DENVER, Colorado (CNN) -- Sixty-seven cadets at the Air Force Academy have confirmed cases of H1N1 influenza -- the so-called swine flu -- and another 30 are showing symptoms of the highly contagious virus, the academy said Tuesday.
None of the cadets has required hospitalization.
All 97 are incoming freshmen, known as "Doolies" in academy slang. They are in isolation while the rest of the class of about 1,300 is in outdoor training in the mountains around the Colorado Springs academy.
Academy officials say Air Force medical personnel are treating the cadets, and they hope to have everyone out of isolation before the beginning of classes August 6.
Another 70 showed symptoms of the swine flu but tested negative and have recovered enough to return to training.
Cadets in the class of 2013 arrived at the academy June 25. By July 6, academy medical staff began noticing an increase in cadets complaining of upper respiratory problems. As cadets have begun showing symptoms, they are moved into a separate dormitory away from other cadets.
Laboratory tests are conducted at an Air Force lab in Texas, and results are forwarded to the Centers for Disease Control and Prevention.
The outbreak forced academy officials to modify "Doolie Day Out" on Saturday. Traditionally, it is the first day off for cadets, and they are allowed to leave the academy grounds. This year, cadets stayed on grounds.