It takes little imagination to ascribe racist attitudes to the white government officials who ran the experiment, but what can one make of the numerous African Americans who collaborated with them?

One of the most chilling aspects of the experiment was how zealously the PHS kept these men from receiving treatment.

Instead, the Tuskegee scientists continued the study without treating any participants and withholding penicillin and information about it from the patients. In addition, scientists prevented participants from accessing syphilis treatment programs available to others in the area.

arguably the most infamous biomedical research study in U.S. history

When he understood the intention of other study members to use deceptive practices, Dr. Clark disagreed with the plan to conduct an extended study.[clarification needed] He retired the year after the study began.

he decided to gain the "consent" of the subjects for spinal taps (to look for signs of neurosyphilis) by depicting the diagnostic test as a "special free treatment"

Several African American health workers and educators associated with Tuskegee Institute unwittingly helped the PHS to carry out its experimentation and played a critical role in its progression.

Nurse Rivers believed that the benefits of the study to the men outweighed the risks.

By the late 1940s, doctors, hospitals and public health centers throughout the country routinely treated diagnosed syphilis with penicillin. In the period following World War II, the revelation of the Holocaust and related Nazi medical abuses brought about changes in international law. Western allies formulated the Nuremberg Code to protect the rights of research subjects. No one appeared to have reevaluated the protocols of the Tuskegee Study according to the new standards.

After penicillin was found to be an effective treatment for syphilis, the study continued for another 25 years without treating those suffering from the disease. After the study and its consequences became front-page news, it was ended in a day.

The aftershocks of this study, and other human experiments in the United States, led to the establishment of the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research and the National Research Act.

It was reported that from 1946 to 1948, American doctors deliberately infected prisoners, soldiers, and patients in a mental hospital with syphilis and, in some cases, gonorrhea, with the cooperation of some Guatemalan health ministries and officials.

A total of 696 men and women were exposed to syphilis without the informed consent of the subjects. When the subjects contracted the disease they were given antibiotics though it is unclear if all infected parties were cured.[15]

ordered to obtain treatment for syphilis before they could be taken into the armed services

PHS researchers attempted to prevent them from getting treatment, thus depriving them of chances for a cure.

A PHS representative was quoted at the time as saying: "So far, we are keeping the known positive patients from getting treatment."

By 1947 penicillin had become standard therapy for syphilis. The US government sponsored several public health programs to form "rapid treatment centers" to eradicate the disease. When campaigns to eradicate venereal disease came to Macon County, study researchers prevented their patients from participating.[13]

Medical ethics considerations were limited from the start and rapidly deteriorated. To ensure that the men would show up for the possibly dangerous, painful, diagnostic, and non-therapeutic spinal taps, the doctors sent the 400 patients a misleading letter titled "Last Chance for Special Free Treatment". The study also required all participants to undergo an autopsy after death in order to receive funeral benefits. After penicillin was discovered as a cure, researchers continued to deny such treatment to many study participants. Many patients were lied to and given placebo treatments so researchers could observe the full, long term progression of the fatal disease.