Sex workers, tired of being blamed for spreading AIDS, said Thursday they could help fight the deadly disease but were being shunned by governments and agencies.

“We are sex experts. We teach a lot of people, men and women all over the world, how to have sex. If we teach people how to have sex, why don’t we teach people how to have safe sex?” Paulo Longo said at an international AIDS meeting in the Thai capital.

The retired Brazilian sex worker, who is now a psychologist, said stigma and discrimination had prevented workers in the world’s oldest profession from playing a bigger role in the fight to halt the spread of the sexually transmitted virus.

“They say we are not educated enough, that we are too demanding, that we use drugs all the time so we don’t concentrate,” said Longo.

But given the chance, he and others like him say they could make a difference. “There is evidence that involving sex workers helps a lot,” he said. “We can help to minimize the impact of the epidemic.”

UNAIDS, the Joint United Nations Program on HIV/AIDS, agrees sex workers should be more involved and equal partners in the consultative process of how to fight the epidemic.

“UNAIDS is trying to ensure their voice is heard,” said Aurorita Mendoza of UNAIDS. “We are acting as facilitators for sex workers with organizers of national programs.”

The 15th International AIDS Conference has highlighted the impact of AIDS on women and the importance of condoms in preventing the spread of the virus. For some women, their only risk factor was being a faithful wife. In the worst affected countries in Africa and Asia, many women cannot insist their husband use a condom.

Carol Jenkins, a medical anthropologist based in Thailand and an adviser on HIV/AIDS, said studies showed that protecting sex workers from HIV protects the whole society. But sex workers had to fight to get agencies and governments to recognize them, she said.

“You have a constituency out there that is very affected by a serious epidemic that is going to ruin your economy. Why aren’t you listening to this constituency?” she said.

Mandating 100 percent condom use by sex workers was not the answer because it can increase stigma and violence against them, Jenkins said. “We want reforms so sex workers can do it themselves,” she said.

Longo and groups representing sex workers at the meeting said they were not against using condoms, but mandating it and registering sex workers violated their right to privacy and free choice.

“Sex workers can be part of the solution,” Longo said, “because we were affected by the problem at the beginning in a huge way.”