Story highlights More than 31,000 lab submissions test positive for fentanyl last year

The DEA calls it "the opioid crisis at its worst"

(CNN) The United States is seeing a dramatic increase in drugs containing fentanyl, newly released data from the Drug Enforcement Administration shows.

From 2015 to 2016, more than twice as many drugs seized by law enforcement agencies and submitted to labs have tested positive for fentanyl, in what appears to be an escalating trend

The National Forensic Laboratory Information System (NFLIS), a program of the DEA, points to a drastic surge of lab submissions that tested positive for fentanyl -- going from 15,209 in 2015 to 31,700 in 2016.

In addition, lab testing of fentanyl analogues -- drugs with close structural resemblance and similar effects to fentanyl -- went from 2,230 in 2015 to 4,782 in 2016.

"Drug use today has become a game of Russian roulette. There's no such thing as a safe batch, this is the opioid crisis at its worst," DEA spokesman Rusty Payne told CNN.

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