Situation Overview
A deadly outbreak of hantavirus aboard the cruise ship Hondius has drawn international attention to a rare but potentially severe infectious disease.
The vessel, carrying approximately 140–150 passengers and crew, reported a cluster of severe respiratory illness during its voyage in the Atlantic. As of the latest international updates, around 9–11 cases have been identified, including 7–9 laboratory-confirmed infections, and three deaths among passengers.
The ship docked in Cape Verde on 3 May 2026, after which passengers were progressively evacuated and repatriated to their home countries for monitoring and quarantine.
On 6 May 2026, the National Institute for Communicable Diseases and the University Hospitals of Geneva confirmed through sequencing that the outbreak involves the Andes virus (ANDV).
Health authorities worldwide, including European and international partners, continue to monitor the situation closely. Based on current evidence, the overall public health risk remains low, despite the severity of individual cases and the confined outbreak setting
Confirmed Andes Virus: Transmission and Risk
The identification of Andes virus significantly changes the epidemiological context of the outbreak.
According to Prof. Piet Maes, ULB and virologist at the European Plotkin Institute for Vaccinology:
- Andes virus is the only hantavirus with well-documented human-to-human transmission
- Transmission typically requires close and prolonged contact
- The overall public health risk remains fundamentally different from highly transmissible respiratory viruses such as COVID-19
However, he cautions that:
- It is scientifically inaccurate to consider Andes virus as “non-transmissible” between humans
- The rarity of cases is largely due to limited exposure to infected rodent reservoirs, not necessarily low transmissibility after infection
Current evidence does not indicate rodent infestation aboard the vessel, making close-contact transmission between passengers an important hypothesis. At the same time, shared environmental exposure during earlier travel in South America remains a plausible alternative explanation.
Further genomic analysis and detailed contact tracing will be essential to fully understand the transmission dynamics of this outbreak.
International Scientific Response
The International Society for Hantaviruses (ISH), together with international experts, has issued a scientific statement on the outbreak.
This collaborative document provides context on:
- Documented person-to-person transmission of Andes virus
- Key epidemiological differences with other hantaviruses
- Current understanding of transmission patterns
- Appropriate, evidence-based public health responses
The statement reflects rapid international coordination between researchers, clinicians, epidemiologists, and public health authorities.
No Targeted Treatments or Vaccines
Hantaviruses remain medically challenging pathogens:
- There are no specific antiviral treatments widely available
- There are no broadly accessible vaccines
- Clinical management is primarily supportive care
This limitation has complicated the response aboard the ship, where medical teams had restricted therapeutic options as cases emerged during the voyage.
EMA Monitoring and Preparedness Efforts
The European Medicines Agency (EMA) is actively monitoring the outbreak and has initiated preparedness actions:
- Mapping developers of antivirals, monoclonal antibodies, vaccines targeting hantaviruses
- Prioritising:
- Repurposed immunomodulators for treatment
- Repurposed antivirals for post-exposure prophylaxis
The EMA also explicitly warns against misinformation, particularly false claims linking hantavirus infections to COVID-19 vaccination, for which no scientific evidence exists.
Conclusion
While the outbreak aboard the Hondius involves a rare virus with unique transmission characteristics, current evidence indicates that the broader public health risk remains low. Ongoing international collaboration, scientific analysis, and careful risk communication will be key to managing the situation effectively.
Further Information and Sources
Additional scientific and public health insights can be found via:
- Statement from the International Hantavirus Society and members of the international hantavirus research and clinical community regarding the current Andes virus outbreak investigation (PDF), published 12 May 2026 | Version v4, by Piet Maes, ULB & European Plotkin Institute for Vaccinology, Brussels, Belgium, and Tischler Nicole, Fundación Ciencia and Vida & Universidad San Sebastián, Spain.
- The New York Times: Hantavirus Vaccines and Treatments Are in the Pipeline, published on 9 May 2026 by Emily Anthes
- EMA actively monitoring cruise ship Hantavirus outbreak, published on 12 may 2026
- Viroloog Piet Maes over de uitbraak van het hantavirus op een cruiseschip (Dutch article in HLN, published 4 May 2026)
- Background info and Q&A on Hantaviruses, published by FPS Health, Food Chain Safety and Environment
