Origins of American Tropical Medicine

     War stimulates medical advances. The surgical treatment of wounds, prevention and treatment of disease, even high altitude and space problems have all benefitted from military considerations. And war created the specialty of tropical diseases in the U.S. 

     In Great Britain tropical medicine as a specialty had gotten off to an earlier start, owing to some 300 years of overseas commercial, military, and colonization activities. Patrick Manson, the "father" of tropical medicine in England, published his important textbook in 1898, after contributing heavily to a similar text 5 years earlier edited by Andrew Davidson (Hygiene and Diseases of Warm Climates, 1893). The London and Liverpool Schools of Tropical Medicine were founded in 1899, putting tropical medicine on a firm academic and research footing.

     In the U.S., by contrast, the term "tropical medicine" was seldom heard until the Spanish-American War, though southern states had wrestled with malaria and yellow fever for some time. A devastating epidemic of yellow fever in 1878, for example, originating in New Orleans and sweeping up the Mississippi as far as Ohio leaving wrecked economies and thousands dead (John H Ellis: Yellow Fever and Public Health in the New South, 1992), generated interest in a national public health system and provoked the first of several committees to study yellow fever.

     By the 1880s the germ theory was well entrenched, and in 1880 Alfonse Laveran discovered the malaria parasite, proposed as an alternative to the marsh bacilli claimed by Klebs and Tommasi-Crudeli as being the cause of malaria.  William Osler, an excellent microscopist, appreciated its importance and published on malarial parasites in 1886, when their significance was still questioned (G C Cook: "William Osler's Fascination with Diseases of Warm Climates", J Med Biog, 1995; 3:20-29). William Councilman, pathologist at Hopkins, and colleagues, wrote groundbreaking papers on cerebral malaria and amebic colitis(Am J Med Sci 1885, 89: 416-29; Johns Hopkins Hosp Rep 1891, 2:395-548). George Sternberg, a military physician and one of the first American experts in microbiology, later to become Surgeon General, wrote an excellent book about malaria and another about yellow fever.

     These were beginnings, but it was the Spanish-American War that impelled research and offered careers in this area. Cuba was the site of the famous experiments of the Yellow Fever Commission led by Walter Reed that delineated the mosquito transmission of yellow fever, allowing the construction of the Panama Canal. It was the Philippines, though, where the war against the Spanish had merged into war against Philippine guerrillas, keeping troops there for years, allowing longer-term research - and career opportunities. Very early in the war the Army established laboratories in the Philippines, mainly for diagnostic purposes, and a Research Board. The original order, from S.Gen. Sternberg, included the phrase, "Special attention shall be given to tropical dysentery, to the malarial fevers prevailing in the Philippines, to beriberi, to intestinal parasites, and, in general, to all tropical diseases, the etiology of which has not been worked out." (Army Med Bull. 1929. "A Synopsis of the Army Medical Research Boards in the Philippines". Much of what follows is found there, as are references to all the original papers)

     The principle hospital laboratory was at the First Reserve Hospital in Manila. The first director died of typhoid fever shortly after arrival, and was succeeded by Richard Strong. Strong was a graduate of the first class at the new Hopkins Medical School, and deliberately enlisted so as to be able to work with tropical diseases, citing Osler, Welch and others as creating his interest in this area. He was also assigned to head the Army Research Bureau. He too was incapacitated by typhoid the year after he arrived, but managed to resume work. The Research Board was disbanded in Jan. 1902, and Strong transferred to the newly organized laboratory of the Philippine Government, which soon became the Biological Laboratories of the Philippine Bureau of Science. 

Philippine Bureau of Science

     As a measure of the disease toll on troops, in the first ten months the First Reserve Hospital had 21,955 admissions, only 1,874 of which were for wounds and injuries. 21% of the rest were cases of dysentery and diarrhea, dysentery (2/3 were amebic) accounting for the highest mortality. Malaria, typhoid, brucellosis, dengue fever, and tropical ulcer were prevalent. In the general population smallpox was endemic, as were leprosy, beriberi, tuberculosis, yaws and other skin ailments, and soon cholera and plague made their entrance(Science 1900, V11 ns,p521-28). Many "fevers" were undiagnosed, the only tests that were helpful being malaria smears, Widal tests, blood counts, and eventually stool cultures and stool examination for parasites.(Bost Med Surg J 1901, 144:175-8)

     Others from Hopkins arrived. James Flexner, pathologist, later director of the Rockefeller Institute, and Llewelyn Barker, later to be chief of medicine at Hopkins, and a pair of medical students plunged into research, one result of which was the description of a new Shiga bacillus causing much of the dysentery, named shigella flexneri after its discoverer.

      A Second Board of Research was established in 1906 under Percy Ashburn and Charles Craig, which lasted considerably longer. This Board made a number of discoveries and elaborated important information. A few examples: Filariasis was first described in the Philippines, originally thought to be  due to a new species, but eventually proved to be Filaria bancrofti; dengue fever was discovered by Charles Craig and Percy Ashburn to be caused by a filterable agent,to be non-contagious, and to be mosquito-transmitted (though an incorrect mosquito was named at first). Craig later was head of the Tropical Medicine Department at Tulane, and Ashburn wrote a text pathology in the tropics and a history of the Medical Department of the Army.  The existence of pathogenic and nonpathogenic amebae, first noted by Schaudinn, was confirmed through both microscopic exam and numerous feeding experiments on prison volunteers (with signed informed consent) done by Andrew Sellards and Ernest Walker. These experiments also delineated the clinical course of amebiasis and uncovered the carrier state (Philipp J Sci 1913, 8:253-330). Sellards went to Harvard, then on to be intimately involved in the development of the French version of the yellow fever vaccine, and Walker came to UCSF to work in the Hooper Foundation where he focused mainly on leprosy(see http://texts.cdlib.org/view?docId=hb0w10035d&doc.view=frames&chunk.id=div00061&toc.depth=1&toc.id=).

       Much effort was expended studying the effect of the tropics on arriving soldiers. It was determined that overall health was seldom affected as long as infectious diseases were avoided, that there was no difference in tolerance to tropical life between blonds and brunettes, and that the use of red-orange underwear (to protect against UV light) made no difference, except that it was less comfortable.(JAMA 1912, 58:998-1002)     

    In addition to military issues, the Philippines were now a U.S. colony and the health of the population was at stake. The Philippine Bureau of Science was heavily involved in this effort. Americans worked hard, for example, to find infectious causes for beriberi, without success. British workers in Malaya had studied dietary factors, gradually focusing on rice polishing and showing that polished rice seemed to be the culprit. The Americans confirmed this idea when their own native scouts developed beriberi and were cured with consumption of unmilled rice, though the exact explanation for this was still obscure (for summary see Carpenter, KJ, Beriberi, White Rice, and Vitamin B, 2000).  

     Victor Heiser arrived as Quarantine Officer with the Marine Hospital Service, later was Health Officer for the Philippines, and dealt with plague, cholera, and smallpox epidemics, the latter suppressed with mass vaccination using material made from caribou. (Phil J Sci 1910, 6:171-9). He later was a major officer in the Rockefeller Foundation's International Health Board. Edward Stitt, a naval surgeon who had studied under Manson and was in the Philippines, wrote the first American text on Tropical Disease, a book that went through six editions and then was taken over by Richard Strong.

Richard P Strong

     Richard Strong, mentioned above, is perhaps the best candidate for the title of the American "father of tropical medicine". In addition to work mentioned, he was the first to show the curative properties of compound 606, which he obtained directly from Paul Ehrlich, in treating yaws, a prevalent disease there (Phil J Sci 1910, 5B:433-54). Strong was called in 1912 to become the first professor of tropical medicine at Harvard. In this capacity he organized several expeditions to Guatemala, South America, and Africa to study tropical disease (as well as local food and cultural practices). In 1915 he headed, through the American Red Cross and Rockefeller Foundation, an expedition to Serbia to combat a massive typhus epidemic, and was part of the Typhus Commission, Medical Research Committee, American Red Cross, that established the louse transmission of trench fever during WWI (Avail. at Hathi Trust). In WWII he served as director of tropical medicine at the Army Medical School. The only blemish on his career was an accidental infection of prisoners with plague during a trial of a cholera vaccine (Rev Inf Dis 1989, v11: 996-1004). He needs a good biography. 

     I could go on, but this is enough to indicate the role of the American occupation of the Philippines in the creation of tropical medicine as a specialty in the U.S. The origin of the American Society of Tropical Medicine is another, and interesting, story for a future blog.