The Tuskegee Syphilis Study had the following survival rates for the participants as of:

In the study, investigators enrolled a total of 600 impoverished African-American sharecroppers from Macon County, Alabama. Of these men, 399 had latent syphilis, with a control group of 201 men who were not infected.
The study continued, under numerous Public Health Service supervisors, until 1972, when a leak to the press resulted in its termination on November 16 of that year. By then, 28 patients had died directly from syphilis, 100 died from complications related to syphilis, 40 of the patients' wives were infected with syphilis, and 19 children were born with congenital syphilis.

Therefore in the Tuskegee study, 32% of participants ended up dying due to syphilis or its complications over a period of 40 years.

What was the approximate expected lifespan for someone infected in the 1930s (so, prior to the discovery of effective treatments) and not participating in a study? Additionally, is it known how many people infected with syphilis in the 1930s ended up passing it to their spouses?

  • 2
    So you are asking "has there been a study on the lifespan of people not in a study"? Commented Jan 15 at 15:57
  • @DJClayworth I assume there's been other studies on syphillis Commented Jan 15 at 16:26
  • @DJClayworth A nice joke, really, I like it, but I think, you do distinguish a medical study of the illness and its effects on a person, and medicines effects, how the poor patient dies, and what he/she feels, and so on, and, on the other side, a statistical study that counts how long they lived, how many they infected and where did they get that infection... Yes, the formulation should be corrected.
    – Gangnus
    Commented Jan 19 at 18:44
  • to the author: DJClayworth reprimands you quite correctly: you mean "not participating in a study of medicines and cure", but you need a statistical study.
    – Gangnus
    Commented Jan 19 at 18:48
  • Some social groups got no cure. Some groups got cure and were cured. What groups are you talking about?
    – Gangnus
    Commented Jan 19 at 18:51

1 Answer 1


The question is effectively unanswerable. Prior to the 1960s there was very little data about syphilis mortality outside of the Tuskegee experiment. An article from 1937 says it directly: "There are no reliable figures to show how many deaths are due to syphilis, either in the white or Negro race."

Based on what few relevant data points I could find, the 32% figure seems quite high and may reflect the poor overall conditions faced by the subject population.

Prior to the Tuskegee experiment there was a a famous "Oslo study" which found that 10% of the people with syphilis in the study (alll untreated) died of it within 40 years.

In the early 1940s an autopy-based study found that "once a diagnosis on clinical or laboratory evidence was made, three out of ten syphilitics developed significant tissue lesions, and one out of five died therefrom," that is, 20%.

  • 1
    On the last paragraph: Is that one out of five of all those diagnosed (20%), or one out of five of those who developed significant tissue lesions (that would be 6.6% of those diagnosed)?
    – DevSolar
    Commented Jan 15 at 16:28
  • @DevSolar I read it as 20% of the total, but I'll edit if you can find evidence to the contrary. I just skimmed the source and didn't read that deeply.
    – Brian Z
    Commented Jan 15 at 20:26
  • IIRC syphillis' virulence also evolved over time and possibly regionally, making it even harder to pin down. Commented Jan 16 at 18:42

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