ELISA testing alone cannot be used to diagnose HIV, even if the test suggests a high probability that antibody to HIV-1 is present.

In 2011, the prevalence of HIV in the United Kingdom was estimated at 96,000, with an estimated 6,840 (in 2007) people were newly diagnosed HIV positive, which was a decline of around 12% from the 2005 figure of 7,800.

Mr. Wiese was diagnosed HIV positive at 19 years old, after several years of sexual promiscuity, he said.

In a brilliant cross-pollination of engineering, physics and biology, scientists have developed an affordable credit-card sized device that can accurately diagnose HIV and syphilis in just minutes.

New tests can reliably diagnose HIV from four weeks after infection, so people no longer have to wait three months to take a test.

Who can diagnose HIV?

"The ways in which we can diagnose and treat HIV have advanced a great deal in 30 years, and making a similar step-change in prevention is well within our grasp."

The results of a rapid HIV test also must be confirmed with a follow-up test before doctors can firmly diagnose HIV.

Tests for HIV: Before and After Diagnosis Some tests help diagnose HIV.