It's a virus the United Nations says affects over 35 million people worldwide and over 25,000 in Australia.
HIV, or human immunodeficiency virus has been the subject of intense research since its discovery in the hope of stopping the deadly virus in its tracks.
This month marks the 30th anniversary of its discovery.
Darren Mara takes a look at the progress that's been made in combating the virus since then and also the stigma still attached to it.
A life-changing diagnosis
Jose Machado has been HIV positive for 24 years.
"I was in a relationship, a same-sex relationship and we decided to get tested one day. This was at a time when people were just getting sick but no one really knew what it was or how it came about, where it came from."
Mr Machado says it was a day that changed not only his life, but also his partner's life - both were diagnosed with HIV by the same doctor on the same day.
"I remember exactly what the weather was like, what the surgery was like, what the doctor was like, but I cannot remember what my reaction was. Whether that's something I've blocked out, I'm not sure, but it's one of those things that I think your mind sometimes can decide to block out."
Mr Machado is now 50 and living as close to a normal life as his treatment allows.
His partner fell prey to AIDS only a few years after being diagnosed with HIV and passed away.
"At that time, it was basically a death sentence. I would say at that time you probably had maybe an expectancy of 2-3 years from diagnosis."
HIV in Australia
More than 25,000 Australians living with HIV, or human immunodeficiency virus.
HIV attacks the immune system, the body's protection against disease.
Left untreated, HIV can lead to AIDS, or Acquired Immune Deficiency Syndrome, which leaves the person vulnerable to infections and illnesses that the body would normally be able to fight off.
It's spread through bodily fluids and can be transmitted through unprotected sex, by sharing needles or syringes, or from mother to child during pregnancy or through breastfeeding.
Jose Machado says treatments have progressed dramatically since the discovery of HIV - but the dark days of frontier HIV treatment are hard to forget.
"It was very frightening. It was something you had to deal with many hours per day because basically some of the treatments involved taking large doses of pills at certain times of the day at certain intervals. Very complex treatments but also very severe on your system."
But 30 years of research and advocacy have brought their benefits.
There are now some 26 different drugs available to HIV patients and treatment is tailored around the individual.
There are still side effects - but Professor Andrew Carr from the HIV unit at St Vincent's Hospital in Sydney says having a broader suite of drugs dramatically improves the efficacy of HIV treatment.
"Now, it isn't so difficult to treat. Back then it was. We had AZT approved for use in about 1987, so it was very rapid development. And then we learnt two drugs was better than one about 1991and then 1996 we learnt that three drugs was better than two and in fact three drugs could switch the virus growth off in some patients and allow their health to recover very dramatically."
One of the newest drugs on the market is known as Tivicay - which has received a federal government subsidy and is now listed on the Pharmaceutical Benefits Scheme.
Dr Fraser Drummond is medical director at ViiV Healthcare Australia which was established by the drug companies, GlaxoSmithKline and Pfizer.
"Tivicay is a medicine that stops the virus from becoming part of the DNA of the immune system. In our trials it's been shown to be very effective in doing that. Some of the advantages it has over current treatments are around the minimal amount of side effects that patients experience," he said.
"It's taking one pill, once a day, a very small pill. You have to take it with other medicines. But the fact it's once a day helps the patients a lot."
The advent of drugs like Tivicay wouldn't have been possible without the work of scientists and researchers such as Dr Robert Gallo, Dr Luc Montagnier and Professor Francoise Barre-Sinoussi 30 years ago.
Dr Gallo is credited with discovering a retrovirus called HTLV-III believed to be the cause of AIDS.
While Dr Montagnier and Professor Barre-Sinoussi also identified the virus around the same time and were subsequently awarded the Nobel Prize for Medicine in 2008 for their work.
Professor Andrew Carr explains the significance of that work.
"It allowed for many things to happen very rapidly. Firstly it allowed us to confirm the link between the virus and AIDS, so subsequently the virus was isolated from many, many people with AIDS, and it wasn't isolated from people who didn't have it. Secondly, if you can grow a virus you can test drugs against it and without that we would never have had treatments."
Despite the availability of HIV treatments, it's estimated that up to half of Australians living with HIV aren't receiving medical help for the virus.
It's also believed that around 20 per cent of HIV cases in Australia remain undiagnosed.
Ann McDonald coordinates national surveillance for HIV in Australia for the Kirby Institute for Infection and Immunity.
She says there's been a steady annual increase in HIV rates since about 1999.
"There has been an increase, particularly in the last year. We had 1,253 diagnoses reported in 2012, which was about a 10 per cent increase over the number seen in 2011."
Bill Whittaker is a spokesman for the National Association of People With HIV Australia.
"Ignorance and stigma and discrimination are some of the best allies that HIV has because if people are being stigmatised and discriminated against they're not going to easily come forward for treatment and care and prevention services, and that's exactly what we want people to be doing, to come forward for testing, to consider early treatment."
Mr Whittaker says HIV testing rates are still quite high - but not high enough.
He says everyone should know their HIV status.
"The whole shift today is towards treating this disease early. Earlier treatment minimises the damage from HIV, from the virus, stops huge amounts of viral replication and helps preserve the health of individuals."
But the damage from HIV can also be emotional and psychological - and can be doled out by an insensitive and ill-informed society.
Fear and stigma
HIV awareness advocates agree negative perceptions and fear of HIV aren't what they were 30 years ago.
But they say the stigma still exists.
Jose Machado says it's a battle he fights every day.
"To advocate for a so-called HIV human face is basically that we're all the same, we just happen to have a virus which is called HIV and basically that doesn't give anyone grounds to discriminate or stigmatise," he said.
"It's just something that we all live with, we all battle with, and the stigma and discrimination has changed to a point, but that battle is still out there to be won."
