LONDON (Thomson Reuters Foundation) - When Bisi Alimi came out as gay in Nigeria, his parents took him to a church where he underwent seven days of isolation, prayers and fasting to be “cured” of homosexuality, he said.

The experience, which prompted him to attempt suicide at the age of 17, is common for gay people from Nigeria to China to the United States, LGBT activists said on Thursday, calling for global action to end this kind of treatment.

For despite gains in LGBT rights, many gay people are still forced to undergo so-called conversion therapy, involving psychoanalysis, injections and electric shocks, based on the idea homosexuality is a mental disorder or medical condition.

Only three countries - Brazil, Ecuador, and Malta - have nationwide bans against conversion therapy, according to the International Lesbian, Gay, Bisexual, Trans and Intersex Association (ILGA).

“It’s a very common thing,” said Alimi, 42, a UK-based campaigner that set up the LGBT rights group Bisi Alimi Foundation, speaking on the sidelines of the Thomson Reuters Foundation’s annual two-day Trust Conference.

“Change will not happen unless people realize that at the centre of this abuse are human beings.”

He said lesbian women in Nigeria undergo another ordeal, with family members sometimes arranging for them to be raped in the belief that it will make them attracted to men.

In China, conversion therapy is performed at government-run hospitals, Human Rights Watch (HRW) said in a report this week.

One victim interviewed by HRW was forced to undergo nausea-inducing injections while watching same-sex porn. Several others were bound and given electric shocks, the rights group said.

In the United States, gay conversion therapy more often consists of psychoanalysis, said Kimahli Powell, executive director of Canadian group Rainbow Railroad, which helps LGBT people facing violence or death flee their countries.

This kind of therapy is only illegal in seven of the 50 U.S. states, according to ILGA, despite rights groups arguing this kind of treatment is outdated and false.

“We’re seeing more and more legal challenges against this type of therapy in the United States,” Powell told the Thomson Reuters Foundation.

He said legalization of same-sex marriage, which has become a major rallying point for LGBT activists, is important but can distract from problems such as conversion therapy.

Australia saw mass celebrations after voting in favour of same-sex marriage this week and is set to become the 26th nation to legalize gay unions if the bill passes.

“Marriage equality is being used as this ultimate marker of LGBTI rights, but for many individuals it’s still about being able to live, and having the will to live,” Powell said.