Health of the Command

The health of the U.S. Army in Vietnam has been excellent. A major consideration in the decision to commit U.S. forces in Southeast Asia was the concern that disease in that area would decimate our troops, and that active combat operations would be impossible. This was not the case. A major contributing factor to the well-being of U.S. troops was the recognition that a 6-week period of adjustment and acclimatization was needed. This "precommitment" period provided, most definitely, one of the lessons learned in Vietnam.

Empirically, it has been observed that it takes about 5 days to adjust to the significant time zone changes and to develop a new diurnal cycle. It also takes 2 to 3 weeks to acclimatize to the heat and humidity of the Tropics, if troop stresses are gradually increased. A total of approximately 6 weeks is required to develop a "relative biological acclimatization" to the types of infectious organisms encountered in the new environment. This 6-week period of adjustment and acclimatization was a necessity; command recognized it as a physiological and biological reality, and senior commanders in Vietnam postponed commitment to major combat operations accordingly.

During this 6-week period, troops spent their time profitably. They learned again to live in the field, mess personnel became more efficient in field sanitation, and all the new arrivals developed a keen awareness of the problem of health and a greater appreciation of the necessity for a vigorous preventive medicine program- both by command and by the individual.

The diseases encountered in Vietnam were those which have plagued all armies through the years: fever of undetermined origin, diarrhea, upper respiratory infections, dermatological conditions, and malaria. Although disease accounted for more than two-thirds of all hospital admissions, the average annual disease admission rate for Vietnam (351 per 1,000 per year) was approximately one-third of that for the China-Burma-India and Southwest Pacific theaters in World War II, and more than 40 percent less than the rate for the Korean War.

Malaria was the most significant medical problem in Vietnam, but it was one which the Army Medical Department had anticipated. Studies undertaken in South America and elsewhere in Southeast Asia after World War II showed that chloroquine-resistant malaria would emerge as a problem in Vietnam. This proved to be the case in 1965, when U.S. troops began operating in the Central Highlands where there had been no real malaria eradication program because of Vietcong domination.

The precipitous rise in the, incidence of P. falciparum malaria among combat troops in contact with the Vietcong indicated that the standard chloroquine-primaquine prophylaxis was not completely effective against