Across Pennsylvania, drug overdose deaths rose by a stunning 37 percent last year, the federal Drug Enforcement Administration announced Thursday. All told, 13 people died every day of a drug overdose in Pennsylvania, sending the state's 2016 death toll to a record high.

Appalling as the Philadelphia numbers were — 907 deaths in the city alone — fatality rates in some suburban counties and parts of Western Pennsylvania, including Allegheny County, which includes Pittsburgh, rose much faster. 

"The numbers are horrific. Absolutely horrific," said Patrick Trainor, spokesman for the Drug Enforcement Administration's Philadelphia Field Division, who worked street-level investigations for nearly two decades. "It's really bad."

The DEA on Thursday released specific numbers for the state and southeastern counties, though other analysts have quantified trends elsewhere in the state. The full DEA report is due later this month. New Jersey's 2016 numbers were not available.

At 4,642, the total number of fatal overdoses in Pennsylvania was nearly four times the number of fatal traffic accidents. Prescription or illicit opioids such as heroin were implicated in 85 percent of the drug fatalities, according to the DEA.

The data, collected from coroners and medical examiners from across the state, was compiled by the DEA and analyzed with assistance from the University of Pittsburgh's School of Pharmacy. The numbers include deaths attributed to accidental and undetermined causes, Trainor said.

Gary Tuggle, head of the local DEA division, called the data evidence of  "an unprecedented epidemic of drug abuse."

"We know that the prescription opioid and heroin epidemic is not limited to inner-city neighborhoods, such as the crack-cocaine epidemic of the 1980s largely was," said Tuggle. "Unfortunately, some of the largest increases in drug-related overdose deaths were in rural counties across Pennsylvania."

Cases involving fentanyl — the extraordinarily potent synthetic opioid sometimes added to heroin without the users' knowledge — rose dramatically, as they have in many parts of the country.

"For the first time, in Allegheny County fentanyl was found in more people than heroin," said Jeanine M. Buchanich, an epidemiologist at Pitt's Graduate School of Public Health who tracks overdose data. She said that fentanyl was found in about two-thirds of drug fatalities there and heroin in about half (many cases included both drugs). The Philadelphia Medical Examiner's Office had earlier reported that fentanyl and heroin were each found in roughly 45 percent of drug overdose deaths last year.

There appear to be two distinct epidemics in Pennsylvania, said Donald S. Burke, who as dean of Pitt's graduate school changed the focus of its modeling unit from infectious diseases to opioids. Southeastern Pennsylvania historically has been a source of extremely pure and cheap heroin, which is now drawing some users whose addictions began with prescription pain pills. Western Pennsylvania is an extension of Appalachia, an epicenter of the opioid epidemic.

Buchanich said that overdose fatalities in several western Pennsylvania counties had increased by 50 percent or more last year. Beaver County's more than doubled, she said.

And very preliminary statistics for the first few months of 2017 show continuing increases in Pennsylvania. "Clearly it is impossible to predict what is going to happen," Buchanich said.