Mr Thorn has spoken at conferences for 15 years
A UK activist has spoken about his role in pushing the US government to overturn a law which bans people with HIV from visiting the country.
Paul Thorn, 38, an expert on HIV and TB, was stopped from speaking at the Pacific health summit in Seattle after admitting his HIV status on his visa entry form.
He was moved to write an impassioned letter which was read in his place, saying the policy was founded in fear and the US had no right to call itself a world leader in the fight against the disease.
He said: "In the past when I have been to the US I have always lied on the form, but this time I thought "no, I'm not going to do that".
"It's annoying that the US gives you two choices: to commit a crime by lying on the form; or tell the truth and be turned away as an undesirable."I didn't think I was either of those things. I decided to make a stand."
Mr Thorn's letter was picked up by Congressman Jim McDermott, who wrote to the Obama administration's health secretary, calling on them to push through the process of repealing the law.
The US Senate voted to overturn the rule, which has been in force since 1987, in July last year.
The provision lifting the ban was part of a bill granting some $50bn in funding for the fight against HIV/Aids throughout the world.
"What we wanted to do was get it moving in the right direction," Mr Thorne, 38, from Brighton, said.
"If the US wants to hold events like the Pacific health summit, and the International Aids Society wants to hold its conference in Washington DC in 2012, you need people from the HIV community there."
With the help of Congressman McDermott and Results - an international lobby group - the ban is set to disappear by the end of this year.
Mr Thorn said: "It means I can go to Disneyland if I want to. It sounds flippant, but when you think about it, why shouldn't people with HIV be able to do that?
"It does mean that people with HIV can visit family and friends in the US, and people who might not have told their employer about it can go there for work without worrying."
He added: "This is all about the US taking its rightful place as one of the leaders in dealing with the problem of HIV - welcome back."