(WBNG) — After years of progress, Tioga County public health officials say they’ve been dealt a major blow in their fight against the opioid epidemic. If there were a silver lining to all of this, health officials have identified the main cause in this recent spike in deaths. “The primary substance was fentanyl; fentanyl is extremely potent, and it is lethal if somebody does not have Narcan available to reverse the overdose,” said Kylie Holochak, a senior public health educator. County health officials say from 2015 to 2018, opioid overdose deaths dropped more than 50 percent in Tioga County; unfortunately, those deaths more than doubled in 2019. According to the Department of Public Health, there were 8 mixed drug toxicity deaths in 2018, but 17 of them in 2019. Officials say not only is this number shocking, but it’s also staggering as they expect the recent declining number of overdoses to continue. Mixed drug toxicity is when multiple substances are found in a person’s system at once. Holochak said she was shocked by these numbers because the sheriff’s office had reported fewer, but it was the more comprehensive coroner’s report that informed her of the increase. She said there are lots of different ways to help addicts and reduce this problem, from increasing treatment programs to spreading awareness to end the stigma, but above all else, health officials say Narcan is the biggest difference between life and death.