Human Immunodeficiency virus (HIV)

• Virus that causes acquired immune deficiency syndrome (AIDS) if untreated.
• The main risk group in NZ are men who have sex with men (MSM), but is seen in others also.

Modern tests are very accurate. Complicated pre-test counselling or consent procedures are not required, and should not be a barrier to testing.

Because HIV is now easily treatable, it is generally only a danger to health if undiagnosed. Effective treatment renders people non-infectious to others, thus limiting the spread of HIV.

• This is why there should be a low threshold for testing.

Testing should be performed in those seeking STI testing, particularly in MSM.

• Periodic testing (at least annually) is recommended in those with risk factors e.g. MSM.

HIV can present in many different ways.

• Test people with unusual presentations, unusual infections, general unexplained decline in health. Testing is simple and straightforward.

Request HIV serology

Modern tests (called ‘4^th generation tests’) detect a combination of antigen (bits of the virus) and antibody (body’s response to the virus).

• These tests become positive much sooner after infection than older tests, where the ‘window period’ could be prolonged because they only detected antibody.
• Excellent sensitivity – a negative test excludes the diagnosis (unless exposure within last 45 days)
• Excellent specificity – a positive test confirms the diagnosis.

HIV viral load (HIV RNA):

• Not recommended as initial diagnostic test for HIV.
• This is generally only used by specialists, and is for monitoring treatment and confirming infection in newly diagnosed patients.