It is a sad, but incontrovertible fact, that despite the great medical advances made over the centuries, the cost of disease to armies is still too high. The death rate due to disease has been significantly reduced over that due to battle injury, but disease casualties still represent the major cause of disability. In World War II, the US armed forces suffered losses of 72 million man-days due to battle wounds, but lost four times as many man-days due to disease. More recent military experiences in Korea, Indochina, Lebanon, Kuwait, India, and Viet Nam have indicated clearly that medical problems of disease and of climate remain of major military importance. Infectious diseases represent the major classification among diseases leading to military ineffectiveness, and among these, arthropod-borne diseases are responsible for the largest percentage.
On this basis, the US Army Medical Research and Development Command has carried out an active program
Sherman JL. Development of a Systemic Insect Repellent. JAMA. 1966;196(3):256-258. doi:10.1001/jama.1966.03100160106030