| The Biology of AIDS (Cont'd.) |
Information and graphics from BBC News
| THE PROGRESSION OF HIV |
| Office of HIV/AIDS Ministry Archdiocese of Atlanta 680 W. Peachtree St., NW Atlanta, GA 30308 Tel. (404) 885-7207 Irene Miranda, Director |
Early Stages
About half of people who contract HIV suffer flu-like symptoms within the first two to four weeks of
infection. These include fevers, fatigue and rashes, sore joints, headaches and swollen lymph nodes.
The graph above shows the course of a typical HIV infection over time. The CD4+ cell count is the
number of CD4+ cells per cubic millimeter of blood, and decreases as the virus progresses.
A healthy immune system has 600 – 1200 cells per cubic millimeter of blood. If this drops as low as
200, the patient is considered to have AIDS.
The "viral load" is the number of virus particles per milliliter of blood. Initially, this peaks as the virus
replicates rapidly in the bloodstream.
Within six to twelve weeks of infection, the body starts producing a specific type of antibody, or
disease-fighting protein.
While not very effective in fighting the virus, the antibody is a reliable indicator of whether someone is
infected.
The most common HIV test detects the antibodies. This means that a person may infect others as
soon as he or she becomes infected, but will not test positive for several weeks.
Some people with HIV may live for several years before developing Aids, feeling healthy and with no
outward signs of the virus.
Others may suffer symptoms such as weight loss, fevers and sweats, frequent yeast infections,
rashes and short-term memory loss while living with HIV.
About half of people who contract HIV suffer flu-like symptoms within the first two to four weeks of
infection. These include fevers, fatigue and rashes, sore joints, headaches and swollen lymph nodes.
The graph above shows the course of a typical HIV infection over time. The CD4+ cell count is the
number of CD4+ cells per cubic millimeter of blood, and decreases as the virus progresses.
A healthy immune system has 600 – 1200 cells per cubic millimeter of blood. If this drops as low as
200, the patient is considered to have AIDS.
The "viral load" is the number of virus particles per milliliter of blood. Initially, this peaks as the virus
replicates rapidly in the bloodstream.
Within six to twelve weeks of infection, the body starts producing a specific type of antibody, or
disease-fighting protein.
While not very effective in fighting the virus, the antibody is a reliable indicator of whether someone is
infected.
The most common HIV test detects the antibodies. This means that a person may infect others as
soon as he or she becomes infected, but will not test positive for several weeks.
Some people with HIV may live for several years before developing Aids, feeling healthy and with no
outward signs of the virus.
Others may suffer symptoms such as weight loss, fevers and sweats, frequent yeast infections,
rashes and short-term memory loss while living with HIV.
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DISCLAIMER
Considering the nature of
the Internet, the
Archdiocese of Atlanta’s
HIV/AIDS Ministry cannot
take responsibility for the
contents of sites that may
be accessed through these
web pages. These links do
not represent, necessarily,
the position of the
Archdiocese of Atlanta’s
HIV/AIDS Ministry, much
less an archdiocesan
endorsement of a
particular site.
A mature selective criteria
on the part of the user is
necessary when using the
Internet. In general, we
strongly recommend
parents to supervise their
children while surfing the
Net. While avoiding
censorship, we make every
effort to post suitable
information and links
which may be of value to
understand HIV/AIDS. It is
the user's responsibility to
decide whether or not a
particular site is
appropriate, according to
the user’s personal criteria.
Considering the nature of
the Internet, the
Archdiocese of Atlanta’s
HIV/AIDS Ministry cannot
take responsibility for the
contents of sites that may
be accessed through these
web pages. These links do
not represent, necessarily,
the position of the
Archdiocese of Atlanta’s
HIV/AIDS Ministry, much
less an archdiocesan
endorsement of a
particular site.
A mature selective criteria
on the part of the user is
necessary when using the
Internet. In general, we
strongly recommend
parents to supervise their
children while surfing the
Net. While avoiding
censorship, we make every
effort to post suitable
information and links
which may be of value to
understand HIV/AIDS. It is
the user's responsibility to
decide whether or not a
particular site is
appropriate, according to
the user’s personal criteria.
INFECTION RISKS
AIDS develops
As the immune system becomes damaged, it loses its capacity to fight disease and infections can
become life-threatening.
People who are HIV positive are more susceptible to widespread diseases such as tuberculosis,
malaria, pneumonia and shingles. Their vulnerability increases as their CD4+ cell count drops.
HIV patients also become vulnerable to a host of "opportunistic infections". These are infections
caused by common bacteria, funguses and parasites which healthy bodies can fight, but which can
cause illness and in some cases death in people with damaged immune systems.
Some of these are likely to occur at higher CD4+ counts than others. Most become active below CD4+
counts of 200, the point where AIDS develops.
If full medical care is available, patients can be given drugs which treat and guard against some of
these infections, although these are sometimes expensive and can cause side effects.
As the immune system becomes damaged, it loses its capacity to fight disease and infections can
become life-threatening.
People who are HIV positive are more susceptible to widespread diseases such as tuberculosis,
malaria, pneumonia and shingles. Their vulnerability increases as their CD4+ cell count drops.
HIV patients also become vulnerable to a host of "opportunistic infections". These are infections
caused by common bacteria, funguses and parasites which healthy bodies can fight, but which can
cause illness and in some cases death in people with damaged immune systems.
Some of these are likely to occur at higher CD4+ counts than others. Most become active below CD4+
counts of 200, the point where AIDS develops.
If full medical care is available, patients can be given drugs which treat and guard against some of
these infections, although these are sometimes expensive and can cause side effects.
Anti-HIV drugs
1. Entry inhibitors bind to the proteins
on the outside of the HIV virus and
stop it from entering the target cell
(Fuzeon only).
2. Nucleoside reverse transcriptase
inhibitors stop HIV copying its genes
into the cell. Nucleosides are the
building block for genes. The drugs
supply faulty versions of these building
blocks (drugs include abacavir, AZT,
ddI, 3TC).
3. Non-nucleoside reverse
transcriptase inhibitors also block the
gene-copying process. They disable
the enzyme that controls it (drugs
include nevirapine and efavirenz).
4. Protease inhibitors disable protease,
an enzyme which plays a key role in
the formation of the new virus (drugs
include amprenavir, lopinavir,
ritonavir, nelfinavir).
on the outside of the HIV virus and
stop it from entering the target cell
(Fuzeon only).
2. Nucleoside reverse transcriptase
inhibitors stop HIV copying its genes
into the cell. Nucleosides are the
building block for genes. The drugs
supply faulty versions of these building
blocks (drugs include abacavir, AZT,
ddI, 3TC).
3. Non-nucleoside reverse
transcriptase inhibitors also block the
gene-copying process. They disable
the enzyme that controls it (drugs
include nevirapine and efavirenz).
4. Protease inhibitors disable protease,
an enzyme which plays a key role in
the formation of the new virus (drugs
include amprenavir, lopinavir,
ritonavir, nelfinavir).
Since the start of the HIV epidemic, a series of drugs have been developed which significantly prolong
the lives of people who are HIV positive. Called "antiretroviral drugs", they block the virus's ability to
replicate.
They can delay the onset of Aids by slowing the loss of patients' CD4+ cells, but they are not a cure.
There are four main classes of drugs, operating at different points in the HIV cycle, as shown on the
diagram above.
A wide range of side effects are associated with antiretroviral therapy. Many patients experience
nausea, vomiting, headaches, fatigue, rashes, diarrhea, insomnia, stomach pain and numbness
around the mouth. Inflammation of the pancreas, damage to the liver and nerves, changes in body
shape, anaemia and muscle pain can also result from some of the drugs.
Antiretroviral drugs should be taken in combination. Usually three different drugs, from at least two
different classes, are used at once.
As HIV mutates, some versions of the virus become resistant to drugs. The chances of keeping it in
check are therefore much higher if several drugs are used.
Pill-taking regimes can be complicated and involve taking tablets at very specific times during the day.
If such programs are not followed properly, the likelihood of the virus growing resistant to the drugs
increases.
Some people are now becoming infected with strains of the virus which are already resistant to
particular drugs.
the lives of people who are HIV positive. Called "antiretroviral drugs", they block the virus's ability to
replicate.
They can delay the onset of Aids by slowing the loss of patients' CD4+ cells, but they are not a cure.
There are four main classes of drugs, operating at different points in the HIV cycle, as shown on the
diagram above.
A wide range of side effects are associated with antiretroviral therapy. Many patients experience
nausea, vomiting, headaches, fatigue, rashes, diarrhea, insomnia, stomach pain and numbness
around the mouth. Inflammation of the pancreas, damage to the liver and nerves, changes in body
shape, anaemia and muscle pain can also result from some of the drugs.
Antiretroviral drugs should be taken in combination. Usually three different drugs, from at least two
different classes, are used at once.
As HIV mutates, some versions of the virus become resistant to drugs. The chances of keeping it in
check are therefore much higher if several drugs are used.
Pill-taking regimes can be complicated and involve taking tablets at very specific times during the day.
If such programs are not followed properly, the likelihood of the virus growing resistant to the drugs
increases.
Some people are now becoming infected with strains of the virus which are already resistant to
particular drugs.
Also, see the GLOSSARY OF HIV AND AIDS TERMS
