The number of Minnesotans infected with a sexually transmitted disease (STD) rose again in 2007 -- as it has each year since 1996.

More than 17,000 people became infected with one of the big three -- chlamydia, gonorrhea or syphilis -- an increase of 3.8 percent over 2006.

Health experts say this intractable epidemic is rooted in inadequate sex education, screening and treatment. It is compounded, they say, by some family doctors and pediatricians who blanche at talking about sex to young patients who are at risk.

The collapse last week of a bill to provide $1.3 million in state money for screening and public education signals next year's numbers are likely to continue the decade-long rise in infections. Other measures to increase treatment and sex education are pending. But health experts say that while every bit helps, it's just not enough to turn around an STD epidemic among teens and young adults poised to continue unabated.

"Especially if we don't do anything about it," said Kathy Wick, director of Dakota County Public Health.

Chlamydia, the bacterial infection that is by far the most common STD, increased by 3.7 percent in 2007, state health officials told the legislature this month. Among black people, who are particularly hard hit by STDs, the number of chlamydia infections grew by 5.2 percent. It can now be found in 1,871 out of every 100,000 black people, they said.

Gonorrhea and syphilis cases are also rising.

Though the state health department does not track annual infection rates of HPV (human papilloma virus), public health experts were shocked earlier this month by a national study showing that 18 percent of teenage girls carry the virus. The same study of 838 girls between the ages of 14 and 19 also found that one in four have at least one of the most common sexually transmitted diseases. Half of black and a fifth of white teenagers were infected, said the researchers with the Centers for Disease Control and Prevention (CDC).

Chlamydia and HPV are silent diseases. Men and women are often unaware that they are infected. But left untreated, chlamydia can cause pelvic inflammatory disease (PID), which leads to potentially fatal ectopic pregnancies and infertility. HPV causes most cervical cancer.

"If we don't do something, we know we are in big trouble down the road," said Fred Evans, who runs Seen On Da' Streets, an STD outreach program for teenage boys and young men in north Minneapolis.

Experts point to poverty and less access to health care as reasons STD rates are higher among blacks. But that does not explain everything, they say. Young blacks are no more likely to be sexually active than their white counterparts and about half of each group use condoms regularly. However, STD rates have been higher in the black community for many years, and that could be causing what experts call a cohort effect.

"Most people tend to choose sexual partners from their social network -- the people they go to school with, who live in the neighborhood, friends of friends. So these higher rates are perpetuated, especially in more segregated areas," said Marla Eisenberg, an expert on adolescent health and an assistant professor at the University of Minnesota.

Sexual activity

STDs are spreading among all teenagers and young adults because most are having sex. Half of high school seniors and more than three-fourths of college students statewide are sexually active, according to surveys of both. But many do not know how the diseases are transmitted, or don't believe they could become infected, say public health experts.

"They are far more concerned about pregnancy prevention than STD protection," said Wick. "We have not done a good job as a community talking about any of this."

Much of the burden is falling on doctors and clinics to screen for STDs. Medical guidelines from the Centers for Disease Control and Prevention say all sexually active women up to age 25 should be screened for STDs. Doctors are urged to suggest it to them.

But most don't. In Minnesota, only 42 percent of women who should be screened are, according to data by Minnesota Community Measurement, a nonprofit health information organization that tracks a number of medical screening rates. STD testing has improved, which is one reason STD rates are also higher, health officials say -- more infections are being found and treated.

Screening teenagers is especially difficult. Experts say teens have to find their way to a clinic like Planned Parenthood or Teenage Medical Services. Or they have to talk about it with their family doctor or pediatrician. That's where problems occur.

"It's a big issue," said Dr. Peter Dehnel, a pediatrician with Children's Hospitals and Clinics who runs an educational network for 23 Twin Cities pediatric clinics. Many teens won't admit being sexually active for fear doctors will tell their parents, he said. Even though teenagers are protected by privacy laws, parents still get a bill or a report from the insurance company that shows a doctor visit.

Many doctors just refuse to ask, he said, because their relationship is as much with the parents as their kids.

Wick said a third of those with STDs in Dakota County are diagnosed by a clinic outside the county. "And it's not for lack of health resources in Dakota County," she said. "We have lots of clinics."

This year Dakota County health officials plan to educate doctors and nurses at 50 family practice and pediatric clinics on STD screening.

Taking it to the boys

Boys are another problem altogether. Unlike girls and young women, they don't seek medical care for birth control or annual exams. They see a doctor only if they have symptoms, experts say.

That's why far fewer STD cases among men are reported to the state, said Peter Carr, head of the STD section for the health department.

"Men, in general, don't go to a clinic," said Evans. So his program recruits young men to go into the community to educate and screen other young men. "We take the clinic to them," he said. In four years they've screened close to 9,000 men, he said.

The Legislature is considering a bill to allow doctors to prescribe antibiotics for chlamydia for both the patient and for the patient to give her sexual partner. That would help prevent at least one vicious circle that perpetuates the disease: Many women who are treated come back within a few months after being re-infected by their partners.

Still, many say that is only a better-than-nothing strategy. The only truly effective way to stop the epidemic is education, experts say.

"It needs to be as loud and flashy as the music videos they are listening to in order to get their attention," Evans said.

That, too, is in the hands of the Legislature this year, as it was last year. Lawmakers are considering whether to require all schools to provide sex education to seventh- through 12th-graders that starts with an abstinence-first approach, but also provides information on contraception and STDs. The House and Senate passed a similar bill last year, but it was withdrawn at the last minute when Gov. Tim Pawlenty threatened to veto it.

This year supporters say they are more optimistic it will become law.

Josephine Marcotty • 612-673-7394