Front line workers and first responders have suspected it for months but now it's been confirmed: carfentanil, the deadly opioid 100 times more toxic than fentanyl, has entered the street drug scene in Metro Vancouver.

Carfentanil was found to be present in 57 of 1,766 urine tests conducted over a two week period last month at drug treatment facilities in Vancouver, Surrey, New Westminster, Maple Ridge and Richmond.

First responders surround an overdose victim on Vancouver's Downtown Eastside. (Gian Paolo Mendoza/CBC)

"It's not good news, it's confirmation of what we had feared," said B.C. Provincial Health Officer Dr. Perry Kendall. "It means the drug supply has become considerably more dangerous than it was beforehand."

LifeLabs developed the urine carfentanil test and has been using it since Jan. 10. Weekly reports are being submitted to the provincial health ministry and the B.C. Centre for Disease Control.

Carfentinil is a synthetic opioid originally developed as a large animal sedative. One or two grains can be fatal in humans.

It is widely believed to have been introduced into the illegal drug stream in B.C. in November of 2016. That's when the number of overdose deaths began to spike, although in the absence of testing officials weren't able to say for sure until now.

Dr. Kendall said because the samples were collected from people already in treatment, the numbers may not be representative of what's happening on the streets.

"It may under-represent the actual extent to which carfentanil is present," he said.

A total of 914 people died of illicit drug overdose last year in B.C.

With files from The Canadian Press