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What is HIV?

HIV stands for human immunodeficiency virus. ‘Immunodeficiency’ refers to the weakening of the immune system by the virus.

If HIV is left undiagnosed and untreated, your immune system can become so weak that you can develop serious infections and cancers. This is known as Acquired Immune Deficiency Syndrome (AIDS).

Increased testing and better treatment means few people in the UK develop serious HIV-related illnesses nowadays. The term AIDS is not used much by UK doctors. Instead, they talk about ‘late-stage’ or ‘advanced’ HIV.

Untreated HIV and transmission

If someone with HIV has a detectable viral load, they can pass on HIV through blood, genital fluids and breast milk. HIV is not passed on by spitting, sneezing or coughing, nor by kissing or general social contact. HIV cannot survive for long outside the human body.

HIV treatment and undetectable viral load

Thanks to early testing and ongoing treatment, people living with HIV in Northern Ireland can now expect to live a full and healthy life. Modern antiretroviral treatment reduces the amount of HIV virus to undetectable levels. When the virus is undetectable, it no longer weakens the immune system.

The Terrence Higgins Trust is running a campaign to emphasise that people living with HIV who are on effective treatment ‘Can’t Pass It On’.

This also supports the UNAIDS campaign ‘U=U’ (Undetectable = Untransmittable).

HIV prevention

There are many ways of preventing the transmission of HIV infection, including:

  • HIV education and awareness
  • knowing your HIV status
  • HIV testing and treatment
  • using condoms correctly when engaging in penetrative oral, anal or vaginal sex
  • fewer sexual partners
  • regular sexual health checkups
  • never sharing needles or other injecting equipment
  • post-exposure prophylaxis (PEP) – this is a course of medication that may prevent you from becoming HIV positive if you take it within 72 hours of possible exposure to HIV
  • pre-exposure prophylaxis (PrEP) – this is a pill available in GUM clinics, which you can take to protect you from HIV

The only way to know for sure if you have HIV is to have an HIV test. Visit our HIV service page for more information.

Living with HIV

Support and advocacy is available for people living with HIV. Adjusting to a HIV diagnosis not only brings personal challenges, but issues of stigma and discrimination.

Peer mentors, social workers, counsellors and mental health professionals are all available to promote resilience and wellbeing. People living with HIV should feel supported throughout their lives.

Early diagnosis and access to treatment is essential to limit the spread of HIV. One of the most important things we can do to prevent the spread of HIV and discrimination of those living with HIV is to find out some basic information about the virus.


More people than ever before are living with HIV in Northern Ireland. More than 1,000 people are known to be living with HIV in Northern Ireland – the highest number ever on record – and it is estimated that hundreds more have HIV and are not aware of it. For further information, read the HIV surveillance in Northern Ireland 2019 report.

Useful links

Sexual Health NI
Terrence Higgins Trust
National AIDS Trust
World AIDS Day
Positive Life
Avert – Global information and education on HIV and AIDS
i-base – HIV treatment information and advocacy
Stigma Index

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