HIV Infection and Acquired Immunodeficiency Syndrome (AIDS)
More details/Information for students
Definition
Stages of infection
Transmission
How HIV is spread
How HIV is not spread
Blood products
Sexual activity: Vaginal intercourse, Anal intercourse, Oral sex,
Non-penetrative sex
Statistics
Testing and counselling
Pre and post test counselling
Advantages of testing
The test
Confidentiality
Treatment
Legal and ethical issues
Prevention
Pre-test Counselling Information
HIV (human immunodeficiency virus) is the causative
virus of AIDS (acquired immune deficiency syndrome). AIDS has no precedent
in medical history. It was first widely recognised in 1981, although
evidence of the virus was found in stored blood collected in 1959, and so
it seems that it has been in existence for longer than was first thought.
The virus primarily attacks the white blood cells (the T-lymphocytes or
CD-4 cells) and macrophages of the body. These cells play a key role in
maintaining a person's immunity to disease. As a result, HIV infected
people become susceptible to illnesses caused by the collapse of the
body's immune system. Individuals infected with the virus are infectious
for the rest of their lives, and can transmit HIV via blood or sexual
fluids.
The common conditions and diseases related to AIDS
include Kaposi's sarcoma (cancer of the lining of the blood vessels),
pneumonia, tuberculosis, toxoplasmosis (viral infection affecting the
central nervous system), cytomegalovirus (CMV) infection (a common viral
infection that can cause retinitis and blindness), candidiasis, and severe
herpes. As the depressed immune system makes the individual vulnerable to
many illnesses, almost any symptom may occur in HIV infection.
Stages of infection
First 12 weeks
Some people develop an illness resembling an acute
glandular fever-like illness within 6 weeks of infection. Symptoms include
fever, headache, swollen glands, tiredness, aching joints and muscles, and
a sore throat. However, most people will not feel unwell or develop any
abnormality for years. Antibodies to HIV usually develop within 2 to 8
weeks, and almost always by 12 weeks. The 12 weeks after initial infection
is called the "window period", where a negative test does not
necessarily indicate that a person is free of the virus and a follow-up
test will be necessary. However, by the end of the window period virtually
all infected people will have a positive blood test (i.e. they will test
"seropositive" or "HIV-positive"). Developing an
HIV-positive test is known as "seroconversion".
After seroconversion
HIV-infected individuals can remain physically well for
many years after initial infection. However, in general the virus slowly
attacks the immune system and, at a critical point, the condition AIDS
develops.
Within 5 years of infection, up to 30% of those
individuals infected with HIV are likely to develop AIDS (i.e. severe
conditions such as cancer and pneumonia). A proportion of people will
develop less severe symptoms, such as persistent generalised
lymphadenopathy (swollen glands), diarrhoea, fever, and weight loss.
Studies indicate that about 50% of adults infected with the virus will
develop AIDS within 10 years of infection.
Of individuals diagnosed as having AIDS, 90% are likely
to die within 2 years if not treated. Antiretroviral therapy with
zidovudine (also known as AZT or Retrovir), which can reduce mortality,
illness, and the numbers of opportunistic infections, is available to
people with diagnosed AIDS. Newer drugs such as ddI, ddC and other
antiretroviral agents are being introduced all the time. However, the
avoidance of infections, the prompt treatment of infections, and a
generally healthy lifestyle with exercise and good nutrition may
substantially reduce the likelihood that an HIV-infected individual will
develop AIDS.
How HIV is spread
How HIV is not spread
Blood products
Sexual activity
Genital ulceration
Mother to baby transmission
HIV is transmitted only through the exchange of infected
body fluids, whereby a substantial quantity of virus gains access to the
T4 cells in a susceptible individual. Although the virus occurs in saliva,
tears, cerebrospinal fluid, and urine, these fluids do not pose a
significant risk because of the low concentration of the virus and the
absence of a common mechanism for them to enter the blood of another
person.
HIV occurs in relatively high concentrations in the
blood, semen, and vaginal and cervical secretions of infected individuals.
Therefore, there is a significant risk of infection when these body fluids
are passed directly into another person's blood or anal or genital tract.
HIV is also present in breast milk, which is a possible vehicle of
transmission to infants.
There are only three significant routes of transmission
for HIV:
- from infected blood or blood products
- from infected sexual fluids
- from infected mother to baby during pregnancy and
delivery (if a pregnant woman is HIV-positive, the baby has a one in 3
chance of being infected).
There is no risk of infection through social non-sexual
contact such as kissing, sharing utensils (e.g. cups), body contact, or
the use of public toilets. HIV is not spread by mosquitoes or other
insects.
Since April 1985 therapeutic blood products have been
made safe in Australia by excluding high risk donors and screening donated
blood. Each donor must sign a declaration stating that she or he does not
have any high risk factors for HIV. This system has largely prevented the
donation of blood by HIV-positive people in South Australia. Thus, blood
transfusions given before 1980 and after April 1985 are not a risk for HIV
infection in Australia.
Unsterilised equipment used for tattooing and
acupuncture could transmit the infection, but this source is unlikely in
South Australia. It is possible for the virus to be transmitted through
needle-stick injuries to health workers, and also during unsafe disposal
of needles and syringes. Fewer than 30 health care workers in the world
are reputed to have been infected in this way, but the high incidence of
needle-stick injuries reported indicates a need for continuing the
precautionary guidelines.
Blood transmission of HIV is virtually confined to
needle and syringe sharing among injecting drug users. Anyone who shares a
needle or syringe with an infected person is at high risk of contracting
HIV because there are large quantities of the virus in blood, which is
then injected directly into the bloodstream.
Exact levels of risk for the various forms of sexual
activity are not known, but some sexual practices have higher risks
associated with them than others.
Vaginal intercourse
Transmission can occur in either direction during
unprotected vaginal intercourse. The risk of infection is greater for the
woman - the risk of infection passing from men to women during vaginal
intercourse is two to three times greater than the risk of it passing from
women to men. HIV can be absorbed into the woman's bloodstream during
unprotected vaginal intercourse via tears in the vaginal wall, genital
ulceration, an inflamed or traumatised cervix caused by cervicitis, or by
absorption through the membrane of the cervical canal. Also, because semen
remains in the vagina and around the cervix after intercourse, the risk of
transmission is increased. Until 1987, only 3% of American men who died of
AIDS had contracted the disease through heterosexual intercourse, whereas
27% of infected women had contracted it in this way (McEgan, 1987).
Anal intercourse
Transmission can occur in either direction, but the
receptive partner is at greater risk. Anal intercourse without a condom is
the highest risk sexual activity because the rectal lining is fragile and
prone to tearing, thus allowing easy access for infected blood and semen.
One San Franciscan study found that a person who has unprotected anal
intercourse is two-and-a-half times more likely to contract HIV than a
person who does not.
Oral sex
The risks of oral sex are unclear. Cuts, infections in
the mouth or throat, and gingivitis (infected gums) could pose some risk.
Clinic 275 advises that it is difficult to ascertain the safety of oral
sex and advises people not to allow semen to be ejaculated into the mouth.
The fluid expressed from the urethra before ejaculation is also likely to
be infectious. Similarly, menstrual blood contains high concentrations of
the virus and should also be avoided.
Clinic 275 suggests that oral sex is relatively safe if
ejaculation of potentially infected semen into the mouth is avoided. They
also recommend the avoidance of teeth cleaning and dental flossing before
oral sex.
Non-penetrative sex
Mutual masturbation and other forms of non-penetrative
sexual activity are safe provided that blood or sexual fluids do not enter
a partner's body.
When there is genital ulceration in either partner, or
when an uninfected male partner is uncircumcised, the risk of transmission
probably increases.
Approximately 30% of infants born to untreated HIV-positive women
are infected. It is not known at what stage of the pregnancy the foetus is
infected, but recent evidence supports the notion that the infant often
becomes infected during the birth process. Further research is being done
in this area.
Global perspective
The first cases of AIDS were reported in the USA in
1981, when young, homosexual men were diagnosed with Kaposi's sarcoma, an
unusual disease among young people. It is now estimated that several
million people are infected with HIV world-wide (see Statistics Section
for details). However, because of the differing abilities of affluent
nations and poor nations not only to respond to the epidemic, but also to
keep track of cases, current estimates may not be accurate and do not
reflect the potential impact on different countries. The largest pool of
infection is in Africa, where transmission predominantly occurs through
heterosexual contact and infected blood given in transfusions (10% of
infections - usually there are no blood-screening programs). Two-thirds of
the estimated global total of AIDS cases, and the majority of HIV-positive
people, are in this region. There is now the potential for rapid spread of
HIV through Asia and India.
The World Health Organisation (1991) estimated that the
distribution of HIV infection in the world is as follows:
- 60% in sub-Saharan Africa
- 30% in North America and Australia
- 6% in Europe
- 4% in Asia and the Middle East
- In addition, the socio-economic conditions and levels
of prostitution in some developing countries (e.g. Thailand) are
conducive to rapid spread of infection.
WHO estimates that HIV is spread in the following way:
- 60% transmitted through vaginal intercourse
- 15% through anal intercourse
- 10% through injecting drug use
- 10% perinatally (i.e. from mother to baby in the
uterus or during the birth process)
- 5% through contaminated blood and other injections
Australia
The first cases of AIDS in Australia were diagnosed in
1982. HIV and AIDS are most common in the eastern states, particularly in
Sydney, and are generally concentrated in urban areas. Transmission is
mainly through unprotected male-to-male anal intercourse and needle or
syringe sharing among injecting drug users.
One Australian study of risk factors for HIV has been
undertaken by Ross (1988). He found that the proportions of individuals,
both male and female, who had had homosexual or sex worker contact were
much lower than those expected (based upon levels found by Kinsey et al in
the 1950s). Levels of injecting drug use were found to be highest among
the 15-24 year age-group, with higher levels among males than females.
Estimated numbers of injecting drug users vary from 20,000 (Australian
Royal Commission of Inquiry into Drugs, 1980) to hundreds of thousands of
users in different categories of use (Drew & Taylor, 1988).
Nevertheless, the size and nature of the injecting drug user population
are very different in Australia compared to the USA. The numbers are
proportionately much smaller, and there is not the same representation of
people from extremely disadvantaged backgrounds. Thus the potential for
spread among heterosexuals is not as great as it is in the USA.
Infection levels among women who work as sex workers in
Australia are low and should remain low among those who do not inject
drugs.
See Statistics page
for South Australian details, and The
National Centre for HIV Epidemiology and Clinical Research for
Australian data.
Testing and counselling
Pre-test counselling
Informed consent
Post-test counselling
implications of negative result
implications of positive result
Preparing for possible positive
test result
Confidentiality
Advantages of testing
The test
The HIV antibody test is the blood test that determines
whether an individual has HIV antibodies. A positive test means that there
are antibodies and that HIV has established itself in the body. As
previously described, it can take as long as 3 months - the window period
- for antibodies to be produced. A negative test can mean that either HIV
is not present in the body, or that the body has not had sufficient time
to respond to the virus by producing antibodies.
It is important that people seeking testing have an
opportunity to explore the issues that may confront them with either a
positive or negative test result. Issues may include guarantees of
confidentiality, the need for support, explanation of the test, personal
issues (e.g. in relation to partners, insurance, safe sex practices, and
safe drug use).
Informed consent should be obtained for all medical
tests, and must be obtained before a HIV test is undertaken. Testing
without consent constitutes an assault (unless authorised by the law). The
person needs to be fully aware of the meaning of the test and its results,
the procedures, and potential consequences. Consent obtained by deceit,
withholding information, or giving misleading information does not
constitute informed consent.
It is important that test results are given face-to-face
by a medical practitioner or counsellor. The main aim of post-test
counselling is to ensure that the person understands the implications and
meaning of the results, and that follow-up is offered in the form of
further appointments or referral. Results should not be given by
telephone.
Implications of a negative test
A negative test result can provide reassurance and an
opportunity to discuss prevention through safe sex and safe drug use. It
is important to be aware that if exposure occurred less than 3 months ago
a repeat test will be necessary.
Implications of a positive test
Since reactions to the diagnosis of HIV infection
varies, it is important that the individual has access to counselling and
support from a person (counsellor, nurse or doctor) experienced in
HIV/AIDS issues. The doctor needs to check if there is a trusted support
person available, to discuss medical follow-up and treatments, provide
assurance of confidentiality, encourage notification of past and present
sexual partners, support lifestyle changes, arrange referral to other
support agencies where necessary, and arrange another appointment for
further counselling. When first confronted with a positive test result,
people frequently may not absorb much of the information they are given
and follow-up appointments are important.
The following needs to be taken into consideration by
the counsellor and the individual diagnosed with HIV infection:
the infection can be transmitted to others, and thus
there is a need for lifestyle changes,
social stigmatisation of people with HIV infection and
irrational, fear-based responses of others make it even more difficult to
come to terms with the infection.
AIDS combines several areas that are subject to enormous
taboos and heavy social conditioning in our society, namely:
- sexual behaviour and sexuality (and often
homosexuality);
- injecting drug use;
- death.
Individual reactions to a positive test result may
depend upon a number of factors such as:
Gay men
Reactions differ, depending on whether the individual:
- identifies with the gay community or has an
unrevealed association with men;
- engages in sexual activity, involving male and female
partners.
Blood or blood-product recipients
Some wish to distance themselves as "innocent
victims".
People who inject drugs
Reactions differ, depending on whether:
- the use is casual and under control or an addiction
problem;
- the person wishes to continue drug use, placing the
emphasis on non-sharing;
- the person wants to discontinue use, placing the
emphasis on social supports.
Sex industry workers
Reactions differ, depending on whether the person:
- is a female or male sex worker;
- injects drugs;
- identifies with the prostitute community or acts
independently;
- perceives a potentially positive role for herself or
himself as an educator in safe sex for clients.
Women
Reactions differ, depending on:
- socio-economic status;
- whether or not a woman has children or is pregnant.
Interpersonal relationships
Will infection destroy an existing relationship, or hinder
new ones?
What kinds of support does the person have?
There may be guilt or hostility relating to who infected
whom.
Does infection disclose unrevealed sexual relationships,
sexual orientation, or injecting drug use?
Likely response of lovers, family, friends.
Pre-existing psychological or intellectual problems
Infection may exacerbate the existing condition.
Intellectual disability may make the spread of infection
more difficult to prevent or increase the risk of unplanned pregnancy and
transmission to the baby.
Knowledge and preparation for a possible
positive result
Studies show that the less knowledge and preparation an
individual has, the greater the impact of the result will be.
This underlines the importance of pre-test counselling.
The most common initial reactions are extreme - severe
shock which may temporarily immobilise the individual, or an apparently
casual acceptance. The individual may deny the reality of the result for
several days, weeks, or longer. Issues, such as relationship difficulties,
self-blame, loss of self-esteem and/or loss of sexual libido may start to
arise later. There are, of course, similarities between coming to terms
with HIV and the process people go through when diagnosed with other fatal
diseases. The difference is that HIV can result in rejection by friends,
family, and health workers, and therefore social isolation. Thus, people
often hide their diagnosis. It is important that individuals are informed
of self-help and other groups available for HIV positive people.
Information about one person should not be disclosed to
another, except in the following circumstances:
- Where another person has a need to know (e.g. a
health service provider) - but it is essential to have the client's
consent in all situations.
- Where required by law (e.g. notifiable diseases).
HIV-positive people may need to be counselled about whom
they wish to tell - many breaches of confidentiality occur when
individuals unwisely tell acquaintances, or leave identifying client
documents around.
Health workers can use a range of strategies to protect
confidentiality (e.g. contacting clients only by a mechanism they have
approved).
- Access to appropriate treatments for HIV-positive
individuals early in the infection can delay the onset of AIDS and
prolong survival.
- The detection of infection at an asymptomatic stage
may avoid a range of severe physical and social complications that may
occur when infection is detected in an emergency situation (e.g. an
accident, in a hospital emergency room, or after admission to hospital
with advanced disease). Breaches of confidentiality and privacy are
more likely in these late stages, and there may not be sufficient time
for the individual to benefit from treatments, come to terms with the
illness, make any necessary practical living arrangements, or prevent
the further spread of infection.
- A negative test result can relieve anxiety after
perceived exposure to infection.
- A positive result can encourage the practice of safe
sex and safe drug use, preventing the spread of infection as well as
protecting the infected person from other STDs, or different strains
of HIV.
- Widespread testing helps to determine the extent and
distribution of infection, which in turn can assist in planning
support and prevention strategies.
- A positive result may affect a person's important
life decisions, for example, about whether or not to have children.
- Individuals may make other lifestyle changes that
improve their health status and life expectancy.
People have the right to make their own choices about
undergoing a test. If an individual chooses not to be tested, it is
important that he or she practises safe sex and injects drugs safely to
protect themselves as well as others. Individuals may not wish to be
tested because they have never been offered pre-test counselling.
Similarly, a more balanced community perception of HIV infection could
help individuals feel less hesitant. Confidentiality should ensure that
other people know an individual's status only if he or she tells them, and
it is important that people who fear a breakdown in confidentiality are
assured of this. People with positive test results need to be selective
about whom they tell. Discrimination on the grounds of HIV infection is
covered by anti-discrimination legislation, and is against the law,
although it can be difficult to prove. Insurance companies will require a
test before underwriting a substantial policy.
From a public health perspective, all individuals at
risk of HIV should be encouraged to have an HIV test.
Four blood tests are available:
- Enzyme immuno-assay; Enzyme linked immunosorbent assay
(EIA; ELISA)
- Western blot (WB)
- Immunofluorescent assay (IFA)
- Radio-immunoprecipitation assay (RIPA)
The most common approach is the use of an EIA test for
screening (the initial test) and a western blot for confirmation. It
usually takes 7 days for the results to be ready.
There are a wide range of medications that will slow the
progression of HIV infection:
Antiretroviral therapy - zidovudine (Retrovir or AZT) is
the most widely used and reduces mortality, illness, and the number of
opportunistic infections when given in combination with other agents such
as ddI or ddC. In Australia, anti-HIV medications are available to people
in the following circumstances:
- A person with a T4 count less than 500;
- Anyone with an AIDS-related condition;
- Someone with needle-stick injuries from a known
HIV-positive person.
The side-effects of zidovudine treatment can include
anaemia, vomiting, insomnia, and myalgia (muscle pain). However, these
side-effects are more common on high-dose regimes. The new low-dose
regimes have fewer side-effects.
Side-effects of ddI and ddC include inflammation of the
pancreas and damage to nerves.
Many new anti-HIV drugs have recently been introduced in
Australia. More information about these medications is available on the HIV
management page in the Diagnosis
and Management section for doctors.
Many of the opportunistic infections that occur with
AIDS can be treated with medications such as antibiotics, anti viral drugs
(aciclovir), and anti malarial medications.
Legal and ethical issues
In South Australia, HIV infection is a notifiable
disease, which means that medical practitioners are required by law to
notify the HIV Epidemiologist in the Public and Environmental Health
Service of the South Australian Health Commission.
Laws cover donor activities, including blood
transfusion.
Anti-discrimination laws apply to employment,
accommodation, education, and the provision of goods and services. The law
applies to any physical impairment, and probably includes asymptomatic HIV
infection.
The Australian Federation of AIDS Organisations (AFAO)
has defined safe sex in the following way:
Safe sex is any form of sex in which HIV does not pass
from the blood, semen, or vaginal fluids of one person directly into the
bloodstream of another person. (AFAO, 1991)
This definition is specific to HIV/AIDS and does not
attempt to deal with other STDs.
There is more information about safe sex available at
the Safe Sex and Condoms page.
HIV-positive people
In addition to providing general support, it is also
important to support HIV-positive people in preventing the spread of
infection. Counselling on safe sex practices so that individuals are clear
about what is and what is not safe, is imperative. Education about clean
needle and syringe use is important for people who choose to continue
injecting drugs. People should be referred to needle exchange programs.
Pre-test Counselling form "The HIV
antibody test"
(Provided to clients at Clinic
275)
See HIV Information in the Information
for Patients section. |
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