Tim Heymans has crisscrossed Minnesota the past 25 years, from Pipestone to International Falls to Winona, as an official state bearer of bad news: Telling people they are at risk for a sexually transmitted disease because a sexual partner has tested positive.

In one case he wanted to meet a widow whose dead husband had a positive test, but she insisted he deliver the news over the phone. "I asked her to promise not to hang up … until I said goodbye first," he recalled.

Spreading warnings about STDs is a tough business — whether for trained state professionals such as Heymans or sexual partners who have just learned of their own infections. But in the face of another record year of STDs in Minnesota — the state on Thursday reported 24,599 confirmed cases of chlamydia, gonorrhea and syphilis in 2014 — health officials said better and faster notification of sexual partners is essential to slow the spread of infections.

"Say I test positive for chlamydia and my one sexual partner is not referred for testing and treated," said Marcie Babcock, who manages an STD prevention unit of the Minnesota Department of Health. "If this person is positive for the infection and has multiple partners, the infection [could] be spread to others who in turn could pass it on to their partners. Partner notification serves as a tool to break the chain of infection."

Thursday's state STD report showed a 6 percent increase, overall, in infections other than HIV (which is reported separately). Chlamydia remains the most common disease, with 19,897 cases identified last year. But health officials were troubled by the 629 syphilis cases — a 17 percent increase — that primarily involved urban men who have sex with other men and a few females. Partner notification is particularly important with syphilis because the disease can be so damaging, said Krissie Guerard, manager of the Health Department's STD section.

"Syphilis … can cause blindness, mental illness, dementia and sometimes even death," she said. "There's a serious need to get people in who are at risk to get tested and obviously get them treated."

Heymans and other disease intervention specialists in Babcock's unit talk with infected patients to identify their sexual partners, a key first step in tracking and containing infections. Then they teach the patients how to break the news to their partners on their own, or — when patients are too frightened or humiliated — contact the partners themselves. Physicians are required to report new STD cases to the Health Department, but the state can't force a patient to disclose the identity of their sexual partners.

The small unit of seven specialists generally focuses on HIV and syphilis — infections that are less common but more severe. But sexual partners of people with other STDs are among the 1,500 people they reach each year to stress the need for testing and treatment.

This spring, the state is launching a cable TV campaign on STD prevention. It also is promoting broader use of expedited partner therapy in clinics — where patients with chlamydia or gonorrhea receive extra prescription antibiotics to give sexual partners whether or not they have been diagnosed with STDs.

But expedited therapy is incumbent on patients being willing to tell their sexual partners of infections. Some are not, and the reasons vary.

Most chlamydia and gonorrhea cases involve teens and young adults ages 15 to 24 who might be embarrassed. Others involve affairs, leaving infected people afraid to tell their paramours or spouses. And some involve one-night stands with sexual partners that infected people don't know by name.

While some patients are angry and ready to notify the partners who infected them, others worry about losing those they love, said Dr. Andrew Zinkel, an emergency physician at Regions Hospital in St. Paul and associate medical director for HealthPartners.

"That might be a relationship-ender," he said. "Those are the cases where there is more resistance."

That's often where Heymans has come in.

Heymans said people are often angry, but calm down as he offers support. The widow on the phone kept her promise, staying on the phone as Heymans broke the news that she might have HIV.

While Heymans is bound by medical privacy laws to never identify the infected person, the widow had had only one partner for decades. She later learned she was HIV positive.

"She expressed her sincere gratitude for the work I do, but she added softly, 'I wish I had never met you.' " Heymans wrote in 2013, in a synopsis of the case.

Finding patients' sexual partners has become simultaneously easier and harder. Social media makes it easier to find people by name, but online apps such as Tinder make it easier for people to have sex with random partners who are difficult to track down later. Heymans has searched for sexual partners at risk of infection with scraps of information as tiny as the person's hair color or apartment number.

How to maximize partner notification has been a national dilemma. A San Francisco agency created the inSPOT website, where infected people could send humorous e-cards to at-risk sexual partners with statements such as, "Sometimes there are strings attached: I got diagnosed with STDs since we were together. Get checked out soon."

Yet efforts by Heymans' unit work; 312 sexual partners of people with syphilis were contacted last year, and 34 new infections were found. Seventeen new HIV cases also were identified.

"I truly believe if we were not investigating these cases," he said, "they would grow exponentially."

Jeremy Olson • 612-673-7744