Opinion – Esper Kallás: The Anniversary of the Tuskegee Study

Syphilis, caused by the sexually transmitted bacterium Treponema pallidum, is an old familiar to humans.

The origin of the agent is still debated, but it is believed that it was already present in the Americas even before the arrival of the European conquerors, in the 15th century. It was later spread throughout Europe and, from there, to the rest of the world.

Some of those infected develop a painless lesion on the genitals called a hard chancre, a hallmark of primary syphilis. If untreated, it can disappear on its own or, weeks later, with the appearance of other lesions. These spread through the skin a few weeks later, including the palms of the hands and soles of the feet, characterizing the secondary form. Even these lesions may disappear when the disease enters the latency phase.

The problem appears decades later. Infection by Treponema pallidum, already in the tertiary phase of the disease, leads to damage to various organs and tissues, most of which are irreversible. The best-known complication of this stage is cerebral syphilis, to which about a fifth of mentally ill patients in the early 20th century was attributed.

Between 1932 and 1972, a group of researchers from the US Public Health System started the Tuskegee study, to understand the evolution of the disease, but its consequences were disastrous.

We included 600 men, all of African descent, who were not informed about their diagnosis, about the nature of the experiment and did not give their consent. Of these, 399 had syphilis and 201 did not have the disease, serving as a control. It should be noted that, when the study began, the basis of the treatment offered used arsenic, mercury and bismuth salts, which are very toxic and ineffective.

It was not until 1942, with the discovery of penicillin, that the treatment of syphilis underwent a revolution. Gradually, it was demonstrated that the revolutionary drug, the first antibiotic discovered, was capable of curing patients, whether in the primary, secondary or latent forms. It was more difficult to treat the tertiary form, when the damage was already more serious and established, although it managed to stagnate its development.

However, the study continued. Follow-up of participants persisted and penicillin treatment was not offered. As a consequence, many developed serious complications from the disease and dozens died as a direct consequence of syphilis or from complications related to the disease. Many tissue samples were obtained from patients who died during the study, including at necropsies.

It was not until 1965 that Peter Buxtun, a psychiatrist born in former Czechoslovakia, an investigator of sexually transmitted diseases, newly hired by the American Public Health Service, began to question the morality in keeping the study going.

It took another seven years before the study was stopped completely in 1972.

This scandal broadened the debate on the conduct of clinical trials, being considered the most important event in the construction of fundamental ethical premises. It marked the adoption of multiple safeguards to protect volunteers, including the right to full information about what any study is proposing and guaranteeing the use of the best available alternative treatment by health services.

The year 2022 marks the 50th anniversary of the study’s completion. Though sad, Tuskegee’s example must always be remembered, lest mistakes be repeated.