Whereas the purpose of this study was to observe the natural history of untreated syphilis; the African-American men in the study were told they were receiving free treatment for "bad blood" from the United States government.The Public Health Service started working on this study in 1932 in collaboration with Tuskegee University, a historically black college in Alabama. Researchers enrolled 600 poor, African-American sharecroppers from Macon County, Alabama in the study. Of these men, 399 had contracted syphilis before the study began, and 201 did not have the disease. Medical care, hot meals and free burial insurance were given to those who participated. The men were told that the study would last six months, but in the end it continued for 40 years. After funding for treatment was lost, the study was continued without informing the men that they were only being studied and would not be treated. Facing insufficient participation, the Macon County Health Department nevertheless wrote to subjects to offer them a "last chance" to get a special "treatment", which was not a treatment at all, but a spinal tap administered exclusively for diagnostic purposes. None of the men infected were ever told that they had the disease, and none were treated with penicillin even after the antibiotic had been proven to successfully treat syphilis.
The most common complication is syphilitic aortitis, which may result in aortic aneurysm formation.Neurosyphilis refers to an infection involving the central nervous system. Involvement of the central nervous system in syphilis (either asymptomatic or symptomatic) can occur at any stage of the infection. It may occur early, being either asymptomatic or in the form of syphilitic meningitis, or late as meningovascular syphilis, general paresis, or tabes dorsalis.Meningovascular syphilis involves inflammation of the small and medium arteries of the central nervous system. It can present between 1–10 years after the initial infection. Meningovascular syphilis is characterized by stroke, cranial nerve palsies and spinal cord inflammation. Late symptomatic neurosyphilis can develop decades after the original infection and includes 2 types; general paresis and tabes dorsalis. General paresis presents with dementia, personality changes, delusions, seizures, psychosis and depression. Tabes dorsalis is characterized by gait instability, sharp pains in the trunk and limbs, impaired positional sensation of the limbs as well as having a positive Rombergs sign. Both tabes dorsalis and general paresis may present with Argyll Robertson pupil which are pupils that constrict when the person focuses on near objects (accommodation reflex) but do not constrict when exposed to bright light (pupillary reflex). Congenital
Congenital syphilis is that which is transmitted during pregnancy or during birth. Two-thirds of syphilitic infants are born without symptoms. Common symptoms that develop over the first couple of years of life include enlargement of the liver and spleen (70%), rash (70%), fever (40%), neurosyphilis (20%), and lung inflammation (20%).