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Transmission of HIV Virus
Transmission of the virus occurs:
Through sexual contact -- including oral, vaginal, and anal sex
Through blood -- via blood transfusions or needle sharing
From mother to child -- a pregnant woman can transmit the virus to her fetus through their shared blood
circulation, or a nursing mother can transmit it to her baby in her milk
1. Sexual transmission: The majority of HIV infections
are acquired through unprotected sexual relations between partners,
one of whom has HIV. Sexual transmission occurs with the contact
between sexual secretions of one partner with the rectal, genital or
oral mucous membranes of another. Unprotected receptive sexual acts
are riskier than unprotected insertive
sexual acts, with the risk for transmitting HIV from an infected
partner to an uninfected partner through unprotected insertive anal
intercourse greater than the risk for transmission through vaginal
intercourse or oral sex. Oral sex is not without its risks as HIV is
transmissible through both insertive and receptive oral sex. The
risk of HIV transmission from exposure to saliva is considerably
smaller than the risk from exposure to semen; contrary
to popular belief. Sexually transmitted infections (STI) increase
the risk of HIV transmission and infection because they cause the
disruption of the normal epithelial barrier by genital ulceration
and/or microulceration; and by accumulation of pools of
HIV-susceptible or HIV- infected cells (lymphocytes and macrophages)
in semen and vaginal secretions.
2. Mother-to-child transmission (MTCT): The
transmission of the virus from the mother to the child can occur in
utero during the last weeks of pregnancy and at childbirth. In the
absence of treatment, the transmission rate between the mother to
the child during pregnancy, labor and delivery is 25%. However, when
the mother has access to antiretroviral therapy and gives birth by
caesarean section, the rate of transmission is just 1%. A
number of factors influence the risk of infection, particularly the
viral load of the mother at birth (the higher the load, the higher
the risk). Breastfeeding increases the risk of transmission by 10–15%.
This risk depends on clinical factors and may vary according to the
pattern and duration of breast-feeding.
3 Through Blood: HIV can be transmitted to a person
receiving blood or organs from an infected donor. Sharing and reusing syringes contaminated with
HIV-infected blood represents a major risk for infection with not
only HIV, but also hepatitis B and hepatitis C. Needle sharing is
the cause of one third of all new HIV-infections and 50% of
hepatitis C infections in Northern America, China, and Eastern
Europe. The risk of being infected with HIV from a single prick with
a needle that has been used on an HIV infected person though is
thought to be about 1 in 150. However, according to the WHO, the
overwhelming majority of the world population does not have access
to safe blood and "between 5% and 10% of HIV infections
worldwide are transmitted through the transfusion of infected blood and blood products".
AIDS Symptoms
HIV virus causing AIDS enters the blood and quickly penetrates white cells. Then they program the white cells, after which there is often little or no trace of
the AIDS virus at all. This situation usually lasts for six to twelve weeks. During this time the person is free of HIV or AIDS symptoms and antibody tests for AIDS and HIV are negative.
First Symptoms of AIDS Illness (HIV Infection): First thing that starts developing in a flu like illness, which may look like glandular fever with swollen glands in the neck and armpits. At this stage the blood test will usually become positive as it picks
up the tell-tale antibodies. Most people do not realise what is happening, although when they later develop AIDS they look back and remember it clearly. Most people have produced antibodies in about twelve weeks.
Latent infection: The person in this stage has a positive HIV test. The virus often seems to disappear completely from the blood again. At least nine out of ten who see these HIV and AIDS symptoms will develop further
problems. Without use of the latest therapies:50% with HIV develop AIDS in ten years, 70% with HIV develop AIDS in fourteen years. Of those with AIDS, 94% are dead in five years
The next HIV AIDS symptoms stage begins when the immune ystem starts to break down. This is often preceded by subtle mutations in the virus, during which it becomes
more aggressive in damaging white cells. Several glands in the neck and armpits may swell and remain swollen for more than three months without any explanation. This is known as persistent generalised lymphadenopathy
(PGL).
Early HIV Virus Progression
As the HIV disease progresses, the person starts
showing up other AIDS symptoms. A simple boil or warts may spread all over the body. The mouth may become infected
by thrush (thick white coating), or may develop some other problem. Dentists are often the first to be in a position to make the diagnosis. People may develop severe shingles (painful blisters in a band of red
skin), or herpes. They may feel overwhelmingly tired all the time, have high temperatures, drenching night sweats, lose more than 10% of their body weight, and
have diarrhoea lasting more than a month. No other cause is found and a blood test will usually be positive. Some used to call this stage ARC, or AIDS related complex.
Late HIV Illness
The AIDS Symptoms: The final stage is AIDS. Most of the immune system is intact and the body can deal with most infections, but one or two more unusual infections become almost impossible for the body to get rid of without medical
help, usually intensive antibiotics. These infections can be a nightmare for doctors and
patients. The desperate struggle is to find the new germ, identify it, and give the right drug in huge doses to kill it. The germ may be hiding deep in a lung
requiring a tube (bronchoscope) to be put down the windpipe into the lung to get a sample. The person is sedated for this. It may be hiding in the fluid covering the brain and spinal cord, requiring a needle to be put
into the spine (lumbar puncture). It may be hiding in the brain itself. It may hide in the liver or gall-bladder or bowel. It can hide anywhere.
WHO disease staging system for HIV infection
In 1990, the World Health Organization (WHO) grouped these
infections and conditions together by introducing a staging system
for patients infected with HIV-1. An update took place in September
2005. Most of these conditions are opportunistic infections
that are easily treatable in healthy people.
Stage I: HIV disease is asymptomatic and not categorized as AIDS
Stage II: includes minor mucocutaneous manifestations and recurrent upper respiratory tract infections
Stage III: includes unexplained chronic diarrhea for longer than a
month, severe bacterial infections and pulmonary tuberculosis
Stage IV: includes toxoplasmosis of the brain, candidiasis of the
esophagus, trachea, bronchi or lungs and Kaposis sarcoma; these
diseases are indicators of AIDS.
HIV Test
Approximately half of those infected with HIV do not know
their HIV status until an AIDS diagnosis is made with an HIV test.
Donor blood and blood products used in medicine and medical research
are screened for HIV using such a test. Typical HIV tests, including
the HIV enzyme immunoassay and the Western blot assay, detect HIV
antibodies in serum, plasma, oral fluid, dried blood spot or urine
of patients. However, the window period (the time between initial
infection and the development of detectable antibodies against the
infection) can vary. This is why it can take 6-12 months to
seroconvert and test positive. Commercially available tests to
detect other HIV antigens, HIV-RNA, and HIV-DNA in order to detect
HIV infection prior to the development of detectable antibodies are
available. For the diagnosis of HIV infection these assays are not
specifically approved, but are nonetheless routinely used in developed countries.
Prevention
During a sexual act, only male or female condoms can reduce
the chances of infection with HIV and other STDs and the chances of
becoming pregnant. The best evidence to date indicates that condom
use reduces the risk of heterosexual HIV transmission by
approximately 80%. The male latex condom, if used correctly without
oil-based lubricants, is the single most efficient available
technology to reduce the sexual transmission of HIV and other sexually transmitted infections.
Medical workers who follow universal precautions or body
substance isolation such as wearing latex gloves when giving
injections and washing the hands frequently can help prevent infection of HIV.
All AIDS-prevention organizations advise drug-users not
to share needles and other material required to prepare and take
drugs (including syringes, cotton balls, the spoons, water for
diluting the drug, straws, crack pipes, etc). It is important that
people use new or properly sterilized needles for each injection.
Information on cleaning needles using bleach is available from
health care and addiction professionals and from needle exchanges.
Many nations have decriminalized needle possession and made it
possible to buy injection equipment from pharmacists without a prescription.
Treatment
There is currently no vaccine against HIV or AIDS, the only
known methods of prevention are based on avoiding exposure to the
virus or, failing that, on antiviral treatment directly after a
highly significant exposure. Also, not a single case has been
documented in which systemic HIV infection has been cured and even
on the theoretical level, no plausible way of eradicating HIV
infection has so far been found. Treatment for HIV can suppress
viral replication to a degree sufficient to apparently stop disease
progression, but success is critically dependent on the patients
ability to keep perfect adherence to their drug schedule, which many
people will fail to achieve. Also, modern combination therapy has
been around for merely ten years, so it is not presently known
whether treatment failure or inacceptable long-term side effects can
be avoided in the majority even of perfectly compliant patients over
a time-span of potentially many decades. However, it is known
that without major medical and scientific breakthroughs, HIV will
not have any problem surviving combination therapy for said decades.
Still, in western countries, most patients survive many years
following diagnosis because of the availability of the highly active
antiretroviral therapy (HAART). In the absence of HAART,
progression from HIV infection to AIDS occurs at a median of between
nine to ten years and the median survival time after developing AIDS
is only 9.2 months. HAART dramatically increases the time from
diagnosis to death, and treatment research continues. Current
optimal HAART options consist of combinations (or
"cocktails") consisting of at least three drugs belonging
to at least two types, or "classes," of
anti-retroviral agents. Typical regimens consist of two nucleoside
analogue reverse transcriptase inhibitors (NRTIs) plus either a
protease inhibitor or a non-nucleoside reverse transcriptase
inhibitor (NNRTI). This treatment is frequently referred to as HAART
(highly-active anti-retroviral therapy).
Anti-retroviral treatments, along with medications
intended to prevent AIDS-related opportunistic infections, have
played a part in delaying complications associated with AIDS,
reducing the symptoms of HIV infection, and extending patients life
spans. Over the past decade the success of these treatments in
prolonging and improving the quality of life for people with AIDS
has improved dramatically.
Various forms of alternative medicine have been used to
try to treat symptoms or to try to affect the course of the disease
itself, although none are a substitute for conventional treatment.
Stigma
AIDS stigma exists around the world in a variety of ways,
including ostracism, rejection, discrimination and avoidance of HIV
infected people; compulsory HIV testing without prior consent or
protection of confidentiality; violence against HIV infected
individuals or people who are perceived to be infected with HIV.
Often, AIDS stigma is expressed in conjunction with one or more
other stigmas, particularly those associated with homosexuality,
bisexuality, and intravenous drug use, and the quarantine of HIV
infected individuals. Those most likely to hold misconceptions about
HIV transmission and to harbor HIV/AIDS stigma are people with high
levels of religiosity, conservative political ideology and less educated people.
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