https://armyhistory.org/the-other-foe-the-u-s-armys-fight-against-malaria-in-the-pacific-theater-1942-45/
The Other Foe: The U.S. Army’s Fight against Malaria in the Pacific Theater, 1942-45
Written By: Seth Paltzer
Disease has always had a major impact on armies at war, often producing more casualties than combat wounds. The history of the U.S. Army is full of examples of this fact. The Civil War Trust estimates that for every three men killed in combat from 1861 to 1865, another five died of disease. By the twentieth century, medical care and preventative measures had been greatly improved, but these advances were often difficult to implement on the front lines, and disease continued to exert an immense force in war, especially in the remote islands of the South Pacific during World War II.
The average soldier serving in the Pacific Theater of Operations (PTO) fighting against the Japanese faced a great many challenges and dangers. Often overlooked by histories of the war, one of the most insidious of these was malaria. This disease, while not typically fatal to the infected soldier, would take him out of action for a prolonged period just as surely as if he had been wounded in battle. The Army’s fight against malaria is a fascinating story of man versus nature, with America’s success in the war against Japan at stake.
''Malaria is a tenacious disease that can have long-lasting effects on the infected person. American soldiers encountered two different types of the disease in the PTO: benign, which causes violent chills, fever, and weakness, and malignant, a form much more likely to cause death. Both types had the potential to turn a battle-ready soldier into a bedridden hospital case in a very short period of time.''
The disease itself is caused by a mosquito-borne parasitic protozoan that attacks the red blood cells and liver of the infected person. The damp, swampy environments encountered on many Pacific islands were ideal breeding grounds for the anopheline mosquitoes that transmit the disease. Furthermore, the many shell craters, foxholes, and ruts created during combat operations all served to collect water, offering plentiful opportunities for the insects to breed and multiply. When the mosquitoes feed on an infected person, they become carriers of the parasite, and then deposit the disease in the bloodstream of another person when they fed again. In this way, the instances of infection could quickly balloon, as each new person infected became a carrier through which more mosquitoes could pick up the disease, and in turn, infect additional victims, establishing a vicious cycle that proved very difficult for the Army to disrupt.
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