In reading this it appears that the typhoid epidemic, something that was not a new occurrence in Serbia had more to do with a lack of Doctors, medicine and facilities to deal with the masses of Serbian refugees and prisoners of war than a deliberate act of germ warfare. And I still argue that the prisoners of war being infected not the fighting force makes no sense. So someone had the Typhoid virus ready and just waiting to infect the soldiers just as they were to be taken as prisoner?
The Austro-Hungarian prisoners of war WERE part of the Austro-Hungarian fighting force. They weren't two separate entities.
Typhus, not typhoid. Bacteria, not virus.
The only way to spread typhus is by lice, so possibly one could put together a “lice bomb” and drop it on the refugees. Seems pretty advanced for 1914.