BEL AIR, Md. (WJZ) — Harford County is grappling with a sudden spike in heroin overdose deaths. Now officials are warning the public that there’s an even bigger threat.

Dozens have died in Harford County from heroin overdoses — a staggering 71-percent increase from last year. Sheriff Jefferey Gahler says five died on Thanksgiving weekend alone.

“We are being aggressive in trying to track down the dealers in this case,” Sheriff Gahler said.

Statewide, heroin deaths in the first six months of 2016 have far surpassed last year’s numbers.

“The heroin problem in Maryland now is at epidemic proportions,” said Deputy Secretary of Public Health Dr. Howard Haft.

Dr. Haft tells WJZ’s Devin Bartolotta the drug is often laced with more potent chemicals.

“We want people to understand that every time you take an illicit drug, you’re rolling the dice,” he said.

Now a new threat is creeping in, synthetic opiates — many times stronger and more deadly than heroin.

“Our fear is that we’re eventually going to see carfentanil. We’ve seen it in in surrounding states, but we haven’t seen it in the state of Maryland yet or in Harford County,” said Sheriff Gahler.

Harford County is now joining forces with University of Maryland Medical Center to map out the worst drug spots in the county, hoping to tackle a tragic problem that’s only expected to get worse.

All crimes in Harford County are down for the year, except theft. The sheriff believes it’s directly tied to the sharp increase in hard drug use.

The Department of Public Health wants to get the word out, narcan, the overdose reversal drug, is available at health departments without a prescription.