AIDS is obviously proving to be one of the major killer of our time. The fate of most such viral
infections is to make peace with their hosts
- and to become less life-threatening. This is what has happened to the equivalent of HIV in our
cousins - for example. However it seems possible that the AIDS epipdemic could get much worse
before it gets better. If medicine fails to come up with an adequate response to it, that is. The
HIV virus has done a good job of learning to hide from the immune system. However it has not done
a very good job of mastering its own transmission - in particular it is poor at spreading through
coughs and sneezes, and doesn't yet know how to make boils and warts. I suspect the virus would
find it advantageous to explore these routes at some stage - even if it means activating the
host's defenses more than usual.
--
__________
|im |yler timtyler.orgtimtyler.orgOpen ↗ [email hidden] Remove lock to
reply.
I don't think it is accurate to state AIDS hasn't mastered its own
transmission if one means by how it is transmitted. I've included a few
articles to read. The first points out how AIDS is and isn't
transmitted. Apparently you disagree but authoritative sources state
AIDS is not caused by coughing or sneezing. The second article talks
about symptoms of AIDS and as you can see the list is long. But right
under "early disease progression" it states warts and boils may develop
over the body. Rather than these warts and boils being modes of
transmission they are symptoms..unless you want to bite off a boil with
your teeth and suck out the pus.
It seems to me there needs to be a widespread effort at education and
funding as well as political pressure to outlaw human hunting of
chimpanzees, monkeys, etc. Apparently the reason why SIV in monkeys and
chimpanzees is not lethal is because they have had tens of thousands of
years to adapt to it. We humans have not had that time.
Reading about what AIDS can do to the human body I don't see how it
could get much more lethal. The modes of transmission for this disease
is not like smallpox. I suppose it could mutate into a deadlier more
strain i.e. more severe symptoms and killing people quicker...but the
fluids and in rare cases breast milk.
Michael Ragland
AIDS is short for Acquired Immune Deficiency Syndrome. It is a disease
that damages the body's immune system (the system that helps fight off
illnesses). When a person's immune system is damaged, he or she is more
likely to become sick from illnesses that might not hurt a person who
has a healthy immune system. The person's body with AIDS cannot defend
itself, and it isn't able to fight off infections and some kinds of
tumors.
Although AIDS is contagious, it is much harder to get than a cold or the
flu. In fact, it's very important to know how people don't get AIDS: you
can't get it from hugging, kissing, or holding hands. You can't get it
from sitting next to someone who has AIDS or by being in school with
someone who has AIDS. It's not spread by coughing or sneezing, and it's
not carried by mosquitoes or other bugs.
AIDS is transmitted when the Human Immunodeficiency Virus (HIV) is
spread from the inside of an infected person's body into the inside of
another person's body. The germ can do this in three main ways:
infected person's blood, a man's semen, and secretions from the vagina
of a woman. Some doctors and researchers think that HIV can get into the
bloodstream through cuts or sores on the vagina, penis, rectum (anus),
and possibly even the mouth. Some of these cuts can be so small that a
person might not even know they were there.
When needles or syringes are shared with an HIV-infected person. People
who inject drugs are at risk of infecting themselves with HIV - this
includes intravenous drugs (drugs that are injected into a vein) as well
as injected steroids. Many people who use needles to take drugs share
the needles with other drug users. When a person infected with HIV does
this, the virus can be spread to another person through tiny amounts of
blood attached to the needle.
Quoted message said:From mother to child, either before or during the child's birth. A
newborn baby can get HIV from his mother if she has the virus in her
body. This can happen before the baby is born or while the baby is being
delivered. In rare cases, mothers can pass HIV on through breastfeeding.
Sometimes, the mother doesn't know that she has HIV until she is already
pregnant. Luckily, scientists have found that pregnant women with HIV
who receive treatment for HIV are much less likely to spread the virus
to their babies when they are born. Babies who are born to HIV-infected
mothers are also given medicine to prevent HIV infection.
In the past, some people became infected with HIV from blood
transfusions. This is very rare today - since 1985, blood has been
examined for HIV. If there is any evidence of the virus, the blood is
thrown away. The blood supply in the United States is very safe.
doesn't have to worry about having HIV or AIDS. There is no way for
someone to tell if a person is infected with HIV, so if person does
If you have more questions about AIDS, talk to an adult you trust - your
doctor, your parents, a health teacher, or another teacher. Don't rely
on your friends for information about AIDS because they may not know the
right answers. If you feel too embarrassed to talk to an adult you know,
there are many people you can talk to without having to say who you are.
Check your telephone book for AIDS hotline numbers or health clinics.
For more detailed information on AIDS, read our kids' article HIV and
AIDS.
Updated and reviewed by: Cecilia DiPentima, MD
Date reviewed: June 2002
Originally reviewed by: Neil Izenberg, MD, and Joel Klein, MD
Note: This chapter of The Truth about AIDS by Dr Patrick Dixon is the
original text as published by Kingsway in 1994 updated 2002 and may be
reproduced with acknowledgment.
First signs of illness
The first thing that happens after infection is that many people develop
a flu-like illness. This may be severe enough to look like glandular
fever with swollen glands in the neck and armpits, tiredness, fever and
night sweats. Some of those white cells are dying, virus is being
released, and for the first time the body is working hard to make
correct antibodies. At this stage the blood test will usually become
positive as it picks up the tell-tale antibodies.
This process of converting the blood from negative to positive is called
`sero-conversion´. 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
Then everything settles down. The person now has a positive test, and
feels completely well. The virus often seems to disappear completely
from the blood again. However, during this latent phase, HIV can be
found in large quantities in lymph nodes, spleen, adenoid glands and
tonsils. We do not know how many people will go on to the next stage. As
we saw in an earlier chapter, at first doctors thought it might only be
one in ten, then two or three out of ten. Now it looks as though at
least nine out of ten will develop further problems.
San Francisco studies show that in developed countries, without use of
the latest therapies, 50% with HIV develop AIDS in ten years, 70% in
fourteen years. Of those with AIDS, 94% are dead in five years. The rate
of progression can be much faster in those with weakened immunity from
other causes---drug users or those in developing countries, for
example. It can be far slower in those on various treatments.
Most scientists and doctors are convinced that if we follow up infected
people for long enough---maybe for twenty years or more---then all or
nearly all will die of AIDS, unless they have died of something else in
the meantime such as a heart attack or cancer. How long can someone live
before some infection triggers production of more virus and death of
more white cells?
The next stage begins when the immune system 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 disease progression
As the disease progresses, the person develops other conditions related
to AIDS. 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.
You can easily panic reading a list of symptoms like this because all of
us tend to read about diseases and think instantly we've got them.
Chronic diarrhoea does not mean you have AIDS. Nor do weight loss, high
temperatures, tiredness and swollen glands. These things can be
particularly common in many developing countries.
At the moment in many countries there is an epidemic of viral illnesses
which cause fevers, tiredness, rashes and other symptoms that last a
long time, always go away completely, and have nothing to do with AIDS.
(STD) or genito-urinary medicine (GUM) if you are unsure.
Late HIV illness---AIDS
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.
Chest infections are common
The most common infection is a chest infection. A twenty-three-year-old
man walks into his doctor's office with a chest infection not responding
to antibiotics. He is flushed and has a high temperature. He has been
increasingly short of breath with a dry cough for several weeks. He
becomes breathless and has an emergency chest X-ray. The X-ray is
strange. No one has seen anything like it before. Could this be AIDS?
Samples are taken from the lung. The man is rushed to intensive care and
is too ill to ask if he would agree to a blood test. Within two days he
is dead. A strange germ is found in his lung: pneumocystis carinii. This
is incredibly rare except in AIDS.
He may or may not be reported as a statistic to the centre collecting
information on AIDS. This is voluntary and doctors are busy. If he had
died a day or two earlier, the cause of death would have been thought to
be pneumonia. Yet another silent victim, unnoticed and unrecorded. Our
statistics may be incomplete, and remember, no test was done for HIV.
He was unlucky. Average life expectancy if you develop your first
pneumocystis pneumonia is just over two years. 78% survive the first
episode, only 40% survive the second. You could live for over three
years, or you might be dead in three months. Each new chest infection
could be your last. Often people seem only an hour or two from death,
then pull around, recover completely, and go home for several months
until the next crisis.
We know that eighty-five out of a hundred people with these chest
infections in Western nations are infected with pneumocystis carinii,
but many are infected with several things at once. Worldwide, the
commonest HIV-related chest infection is tuberculosis. As HIV spreads,
TB is on the increase, with possibly a million extra cases a year at
present as a result of HIV. Latent TB infection is common in the general
population. HIV damage to CD4 white cells allows reactivation, rapid
deterioration and death.
Damage to nervous system
Half of the people with AIDS will develop signs of brain impairment or
nerve damage during their illness. In one person out of ten it is the
first symptom. HIV itself seems to attack, damage and destroy brain
cells of the majority of people with AIDS who survive long enough.
The virus is probably carried into the brain by special white cells
called macrophages, which then produce more virus there. Brain cells
have a texture on their surfaces similar to CD4 white cells which
enables the virus to latch on and enter.
The damage happens gradually and often is not noticed until a
significant part of the brain has been destroyed: a brain scan shows a
shrunken appearance with enlarged cavities. The signs can be threefold:
difficulties in thinking, difficulties in co-ordinating balance and
moving, and changes in behaviour. Sometimes the problems are caused by
other infections spreading throughout the body, or by tumours, all
brought on by AIDS.
Brain damage affects children as well. In one study, sixteen out of
twenty-one children with AIDS developed progressive brain destruction
(encephalopathy). But any part of the nervous system can be damaged in
adults or children, not just the brain, and AIDS can mimic just about
any other disease of nerves.
The 1993 AIDS Surveillance Case Definition of the U.S. Centers for
Disease Control and Prevention A diagnosis of AIDS is made whenever a
person is HIV-positive and:
he or she has a CD4+ cell count below 200 cells per microliter OR his or
her CD4+ cells account for fewer than 14 percent of all lymphocytes OR
that person has been diagnosed with one or more of the AIDS-defining
illnesses listed below.
AIDS-Defining Illnesses
Candidiasis of bronchi, trachea, or lungs (see Fungal Infections)
Candidiasis, esophageal (see Fungal Infections) Cervical cancer,
invasive‡ Coccidioidomycosis, disseminated (see Fungal Infections)
Cryptococcosis, extrapulmonary (see Fungal Infections)
Cryptosporidiosis, chronic intestinal (>1 month duration) (see Enteric
Diseases) Cytomegalovirus disease (other than liver, spleen, or lymph
nodes) Cytomegalovirus retinitis (with loss of vision) Encephalopathy,
HIV-related† (see Dementia) Herpes simplex: chronic ulcer(s) (>1 month
duration) or bronchitis, pneumonitis, or esophagitis Histoplasmosis,
disseminated (see Fungal Infections) Isosporiasis, chronic intestinal
(>1 month duration) (see Enteric Diseases) Kaposi's sarcoma Lymphoma,
Burkitt's Lymphoma, immunoblastic Lymphoma, primary, of brain (primary
central nervous system lymphoma) Mycobacterium avium complex or disease
caused by M. Kansasii, disseminated Disease caused by Mycobacterium
tuberculosis, any site (pulmonary‡ or extrapulmonary†) (see
Tuberculosis) Disease caused by Mycobacterium, other species or
unidentified species, disseminated Pneumocystis carinii pneumonia
Pneumonia, recurrent(see Bacterial Infections) Progressive multifocal
leukoencephalopathy Salmonella septicemia, recurrent (see Bacterial
Infections) Toxoplasmosis of brain (encephalitis) Wasting syndrome
caused by HIV infectionAdditional Illnesses That Are AIDS-Defining in
Children, But Not Adults
Multiple, recurrent bacterial infections† (see Bacterial Infections)
Lymphoid interstitial pneumonia/pulmonary lymphoid hyperplasia
Children with HIV
Worldwide, over 3 million children have HIV infection and half a million
die every year. Altogether, 83% of children with HIV will show some
kind of abnormality in their white cells, or will have symptoms, by the
time they are six months old. Problems seen can include large lymph
nodes, enlarged liver and spleen, failure to thrive (small for age),
small head, ear infections, chest infections, unexplained fever,
encephalopathy (brain deterioration).
Of those showing symptoms within the first year of life, half die before
the age of three.
However, with improved treatments children are surviving longer. A
common pattern is beginning to emerge of a child who becomes unwell in
the first year or two of life with different chronic or acute
infections, yet with treatment carries on for many years, possibly even
into adolescence with many ups and downs. Pain and other symptoms are
often overlooked in these children.
Blood tests are often confused by the presence after birth of the
mother's own antibodies.
All babies of infected mothers will test positive for around the first
year, whether infected or not. Most babies who test positive at birth
turn out to be uninfected. The greatest risk to the baby is the birth
process itself and breast milk. Dramatic reductions in infection
rates can be made if the mother is given anti-viral medication before
and immediately after birth. This is one of the most appropriate
occasions to use anti-viral drugs in the poorest nations. But it
should always be done under strict medical supervision.
There is a very slight risk that children who later test negative may
still carry HIV. If first infected in the womb, the child may regard HIV
as part of itself and not react to it. We are still in the early stages
of learning about HIV in children.
Skin rashes and growths
The majority of people with AIDS develop skin problems which are usually
an exaggeration of things common to most people, such as acne and rashes
of various kinds. Cold sores and genital herpes may develop, or warts.
Athlete's foot in severe forms, ringworm and thrush are common. Rashes
due to food allergy are also common---no one knows why. Hair frequently
falls out. Drug rashes frequently occur, often due to life-saving
co-trimoxazole used for treatment or prevention of the pneumocystis
carinii pneumonia.
Kaposi's sarcoma develops in up to a quarter of the people with AIDS
(depending on the country and route of infection). This produces blue or
red hard painless patches on the skin, often on the face. In the
majority of these people it is the first sign of AIDS. Tumours can
spread to lymph nodes, gut lining and lungs where they can be confused
with pneumocystis pneumonia. The growths may be caused by a second virus
that is allowed to grow more easily if you have AIDS. Treatment consists
mainly of radiotherapy and chemotherapy, including injections of the
lesions.
Because it often affects the face or may be visible elsewhere on the
body and is so distinctive, people who develop Kaposi's sarcoma often
feel especially vulnerable. In fact people usually live longer if they
first develop this tumour than if they first develop a pneumonia.
Kaposi's sarcoma is less common in drug users with AIDS, presumably
because it is caused by a second virus also found in , which is then
activated by HIV.
The other common cancer is a tumour (lymphoma) which develops in the
brain or elsewhere in the body.
Problems in gut, eyes and other organs
Almost all people with AIDS have stomach problems from strange
infections and cancers caused by AIDS and HIV attacking the gut
directly. All three cause food to be poorly digested resulting in
diarrhoea and weight loss. Stool samples can be examined or samples can
be taken from within the gut using special tubing (endoscopy) to see if
there is a second treatable infection in addition to HIV.
AIDS can also seriously affect sight in up to a quarter of all those
with HIV by allowing an infection of the back of the eye (retinitis).
This is usually caused by cytomegalovirus and is sometimes amenable to
treatment. In addition, the virus can cause damage to other organs of
the body such as the heart.
Changing disease pattern in adults
In different parts of the world, AIDS tends to have its own
characteristics. This may be due to the pattern of other illnesses
present in different communities, which explains why TB is the commonest
cause of death from AIDS in Africa and Asia. Different patterns may be
related to different co-factors ( compared to drug injectors, for
example), viral differences or possibly genetic differences.
However, patterns are changing. For example, the incidence of Kaposi's
sarcoma is falling among with HIV in a number of countries, while it is
rising among drug users. Some of these changed patterns are because of
altered treatments; others are due to other factors.
As survival times have increased, other problems have emerged which are
far more difficult to treat. These include blindness due to
cytomegalovirus, progressive multifocal leucoencephalopathy (weakness,
muscle wasting, difficulty thinking), cryptosporidiosis (causes various
infections), mycobacterium infections and cryptococcal meningitis.
In addition, as we have seen, advanced Kaposi's sarcoma can bring its
own problems, with lung involvement causing shortness of breath and
triggering chest infections, gut involvement causing obstruction or
sudden bleeding, and with blockage of lymphatic drainage causing swollen
limbs or face, skin ulceration and infection.
In a quarter of those dying with AIDS, the exact cause of death may be
difficult to establish, with profound weakness, loss of weight and
multi-system failure. Many infections can be chronic, low grade and
difficult to diagnose, and when diagnosed can be hard to treat. Indeed,
post-mortem examinations show that half of all HIV-related diseases
found at autopsy have not been diagnosed during life.
In the early days in many countries, those with AIDS often spent a long
time in hospital as doctors battled to get to grips with the complex
spectrum of illnesses. Now people with AIDS are usually able to spend
more time at home, with many treatments given in clinics or in the home.
However, many have multiple problems and need practical help, backed by
nursing care and symptom control, to stay at home in comfort and in
control of their own lives. Later on in this book we will look at the
practicalities of setting up community care programmes.
Many people who are ill are now opting not to have every symptom
investigated, when the price is valuable time spent in hospital,
unpleasant tests, and treatments that may have side effects.
AIDS diagnosis in developing nations
In developing countries it can be hard to make an accurate diagnosis of
AIDS because of the lack of HIV testing facilities. The World Health
Organisation proposed a clinical case definition, combining symptoms and
signs common in AIDS (see table below). This has been used as the basis
for AIDS statistics in many countries, but is inaccurate.
A study of hospital patients in Zaire showed that the case definition
missed 31% of AIDS cases (definition not very sensitive), and 10% of
those it identified as having AIDS were errors.
The case definition misses people dying with severe HIV illnesses which
do not fit the definition. For example, deaths from streptococcal
pneumonia are far more common in those with HIV, yet such deaths were
not included.
The commonest manifestations of AIDS in Africa are gross weight loss,
chronic diarrhoea and chronic fever---the picture of `slim disease´ as
AIDS is known in African countries. However, it is difficult to exclude
other causes for the same symptoms and signs.
Deaths from tuberculosis are another problem. TB is probably the most
important infection in those with HIV in Africa. High rates of TB
infection are found in those with HIV and the risk of death from TB is
greatly increased in those with HIV. However, it is questionable whether
all those with TB and HIV can be diagnosed as AIDS cases, since many
have TB anyway. Many with TB lose weight and have fever as well as a
cough. Therefore in the absence of HIV testing, many with advanced TB
are likely to be labelled as AIDS cases using the WHO case definition.
In the light of all these problems, a revised case definition has been
agreed. You may wonder how it is possible to be sure of the right
diagnosis at all without laboratory facilities, and the answer is that
it is very difficult.
Some have pounced on this difficulty to suggest that there is no AIDS in
Africa at all. As we see elsewhere, this is not very convincing for two
groups as HIV infection rates have risen. TB and other illnesses have
been around and studied in detail for decades. Something new is
happening. Secondly, when people with AIDS from African nations are
cared for either in countries like the UK, or in very well-equipped
hospitals nearer home, it is clear that there are gross abnormalities of
their immune systems indicative of AIDS, with positive antibodies for
HIV and damaged white cells.
You are in: Health24 : News : HIV/AIDSHIV/AIDS
Missing Aids link found13/6/2003Researchers say they've discovered
evidence that an early form of Aids infected two monkey species before
moving on to chimpanzees and then to humans. The findings boost theories
suggesting that the virus has a history of jumping from species to
species and may have moved into man through the simple act of hunting.
The report comes as the Sars and monkeypox outbreaks attract attention
to the transmission of disease between animals and people. People don't
like the idea that this can happen because it's a very scary thought.
You can't control it, said study co-author Dr Beatrice Hahn, a professor
of medicine at the University of Alabama at Birmingham.
SIV similar to HIV-1
Scientists suspect that chimpanzees transmitted Aids to humans because
their strain of SIV, or simian immunodeficiency virus, is very similar
to HIV-1, the most common strain of the Aids virus in humans. What we
don't know is how this transmission occurred, Hahn said.
HIV is, of course, a devastating epidemic in humans. But while SIV
infects chimpanzees and monkeys, it doesn't appear to hurt them. The
hypothesis is that these species have had their infections for a long,
long time. They have simply learned to adapt, Hahn said.
Some experts suspect that humans became infected by eating chimpanzees,
while others have blamed manmade factors, like the polio vaccine, for
making people more susceptible.
Genetic links in chimpanzees and monkeys studied
Hahn is a member of a team of international researchers who have spent
nearly a decade investigating HIV and its precursors in apes. In the new
study, they examined genetic links between SIV in chimpanzees and in two
kinds of monkeys - red-capped mangabeys and greater spot-nosed monkeys.
(Chimpanzees are apes, not monkeys.)
Mangabeys are already well-known to Aids researchers because they appear
to have transmitted the virus that became HIV-2 to humans. (HIV-2 is
milder than the more common HIV-1 and found mainly in West Africa.)
According to the researchers, the genetic analysis suggests that strains
of SIV in the monkeys appear to have combined in the chimpanzees to
create a new strain. The theory makes sense, they say, because
chimpanzees hunt the monkeys, and the disease is spread through blood.
Disease probably spread naturally
It's not clear when the disease jumped from the monkeys to chimpanzees,
but it was probably tens of thousands of years ago, Hahn said.
If SIV can jump from monkey to chimpanzee through hunting, it adds
support to the theory that the disease could have spread from
chimpanzees to humans naturally instead of due to an unusual factor like
human vaccination, she said. The monkeys and chimpanzees weren't
vaccinated, I can tell you that, she said.
While the study findings don't appear to have any immediate relevance
for efforts to fight Aids in people, an expert said it's vital to
understand how the disease evolved, especially considering that monkeys
and chimpanzees aren't sickened by it.
HIV is here to stay
We will never be rid of HIV. It will be in our population forever. It's
not like smallpox that can be eliminated, said Dr Shawn O'Neil,
assistant professor of pathology at the New England Primate Research
Center. We have to control its transmission and figure out how to
control it so it doesn't kill us. It's important to learn how these
other species have lived with this virus.
On the other hand, the study findings suggest the possibility that more
deadly diseases could move from monkeys and chimpanzees to humans
through hunting, said Murray Gardner, professor emeritus of pathology at
the University of California at Davis and an expert in Aids-like disease
in monkeys. Will it happen again? Let's hope not, but this raises the
potential. - (HealthDayNews)
