Passengers and crew from two American Airlines flights arriving at Philadelphia International Airport have been held by authorities pending a medical review, after 12 people became ill with flu-like symptoms.
It's comes just a day after all 500 passengers onboard an Emirates A380 flight landing in New York from Europe were screened following reports of multiple passengers suffering from similar symptoms.
Emirates confirmed about 10 passengers from the flight were taken ill.
It was first thought that food poisoning could have been to blame for the outbreak on the Emirates flight, but officials now suspect some of the passengers who boarded the plane were already infected with the flu.
A number of the passengers had been in Mecca, which is currently experiencing a flu outbreak.
A total of 250 passengers from the flights to Philadelphia underwent medical evaluation as a precaution, and the US Centres for Disease Control and Prevention was notified.
One of the flights to Philadelphia came from Paris, the other from Munich.