Chlamydia drives record number of STD cases in state

The number of cases of sexually transmitted disease in Minnesota climbed to a record high in 2006, with the vast majority involving teenagers and young adults with chlamydia, a largely "silent" infection.

The rate of chlamydia -- which can cause infertility -- has more than doubled in the past 10 years, according to the Minnesota Department of Health. Health officials say they can't explain the reasons for the sharp rise, but Minnesota's findings echo national trends.

Chlamydia accounted for more than three-fourths of the 16,428 cases of sexually transmitted diseases (STDs) reported last year, according to the department's annual report released Monday. The total, up 2 percent from the year before, did not include AIDS cases, which are reported separately.

The rising numbers may be, in part, because of better reporting and testing, said Peter Carr, director of the STD program at the Health Department. "That's likely to account for some of it, but not a doubling of the rate over the last 10 years," he said. "This is the part we are at a loss to explain."

Overall, gonorrhea and syphilis cases declined last year, according to the annual report. But the increase in chlamydia more than made up for the drop in the other diseases.

Health officials have been watching the trend with alarm -- especially among the 15-24 age group. Nearly 70 percent of chlamydia cases were in that age group, as were 56 of the gonorrhea cases, according to the Health Department.

"This is something we've seen escalate in our clinics," said Dr. David Aughey, medical director of adolescent medicine at Children's Hospitals and Clinics of Minnesota. Chlamydia, he said, "has led the way." Although it can be treated with antibiotics, the biggest problem, he said, is that chlamydia causes no symptoms in most people. On rare occasions, it can cause abnormal bleeding, genital discharge or pain.

But most people don't know they have it unless they're tested, he said. That's why health officials have been trying to encourage sexually active young people to get tested, especially if they have multiple partners.

Aughey estimated that one in seven teenagers tests positive at his clinic, known as Teenage Medical Services in Minneapolis. But in many cases, he said, teenage girls are reluctant to tell their sex partners, and young men avoid treatment.

"They don't believe they have it because they don't have symptoms," he said. And that just perpetuates the cycle. "We test women, we get them treated, and on average within four months they're reinfected," he said.

Up to 40 percent of women with untreated chlamydia develop a painful condition called pelvic inflammatory disease, which can lead to infertility. The infection can also be transmitted to newborns during childbirth.

Gonorrhea, which can also cause infertility, was reported in 3,303 cases last year, down 6 percent from 2005. Overall, gonorrhea rates have increased by 19 percent in the past 10 years, said Hodan Guled, a state epidemiologist who helped prepare the annual report.

Syphilis, which accounts for the smallest number of cases, declined by 34 percent to 190 cases. The majority were reported in gay and bisexual men.

Since 1996, the rate of chlamydia has risen from 115 per 100,000 people to 263 per 100,000, the Minnesota report said. Young adults 20-24 had the highest rate, with 1,549 cases per 100,000 people.

Overall, the disease rates remained higher for racial minorities than for whites, as they have been for years, state officials said. Blacks had 15 times the rate of chlamydia as whites, and 47 times the rate of gonorrhea, Guled said.

Guled said the racial disparities have been attributed to a number of factors, including poverty and access to health care.

Carr, of the Health Department, said people can reduce their chances of getting infected by using condoms and limiting their number of partners.

Maura Lerner • 612-673-7384 • mlerner@startribune.com