP et al. "Person-to-person transmission of Andes virus." Emerg Infect Dis. 2005;11(12):1848-1853