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 carrying 147 passengers and crew of 23 nationalities. The first known case fell ill on 6 April and died aboard on 11 April. A multi-country investigation now spans approximately a dozen countries, with confirmed cases in South Africa, the Netherlands, Switzerland, Germany, the United Kingdom, France and Saint Helena.

The World Health Organization is coordinating the response under the International Health Regulations (IHR). On 7 May, WHO Director-General Tedros Adhanom Ghebreyesus stated: "While this is a serious incident, WHO assesses the public health risk as low."

Index case and presumed exposure

Investigators believe the index case, a 70-year-old Dutch national, was infected before boarding. He and his wife had completed a bird-watching trip through Argentina, Chile and Uruguay prior to the cruise, including visits near a landfill outside Ushuaia where the long-tailed pygmy rice rat — the Andes virus reservoir species — is known to be present.

The wife developed symptoms after disembarking at Saint Helena on 24 April and died on 26 April upon arrival in Johannesburg, South Africa. Her infection was confirmed by PCR on 4 May. Both the husband and wife are confirmed Andes virus deaths. The ship doctor, who treated the index cases, is among those subsequently infected.

Timeline

Geographic dispersal

Following disembarkations at Saint Helena (24 April) and during the journey to Tenerife, passengers and crew have been traced to: Argentina (origin), Saint Helena, South Africa, Netherlands, Germany, Switzerland, France, United Kingdom, Spain, Singapore, Canada, United States. U.S. health officials are monitoring seven returning passengers across Arizona, California, Georgia, Texas and Virginia — none symptomatic as of 10 May.

Contact tracing — flight exposures

Beyond direct ship contact, secondary contact tracing has been initiated for two flight exposures:

• Saint Helena → Johannesburg, 25 April — Case 2 flew while symptomatic. Eight French nationals identified as close contacts; one with mild symptoms.
• KLM Johannesburg, 25 April — Connecting flight; Dutch and other nationals on board notified.

Risk assessment

Andes virus is the only hantavirus species with documented person-to-person transmission, but transmission requires close, prolonged contact — typically intimate partners, household members or healthcare workers without adequate PPE. The largest historical person-to-person cluster (Epuyén 2018-19) reached 34 cases and resolved within months.

Current WHO assessment: public health risk low. CDC HAN advisory states "the risk of broad spread to the United States is considered extremely unlikely at this time."

Sources

• WHO Disease Outbreak News — DON599 (4 May 2026), DON600 (8 May 2026, revised 9 May)
• CDC Health Alert Network — HAN528 (8 May 2026)
• WHO press briefings — 7 May 2026, 10 May 2026
• Argentina Ministerio de Salud reports
• UKHSA, RIVM (Netherlands), RKI (Germany), national reference labs

Related

• Andes virus — strain reference
• Argentina — country surveillance
• What we know about the MV Hondius hantavirus cluster