MV Hondius hantavirus cluster

Summary

The MV Hondius is a Dutch-flagged polar expedition vessel operated by Oceanwide Expeditions. The ship departed Ushuaia, Argentina on 1 April 2026 with 175 passengers and crew, following an itinerary across the South Atlantic that included mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension ^[1]. Passengers and crew represent 23 nationalities, including 9 EU/EEA countries ^[2].

The first known case fell ill on 6 April and died aboard on 11 April with no microbiological tests performed at the time ^[1]. On 2 May 2026, WHO was notified of the cluster via the UK National IHR Focal Point following PCR confirmation of hantavirus infection in a critically ill patient hospitalised in South Africa ^[1]. On 6 May, WHO confirmed the responsible strain as Andes virus (Orthohantavirus andesense) ^[3].

WHO's risk assessment for the global population is "low" ^[1]. ECDC's risk assessment for the EU/EEA general population is "very low" ^[2]. The US CDC classified its response as Level 3 ^[4].

Index case investigation

The index case was a 70-year-old Dutch male ^[4]. On 6 May, the Argentine Ministry of Health published a report detailing his pre-cruise movements: a four-month road trip between 27 November 2025 and 1 April 2026 spanning Chile, Uruguay, and Argentina. The index case had returned to Argentina from Uruguay only four days before boarding ^[4]. Argentine biosurveillance teams initiated rodent trapping along the index case's documented travel route to identify the likely zoonotic exposure site.

The index case's wife (Case 2) disembarked at Saint Helena on 24 April with gastrointestinal symptoms, deteriorated during a repatriation flight to South Africa on 25 April, and died on arrival in Johannesburg on 26 April. Her infection was confirmed by PCR on 4 May ^[1].

Timeline

Geographic distribution of cases and contacts

Per Wikipedia's tracking of ECDC's involved-country list as of 8 May, passengers were hospitalised in South Africa, the Netherlands, Germany, Saint Helena, Spain and Switzerland ^[4]. Subsequent country additions (11–12 May): United States (Nebraska, Atlanta), France (Paris). UK Health Security Agency is contact-tracing the 29 Saint Helena disembarkation cohort across 12 countries. US state health departments are monitoring returning passengers in California, Maryland, Texas, Georgia, Virginia, Arizona, and New Jersey ^[6].

Contact tracing — known flight exposures

• KLM KL592, 25 April 2026 (Johannesburg → Amsterdam): Case 2 boarded but was removed before takeoff. Codeshare flights AF8282, DL9560, SK6855 also affected by passenger manifest cross-checking. ^[4]
• Saint Helena → repatriation flights (24 April onward): 29 disembarked passengers traced by UKHSA across 12 countries. ^[4]
• Tenerife → Eindhoven, 10–11 May: Plane carrying disembarked passengers and crew landed at Eindhoven Airport, Netherlands. ^[6]
• Tenerife → Offutt AFB, 11 May: US medical repatriation flight, 18 American passengers + crew. ^[5]
• France: 22 high-risk contacts identified. 8 ordered to isolate following confirmed French case. ^[6]

Risk assessment

Andes virus is the only hantavirus species with documented person-to-person transmission, first identified during the 1996 El Bolsón outbreak in Argentina and subsequently characterised in the 2018–19 Epuyén outbreak (34 cases, 11 deaths) ^[7]. Transmission requires close, prolonged contact and is typically observed among household members, intimate partners, or healthcare workers without adequate PPE.

Per CDC, the case fatality rate for hantavirus pulmonary syndrome in the Americas is approximately 38% ^[5]. Wikipedia's Andes virus reference cites approximately 40% ^[8]. WHO's range for the Americas is up to 50% ^[1]. The Yosemite 2012 cohort had a CFR of 30%; the Epuyén 2018–19 outbreak had a CFR of 32%; the 1993 Four Corners cohort had a CFR of 54%.

Sources

1. World Health Organization, Disease Outbreak News (DON599), Hantavirus cluster linked to cruise ship travel — Multi-country, 4 May 2026 (corrigendum 5 May). who.int/emergencies/disease-outbreak-news/item/2026-DON599
2. European Centre for Disease Prevention and Control (ECDC), Andes hantavirus outbreak in cruise ship, 11 May 2026. ecdc.europa.eu
3. CDC, Hantavirus: Current Situation, 6 May 2026 (WHO confirms Andes virus). cdc.gov/hantavirus/situation-summary
4. Wikipedia, MV Hondius hantavirus outbreak, accessed 12 May 2026 (real-time consolidation of WHO, UKHSA, NICD, virological.org, Argentine MoH, Spanish MoH, multiple wire). en.wikipedia.org/wiki/MV_Hondius_hantavirus_outbreak
5. CDC, HAN 00528: 2026 Multi-country Hantavirus Cluster Linked to Cruise Ship, 1 May 2026 (updated 8 May). cdc.gov/han/php/notices/han00528.html
6. CGTN reporting on WHO 12 May briefing, French Ministry of Health, Spanish Ministry of Health, and Radboud UMC. news.cgtn.com. Also: NPR, ABC News, Good Morning America live coverage 10–12 May.
7. Martinez et al., "Super-Spreaders" and Person-to-Person Transmission of Andes Virus in Argentina, New England Journal of Medicine, 383(23):2230-2241, 3 December 2020. DOI: 10.1056/NEJMoa2009040. nejm.org
8. Wikipedia, Andes virus, accessed 12 May 2026. en.wikipedia.org/wiki/Andes_virus

Daily reports

The MV Hondius cluster has been tracked in structured daily reports since 8 May 2026:

• 12 May — Nebraska/Atlanta arrivals; France and Spain provisional positives; Radboud UMC quarantine
• 11 May — Disembarkation continues; UK supplies airdropped to Tristan da Cunha
• 10 May — MV Hondius arrives Granadilla port, Tenerife
• 9 May — UK confirms 2 Britons; Argentine kits dispatched
• 8 May — UKHSA contact tracing; Swiss genome published; CDC Level 3

Related

• Andes virus — strain reference
• Argentina — country surveillance and index case investigation
• 2018–19 Epuyén outbreak — closest historical analogue for Andes virus P2P transmission
• HantaOSINT methodology — sources, verification, corrections policy