By Pat Loeb

PHILADELPHIA (CBS) - The Kingsessing recreation center has had an unusual accessory for the last few weekends. Each Thursday, Friday and Saturday, since late July, a big white van has parked nearby, from 4 to 8 p.m., with traipsing in and out of it all day.

The van is a mobile HIV testing lab, the key tool in a two-year project to attack AIDS geographically by persuading 12,000 people in the 19134 zip code, which has among the highest number of HIV infections and AIDS cases in the city, to get tested.

The project, “Do One Thing,” was conceived by Brown University researcher Amy Nunn and funded by a drug company. Normally, AIDS prevention efforts focus on high risk behavior groups but “Do One Thing” is hoping to show a geographic attack, stressing testing, can be effective.

Health care workers knock on doors, buttonhole passersby, put up signs in local businesses, work with local churches– anything to get the word out.

“A beauty shop had us do testing,” says director Gladys Thomas, “and that was really exciting to talk with youth and do testing.”

Thomas was tickled, recently, when she stopped a stranger on the street and began her pitch to visit the van and get tested, only to have the man tell her he already knew all about it.

“I heard it through the grapevine,” he said, and headed off to the van.

More than 100 local residents have gotten tested in the van, so far, including Carlos Estavero.

“They took a swab, it took about 20 seconds and it was painless,” says Estavero. “I recommend more people get this done because in this day and time, it’s good to know your status, you know?”