Mayor of London Boris Johnson is backing an HIV awareness campaign by the Terrence Higgins Trust in the run up to Britain’s first-ever National HIV Testing Week from Monday.

Details of a campaign aimed at increase testing among the most at risk in the population were given at a City Hall reception today (Mon) marking the 30th anniversary of the charity first established in East London at offices at Mile End.

“It is vital that people who might be at risk get tested,” said the mayor. “This would reduce the risk to others and ensure those affected get the life-saving treatments available.”

Almost half those living with HIV in Britain are in London. One-in-four are unaware they carry the virus, says City Hall.

The trust has been campaigning on HIV and sexual health issues since 1982 when it was set up by friends of Terry Higgins, the first person in Britain to die of Aids.

Today it provides services for thousands of people a year all over the country—but London remains the centre of the epidemic in the UK. The former Mildmay Hospital in Shoreditch was the main treatment centre in the country.