Imani Henderson struggled through tears to explain how special her best friend of 12 years was before the church full of more than a hundred family and friends who gathered Friday.

“Our next best friend goal was to graduate high school,” said Henderson, dressed in a white shirt and jeans. “Now, I have to graduate not just for myself, but for Jayla too.”

The funeral came just two weeks after Jayla died of a suspected opioid overdose, just one of an increasing number of fatal opioid overdoses in the District and across Maryland and Virginia. Health officials point to a rise in fentanyl-laced substances, including opioids, marijuana and cocaine for the recent increase in overdoses, with a suspected bad batch of fentanyl circulating in the region exacerbating the trend.

In the District, the city’s medical examiner identified fentanyl in 95 percent of the 87 overdose deaths through March this year, a number that has risen steadily in recent years; 281 overdose deaths in 2019 and 411 in 2020. Black residents, who make up 46 percent of the city according to census data, have been disproportionately affected. More than four out of five people who die of overdoses in the city are Black, according to data from city officials.

The Arlington County Sheriff’s Office tweeted recently that the trend has worsened in the past two weeks because of a reportedly bad batch of fentanyl that has led to at least 15 fatal overdoses in the region, including six in Arlington alone.

Alexandria has already recorded 59 fatal and nonfatal overdoses through June 30, which is on pace to break last year’s high of 104.

Emily Bentley, Alexandria’s opioid response coordinator, attributes the recent spike to dealers lacing substances with the cheaper, more addictive fentanyl. She noted that unsuspecting marijuana users may be taking drugs laced with the synthetic opioid, broadening the types of drug users who could be impacted.

“We need to reach an audience we’ve never targeted before,” she said.

Police reports in Montgomery County, Maryland’s largest county, show that fatal opioid overdoses are up 33 percent, and nonfatal overdoses are up 57 percent this year as of the end of June, compared with the same period in 2020.

Montgomery County Assistant Chief of Police Dinesh Patil said that 98 percent of the county’s fatal overdoses involve fentanyl.

“It’s Russian roulette,” Patil said. “This is not experimental. This is life and death.”

Mark Robinson, the syringe services program coordinator for the nonprofit Family and Medical Counseling Services, said outreach workers initially saw drug users fearing fentanyl. But the potency and price of the drug quickly boosted demand, particularly from heroin users.

Robinson’s program serves about 2,000 people in the District and in Prince George’s County.

“It rapidly became the drug of choice. As the demand increased, so did the overdose rates go up,” Robinson said. “The poison has been poisoned.”

As concerns from police and public health workers mount, families across the region mourn the loved ones they lost to fentanyl.

Deena Loudon, 52, found her 21-year-old son, Matthew Loudon, and another friend in the downstairs of her Olney home, showing “classic overdose symptoms” on Election Day in November.

She said she had just spoken to Matthew about the dangers of fentanyl poisoning the day before. Matthew, whose family said he struggled with depression and anxiety, told her he had done all his research. The family tried to help him go to rehab for his use of pills, but Matthew wouldn’t go, Deena said.

He didn’t know he was taking a pill laced with fentanyl the day he died. The family now keeps a blanket of his ice hockey jerseys, Matthew’s passion, as a remembrance of his life.

“Matthew thought that he knew everything about what he was doing … he thought he could pick out a fake pill if he ever got one,” said Matthew’s older brother, Ryan Loudon, 27. “And, fact is, you don’t. You don’t always know.”

Data from the Centers for Disease Control and Prevention shows that in 2019, overdose deaths from synthetic opioids were 12 times higher than they were in 2013, when counterfeit narcotics and drugs laced with more lethal synthetic substances such as fentanyl started becoming more prevalent.

When Shekita McBroom walked into the church Friday for her daughter’s funeral, Pastor Leslie Price embraced her.

“It might be hard now, but just know it will be okay,” Price said.

Later, McBroom swayed and rocked through the songs and prayers of the service, the involuntary movements of unimaginable loss. She is awaiting a toxicology report to confirm what killed Jayla. But McBroom, the advisory board commissioner for Ward 8 — which has been disproportionately affected by fatal overdoses — said she intends to channel her sorrow into prevention efforts throughout the city.

Local jurisdictions are also ramping up prevention programs.

In the District, health officials are “deploying teams to hotspots” to inform users about and overdose survivors about treatment services. They also hand out naloxone, the drug known by its brand name Narcan that is used to treat overdoses and prevent fatalities. Nearly 45,000 naloxone kits in the District were distributed in 2020, up from more than 15,000 in 2019, according to city officials. To help survivors, six community hospitals are participating in an addiction treatment program, starting in the emergency room and then providing patients with peer support.

In Northern Virginia, officials are encouraging both opioid users and nonopioid users to request free fentanyl test strips from the Chris Atwood Foundation, which allows users to see whether the drug they are using could contain fentanyl. They are also asking people to carry naloxone on them.

Montgomery police have partnered with the local health and human services department, school system, state’s attorney office and the drug abuse advisory council to launch the Community Opioid Prevention Education (COPE) trailer. The display features a replica bedroom and bathroom aimed at flagging signs of opioid abuse, such as prescription bottles with no prescription sticker on them and containing non-matching pills.

Deena Loudon said her son had taken up gardening and loved to cook. To keep the tradition going, the family built a greenhouse, growing tomatoes, peppers and herbs. They sit around the table as a family and talk about Matthew all the time, she said.

Loudon said it might sound cliche to describe finding her son dead as a “parent’s worst nightmare,” but the mother said it was exactly that.

“It’s the most horrible thing,” she said, “and I’ll never get that vision out of my head.”