Planes can harbor bacteria for days, a new study suggests.

According to research presented at the American Society for Microbiology, some of the deadliest germs can survive for up to seven days on airplane surfaces like seats, armrests, tray tables, and other surfaces.

Kiril Vaglenov, of Auburn University who presented the data, described the results of this first step in identifying and analyzing the potential danger of catching a dangerous disease from other airplane passengers given the extended amount of time people spend in crowded air cabins.

Disease-causing bacteria must survive the conditions on an airplane in order for it to transfer from a surface to a person. Vaglenov and colleagues tested how well two pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and E. coli O157:H7, were able to live on common surfaces of an airplane.

Six different surfaces were analyzed, including armrests, tray tables, window shades, toilet buttons, seat pocket cloths and leather. These surfaces were then inoculated with the bacteria and placed in similar airplane environmental conditions.

The researchers discovered that MRSA lived the longest on seat pocket cloth (168 hours), and E. coli O157:H7 lived longest on armrests (96 hours).

“Our data show that both of these bacteria can survive for days on the selected types of surfaces independent of the type of simulated body fluid present, and those pose a risk of transmission via skin contact,” said Vaglenov in a statement.

The researchers are currently testing other pathogens, including bacteria that causes tuberculosis.