A new federal analysis has found that deaths related to the powerful opioid fentanyl more than doubled nationally from 2013 to 2014. But the drug has not caught on in Los Angeles County, according to a senior public health official.

At the same time, a federal drug official says more and more fentanyl is passing through California on its way to other parts of the country.

An analysis of death certificates by the Centers for Disease Control and Prevention's National Center for Health Statistics found that there were 1,905 fentanyl-related deaths nationwide in 2013, and 4,200 in 2014.

The number of fentanyl-related deaths in L.A. County has remained relatively low in recent years. The county averaged 40 fentanyl-related deaths between 2011 and 2013, 62 in 2014 and 46 in 2015, according to Dr. Gary Tsai, medical director of the county Department of Public Health’s substance abuse prevention and control unit.

Fentanyl is generally used to treat advanced cancer pain, because it’s up to 100 times more powerful than morphine. It’s sold on the black market for its heroin-like effect; because it’s so strong, a tiny amount can be fatal.

Even though fentanyl has not become a leading drug of choice in Southern California, more and more of it is getting smuggled through the region, said Tim Massino, spokesman for the L.A. office of the Drug Enforcement Administration.

"Over the past year and a half DEA Los Angeles has observed an increase in the amount of fentanyl and fentanyl-related compounds seized in the area," he said. "There’s both more seizures of fentanyl and more fentanyl being seized."

Statewide, federal agents seized about 172 kilos of fentanyl between Jan. 2015 and June 2016, said Massino. Most fentanyl enters California from Mexico, but some of it originates in China, he said.

The next highest amount of the opioid seized during those 18 months was 42 kilos in Georgia, said Massino.

There's been a jump in the number of seizures nationally, he said. In 2012, fentanyl-related seizures numbered 643, but in 2015, the number jumped to 9,361, according to the DEA’s National Forensics Laboratory.

The numbers regarding fentanyl-related deaths can be misleading, said Tsai. The statistics don't "distinguish between a fentanyl overdose as a result of misuse, or someone who died and required an autopsy and happened to be on fentanyl," he said.

Fentanyl overdoses have proved challenging to track, according to Tsai's unit.

First, doctors treating overdose victims are mainly looking for the better-known opioids, like Vicodin. And when they check for drugs, standard tests often miss fentanyl. A special lab analysis is often necessary, and doctors – especially in busy ER's – don't always think of that. Another problem is that not all hospitals are set up to conduct the special lab analysis.

All of this is complicated by the fact that illegally-manufactured fentanyl may be mixed with heroin or counterfeit pills that look like normal prescription medications, so people may not be aware that they're exposing themselves to the drug.

Earlier this month, Congress passed the 21st Century Cures Act, which includes $1 billion for combating the opioid epidemic. The money will be allocated to states hit hardest by the crisis, to fund prescription drug monitoring, abuse and overdose prevention efforts, and expanded access to treatment.

There’s been an uptick in the number of opioid-related emergency room visits and hospitalizations since 2006, said Tsai, but not to the extent that it’s affected places like Ohio and Indiana. He says this is partly due to economics and partly due to cultural differences.

"Pain management, the use of opioid pain medications, and prescription drugs is very much a cultural issue," he said. "There are certain cultural groups that reach for medications more often." The data, he says, show that Latinos and Asians are much less inclined to use or abuse pain medication.

"The point is that the diversity of Los Angeles County may actually be protective when it comes to the opioid epidemic," he said.