Relatively few men were killed in action during the brief Spanish-American War of 1898. After the Maine explosion, 968 American soldiers were killed in actual combat. The War department was not at all pleased, however, with the total number of wartime deaths. Over 5,000 soldiers died of disease. Yellow fever was the most feared of the many diseases that swept through the American camps: its mortality rate was known to reach 85 percent.
Government officials must have been aware of the yellow fever danger in Cuba. The disease had been continually prevalent there since 1650. Unfortunately, the War department planned the Santiago campaign for July and August, when yellow fever was most likely to strike.
General William R. Shafter, commander of the Fifth Army Corps, and Lieutenant Colonel Theodore Roosevelt knew that their men were at risk. Immediately after the victory at Santiago (July 1-3), they urged Secretary of War Russell Alger to allow the army to move away from the city of Santiago to higher, and presumably healthier, ground. In a letter purposely leaked to the Associated Press to stir Alger to action, Roosevelt wrote: “If we are kept here it will in all human possibility mean an appalling disaster, for the surgeons here estimate that over half the army, if kept here during the sickly season, will die.”
Yellow fever invaded the American camp in July and infected nearly 2,000 soldiers. Most recovered after several days of high fever and intense muscle and joint pain, but others, after a brief rest from the suffering, showed the final and most severe symptoms: projectile vomiting of blackened blood, and jaundice produced by destruction of the liver—hence the two most popular names of the disease, “the black vomit” and “yellow fever.”
Secretary of War Alger ordered Shafter to separate his army into sick and well camps. Only those who had not yet contracted yellow fever could be sent back to the States; the victims were sent to the yellow fever hospital at nearby Siboney.
The Twenty-fourth Infantry, an African-American regiment, was sent to Siboney hospital to care for the sick. The experience of the Twenty-fourth contradicted the popular notion that African-Americans possessed “special immunity” to tropical diseases. In 40 days, more than one third of the regiment’s 460 men died of yellow fever or malaria at Siboney hospital.
Fortunately for the American army, Spain sued for peace July 17; the army might not have survived the next wave of yellow fever. Shafter’s entire corps was back in the United States by the end of August.
After the ratification of the Treaty of Paris, American leaders were forced to address the problem of yellow fever. 50,000 American soldiers were stationed in Cuba as part of the First Occupation (1898-1902). Something had to be done to protect vulnerable U.S. soldiers and civilians from the yellow scourge if American officials intended to remain on the island until political order was restored.
The men responsible for the health of Americans in Cuba, George Miller Sternberg (Surgeon-General of the Army) and Leonard Wood (Governor-General of Cuba), shared supreme confidence in American medicine. Since they also shared the belief that Cuba was the heartland of yellow fever in the western hemisphere, Sternberg and Wood saw the occupation of Cuba as a unique opportunity for an American study of the disease at its source.
Sternberg was one of few nineteenth-century American bacteriologists who followed the revolutionary and meticulous methods of Koch and Pasteur. His careful research, particularly his extensive studies of yellow fever, won the respect of the scientific community. In 1898, Sternberg issued strict orders for the sanitation of Cuba. He believed, like most of his contemporaries, that yellow fever was somehow connected with filthy living conditions. According to Sternberg, the disease “could fairly easily be controlled” if his rules of hygiene were closely followed.
Leonard Wood first entered the army as a surgeon. His medical prowess and charm caught the attention of prominent military and political leaders such as General Nelson A. Miles and Theodore Roosevelt. With their support, Wood set aside medicine for military and political pursuits. In 1898, he was made commander of the famous “Rough Riders,” and after the war he was appointed Governor-General of Cuba.
Wood and Sternberg assigned Major William Crawford Gorgas and his sanitation officers to clean private residences and clear garbage and sewage from the American camps and from the streets of Havana. Wood was sure that his government’s sanitary measures had “virtually stamped out” yellow fever in Cuba when yellow fever did not appear in the early summer of 1899.
But in mid-July, yellow fever struck again. Though not as severe as the 1898 outbreak, hundreds more Americans and Spanish immigrants were infected. In the spring of 1900, Sternberg and Wood appointed a team of army research scientists to study the cause and spread of the disease in Cuba. They selected Major Walter Reed to lead the commission, with James Carroll, Aristides Agramonte, and Jesse Lazear as his assistants.