The number of sexually transmitted diseases increased in Minnesota last year, continuing an unwelcome trend and giving health officials a reason to remind people at risk of infection to get tested at least once a year.

“A lot of people assume they only need to get tested if they have symptoms,” Krissie Guerard, manager of the STD, HIV and TB section at the Minnesota Department of Health, said in a prepared statement. “The truth is that STDs, HIV and hepatitis C often have no symptoms. We urge people who are sexually active and people who inject drugs to get tested at least yearly.”

All told, the state reported 30,981 cases of chlamydia, gonorrhea and syphilis in 2017, a record high. That was up from the previous high of 28,631 cases in 2016 and from 25,986 in 2015.

The 23,528 chlamydia cases in Minnesota represented a 4 percent increase from 22,675 cases in 2016, the Health Department reported.

The increase was much sharper for gonorrhea, 28 percent from 5,104 cases in 2016 to 6,519 cases last year.

Syphilis cases increased by 10 percent, from 852 to 934. For both gonorrhea and syphilis, a large majority of cases were reported in the Twin Cities metro area, but one of every three chlamydia cases occurred in greater Minnesota, according to the Health Department.

Chlamydia also hits the young disproportionately hard — 62 percent of cases occur in those between ages 15 and 24, according to the report.

The number of new HIV cases reported dropped from 290 in 2016 to 284 last year, the department reported. That number has remained near 300 for the past five years.

STDs affect some groups more than others, Health Commissioner Jan Malcolm said.

“Communities of color, men who have sex with men and people who inject drugs continue to have higher rates of STDs, HIV and hepatitis C,” she said. “This latest information underscores the importance of continuing our focus on advancing health equity.”