National HIV Testing Day is taking place in the United States on Friday.

The event has the official support of the US Federal Government and is designed to encourage people to test for the virus.

Figures show almost half of the US population has never been tested for HIV.

It’s estimated that of the 1.1 million Americans living with HIV – 20% are unaware of their status.

Gay and black communities remain disproportionally affected by the epidemic.

The New York State HIV/AIDS Surveillance Annual Report, released in August 2013, showed there were 16,189 men who have sex with men (MSM) living with HIV in 2011 in New York – and a further 18,644 classified as living with AIDS – a combined figure of 34,833.

The city of Atlanta has among one of the highest concentrations of young black gay men living with HIV in the US – and also of any western city.

Special community testing sessions will be taking place in scores of US cities on Friday.