"More fatal than powder and shot": dysentery in the U.S. Army during the Mexican War, 1846-48.

In terms of deaths due to disease, the Mexican War (1846-48) was the deadliest of all American wars. Nearly 13% of the entire U.S. force perished from disease. Of the total 12,535 war deaths, 10,986 (88%) were due to infectious diseases (overwhelmingly dysentery, both bacterial and amoebic); seven men died from disease for every man killed by Mexican musket balls. Camp pollution was the greatest error committed by U.S. troops in the Mexican War. The indifference of line officers and recruits to the need for proper sanitation and military hygiene fueled the dysentery outbreaks, and the poor conditions in military hospitals contributed further to the spread of disease. This defect in military culture undermined the health of the army and led to medical disaster. Disease caused an enormous drain on the U.S. Army's resources, eroded troop morale, and influenced strategy and tactics. As we enter the 21st century, dysentery is still a major public health threat, killing hundreds of thousands of people annually-primarily children in developing countries where personal hygiene is poor and disposal of human and animal wastes is indiscriminate.