CDC says no U.S. hantavirus cases amid cruise ship outbreak

U.S. health officials were watching a cruise ship hantavirus outbreak closely on Friday even as they said no cases had been confirmed in the United States. The Centers for Disease Control and Prevention said the risk to the American public and travelers remained extremely low, but 41 people were still being monitored for possible infection, including 18 quarantined in Nebraska and Atlanta.

The concern centers on Andes virus, a type of hantavirus tied to the Dutch-flagged MV Hondius, which left Ushuaia, Argentina, on April 1 and traveled through Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena and Ascension Island. The World Health Organization said the ship carried 147 passengers and crew. By May 4, health officials had identified seven cases, including three deaths, one critically ill patient and three people with mild symptoms. By May 12, the number of reported cases had risen to 11, with illness onset dates ranging from April 6 to April 28.

The U.S. monitoring effort reflects how quickly public health agencies try to separate real exposure from rumor when a rare virus crosses borders. The CDC said the people under watch included passengers who had already returned to the United States before the outbreak was recognized, as well as travelers exposed on flights where a symptomatic case was present. Those under monitoring were told to stay home and avoid contact with others for the full 42-day window, a standard six-week period meant to catch symptoms before they turn into new chains of infection.

One of the most closely watched names was Stephen Kornfeld, initially reported as the lone American to test positive aboard the ship. He later tested negative three times, and the CDC said the onboard result was likely a false positive. The agency also said he did not have hantavirus antibodies, suggesting he was likely never infected. After those results, the total number of reported cases fell to 10.

Officials said the response included more than 100 CDC staff members and coordination with state and federal partners to repatriate passengers to the Nebraska Biocontainment Unit and Emory University Hospital in Atlanta. That mix of testing, isolation and high-containment care shows where vigilance matters most: hantavirus spreads through contact with infected rodents or their droppings and urine, not through casual community spread. The shift from caution to concern would come only if confirmed U.S. positives emerged, secondary exposures widened, or a clear pattern of person-to-person transmission appeared. For now, the World Health Organization has described the global risk as low, and has said the outbreak is not comparable to COVID-19 and does not pose a pandemic threat.