MV Hondius Andes Virus Outbreak: Final Case Count and Transmission Facts

The Andes virus outbreak linked to the expedition ship M/V Hondius ended with 13 reported cases, including three deaths. On July 2, 2026, the World Health Organization declared the outbreak over after all identified contacts completed 42 days of follow-up without additional secondary cases.

The final total included 12 laboratory-confirmed infections and one probable case. WHO said the event no longer posed a public-health risk and expected no further related transmission.

What caused the outbreak?

The infections were caused by Andes virus, a hantavirus carried by wild rodents in parts of South America. People are usually infected after breathing dust contaminated by the urine, droppings, or saliva of an infected rodent, especially in an enclosed or poorly ventilated space.

Andes virus is unusual because it is the only hantavirus known to spread between people. That route is rare and is generally associated with prolonged close contact with a symptomatic person or exposure to bodily fluids.

Why the source was difficult to identify

Passengers travelled through several locations before and during the voyage, while Andes virus symptoms can appear 4 to 42 days after exposure. This created several possible pathways: exposure to infected rodents before boarding, a shared contaminated environment, or limited person-to-person spread among close contacts.

Public reporting during the response sometimes presented those possibilities as a disagreement. They were not mutually exclusive, and a precise origin could not be assigned from timing alone. Epidemiological investigation, exposure histories, and laboratory sequencing are needed to distinguish them.

How the response developed

• WHO was notified on May 2 after severe respiratory illness was reported among passengers on the Netherlands-flagged ship.
• Countries coordinated testing, medical care, disembarkation, repatriation, and contact tracing under the International Health Regulations.
• More than 650 contacts in 33 countries and territories were identified and followed.
• The final contact completed monitoring on July 2, with no additional secondary cases detected.

Among the ten living cases treated in hospital, eight had recovered and been discharged by the final WHO update; two were still receiving medical treatment at that time.

Symptoms and when to seek care

Early illness can resemble flu and may include fever, fatigue, muscle aches, headache, dizziness, chills, nausea, vomiting, diarrhea, or abdominal pain. Some patients later develop cough and shortness of breath as hantavirus pulmonary syndrome progresses.

If you develop symptoms after a known Andes virus exposure, contact a medical professional immediately and mention the exposure before arriving. Rapid worsening is possible. There is currently no specific antiviral treatment or vaccine; care focuses on early monitoring and support for breathing and circulation.

Reducing the risk of infection

• Avoid rodent-infested buildings or storage areas, particularly in affected parts of South America.
• Do not sweep or vacuum dry rodent waste, which can put contaminated dust into the air; follow local public-health guidance for wet disinfection and protective equipment.
• Wash hands frequently after possible exposure.
• Avoid kissing, sexual contact, shared drinks, smoking devices, utensils, or food with someone who may have symptomatic Andes virus infection.
• Follow isolation, testing, and monitoring instructions from health authorities after a confirmed exposure.

For the completed outbreak timeline, see the WHO final outbreak update. The CDC's Andes virus overview explains symptoms, transmission, and current precautions.