Human immunodeficiency virus infection (HIV and AIDS) - including symptoms, treatment and prevention

Without treatment, human immunodeficiency virus (HIV) infection will usually result in acquired immune deficiency syndrome (AIDS). However, in Australia the HIV therapies introduced in the mid-1990s, which are available to all Australians living with HIV, have resulted in fewer AIDS related illnesses and deaths. Therefore, whilst a cure is yet to be found for HIV and it remains a lifelong infection, HIV in Australia is now considered a chronic manageable condition.

Human immunodeficiency virus is a notifiable condition1

How HIV is spread

HIV infection occurs when particular body fluids (blood, semen, vaginal fluid and breast milk) containing the virus come into contact with another person’s tissues beneath the skin (for example, though needle puncture or broken skin), or mucous membranes (the thin moist lining of many parts of the body such as the nose, mouth, throat and genitals).

In Australia, most infections now result from unprotected sex (anal or vaginal intercourse without a condom) and/or the sharing of injecting equipment.

Receiving blood or blood products presented a risk prior to the introduction of screening for HIV in the Australian blood supply in 1985.

Mother-to-baby transmission during pregnancy, birth or breastfeeding is now rare and only occurs where the mother has untreated HIV infection.

Routine social or community contact with an HIV infected person carries no risk of infection. There is no evidence of spread of HIV through social contact in schools, at home or in the work place. HIV has not been transmitted through:

  • air or water
  • swimming pools or toilets
  • sharing of plates, cups or cutlery
  • kissing
  • coughing
  • sneezing or spitting.

In addition, there is no evidence HIV can be spread by mosquitoes or other biting insects.

Signs and symptoms

A few weeks after infection with HIV, the infected person may develop an illness (seroconversion illness) consisting of:

  • muscle aches
  • low-grade fever
  • headaches
  • sometimes a rash
  • swelling of the lymph glands may also occur.

This flu-like illness may be so mild it goes unnoticed, or in some people it may be quite severe and last for a few weeks before there is a return to seemingly normal health. Either way, this illness at the beginning of the infection is so similar to many other viral infections that the diagnosis of HIV infection may not be made at this time.

In Australia it is now recommended that HIV treatment starts as soon as possible after diagnosis. Whilst it is not a cure, treatment is known to slow or even halt the disease progression that would otherwise have led to AIDS.

Untreated HIV

In some individuals treatment may not be commenced as recommended and disease progression may occur. The length of time that people with untreated HIV infection may live without symptoms varies widely. Some people experience rapid development of symptoms or disease due to their HIV infection, whereas others may remain free of any symptoms for years.

When symptoms develop in untreated HIV, they may not be specific and can include:

  • chronic loss of appetite
  • diarrhoea
  • weight loss
  • fever
  • lethargy
  • fatigue.

Untreated HIV destroys certain cells within the immune system (CD4+ or helper T cells) from the time of infection onwards, causing more and more damage. Eventually the damage to the immune system is so great the body can no longer stop some infections or cancers it normally fights successfully. Infections not usually seen in healthy people, called opportunistic infections, and certain unusual tumours such as Kaposi’s sarcoma, may occur. Women with untreated HIV infection are at increased risk of developing cervical cancer and both men and women are at increased risk of anal cancer. Untreated HIV can cause infection in the brain, which can lead to nervous system disorders or dementia in some people with HIV infection.


Diagnosis of HIV infection is made using blood tests. A positive blood test indicates the development of antibodies to HIV and therefore the presence of the virus. Antibodies to HIV usually develop within a few weeks to three months. Even though the blood test for antibodies may not be positive during the early stage of infection, the virus will be present in blood and body fluids, making the person infectious to other people. Polymerase chain reaction (PCR) tests in a pathology laboratory can be used for the early detection of HIV genetic material in the blood.

Clinic 275 can offer you a confirmatory HIV test.

Incubation period

(time between becoming infected and developing symptoms)

Illness may not occur for months or years after untreated HIV infection. Without treatment, most adults will develop severe disease within 10 years of infection. Treatment of HIV with drug therapy has become much more effective in the past few years, prolonging life and increasing quality of life in people with HIV.

Infectious period

(time during which an infected person can infect others)

Once a person has been infected with HIV he or she remains infected for life and is able to transmit the virus to others. The risk of transmitting the infection to another person is dependent on the level of virus in body fluids of the infected person.

The risk of transmitting the virus to others is higher when the viral load (the amount of HIV in the blood) is higher, in particular in early infection (when a person may not even be aware he or she has HIV) and late in untreated infection (when the immune system is failing). Research demonstrates that having a consistently low (undetectable) viral load dramatically reduces infectiousness and that together with consistent condom use and/or safe injecting practices, lowers the risk of transmission to almost zero. However certain factors, including poor treatment adherence or the presence of other STIs can increase the risk of transmission.


HIV treatments (antiretrovirals) are available and all people with HIV infection in Australia have access to this treatment. Available HIV treatments have dramatically improved the outlook for people with HIV.

The majority of people on HIV treatment in countries like Australia will have long-term suppression of symptoms and a reduced viral load. Without HIV treatment people with HIV may develop AIDS and die from infections, cancers and other illnesses the immune system can no longer fight.

HIV treatment outcomes over a whole lifetime are not yet known and drug resistance can limit the treatment options available to the person. Some of the drugs have significant side effects and all must be taken very accurately, requiring quite some effort on the part of the HIV infected person to take the medications for a long period, probably for life.

There is no vaccine against HIV. There is no drug yet which can cure HIV infection.

When HIV infection is advanced, either through treatment failure or in untreated infection, and has caused immune system destruction, secondary infections (opportunistic infections) can occur. Using other antiviral drugs and antibiotics to prevent secondary infection may prevent severe illness and premature (early) death.

Early treatment, even at the point of diagnosis, is now recommended in Australia. Regular assessment is important in monitoring the effects of HIV infection, and in monitoring the effect of therapy or the development of complications.

Measurement of the viral load and the levels of CD4+ cells assists in indicating the effectiveness of treatments.

An infectious diseases specialist or general practitioner with expertise in HIV medicine is recommended to undertake these assessments.


Exclusion from childcare, preschool, school and work is not necessary. Children with HIV infection may be advised to stay away from school during outbreaks of infectious disease (for example, chickenpox) to prevent them getting the infection.

Health Care Workers with HIV infection must comply with the requirements of their professional boards.

Although there is no HIV vaccine, HIV infections are entirely preventable through safe behaviour. Everyone has a responsibility to help prevent transmission of HIV and to take care of themselves and others. This means:

  • Practising safer sex – use condoms and water based lubricants for penetrative sex. These reduce the risk of getting HIV, as well as other sexually transmitted infections (STIs). Having any STI increases the risk of getting HIV infection.
  • Not sharing any injecting equipment (including needles, syringes, filters, spoons, swabs, tourniquets).
  • Safely disposing of found or used needles and syringes in a sharp safe, or other sealable and puncture-proof container.
  • Always using standard precautions if blood or body fluids must be handled. This will minimise and generally eliminate the risk of transmission of HIV.
  • Covering any open sores, cuts or abrasions with waterproof dressings.
  • Understanding the risk of body tattooing or any body piercing. The risk of being infected with HIV through these practices is lower than for hepatitis B or hepatitis C, but there is still a risk if there is use of unsterile equipment or re-used dyes.

People with HIV or at risk of infection with HIV should not donate blood, organs or other tissue. In Australia, all donated blood and body organs are screened for HIV infection.

Post Exposure Prophylaxis (PEP) for HIV

PEP for HIV is a four week treatment that may prevent you from becoming infected if you have been exposed to HIV.

PEP needs to begin as soon as possible within 72 hours after exposure to be effective.

Prevention of mother-to-child transmission of HIV

Administration of HIV treatment to HIV-positive pregnant women during pregnancy and labour and after delivery, as well as to the newborn baby, dramatically reduces the risk of mother-to-baby transmission of HIV.

Useful links

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.

^ Back to top