Mayor Nutter recently launched Philadelphia’s biggest new campaign against sexually transmitted diseases in at least two decades, unveiling a hoped-for conversation-starter - The Freedom Condom - that is aimed directly at teens.

Then, Health Commissioner Donald F. Schwarz unwrapped one. “We need to show kids that we touch these things,” he said at a City Hall news conference, because otherwise “they will never believe that it is appropriate and normal to use them.”

It was a scene that never would have happened 20 years ago, when public discussion of condoms provoked anger and controversy.

Now, with new HIV cases among city teens and young adults up 40 percent over three years - rates of other sexually transmitted diseases are rising, too - public health officials are seeking to jump-start talk about safe sex in any way they can.

Designed with young people in mind: A website (www.takecontrolphilly.org, with free online ordering), a Facebook page, and GPS-enabled iPhone app to get you to the nearest of more than 100 distribution sites.

The prevention campaign will include broader education about sexually transmitted diseases and stepped-up efforts to find and treat infected teens, their partners, and even others in their “sexual network,” officials said, although few details were available.

“I do believe that abstinence is a good theory,” Schwarz said in an interview. “In the meantime, a lot of kids are going to be put in harm’s way if we don’t find a way to make sex safer.”

He acknowledged, however, that a condom campaign alone would not solve the problem, calling it a “necessary but not sufficient” part of the equation.

While access to condoms may help, experts say that many teenage boys, perhaps even more than men, object to how they feel. And girls often do not push the issue.

“I don’t know if there is a single answer to it,” said 21-year-old Brittany Langford, reflecting on why she barely asked guys to wear a condom during the three years that she was moving from shelter to shelter, often having sex for money or a place to stay.

Fear was a big part of it, she said. “I didn’t want them to think I was infected.”

Langford, who said she managed, against the odds, not to get infected with any STDs, is now finishing her studies at Community College of Philadelphia and living in the Northeast with her fiance; their baby is due in June.

Her life was very different four years ago, when she spotted a flier for “free food” and showed up at the Youth Health Empowerment Project (Y-HEP) on North Broad Street, where she spoke about her experiences the other day. For six months, she came by only for food, clothing, and tokens, all free.

“Then I started talking and really asking for help,” she said.

Eventually she helped lead group discussions about STDs and HIV, with the candid talk more often than not turning into exercises on trust, patience and power.

Langford’s experience illustrates the limits of condoms as a prevention strategy.

“Part of it is to get these kids to realize that they do have a future and that if they get HIV and have unplanned pregnancies that these can interfere with their ability to achieve their future goals,” said John B. Jemmott, who studies HIV prevention here and in South Africa.

Jemmott, a professor of communication and psychiatry at the University of Pennsylvania, last year published one of the few studies to find clear evidence that abstinence education helped delay teen sex. The program focused on far more than abstinence, and included discussions about peer pressure, decision-making, dreams and goals.

It examined when teens begin to have sex, not specifically STD prevention.

“Unfortunately, if there was a simple answer then those of us who work with youth every day and those who work in public health would have figured it out,” said Nadia Dowshen, a pediatrician who specializes in HIV-positive youth at Children’s Hospital of Philadelphia.

“When I see youths in the office, a lot of what we focus on is communication skills and talking more about relationships in general,” Dowshen said. It is a cost-effective approach considering the expense of treating someone with HIV for life, she said, but no public health department has the money to individually counsel an entire teenage population.

The condom campaign is a relative bargain: $30,000 for the first run of 200,000 custom-labeled packages, with that and the remaining expenses for an expected distribution of one million condoms paid by a federal grant.

Dowshen is particularly pleased that the new campaign is “meeting youth where they are at, literally, in terms of technology.”

Recently, she presented at a medical conference the results of her own pilot study showing that simple daily text messages - chosen personally but sent automatically - helped HIV-positive young people stick to their daily regimen of antiretroviral drugs.

The city’s new website cannot send text messages, at least not yet, but it quickly found an audience. The first online order came in just minutes after the site went live, well before it was announced, officials said; 30 more had come in by 4:15 p.m.

From the city’s perspective, this was not a moment too soon.

More than 30 percent of girls and 12 percent of boys test positive for at least one STD over the course of their high school career. Infectious syphilis, gonorrhea and Chlamydia all have been rising rapidly in teens and young adults.

A recent health department analysis of screening data going back 10 years determined that a youth who tests positive for any of them is 2.5 to 3 times more likely to contract HIV than one who tests negative.

“I am worried that we are going to see an increase of newly diagnosed HIV cases in youth,” said Kathleen A. Brady, medical director of the city’s AIDS Activities Coordinating Office.

The city lost $2 million in state prevention money during the last year of Gov. Ed Rendell’s administration. Schwarz, the health commissioner, said that there had been no further cuts proposed - so far - by Gov. Corbett or the Obama administration.

He added: “We believe that with an increased number of cases we are going to need more funding. That we don’t have.”

At the news conference, Mayor Nutter introduced Michael Bodenberger, the 23-year-old IT worker who designed the winning wrapper, and handed him a (wrapped) Freedom Condom.

Nutter’s participation underscored the importance that the city is placing on the prevention campaign. But that was not the only reason he stood at the front of the room.

During recent high school screening for STDs, city health workers surveyed about 500 students on various aspects of the campaign. A slogan - “Why Risk It?” - came out of that survey.

The students were also asked who would be influential in promoting a condom campaign. The question was open-ended.

“No. 1 was (actor) Will Smith. No. 2 was Michael Nutter,” said Schwarz. “I was blown away.”