Health officials alarmed by the increase but unsure of its cause.
After an encouraging drop in 2009, the number of sexually transmitted diseases in Minnesota climbed to a record last year, with the number of new syphilis infections almost doubling and chlamydia cases hitting an all-time high.
Overall, the state recorded 17,760 cases of sexually transmitted disease (STD), up 5 percent from 2009, the Minnesota Department of Health said in an annual report released Wednesday.
State health officials couldn't pinpoint a cause, but expressed alarm -- particularly at the increase in chlamydia, an infection that produces few physical symptoms but can eventually result in infertility and premature births.
While an increase in unprotected sex might explain the rising numbers, it's equally possible that an increase in screening is finding more previously hidden cases, said Peter Carr, who directs the health department's STD surveillance section. Screening has increased steadily over the past decade. "The more aggressively populations are screened," Carr said, "the more cases you'll find."
Chlamydia was, by far, the most common infection, with 15,294 cases last year. Gonorrhea was second (2,119) and syphilis was third (347).
Mathematical models suggest continued screening will eventually reduce the number of infections, because it will identify infected people before they can spread the diseases, Carr said.
Prevention advocates nevertheless worried about future infection tallies, especially if state or federal budget cuts weaken or eliminate family planning or disease-prevention programs.
While chlamydia rates are increasing in the suburbs, rural areas and even among nontraditional populations such as men over 50, they continue to be highest among young adults, blacks and high-poverty communities such as Minneapolis.
Minorities and urban residents are the populations that will suffer most if there are funding cuts to public screening and treatment programs, said Sarah Stoesz of Planned Parenthood Minnesota, North Dakota, South Dakota.
"These figures," she said, "expose absolutely inexcusable inequities in access to health care services for the most vulnerable populations in our community."
A paradox in the numbers is the record low number of gonorrhea infections in 2010. There was no special emphasis on combatting that infection, Carr said, so there is no reason why the rate should drop when the rate of chlamydia rose.
Efforts to screen and test sexual partners of infected individuals should lower the rate of both infections, he noted.
A new statewide strategy for reducing chlamydia is being announced next week. Carr said it should help by focusing doctors, health insurers and other organizations on the infection and ways to prevent it.
The number of syphilis infections remained small, but troubling, Carr said. Most cases involve men who have sex with other men. Many subsequently contract HIV. (Wednesday's report didn't include HIV figures, which will be reported separately this month.)
That suggests that infected men are still having unprotected sex, Carr said.
Authorities worry there is growing apathy about HIV and syphilis, which can be treated with antibiotics but can result in blindness, dementia and mental illness if untreated.
"For older, gay men, they have been hearing the safe-sex message for decades. It gets old," Carr said. "Younger, gay men have lived in a world where HIV is treatable. So it's not as scary. ... It's not a death sentence like it was in the '80s."
Jeremy Olson • 612-673-7744