Estimates for Ottoman military casualties vary widely, as the disintegration of the Ottoman bureaucracy and government meant 1,565,000 men simply became unaccounted for in the records following the end of the war. The Ottoman official casualty statistics published in 1922 were 325,000 dead (50,000 killed, 35,000 died of wounds, 240,000 died of disease), 400,000 wounded, and an unknown number of prisoners. The United States War Department used the same killed and wounded figures, and estimated that 250,000 Ottoman soldiers had gone missing or become prisoners before the end of the war, for a total of 975,000 casualties. American historian Edward J. Erickson, based on non-published individual World War I campaign histories in the Ottoman Archives, estimated Ottoman military casualties at 1,680,701: 771,844 dead/missing (175,220 killed in action, 68,378 died of wounds, 61,487 missing action, and 466,759 deaths due to disease), 695,375 wounded (total of 763,753 wounded including those who died of wounds and 303,150 actually listed in records; the author assumes these are only the seriously wounded, and estimates the rest), and 145,104 prisoners of war. The very high ratio of disease deaths to combat deaths is attributed to the breakdown of the Ottoman medical services, which resulted in afflictions that would normally be treated after evacuation from the theater in the British army often being fatal in the Ottoman army. Including those who died of disease, 3,515,471 Ottoman troops fell sick during World War I.