Andes virus kills three on MV Hondius cruise ship; US passengers enter quarantine

A deadly outbreak of Andes virus, a rare strain of hantavirus capable of human-to-human transmission, has claimed three lives and sickened at least eight people aboard the MV Hondius cruise ship in the Atlantic Ocean. As of the latest updates, health authorities report a total of eight cases—including six confirmed and two probable—with a case fatality ratio of 38 percent. The World Health Organization has identified all confirmed cases as the Andes strain, which originates from South America and differs from most hantaviruses by its potential for person-to-person spread, typically through close contact.

The outbreak emerged among passengers and crew during a voyage that began earlier in April, with the first symptoms appearing around April 27. Affected individuals include a ship guide who experienced mild respiratory and gastrointestinal issues, and the ship's doctor, who developed fever, fatigue, muscle pain, and respiratory symptoms by April 30 before being medically evacuated to the Netherlands for isolation. Three patients were airlifted to the Netherlands for treatment, while the vessel, initially moored in Cabo Verde, has moved toward the Canary Islands, where healthy passengers are allowed to disembark and return home. One passenger who fell ill after leaving the ship is now hospitalized in Switzerland with the confirmed Andes strain.

Repatriation efforts are underway across multiple countries, with heightened precautions due to the virus's 4-to-42-day incubation period. In the United States, 17 American citizens from the ship are being flown to a quarantine facility in Nebraska, coordinated by the Centers for Disease Control and Prevention (CDC) and the State Department. CDC Director has emphasized that this is "not like Covid", noting the overall risk to the American public and travelers remains extremely low, with no U.S. cases linked to the outbreak so far. Routine travel continues as normal, according to CDC assessments.

Recent developments include three additional infections confirmed among remaining passengers as the last individuals leave the ship, though lab results for one American case were inconclusive. Experts like Michael Osterholm from the University of Minnesota's Center for Infectious Disease Research and Policy suggest the infections likely occurred before boarding, given the typical 10-to-20-day incubation, and describe it as an isolated event rather than a widespread threat. The primary transmission route is still under investigation but is believed to involve rodent exposure, far more common than human spread.

Hantavirus pulmonary syndrome (HPS), caused by the Andes strain, starts with flu-like symptoms such as fatigue, fever, muscle aches, headaches, dizziness, chills, nausea, vomiting, diarrhea, and abdominal pain. It can rapidly progress to severe respiratory distress, fluid buildup in the lungs, hypotension, and potentially fatal complications affecting the heart and kidneys. About half of patients experience these early signs, and those with respiratory symptoms face a 38 percent mortality rate.

Public health officials urge anyone potentially exposed—such as those on the ship or related flights—to monitor for symptoms for up to 42 days, practice frequent hand hygiene, self-isolate if ill, and wear respirators if respiratory issues arise. Immediate medical evaluation is advised for early or sudden symptoms. While cruise ships have historically been vulnerable to outbreaks due to close quarters, authorities stress that hantavirus remains rare, and current measures aim to contain it effectively without broader disruption.