A recent incident on a United Airlines flight from Canada to Houston highlights concerns.
Seventy-five passengers returning from a cruise fell ill with flu-like symptoms during the flight.
Upon landing, the CDC quarantined the plane, delaying disembarkation for about 45 minutes while passengers underwent health screenings.
Three passengers were taken off the plane but did not require hospitalization.
Despite concerns online, the CDC determined no further public health action was necessary.
