by Gabriel Rotello

About the author: Gabriel Rotello is the author of Sexual Ecology: AIDS and the Destiny of Gay Men.

In 1936, Thomas Parran, the director of the nation’s anti-venereal-disease program, told a conference of medical professionals, “Every case must be located, reported, its source ascertained and all contacts then informed about the possibility of infection and if infected, treated.”

And so it has been ever since for sexually transmitted diseases. Except for AIDS. And for good reason.

During epidemics of most sexually transmitted diseases, state public health authorities routinely test large numbers of people, sometimes without their knowledge, report names of the afflicted to health departments and try to trace and inform their sexual partners. The main goal is...