SYRACUSE, N.Y. -- Twenty-nine people in Onondaga County died of opioid drug overdoses during the first three months of 2017, nearly three times more than previously estimated.

Opioids include heroin, fentanyl and prescription drugs like oxycodone.

The Onondaga County Health Department published the revised number on its website Monday.

In April the county's preliminary estimate showed 10 opioid deaths for the first quarter. There were 34 reported opioid deaths for the same three-month period of 2016.

Health Department officials said preliminary quarterly data does not accurately reflect the number of overdoses in the community. That's because autopsies conducted by the county Medical Examiner's Office in many overdose cases are not completed during the same quarter the deaths occur.

Toxicology testing to identify drugs taken by overdose victims is the most time-consuming part of drug-related death investigations, according to Dr. Robert Stoppacher, Onondaga County's chief medical examiner.

Multiple samples must be tested to identify a large number of possible drugs, he said. New synthetic opioids such as Fentanyl can be difficult to detect.

Drug deaths investigated by the county Medical Examiner's Office increased 50 percent in 2016.

Because of the backlog of cases, the health department said it will not report overdose death numbers for the first six months of the year until October.

Of the 29 first-quarter deaths, 12 involved fentanyl, nine involved both heroin and fentanyl, four involved heroin and four involved other opioids.

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