Contact Tracing and the Control of Human Immunodeficiency Virus Infection

Contact tracing, the practice of identifying and treating individuals exposed to certain communicable diseases, has long been a bulwark of public health practice in the United States.¹,²Originally proposed in 1937 by Surgeon General Thomas Parran for the control of syphilis, it became firmly established in syphilis control programs by the late 1940s.³⁻⁶The central strategy in syphilis contact tracing was the early identification and treatment, first with arsphenamine and later with See also p 3563. penicillin, of asymptomatic individuals who had been sexually exposed to the disease and were therefore at risk of being infected and infective.⁵By tracing chains of syphilis transmission from a patient with known infection, and by treating all potentially infected contacts, transmission could be interrupted. The success of contact tracing was perhaps best seen in the declining prevalence of syphilis in the 1950s and in the control of localized outbreaks of