In this 2007 photo, Ron Daniels drove the streets of the District as part of a needle-exchange program he spearheaded. (Nikki Kahn/The Washington Post)

Those who knew Ron Daniels have tried this week to calculate how many lives he saved in Washington serving the city’s most vulnerable. But the number is elusive.

How do they count the number of people he handed clean syringes to during the more than 15 years he ran needle-exchange programs in the city?

How do they count the many addicts he persuaded to seek treatment, some who later became his co-workers?

How do they count the people he trained near and far over the years to do what he did?

“Ron Daniels saved thousands of people’s lives, just person by person by person, clean needle by clean needle by clean needle,” said Patricia Wudel, who runs Joseph’s House, a hospice for the homeless that once honored Daniels for his work.

Ron Daniels with Sheila Johnson, co-founder of Black Entertainment Television. (Family photo)

But for all the lives he saved, his own life was cut short.

Daniels died in his sleep from heart complications Sunday night in his Northeast Washington home, his family said. He was open about being HIV-positive and having chronic obstructive pulmonary disease, but his death at age 57 has stunned many in the advocacy world, where he was a pillar.

“We’re devastated,” said Diane Jones, who worked with Daniels at Family and Medical Counseling Service, where he spearheaded the needle-exchange program. “We knew he was sick, but we thought we had more time. I’m going to miss my friend.”

Jones said that Daniels, who had done needle-exchange work since the late 1990s, built their organization’s program from the ground up in 2008. It is the city’s largest program, collecting more than 300,000 dirty syringes a year. Its mobile unit, a Winnebago that Daniels outfitted, stops at a dozen sites across the District.

“He was Mr. Needle Exchange in D.C.,” Jones said. “He knew everything about it. People called him from all over to come speak about it.”

But if in the advocacy world he was an expert, on the streets Daniels was a lifeline. Before heading out in the Winnebago, he would put cash in his pockets just so he could hand it out. He was also known to buy a hamburger for someone hungry and to freely give out his cellphone number, which was always ringing.

“The clients are really reeling from the loss of him,” Jones said. “He was everything to them. He was reachable. He was attainable. He was them.”

In a 2004 Washington Post profile of Daniels, he talked about his drug use and how he contracted HIV. The addiction started at age 15 with alcohol and progressed to heroin, he said. He managed to graduate high school and study social science at the University of the District of Columbia. Then his girlfriend told him she was pregnant, and he joined the Navy.

When he returned home in 1984 after completing two tours at sea, his drug habit worsened. In 1989, he tested positive for HIV after sharing a dirty needle.

Daniels described a life littered with broken relationships and jail stints until he ended up in the hospital in 1997. That’s when he decided to change, he said.

“The bottom line is it all starts and ends with you,” he said.

Daniels was proud of his work on the streets, fiercely defending the exchange program, which faced ample criticism over the years. When the Post profile was published, the District was the only city in the country barred by the federal government from using local tax funds for a needle-exchange program. That ban lasted from 1998 until 2007. During that time, Daniels worked for PreventionWorks, which operated a needle-exchange program using private funding.

“I didn’t wake up one day, you know, and say, ‘I want to be a drug addict,’ ” Daniels said. “I didn’t wake up one day, you know, and say, ‘I want to be HIV-positive.’ But in the last 25 years, both of those things have been a part of me. Who would have ever thought I’d get here? That I’d come full circle? That after all those years I’d get to help people out, people who were just like me?”

Daniels’s two children describe their father as a loving man who made them proud with how he took control of his past and used his experience to help others.

“There are not too many people who can come back from the road he came from and make the effort he made,” said his son, Kevin Daniels. “You have some people who are living because of the program my father started.”

Daniels’s daughter, Kiayanna Daniels, said he will be “tremendously missed” by his children, five grandchildren and fiancee, Ericka Dennis. But her hope is that the people he helped don’t let his loss hurt their own efforts.

“Don’t let his death be in vain,” she said. “Just continue the good work, continue the road to recovery.”

“If my father helped you and you got yourself together, go help someone else,” Kevin Daniels said. “And if everyone does that, the next thing you know there are thousands and millions, and we can fix this problem one step at a time.”

Channing Wickham, the director of the Washington AIDS Partnership, was on the founding board of PreventionWorks and said that over the years he has seen Daniels mentor countless people and inspire them to start careers in public health.

“I don’t think he ever had any idea how amazing he was and how much respect everyone had for his commitment, drive and dedication,” Wickham said. “He treated people with great respect, no matter who they were, whether they were a client of one of the organizations where he provided needle exchange or Eleanor Holmes Norton.”

He recalled seeing Daniels at the International AIDS Conference in the District several years ago, proudly giving tours of his Winnebago, which was on display inside the convention center.

“He’s much bigger than just the city,” Wickham said. “He’s part of the national movement. Just at the International AIDS Conference, the number of people he touched was clearly in the thousands.”

A funeral for Daniels is scheduled for 11 a.m. on Jan. 19 at Westminster Presbyterian Church in Southwest Washington.

It is a fitting location for his life to be celebrated. In 2007, Daniels helped start a needle-exchange program at the church.