The Sussex Beacon is urging people in Brighton and Hove to have a quick and simple HIV check during National HIV Testing Week.
The charity said that there were almost 3,000 people in Sussex with HIV last year, with the highest prevalence in Brighton and Hove.
It urged people to take the test the day before the start of the national awareness week which starts tomorrow (Saturday 19 November) and runs until next Friday (25 November).
The Brighton charity said: “Around 17 per cent of people living with HIV are unaware they have it and the majority of new infections are as a result of these individuals unknowingly passing the virus on.”
It added: “Forty one per cent of people with HIV in the south of England are diagnosed late, when the virus is already affecting their immune system.
“Those diagnosed late are more likely to have serious health complications or face premature death.”
The charity is particularly keen to encourage testing among high-risk groups, including gay men and the African community.
Sussex Beacon chief executive Simon Dowe said: “Too many people are diagnosed with HIV late. These people may face serious health complications as a result or may pass the virus on.
“If you think you might have been at risk, please take the test. It will either put your mind at rest or get you the treatment you need to stay well.
“It could be the most important test you ever take.”
The team from the Sussex Beacon will be raising awareness and urging people to test throughout the week, both directly and via social media.
At the end of the week, on Saturday 26 November, the Sussex Beacon will be at a Brighton and Hove Albion football match as the club’s charity partner. It will use the opportunity to get the testing message across to fans too.
HIV testing is free and completely confidential. Testing methods vary and people may be offered a swab, a rapid finger prick test or a blood test.
To find out where to take a test locally, visit www.brightonsexualhealth.com or www.tht.org.uk/brightontests. Alternatively, for a sampling kit to use at home visit www.test.hiv.
National HIV Testing Week is co-ordinated by HIV Prevention England.
The Sussex Beacon provides specialist support and care for people living with HIV. The charity provides both inpatient and outpatient services to promote independence and improve health.
For more information visit www.sussexbeacon.org.uk.