Patients who have the test, using a mouth swab or finger prick blood sample, will be given their results within just 30 minutes - instead of having to wait until the end of the day.

They are seen by a doctor or health advisor at the Genito-urinary Medicine clinic at St Helens Hospital for a discussion about the test before a quick sample is taken.

The sample is put into a liquid solution and the results show up either positive or negative, similar to a pregnancy test.

The specialist team then discuss the result with the patient and offer the appropriate support, from counselling to advice on health promotion and follow-up treatment.

Initially, the rapid testing is available to men who have sex with men, commercial sex workers, victims of sexual assault and other high risk patients.

Ann Marr, Trust chief executive, said: "The Trust is committed to providing the very best possible care to our patients. By becoming the first Trust on Merseyside to introduce the rapid HIV test, we are reducing waiting times and anxiety for our patients and making sure they get the most appropriate care, support and treatment as quickly as possible."