We head back down the corridor, past a second stairwell Richardson says she won’t use. “Stick your head in there,” she says. I do, and yank it back as the stench of urine hits my nose.

The girl shakes her head again. “But my sister might know him. I can ask her when she gets home.”

Later the sister calls the clinic to say she’s never heard of Andrew Cole.

Every morning half of these workers fan out into the city’s neighborhoods, trying to find people who have had sex with or may have had sex with someone who was infected. The rest work in the Health Department’s five STD clinics, counseling patients and doing the tedious paperwork needed to keep track of a burgeoning caseload.

She grew up in Ohio. Tired of northern winters by the time she graduated from college, she moved to Atlanta, where she worked for a time as a teacher and then as a consultant for a reading program. After watching a close friend die of AIDS, she took a job as an educator with an HIV-prevention program whose focus was women. “Early on people were talking about homosexuals. I said, ‘Let’s talk about women. Let’s talk about teenage girls.’” She wrote grants and organized large, festive meetings that attracted lots of young people. Two years ago she applied to the CDC, hoping to work in HIV prevention, only to find that the agency requires its workers to start with syphilis control. She signed up anyway.

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The investigators try to interview all people known to be infected, gently prying out the names of those they might have infected, pointing out that the Health Department guarantees their names won’t be revealed to anyone they identify or to any other agency–a promise that’s broken only when it’s clear someone has been molesting a child. A person in the first stage of syphilis will be asked for the names of contacts within the past three months, and someone in the secondary stage for contacts within the past six months. Nearly half the people interviewed acknowledge at least two contacts, though one out of ten won’t or can’t name anybody.