James Tonges, who was travelling on one of the flights, said he felt a needle in his mouth after biting into a sandwich.
BBC: Needles found in Delta Air Lines on-board sandwiches
2.
Mr Tonges said he was taking Truvada, a drug just approved in the US for HIV prevention, while officials investigated for "any type of substance on the needle".
BBC: Needles found in Delta Air Lines on-board sandwiches