Jessica Forsyth is frantically searching for mints. It’s not just because she’s four months pregnant and craving. As the coordinator of Health and Education for Youth (HEY) and Teens Introducing Matters to Each Other (TIME), she knows that Tic-Tacs are a must. That’s because the Orasure HIV tests that Forsyth, 30, administers at teen hangouts and health fairs, like today’s, leave a sickly taste.

As I hunt in my bag, Forsyth does pretest counseling with LaShauna, a quiet 15-year-old brought in by her 30-ish mom. In St. Louis, officials track the epidemic through zip codes. La-Shauna lives in Blumeyer Village, a housing project populated mainly by African-American single mothers. It’s in 63106, one of the city’s hardest hit.

I find some Certs just as Forsyth asks LaShauna when she last had sex.

“January 22,” she says. “That’s when I got pregnant.”

Forsyth gasps—surprised not that a 15-year-old is having a baby, but that she didn’t spot the third-trimester belly under the baggy t-shirt.

When LaShauna leaves to get her mother, who also wants a test, Forsyth talks a mile a minute about the need for HEY, the only adolescent-specific health program in St. Louis. Its teen clinic has enough resources to operate three days a month. “And LaShauna shows why we’re needed,” Forsyth says. “She said she went to the hospital for prenatal care, but she told us this was her first test.” Forsyth frowns. “They probably tested her, and she didn’t realize it. I doubt any counseling happened. I mean, ‘You’re being tested’ is pretty fundamental.”

Outside, in the 94-degree heat, TIME peer educators hand out condoms and info. Of all the tables at the fair, theirs is the most popular. With two years of peer ed under her belt, Tshepiso, a 19-year-old native of Botswana with blue contacts, can rattle off a prevention message the way other teens recite radio lyrics. Kenni-marie, 17, is chatty and pretty like the singer Monica.

A girl in a Winnie the Pooh t-shirt quietly asks for condoms. She says she’s 18, and while I know she is nobody’s 18, you only have to be 13 to get condoms in Missouri. After listening to the drill—punctuated with a “this doesn’t mean ‘go have sex’”—she gets the condoms, one wrapped like a lollipop.

Tshepiso eyes a cop leading a police dog over to some children. Though the police presence is billed as a sort of petting zoo with horses and K-9 patrollers, the girls are suspicious. “Now, why do they have to be here sniffing for drugs?” Tshepiso asks. When I say it’s just PR, she smiles at me, and I’m the naïve one.

Kennimarie and I decide to head over to the ice-cream van. I ask what she wants to be in life. “A motivational speaker,” she says. What she’ll talk about? She says she’s not sure yet, and goes with a chocolate eclair bar.

Soon things wind down. Just as everything is packed up and we’re about to head out, a 23-year-old, one of the few guys to come to the table today, approaches to ask for condoms. Tshepiso sighs, reopens the cardboard box and recites the speech as she has done so for two years and counting.