Inexpensive testing and antibiotic treatment could wipe out one of Minnesota's fastest-growing public health problems — the rise in sexually transmitted chlamydia infections — if only the sex talk didn't get in the way.

But it does. Many teens and even early twenty-somethings don't want to disclose they have had sex — a standard question before chlamydia testing — or get screened if there is a chance their parents could find out, state and clinic officials say.

The result is that fewer than half of sexually active females aged 16 to 24, a high-risk group for infection, get tested at their primary care clinics, and that chlamydia infections in Minnesota have increased every year for two decades. The 18,724 new infections last year, detailed in a Health Department report last month, are double the amount in 2000.

"You go into a teenager's mind, which can be a very interesting place, and in their world, it's a very, very big deal," said Kelly Boie, a nurse practitioner for Wayzata Children's Clinic. "You tell them, 'This could be your life. This could be your fertility,' and they'll say, 'Yeah, but you're still not going to tell my parents, right?' "

While doctors can promise confidentiality in the clinic, they have no control over off-site labs sending results in the mail or insurance companies listing STD tests on their benefit statements.

The trend is disheartening for public health officials because untreated carriers are spreading the bacteria without knowing it and exposing women to eventual risks of infertility and birth complications. Worse, this isn't a new problem. The Minnesota Chlamydia Partnership was created in 2010 specifically to reduce STD cases, but clinic testing rates haven't improved since then.

Sophomore Madison Andrews is a health advocate in her residence hall. She says talking in public about STDs is still taboo.

Even in the parent-free confines of the residence halls at the University of Minnesota, discussion about sexual health can still seem inhibited, said sophomore Madison Andrews, a psychology major and health advocate who distributes condoms and dental dams provided for free by the U.

"I still feel like it's almost taboo to talk about STDs or STIs in a public forum," Andrews said. "There are still people who are embarrassed to come to me to ask for a condom."

Universal testing?

Minnesota's clinic leaders are fully aware of the challenge. But even so, a talk about STDs doesn't get easier in a doctor's office — especially when teens and parents aren't expecting it, said Val Overton, vice president of quality and innovation for Fairview Medical Group.

"That may get a little uncomfortable, especially when a father has brought his 17-year-old daughter in because she has strep throat and a 101-degree fever."

One alternative is to just screen all young men and women, without asking if they are sexually active. So-called universal screening isn't recommended by federal authorities, though, because some chlamydia tests can produce "false positives," leaving sexually active teens stressed and abstinent teens bewildered.

Among high-school juniors in Minnesota, 37 percent have had sex, according to 2013 Minnesota Student Survey data, and that makes universal testing inefficient as well.

A group of Twin Cities pediatric clinics tried universal screening in 2006 — testing 1,100 teens and young adults regardless of sexual history — but found only eight cases of chlamydia, all involving teens who were open about their sexual histories. So the clinics returned to asking about sex before offering screening, though pediatricians suspect they are missing cases as a result.

"Privately, they may admit they are sexually active, but they are very clear that they don't want their parents to know," said Ellen Pinkowski, director of specialty services for Children's Physician Network, which includes 42 pediatric clinics in the Twin Cities.

Clinic strategies

Strategies to improve screening rates include a "tool kit" created in 2013 and funded by four health insurers to teach doctors how to talk to young patients about STDs. A chlamydia partnership in north Minneapolis, which has one of the highest infection rates of any region in the state, also is seeking teens' input about how STD testing should be offered.

"It's a very gentle conversation, and you don't start it unless you know how to finish it," said Becky Fink, executive director of the Nucleus Clinic, a charitable reproductive health clinic in Coon Rapids.

Fairview primary care clinics have adopted a sort of "opt out" strategy, presuming that young patients will be tested even if they aren't sexually active or are in monogamous relationships. Instead of saying " 'I know you've been with Bill for 10 years. You should be low risk for chlamydia. Do you really want that test?" doctors are telling such patients that " 'The medical literature still says I should test you,' " Overton said.

Pop-up reminders in electronic medical records also emphasize that screening is medically recommended, and Fairview doctors are given performance bonuses for improving their screening rates.

HealthPartners similarly rewards doctors in its health insurance plan networks who screen at least 75 percent of their at-risk female patients. None reached that target last year, though, so the insurer instead rewarded the clinic that came closest.

Data on clinic screening in Minnesota, compiled by a nonprofit known as Minnesota Community Measurement, does not include charitable clinics such as Nucleus or the Annex Teen Clinic in Robbinsdale, which can provide greater privacy by charging teens sliding fees and not billing their parents' insurance.

Another step in reducing chlamydia is follow-up testing for infected patients after treatment, because of the chance that they could be reinfected if their sexual partners aren't treated. Teens won't return unless clinics nag them to, Fink said. "If you remember when you were 22 years old and somebody told you to do something in three months, you probably said, 'Yeah, whatever.' "

Such strategies might cut chlamydia infections in future years, Fink said, but major progress will require more honest discussions between sexually active teens and their parents about STD testing.

"You use your teeth and you get your teeth cleaned," she said. "Think of it like that. It's just something you do. It doesn't mean you're bad if you have to get some plaque cleaned off."

Jeremy Olson • 612-673-7744

Rebecca Harrington, a University of Minnesota student reporter on assignment for the Star Tribune, contributed to this report.