Sexually transmitted infections in Minnesota reached another record high in 2016, according to a report issued this month, but another trend has state public health experts concerned: A spike in hepatitis C infections that is tied to the opioid abuse epidemic and the misuse of intravenous drug needles.

The Minnesota Department of Health identified 51 new hepatitis C infections last year, compared with 37 in 2015. That's the highest number of new infections identified in one year since at least 1998.

"That's a pretty high number for us," said Kristin Sweet, supervisor of the department's hepatitis unit.

Hepatitis C is spread through contact with infected blood, making the reuse of contaminated needles by users of heroin and other IV drugs a common means of transmission. While the infection can lie dormant for years, it can severely damage the liver over time and result in the need for a liver transplant.

The classic diagnosis used to be an older Minnesotan who had been symptom-free and whose infection traced back to drug use 30 or more years ago. Now doctors are finding the infection in people 40 and younger, meaning the virus is spreading anew.

While the A and B forms of hepatitis are easier to spread — the former mostly through contaminated food and the latter mostly through sexual contact — Sweet said "hepatitis C is the infection of most concern right now."

In some ways, health officials are better positioned to confront an uptick in hepatitis C, because new drugs such as Sovaldi effectively cure the infection. The Health Department listed 3,502 "resolved" infections since 2012, leaving the state with 35,623 people in the state with the virus.

But the new drugs are expensive. The state Department of Human Services is spending more than $9 million a year on them through its fee-for-service Medical Assistance program, up from less than $1 million not long ago. And that increase has come despite restrictions to ensure that recipients are no longer abusing IV drugs, which would make them risks to get reinfected after treatment.

Curative drugs should pay off, because they are cheaper than liver transplants. But Sweet noted that prevention is still the cheapest strategy, either by abstaining from IV drugs or using clean needles.

The Health Department website lists pharmacies that collect used needles and sell clean ones without prescriptions. "Certainly we recommend that people who are at risk get screened," Sweet said, "so they can make decisions with that knowledge in mind."

Jeremy Olson • 612-673-7744