In 1972, reports began to emerge about a US Public Health Services study of syphilis. Some 400 low-income African-American men known to be infected with syphilis had been tracked for 40 years by researchers seeking to understand the natural course of the disease. The researchers hid the subjects 'disease from them, and withheld treatment even after penicillin was revealed to be effective against the condition.
1972 年，美國公共衛生署的梅毒研究被揭發，當年 400 名非裔貧苦男性被證實感染梅毒，在長達 40 年的追蹤期裡，研究者為了透過他們瞭解梅毒的自然病程發展，竟隱瞞其罹病事實，甚至在盤尼西林療法已確定有效後，仍沒有給予任何治療。