WILLIAMSPORT -- Fifty-one overdose patients were treated at two Northcentral Pennsylvania hospitals in the past 48 hours, a spokeswoman for UPMC Susquehanna said Friday.

The rate at which patients are being treated at Williamsport Regional Medical Center and Soldiers an Sailors Hospital in Wellsboro -- both UPMC facilities -- appears to be slowing.

"We believe the situation is stabilizing in our facilities," the spokeswoman said.

The Williamsport hospital treated 38 overdoses in the first 24 hours, while Soldiers and Sailors treated six overdoses during that time.

UPMC Susquehanna records show eight were treated at the Wellsboro hospital but Tioga County District Attorney Krista Deats said as of 2 p.m. Friday her office was aware of 12 overdoses.

Neither Geisinger Medical Center near Danville nor Jersey Shore Hospital reported any increases drug overdose patients.

There has been only one reported death to date, that being a Philadelphia area man found in a Williamsport apartment Thursday.

In his 27 years in law enforcement Williamsport Police Chief David Young says he has never seen anything like the number of heroin overdose in the past two days.

He believes the overdoses may be caused by a bat batch of heroin laced with something. "It's tough to put a finger on it since we don't know what it is or where it came from," he said.

Samples have been set to a lab but no results have been received, he said. "Hopefully this batch is out of here," he said.

The substance causing the overdoses is in blue and white bags with the label "killer," Deats said state police told her.

It identified as heroin but in reality is a fentanyl or carfentanyl-based, she said she was told. Young would not say if that is the case in Williamsport.

The Tioga County Emergency Services Department has cautioned first responders to use caution because it has learned the substance has been identified as being transdermal meaning it could be absorbed through the skin if contact is made with it.

Its news release states first responders have had to administer multiple doses of Narcan, a countering agent, to revive patients.

Whatever it is takes effect immediately, Young said. There was one case this week when a woman passed out with a needle still in her arm, he said.

The investigation into trying to identify those responsible for the drug involves local, state and federal agencies and is multi-county, Lycoming County District Attorney Eric R. Linhardt said.

Arrest records show people from surrounding counties travel to Williamsport to buy drugs.

Philadelphia, Newark, N.Y., and the Bronx, N.Y., are sources of most of the heroin in the area, Linhardt said.

In the last year or so there has been an increase in the amount of heroin laced with fentanyl, he said.

More recently investigators have discovered straight fentanyl being sold as heroin, he said.

Until results are received for the lab it will not be known if the overdoses have been caused by heroin laced with fentanyl or a new mixture, Linhardt said.