UNAIDS's Michel Sidibé and Sir Elton John at AIDS 2012 (Image UNAIDS/Y. Gripas)

Despite still existing in 46 countries, territories and areas, travel restrictions imposed on people living with HIV are based on fear, not science and should be rescinded immediately, delegates at this year's International AIDS Conference have said.

According to UNAIDS, the world is now better informed about HIV and has a greater understanding of its prevention and treatment such that HIV-related travel restrictions "have no public health justification".

"HIV cannot be transmitted by the mere presence of a person with HIV in a country," a statement from the UN read.

The UNAIDS executive director Michel Sidibé called the restrictions "discriminatory" claiming they violate international human rights standards.

"People living with HIV should have equal access to opportunity and freedom of movement in today's globalized world," he said.

At the opening of the conference, chief executives from some of the world's leading companies signed a pledge to oppose HIV-related restrictions on entry, stay and residence, claiming that while obviously discriminatory, the restrictions are also "bad for business".

"In today's competitive landscape where global business travel is essential, we need to be able to send our talent and skills where they're needed", Levi Strauss & Co. chief executive Chip Bergh said.

Virgin Unite founder Richard Branson also lent his voice to the campaign, decrying the restrictions as "archaic".

"Everyone should have a chance to travel freely."

The call for an end to all HIV-related travel restrictions has coincided with the return of the International AIDS Conference (AIDS 2012) to the United States after over two decades away.

Prior to 2010, when President Obama lifted a ban barring HIV-infected people from entering the United States, an international AIDS conference was unlikely to be hosted by the USA, as potential HIV-positive delegates would have been denied entry.