Passengers quarantined after Asiana flight diverted to Winnipeg over suspected 'highly contagious' illness

Passengers on an Asiana Airlines flight from Seoul to New York were temporarily quarantined after the aircraft was diverted to Winnipeg on Wednesday amid concern about a "very contagious" illness, health officials said.

The flight was diverted to Winnipeg Richardson International Airport at about 6:30 a.m. local time. After landing, one passenger was removed from the aircraft and transported to St. Boniface Hospital, where the individual was placed in a social containment unit, a government spokesperson told Canadian media. The passenger was later taken out of the containment unit, the spokesperson said. The aircraft and the remaining passengers remained parked on the tarmac for nearly four hours before the plane resumed its journey and landed at John F. Kennedy International Airport at 2:35 p.m. Eastern time.

Officials did not disclose the suspected illness or provide details on the passenger's condition. The spokesperson described the measure as a precaution and said "all necessary precautions were taken" and that there was "no threat to anyone on board the plane." Canadian and U.S. authorities routinely coordinate at ports of entry when a traveler is suspected of carrying an infectious disease.

Under U.S. law, federal public health authorities may authorize isolation or quarantine at ports of entry for a limited set of communicable diseases, including cholera, diphtheria, active tuberculosis, plague, smallpox, yellow fever, viral hemorrhagic fevers such as Ebola and Marburg viruses, severe acute respiratory syndromes, influenza A and measles. Officials did not indicate whether any of those illnesses were suspected in this incident.

Public health officials have increasingly focused on international travel as a route for importation of contagious diseases. During the 2025 U.S. measles outbreak, public health data show that 1,454 cases were reported nationwide, of which 21 were linked to international visitors traveling to the United States. Measles is highly transmissible through airborne droplets produced by coughing or sneezing; such droplets can linger in an enclosed space for up to two hours and the incubation period typically ranges from seven to 21 days.

Other pathogens that can prompt quarantine protocols include viral hemorrhagic fevers, such as Ebola, which spreads through contact with blood or bodily fluids and can have high mortality without treatment. Internationally, an outbreak in the Democratic Republic of the Congo in 2025 had infected dozens of people. Tuberculosis, a respiratory disease caused by Mycobacterium tuberculosis, remains more common in some countries, including South Korea, and is a frequent consideration in cross-border public health evaluations. The World Health Organization estimates tuberculosis kills more than a million people worldwide each year. Viral hepatitis, which includes types spread by contaminated food or water, shared needles or contact with infected bodily fluids, also occurs with varying frequency internationally; U.S. estimates place annual infections at thousands for hepatitis A, B and C combined.

Authorities did not say whether any passengers or crew were identified for follow-up monitoring, or whether contact tracing was initiated. Asiana Airlines and hospital officials declined to provide additional information beyond the statements released to media. Local and international public health agencies routinely investigate potential exposures on flights to determine whether additional measures are needed to protect the public.