Several flights across the country have been quarantined and evaluated over the past few days after some passengers showed signs of sickness.
On Wednesday, a flight from Dubai to John F. Kennedy Airport was quarantined after at least 19 passengers suffered from a confirmed case of the flu, according to ABC News.
The CDC quarantined the Emirates aircraft, which held 520 passengers. The CDC evaluated 100 passengers, who said they suffered from coughs, headaches, sore throats and fevers, ABC News reported.
At least 10 people were hospitalized as a "precaution." The rest were cleared.
"Given the symptoms that we are seeing in the patients and given the history that they present, it looks like this is probably influenza," acting New York City Health Commissioner Dr. Oxiris Barbot said. "But again, until we have our final results late tonight we won't be able to give a final determination on what the underlying cause is of this illness."
Similarly, Southwest Airlines passengers on four flights between Dallas, Houston and Harlingen, Texas, may have been exposed to measles, the airline company told KTRK-TV.
The airline said it contacted customers who traveled on the plane two weeks ago to see if anyone onboard had the highly contagious virus.
The Houston Health Department is working with the Centers for Disease Control and Prevention to speak with the passengers.
The department told KTRK that the passenger who had the virus did not visit the airport after their flight. They stayed in a waiting room for an hour after the flight.
And, as The Verge reported, two more international flights were evaluated after passengers were caught coughing and showing signs of sickness.
Both flights were from American Airlines, flying from Munich and Paris to Philadelphia International airport. About 12 people on each flight felt sick, according to a statement from the airport.
The airport said "all passengers on the two flights — totaling about 250 plus crew — were held for a medical review and the CDC was notified."
Allen Parmet, an aerospace medicine expert, told The Verge, "It's actually pretty common to have somebody coughing in a plane."
"If it turns out to be the flu, this could be an early forecast of the flu season ahead. And the CDC has some tips for keeping the virus from spreading: get vaccinated, and stay home when you're sick, if you can," according to The Verge.