Andes Virus Cruise-Ship Outbreak: U.S. Monitoring Ended June 21

CDC ended its U.S. public-health response to the M/V Hondius Andes virus outbreak after monitoring concluded on June 21, 2026. In its June 24 briefing, the agency said none of the U.S. contacts monitored through the 42-day period developed hantavirus disease. The earlier outbreak coverage should be read alongside that outcome.

Correction, October 15, 2026: This article previously displayed numerical bars beside qualitative risk categories. CDC did not assign those percentages. They have been removed, and the account now includes the conclusion of U.S. monitoring.

The cover is an illustrative photograph of a cruise ship at sea, not the M/V Hondius.

What changed between May and July

Update, October 20, 2026: The WHO report dated July 2 provides the subsequent international outcome. WHO said all identified contacts had completed the 42-day follow-up period without additional secondary cases, confirming containment. The agency did not expect further transmission related to this outbreak. That dated conclusion is distinct from a guarantee that Andes virus cannot cause another outbreak.

Why low and high were both accurate categories

CDC's May 29 assessment evaluated the general public separately from U.S. residents aboard the affected ship between April 6 and May 10. It combined the likelihood of infection with the potential impact of disease. Its categories were qualitative: a high-risk label did not mean an 88% infection probability, and low risk did not mean 24%.

The distinction is useful beyond this event. Before comparing two risk statements, check whether they describe the same population, time period and outcome. A statement about the consequences of disease cannot be substituted for the chance of catching it. Confidence in an assessment is another separate idea; it is not a percentage of people expected to become ill.

What the monitoring result can establish

The June briefing described a response involving repatriation, state and local health departments, monitoring and coordination with international partners. CDC also said its scientific work continued, including work with Argentine partners to investigate the outbreak's origins.

The reported absence of disease among monitored U.S. contacts is a meaningful endpoint for that group. It does not establish that nobody elsewhere became ill, resolve every transmission question aboard the ship or make a general promise about future outbreaks. Keeping the denominator visible prevents a reassuring local outcome from becoming an unsupported worldwide claim.

For readers revisiting an outbreak story months later, the most useful question is whether the response remains active and whether a later official outcome has replaced an earlier forecast. This account preserves the earlier assessment, the U.S. monitoring outcome and the later international containment report with their dates. Our CDC coverage provides further reporting on the agency's assessments and public-health decisions.