What is hantavirus?

Hantaviruses are rodent-borne viruses that can cause two main clinical patterns in humans: haemorrhagic fever with renal syndrome (HFRS) in Europe and Asia, and hantavirus cardiopulmonary syndrome (HCPS/HPS) in the Americas. Infection usually follows inhalation of aerosolised rodent urine, droppings, or saliva.1,4,5

Status of the MV Hondius case

According to WHO's Disease Outbreak News update, a cluster of severe respiratory symptoms was reported on 2 May 2026 on the Dutch cruise ship MV Hondius. In the situation published by WHO on 4 May 2026, the vessel had 147 passengers and crew members, and seven identified cases: two laboratory-confirmed hantavirus infections, five suspected cases, and three deaths.2

According to WHO's media update of 7 May 2026, eight cases had then been reported, five of them confirmed as hantavirus. WHO also stated that the virus involved was Andes virus and that the global risk to the general population was still assessed as low, although additional cases could still appear because of the incubation period.2,3

What makes Andes virus unusual

In the MV Hondius case described above, Andes virus is what makes the situation unusual. According to WHO, Andes virus is a hantavirus found in South America, especially in Argentina and Chile. It is currently the only hantavirus for which limited human-to-human transmission has been documented. ECDC describes the same exception: person-to-person transmission has so far only been shown for Andes virus, usually in close and prolonged contacts.1,3,4

Typical course of symptoms

According to WHO, symptoms usually begin 1 to 8 weeks after exposure. In WHO's MV Hondius report published on 4 May 2026, the HCPS/HPS disease described in some patients progressed rapidly to respiratory failure and shock.1,2

1. Early phase (usually a few days):1

  • + Fever
  • + Marked fatigue and muscle aches, especially in the back, hips, and thighs
  • + Headache, dizziness, or chills
  • + Nausea, vomiting, abdominal pain, or diarrhea

2. Cardiopulmonary phase (can start suddenly):1,2

  • + Sudden cough and shortness of breath
  • + Fluid accumulation in the lungs (pulmonary edema)
  • + Low blood pressure and circulatory collapse
  • + Need for close monitoring, oxygen, or ventilatory support
  • + Rapid progression to respiratory failure and shock is possible

Severity of the disease

According to WHO, the case-fatality rate of HCPS/HPS in the Americas can be as high as 50%.1

Both WHO and ECDC emphasize that the condition can worsen quickly. Early hospital assessment and intensive-care readiness are therefore essential.1,2,4

Treatment and monitoring

According to WHO and ECDC, there is no licensed antiviral drug for hantavirus disease and no widely used vaccine.1,4

Treatment is supportive hospital care and may include supplemental oxygen, mechanical ventilation, circulatory support, dialysis, and ECMO in the most severe cases.1,2,4

Sources

  1. WHO - Hantavirus ↗General overview, transmission, incubation, symptoms, HCPS/HPS severity, and treatment. Updated 6 May 2026.
  2. WHO - Disease Outbreak News: Hantavirus cluster linked to cruise ship travel, Multi-country ↗MV Hondius chronology, case counts as of 4 May 2026, and WHO’s outbreak risk assessment.
  3. WHO - WHO’s response to hantavirus cases linked to a cruise ship ↗Updated status on 7 May 2026: eight reported cases, five laboratory-confirmed.
  4. ECDC - Factsheet on orthohantavirus infections ↗European disease patterns, Puumala virus, the Andes virus person-to-person exception, and treatment context in Europe.
  5. CDC - About Hantavirus ↗Plain-language overview of HPS, HFRS, and rodent-borne transmission.