According to the South Dakota Health Department’s 2008 infectious disease report, the Midwestern state saw an increase in HIV/AIDS cases, The Associated Press reports.

South Dakota’s number of HIV/AIDS infections rose from 25 in 2007 to 34 in 2008, matching the number of cases reported in 2006. Chlamydia cases reached an all-time high of 2,948—up more than 300 from the previous year—while reports of gonorrhea rose 29 percent to 370.

State epidemiologist Lon Kightlinger believes the increase in sexually transmitted infection (STI) cases resulted from not following preventative methods such as monogamous sex or abstinence. “Sexually transmitted diseases are a complex bag of prevention, treatment and personal behavior,” Kightlinger said. “There needs to be more abstinence, monogamy and, if that fails, safe sex.”

The South Dakota Health Department’s report indicates that STIs are still most often found in people ages 15 to 24, followed by 25 to 39.