Outbreak on the MV Hondius: The 2026 Andes Hantavirus Crisis

A multi-national outbreak of Andes hantavirus—a rare strain capable of limited person-to-person transmission—originated on the expedition cruise ship MV Hondius in April-May 2026. The tragedy resulted in 13 confirmed cases and three deaths, triggering a complex international public health operation coordinated by the World Health Organization (WHO) and multiple national governments.

Health authorities consistently assessed the risk to the general public as low.

Timeline and Origin

The MV Hondius, operated by Oceanwide Expeditions, departed Ushuaia, Argentina, on April 1, 2026, with a multi-national complement of passengers and crew.

• The first case, a 70-year-old Dutch man, developed symptoms on April 6 and died on April 11 while the ship was at sea.
• His 69-year-old wife, a close contact, developed symptoms, disembarked on St. Helena on April 24, and died at a hospital in Johannesburg, South Africa, on April 26.
• A German passenger died on the ship on May 2.
• A British national who fell ill was medically evacuated from Ascension Island to a hospital in South Africa, where he was treated in intensive care and tested positive.
• Additional cases were identified among passengers who had already disembarked in Saint Helena and returned home, including a Swiss national hospitalized in Zurich.

The World Health Organization (WHO) was notified of a cluster of severe respiratory illness on the ship on May 2. Investigators established a working hypothesis that the index case (the Dutch man) was infected prior to boarding, likely on a bird-watching tour in South America. Subsequent human-to-human transmission occurred onboard due to close and prolonged contact—a known characteristic of the Andes virus strain.

The Pathogen: Andes Hantavirus

The outbreak was caused by the Andes virus (ANDV), a species of hantavirus endemic to South America. Unlike most hantaviruses, which are primarily transmitted from rodents to humans, the Andes virus can be transmitted between humans.

Transmission

The virus is primarily spread through inhalation of aerosolized particles from the urine, droppings, or saliva of infected rodents. Person-to-person transmission is rare and requires prolonged, close contact with a symptomatic individual, such as living in the same household or sharing a cabin.

Symptoms and Incubation

The incubation period ranges from one to eight weeks (median ~18 days). Initial symptoms include fatigue, fever, and muscle aches, which can progress rapidly to hantavirus pulmonary syndrome (HPS)—characterized by coughing, shortness of breath, and fluid in the lungs.

Fatality Rate

HPS caused by Andes virus has a high case fatality rate, historically between 35% and 50%. In this outbreak, the case fatality ratio was approximately 23% (3 deaths out of 13 cases).

Genomic Analysis

The Pasteur Institute in France sequenced the virus from a French passenger and confirmed it was genetically near-identical to known strains of Andes virus circulating in South America. There was no evidence that the virus had become more transmissible or dangerous.

The Public Health Response

The response involved a multi-national coalition of health authorities coordinated by the WHO under the International Health Regulations.

Evacuation and Repatriation

Quarantine and Monitoring

The WHO recommended active monitoring for all high-risk contacts for 42 days from their last potential exposure. Individual countries implemented their own protocols:

• United States: 18 U.S. passengers and one dual British-U.S. national were flown to the National Quarantine Unit at the University of Nebraska Medical Center. Some later completed quarantine at home under 24/7 monitoring.
• Australia: Five Australians and one New Zealander were repatriated via the Netherlands and placed in mandatory quarantine at the Centre for National Resilience in Bullsbrook, Western Australia—later extended to the full 42-day incubation period.
• Spain: 14 Spanish passengers were quarantined at a military hospital in Madrid. Two subsequently tested positive.
• France: Five French nationals were placed in strict isolation in a Paris hospital. One woman tested positive and was treated in critical condition.
• United Kingdom: Passengers were initially taken to a hospital near Liverpool for testing and a 72-hour quarantine.
• Canada: Four Canadian passengers entered isolation. One later tested positive and was hospitalized in Victoria, British Columbia.
• The Netherlands: The final 25 crew members and two medical staff remained on the ship as it sailed to Rotterdam for disinfection, then disembarked for quarantine.

Investigation and Ship Management

• Contact Tracing: Health authorities in South Africa, the United Kingdom, the United States, and other countries conducted extensive contact tracing for individuals who shared flights or were in close contact with confirmed cases.
• Ship Disinfection: The MV Hondius arrived in Rotterdam on May 18, 2026, for thorough cleaning and disinfection. The vessel was cleared to resume operations.
• Argentina: The Argentine Health Ministry launched an investigation into the origin of the outbreak, including trapping rodents in Ushuaia. Local authorities disputed the theory that the infection occurred there, noting no previous cases had been recorded in the province.

Confirmed Cases and Fatalities

According to the final WHO report, the outbreak resulted in 13 confirmed cases of Andes hantavirus infection and three deaths.

No new fatalities were reported after May 2, 2026. The virus did not spread beyond the passengers and crew of the MV Hondius. The WHO assessed the global public health risk as low.

Key Official Statements

Dr. Tedros Adhanom Ghebreyesus (WHO Director-General): "This is not another COVID... The risk to the public is low. They shouldn't be scared and they shouldn't panic."

Dr. Maria Van Kerkhove (WHO Epidemic Chief): "This is not the start of a COVID pandemic... This is not a virus that spreads like flu or like COVID. It's quite different."

U.S. Centers for Disease Control and Prevention (CDC): "The risk to the American public is extremely low."

Dr. Ann Lindstrand (WHO Official in Cape Verde): The risk of a pandemic-level threat is low due to low human-to-human transmission.