Laws that criminalize gay behavior create a a host of legal tangles that waste resources and hinder an effective response to HIV/AIDS worldwide, an independent commission reported on Monday.
The report by the Global Commission on HIV and the Law also pointed to laws that make sex work a crime, laws that prevent interventions with injecting drug workers, and legislation that denies youths access to sex education.
"Too many countries waste vital resources by enforcing archaic laws that ignore science and perpetuate stigma," said a statement by former president of Brazil Fernando Henrique Cardoso, who serves as chair of the commission.
"We have a chance to free future generations from the threat of HIV. We cannot allow injustice and intolerance to undercut this progress."
The commission is made up of former heads of state and top global experts in the human immunodeficiency virus. The panel is supported by the United Nations Development Program.
Its report is based on "extensive research and first-hand accounts from more than 1,000 people in 140 countries," the commission said in a statement.
Other key woes include laws and customs that deny the rights of women and girls, from genital mutilation to denial of property rights to allowing marital rape, because such practices can undermine their ability to negotiate safe sex.
More than 60 countries make it a crime to expose another person to HIV, which can discourage people who think they may be infected from getting tested to find out their status.
"There have been over 600 HIV positive cases of convictions in some 24 countries over the last number of years for transmission and non-disclosure and the majority of those lie in the United States and Canada," said Stephen Lewis, co-founder of AIDS-Free World.
California Congresswoman Barbara Lee said that 34 US states have laws on the books that make it a crime to expose another person to HIV, and as many as 39 states have prosecuted people for exposure, non-disclosure, and/or transmission of HIV.
Such legal practices can impede access to testing and treatment among critical populations like African-American gay and bisexual men, and African-American women who make up 60 percent of new infections in the US, said Lee who has authored a bill seeking to remove those laws.
"When a country such as the United States -- and many countries throughout the world -- has punitive laws or practices directed to these populations they directly impact and undermine the prevention and treatment efforts from these communities," said Lee.
She also lamented the stance taken by the US President's Emergency Plan for AIDS Relief (PEPFAR) that any organization receiving funds must explicitly oppose prostitution and sex trafficking.
PEPFAR's anti-prostitution pledge "doesn't make any sense. It impedes the global HIV response by preventing international health organizations from providing evidence-based services to at-risk groups," she said.
In addition, complicated intellectual property restrictions can make it impossible to provide low-cost AIDS drugs to people in need, the report said.
The commission singled out several countries by name, including Iran and Yemen which impose the death penalty for homosexual acts; and Cambodia, China, Myanmar, Malaysia and the Philippines for criminalizing interventions for drug users.
Some better approaches are seen in Switzerland and Australia, where programs to provide clean needles to injecting drug users have "almost completely stopped new HIV infections" in that group, the report said.
Lee also praised for South Africa, Botswana, Malawi and Indonesia for "moving in the right direction."
Almost 60 million people have been infected by HIV, while 25 million people have been killed by causes related to the virus since the epidemic started some three decades ago, according to data published by UNAIDS.