The Austro-Hungarian prisoners of war WERE part of the Austro-Hungarian fighting force. They weren't two separate entities.
“Austro-Hungarian POWs were the source of typhoid fever, not Austro-Hungarian fighting force. Fighting force was not infected in advance, because they could not fight. Typhoid has short onset. The first week there is mailaise, second week fever and delirium.”
Quote from DTA, can’t have it both ways. Either they were infected while still an “effective” fighting force or they were infected after loss of battle prior to being taken as POW’s. Either way does not make sense.