The Health Protection Agency (HPA) in the UK has reported that a quarter of people living in the region with HIV remained undiagnosed.
According to figures revealed by HPA, 6,280 new HIV diagnoses were found in 2011, taking the total number of HIV infected people in the UK to around 96,000.
HPA HIV surveillance head Dr Valerie Delpech said promotion of HIV testing and safe sex programmes helps tackle high transmission rates.
"National HIV Testing Week is a great opportunity to encourage people to get tested. We also encourage clinicians to take every opportunity to offer the test to those in higher risk groups and, in high prevalence areas, to all general medical admission and new GP registrants," Dr Delpech said.
"The good news is that with the excellent services and treatments available nowadays, if diagnosed and treated early someone with HIV can look forward to a normal lifespan, as well as protecting their sexual partners from infection."
The HIV in the UK report also revealed that new diagnoses among men who have sex with men reached an all-time high in 2011, and the black African community also remained at higher HIV risk.
Nearly half of all newly diagnosed cases were acquired heterosexually and overall HIV occurrence in the UK was 1.5 per 1,000 population.
According to the data, a minor decline in the total new diagnoses is because of reduction in diagnoses among people born outside the UK.