The number of reported cases of sexually-transmitted diseases has increased in Minnesota, according to health officials.

A Minnesota Department of Health report released Thursday said the number of cases increased 10 percent in 2012 over the previous year. There were about 21,500 cases in 2012 compared to about 19,500 in 2011.

Reportable STDs in Minnesota include chlamydia, gonorrhea and syphilis.

In Freeborn County alone, cases of chlamydia increased from 73 reported cases in 2011 to 101 cases reported in 2012. Three cases of gonorrhea were reported each year.

The number of reported chlamydia cases countywide has almost doubled in the last five years. In 2006 to 2008, between 53 and 59 cases of chlamydia were reported each year.

Chlamydia is the top reported infectious disease in the state and reached a new high of about 18,000 cases in 2012 compared to nearly 17,000 the previous year. The majority of cases occurred in teens and young adults ages 15 to 24.

One in three cases occurred in Greater Minnesota.

Gonorrhea was the second most commonly reported STD in Minnesota with about 3,000 cases reported in 2012, compared to about 2,300 in 2011.

Nearly two-thirds of all gonorrhea cases occurred among the 15-24 age group, and more than 80 percent were in the Twin Cities metropolitan area.

Syphilis cases dropped 8 percent with 335 cases.

Minnesota Commissioner of Health Ed Ehlinger said the state’s epidemiologists and disease control specialists are investigating the data and hope to develop a response plan in the next few months to work with community partners.

The Department of Health states untreated chlamydia and gonorrhea can lead to infertility in women and men and can be passed from an infected woman to her newborn children, causing premature delivery, infant pneumonia and blindness.

Untreated gonorrhea can spread to organs and joints, leading to life-threatening conditions, and untreated syphilis can cause blindness, mental illness, dementia and death.

“The encouraging news within the report shows that we had a drop in syphilis cases,” Ehlinger said.

He said because STDs often don’t show symptoms, it is important for people to get tested regularly if they are sexually active.

People can prevent getting or spreading STDs by abstaining from sexual contact, delaying the start of sexual activity, limiting the number of sexual partners, using latex condoms and not sharing needles for drug use, piercing or tattooing, according to the Health Department.

Mower County Public Health Director Lisa Kocer could not be reached for comment.