Victor clearly recalls the day 10 years ago that changed his life.

It was a Sunday, and he had gone to Hong Kong charity Aids Concern, where he volunteers, to have a rapid antibody test for human immunodeficiency virus (HIV), an infection that attacks the body’s immune system.

For weeks, he had been experiencing diarrhoea that his friends told him was probably a severe case of food poisoning. Victor’s instincts told him it was something more serious.

His fears were amplified because he had been engaging in high-risk sexual behaviour – unprotected sex with numerous partners – following a painful break-up with his boyfriend that left him feeling empty.

He turned to dating apps to ease the loneliness, with one hook-up leaving him particularly worried that he might have caught a disease. His instincts proved correct.

“I remember staring at the test and watching it turn positive,” says Victor, 35, who moved to Hong Kong from mainland China with his family when he was 10. “It was a real shock – it felt like everything had suddenly become muted.”