Dr. Margaret Craven discusses HIV/AIDS from the perspective of a front-line clinician. AIDS is unprecedented in both the speed with which it spread across the globe and in the mobilization of efforts to control it. It is a disease of modernity. Along with the relative ease and velocity of modern transportation methods, other background conditions include Western medicine, with hypodermic needles and bloodbanking, intravenous drug use, and the development and concentration of gay culture.

The Tuskegee Syphilis Study, carried out in Macon, Alabama, from 1932 to 1972, is a notorious episode in the checkered history of medical experimentation. In one of the most economically disadvantaged parts of the U.S., researchers deceived a group of 399 black male syphilitics into participating in a study with no therapeutic value. These "volunteers" were not treated as patients, but rather as experimental subjects, or walking cadavers. Even after the development of penicillin, the Tuskegee group was denied effective treatment.

Reliable records of influenza, dating back to the 1700s, suggest a pattern of one major pandemic every century. Among the pandemics for which there is solid documentary evidence, the outbreak of 1918-1920 is by far the greatest. The so-called Spanish Lady caused somewhere between 25 and 100 million deaths worldwide. It is distinctive both for its high mortality rate, in comparison to other flu pandemics, and for its unusual demographic effect: whereas the flu typically targets the very young and old, the 1918-1920 epidemic struck adults in the prime of life.

The cultural transition from the romantic era of consumption to the era of tuberculosis derived not only from the germ theory of disease and the triumph of contagionism over anticontagionism, but also from political considerations. Worries over population decline and growing working-class militancy were aggravated by what now appeared to be a social disease, or a disease of poverty. One of the strategies deployed against the disease was the sanatorium, an institution which was capable both of instructing patients in contagionism and in imposing a practical quarantine.

An ancient disease, tuberculosis experienced a major upsurge in Western Europe in the nineteenth century, corresponding with increasing industrialization and urbanization. Poor air quality and cramped living conditions increased susceptibility to the disease. Tuberculosis also had a significant impact on European culture.

In the last decade of the nineteenth century, malariology emerged as the most prestigious and intellectually exciting field in the new discipline of tropical medicine. The disease's complexity and resistance to conventional public health strategies posed a major challenge to doctors and scientists. Plague measures and social hygiene had no effect in curbing malaria, and the disease proved difficult to classify. The case of Italy, and the malaria eradication program of 1900-1962, furnished a model for other efforts across the world.

Of all the diseases studied in this course, malaria has been responsible for the most human suffering. It has evolved alongside humans, and impacted human biology as well as civilization. In the former case, this impact is evident in genetic diseases like sickle-cell anemia which, while increasing vulnerability to a host of other illnesses, has the advantage of conferring substantial resistance to malaria.

The sub-discipline of tropical medicine furnishes a clear example of the socially constructed character of medical knowledge. Tropical diseases first enter medical discourse as a unique conceptual field and topic for specialization at the end of the 19th century, and the heyday of tropical medicine--from the 1890s to the First World War--corresponds to the golden age of Western colonialism in Africa and Asia.

Although the development of the germ theory of disease in the latter half of the nineteenth century marks a major revolution in medical science, comparable to the discoveries of Galileo in astronomy or Darwin in biology, it cannot be reduced to the heroic efforts of a single researcher or group of researchers. Rather, a number of conceptual, technological and institutional preconditions made the germ theory possible. Among these, contagionism, microscopy and hospital medicine all played a major role.