Authorities say 12 passengers on two flights from Europe were evaluated for sore throats and coughs upon arrival at Philadelphia International Airport.
A federal Customs and Border Protection spokesman says the sick passengers had been attending the hajj in Mecca, Saudi Arabia.
According to officials, passengers from the two flights Thursday afternoon who weren't sick continued on with their travel plans.
None of the illnesses were considered severe.
The Centers for Disease Control and Prevention says none of the 12 passengers coming to Philadelphia on American Airlines flights from Paris and Munich exhibited fevers.
An American Airlines spokeswoman says the plane wasn't quarantined.
AP wire services helped contribute to this report.