Alaska is reporting a major spike in the number of young people diagnosed with hepatitis C virus (HCV) across the state, possibly because of rising drug use in the remote region, the Juneau Empire reports.

In a bulletin posted last week by the Alaska Section of Epidemiology, researchers reported that the rate of hepatitis C infection among Alaskans ages 18 to 29 has risen rapidly between 2011 and 2015. The epidemic is at its worst in Southeast Alaska (a.k.a the Alaska Panhandle), where the rate of hep C infection for 18- to 29-year-olds has gone up nearly 500 percent in just four years.

The rugged, mountainous region is well known for its mining, logging, fishing and tourism industries. In 2011, Southeast Alaska’s overall rate of infection was 187 per 100,000 people. By 2015, that rate had increased to 247 per 100,000 people. Health authorities in the region say Alaska’s rising heroin use rate is believed to be contributing to the outbreak.

The report also noted that Thursday’s study should not be considered the final word on Alaska’s HCV rate, since many people living with hepatitis C are not diagnosed until years after their initial infection. The paper concluded that efforts to curb injection drug use across the state would help stop the spread of the disease. However, with few harm reduction centers outside of Alaska’s major cities, implementing these strategies may prove difficult.