If soldiers in WWI thought the Axis Powers were scary, they had nothing on chlamydia.

During the war, the U.S. military lost more than 7 million “person-days” and were forced to discharge more than 10,000 men due to sexually transmitted diseases.

Mere months into the war, top official realized this could become a serious problem. William H. Zinsser, Chairman of Council of National Defense’s Sub-Committee for Civilian Cooperation in Combatting Venereal Diseases, said:

 “One nation, during the first year and a half of war, lost the services of more men through venereal disease than through death or wounds in battle. One regiment which participated in a furious attack in Northern France was sent back of the lines to recuperate, and there joined another regiment which had been encamped behind the front for some time and had seen no actual fighting at all. Will you believe that the latter regiment, the one that had not been in action, had lost the services of more men through venereal disease during its stay behind the lines than the one back from the firing line had lost in the attack?”

Barring Sex Disease from the American Army: For the First Time in History a Nation Takes Advance Steps to Avert an Evil Worse Than Battle Casualties

From Sunday, October 28, 1917