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Essay on AIDS - Whats New
| Date: |
10-25-03 12:28pm |
| Subject: |
Social Issues |
| Word Count: |
3046 |
| Page Count: |
12.18 |
AIDS - What's new
AIDS - What's new
Is the message getting through? We already
know enough about AIDS to prevent its spread, but ignorance, complacency,
fear and bigotry continue to stop many from taking adequate precautions.
We know enough about how the infection
is transmitted to protect ourselves from it without resorting to such extremes
as mandatory testing, enforced quarantine or total celibacy. But too few
people are heeding the AIDS message. Perhaps many simply don't like or
want to believe what they hear, preferring to think that AIDS "can't happen
to them." Experts repeatedly remind us that infective agents do not discriminate,
but can infect any and everyone. Like other communicable diseases, AIDS
can strike anyone. It is not necessarily confined to a few high-risk groups.
We must all protect ourselves from this infection and teach our children
about it in time to take effective precautions. Given the right measures,
no one need get AIDS.
The pandemic continues:
Many of us have forgotten about the virulence
of widespread epidemics, such as the 1917/18 influenza pandemic which killed
over 21 million people, including 50,000 Canadians. Having been lulled
into false security by modern antibiotics and vaccines about our ability
to conquer infections, the Western world was ill prepared to cope with
the advent of AIDS in 1981. (Retro- spective studies now put the first
reported U.S. case of AIDS as far back as 1968.) The arrival of a new and
lethal virus caught us off guard. Research suggests that the agent responsible
for AIDS probably dates from the 1950s, with a chance infection of humans
by a modified Simian virus found in African green monkeys. Whatever its
origins, scientists surmise that the disease spread from Africa to the
Caribbean and Europe, then to the U.S. Current estimates are that 1.5 to
2 million Americans are now probably HIV carriers, with higher numbers
in Central Africa and parts of the Caribbean.
Recapping AIDS - the facts:
AIDS is an insidious, often fatal but
less contagious disease than measles, chicken pox or hepatitis B. AIDS
is thought to be caused primarily by a virus that invades white blood cells
(lymphocytes) - especially T4-lymphocytes or T-helper cells - and certain
other body cells, including the brain. In 1983 and 1984, French and U.S.
researchers independently identified the virus believed to cause AIDS as
an unusual type of slow-acting retrovirus now called "human immunodeficiency
virus" or HIV. Like other viruses, HIV is basically a tiny package of genes.
But being a retrovirus, it has the rare capacity to copy and insert its
genes right into a human cell's own chromo- somes (DNA). Once inside a
human host cell the retrovirus uses its own enzyme, reverse transcriptase,
to copy its genetic code into a DNA molecule which is then incorporated
into the host's DNA. The virus becomes an integral part of the person's
body, and is subject to control mechanisms by which it can be switched"on" or "off". But the viral DNA may sit hidden and inactive within human
cells for years, until some trigger stimulates it to replicate. Thus HIV
may not produce illness until its genes are "turned on" five, ten, fifteen
or perhaps more years after the initial infection.
During the latent period, HIV carriers
who harbour the virus without any sign of illness can unknowingly infect
others. On average, the dormant virus seems to be triggered into action
three to six years after first invading human cells. When switched on,
viral replication may speed along, producing new viruses that destroy fresh
lymphocytes. As viral replication spreads, the lymphocyte destruction virtually
sabotages the entire immune system. In essence, HIV viruses do not kill
people, they merely render the immune system defenceless against other"opportunistic: infections, e.g. yeast invasions, toxoplasmosis, cytomegalovirus
and Epstein Barr infections, massive herpes infections, special forms of
pneumonia (Pneumocystis carinii - the killer in half of all AIDS patients),
and otherwise rare malignant tumours (such as Kaposi's sarcoma.)
Cofactors may play a crucial contributory
role:
What prompts the dormant viral genes suddenly
to burst into action and start destroying the immune system is one os the
central unsolved challenges about AIDS. Some scientists speculate that
HIV replication may be set off by cofactors or transactivators that stimulate
or disturb the immune system. Such triggers may be genetically determined
proteins in someone's system, or foreign substances from other infecting
organisms - such as syphilis, chlamydia, gonorrhea, HTLV-1 (leukemia),
herpes, or CMV (cytomegalovirus) - which somehow awaken the HIV virus.
The assumption is that once HIV replication gets going, the lymphocyte
destruction cripples the entire immune system. Recent British research
suggest that some people may have a serum protein that helps them resist
HIV while others may have one that makes them genetically more prone to
it by facilitating viral penetration of T-helper cells. Perhaps, says one
expert, everybody exposed to HIV can become infected, but whether or not
the infection progresses to illness depends on multiple immunogenic factors.
Some may be lucky enough to have genes that protect them form AIDS!
Variable period until those infected develop
antibodies:
While HIV hides within human cells, the
body may produce antibodies, but, for reasons not fully understood, they
don't neutralise all the viruses. The presence of HIV antibodies thus does
not confer immunity to AIDS, nor prevent HIV transmission. Carriers may
be able to infect others. The usual time taken to test positive for HIV
antibodies after exposure averages from four to six weeks but can take
over a year. Most experts agree that within six months all but 10 per cent
of HIV-infected people "seroconvert" and have detectable antibodies.
While HIV antibody tests can indicate infection,
they are not foolproof. The ELISA is a good screening test that gives a
few "false positives" and more "false negatives" indicating that someone
who is infected has not yet developed identifiable antibodies.) The more
specific Western Blot test, done to confirm a positive ELISA, is very accurate.
However, absence of antibodies doesn't guarantee freedom form HIV, as someone
may be in the "window period" when, although already infected, they do
not yet have measurable levels of HIV antibodies. A seropositive result
does not mean someone has AIDS; it means (s)he is carrying antibodies,
may be infectious and may develop AIDS at some future time. As to how long
seropositive persons remain infectious, the June 1987 Third International
Conference on AIDS was told to assume "FOR LIFE".
What awaits HIV-carriers who test positive?:
On this issue of when those who test HIV
positive will get AIDS, experts think that the fast track to AIDS is about
two years after HIV infection; the slow route may be 10, 15, or more years
until symptoms appear. Most specialists agree that it takes at least two
years to show AIDS symptoms after HIV infection, and that within ten years
as many as 75 per cent of those infected may develop AIDS. A report from
Atlanta's CDC based on an analysis of blood collected in San Francisco
from 1978 to 1986, showed a steady increase with time in the rate of AIDS
development among HIV-infected persons - 4 percent within three years;
14 percent after five years; 36 percent after seven years. The realistic,
albeit doomsday view is that 100 percent of those who test HIV-positive
may eventually develop AIDS.
Still spread primarily by sexual contact:
AIDS is still predominantly a sexually
transmitted disease: The other main route of HIV infection is via contaminated
blood and shared IV needles. Since the concentration of virus is highest
in semen and blood, the most common transmission route is from man to man
via anal intercourse, or man to woman via vaginal intercourse. Female HIV
carriers can infect male sex partners. Small amounts of HIV have been isolated
from urine, tears, saliva, cereb- rospinal and amniotic fluid and (some
claim) breast milk. But current evidence implicates only semen, blood,
vaginal secretions and possibly breast milk in transmission. Pregnant mothers
can pass the infection to their babies. While breastfeeding is a rare and
unproven transmission route, health officials suggest that seropositive
mothers bottle feed their offspring.
AIDS is not confined to male homosexuals
and the high risk groups: There are now reports of heterosexual transmission
- form IV drug users, hemo-philiacs or those infected by blood transfusion
to sexual partners. There are a few reported cases of AIDS heterosexually
acquired from a single sexual encounter with a new, unknown mate. And there
are three recent reports of female-to-female (lesbian) transmissions.
Spread of AIDS among drug users alarming:
In many cities, e.g. New York and Edinburgh,
where IV drug use is wide-spread, IV drug users often share blood-contaminated
needles. In New York, more than 53 percent of drug users are HIV-infected
and may transmit the infection to the heterosexual population by sexual
contact and transmission from mother to child. Studies in Edinburgh, where
51 percent of drug users are HIV-infected, show that providing clean needles
isn't enough to stem infection. Even given free disposable needles, many
drug abusers preferred the camaraderie of shared equipment. Only with added
teaching programs and free condom offers, are educational efforts likely
to pay off. In New Jersey, offering free treatment coupons plus AIDS education
brought 86 percent of local drug users to classes. A San Francisco program
issued pocket-size containers of chlorine bleach to IVDAs with instructions
on how to kill HIV viruses. The Toronto Addiction Research Foundation notes
a similar demand for AIDS information.
Risk of infection via blood transfusion
very slight:
Infection by blood transfusion is very
rare in Canada today. As of November 1985, the Red Cross, which supplies
all blood and blood products to Canadian hospitals, had routinely tested
all blood donations for the HIV antibody. In 1986, when we last discussed
AIDS, the Red Cross reported the incidence of HIV-positive blood samples
as 25 in 100,000. Now, at the start of 1988, only 10 per 100,000 blood
samples are found to be infected - which, of course, are discarded. Only
a tiny fraction of HIV-positive blood (from HIV-infected people who haven't
yet developed detectable antibodies) can now slip through the Red Cross
screening procedure. The minimal risk is further decreased by screening
methods, medical history-taking, questionnaires and donor inter- views.
Very few people at risk of AIDS now come to give blood. The "self- elimination
form", filled out in a private booth, allows any who feel compelled by
peer pressure to donate blood, total privacy to check the box that says
"Do not use my blood for transfusion."
As to banking one's own blood, or autologous
donations, the Red Cross permits a few "medically suitable" people, referred
by their physician, to store their blood if they are likely to need blood
transfusion in upcoming elective surgery. They can bank up to four units
of blood, taken in the five weeks before surgery.
Finally - it can be categorically stated
- IT IS ABSOLUTELY IMPOSSIBLE TO GET AIDS BY GIVING BLOOD!!!
Minimal risk to health care workers:
While health care personnel face a slight
risk of HIV infection, all cases reported to date have been due to potentially
avoidable mishaps or failure to follow recommended precautions. Of thousands
caring for AIDS patients worldwide, only a tiny percentage has become infected,
and so far no Canadian health personnel have become HIV-infected. A survey
done by the Federal Centre for AIDS (FCA) of 50 workers occupationally
exposed to AIDS showed that none became infected. A british hospital study
on staff looking after 400 AIDS patients over several years found none
who became HIV-positive. In one U.S. survey, 7 out of 2,500 health care
workers seroconverted and developed HIV antibodies all by potentially avoidable
accidents such as needle pricks, exposure to large amounts of blood, body
fluids spattered into unprotected mouth, eyes or open sores. The reported
mishaps underscore the need for rigorous, vigilant compliance with preventive
guidelines.
Universal body substance precautions (BSP)
urged:
The newest guidelines suggest that every
health care worker, including dentists, should handle all blood and body
fluids as if infectious. Testing all patients for HIV is not practical
and does not confer protection. Rely-ing on tests that are not 100 per
cent accurate would only induce a false sense of security. Rather than
trying to identify infected persons, the CDC and Ottawa's FCA now promote
a philosophy that regards all patients as potentially infected. (At Johns
Hopkins in Baltimore, about six percent of admissions to the Traumatic
Emergency Unit recently tested HIV-positive.) Hospital and health care
workers (including those caring for patients at home) are encouraged to"think AIDS" and protect themselves. All patients should be handled in
a way that minimizes exposure to blood and body fluids, e.g. by always
wearing gloves when touching open sores, mucous membranes, taking blood,
attending emergencies, putting in IV needles, touching blood- soiled items,
with scrupulous hand-washing between patients (and whenever gloves are
removed), wearing masks, eye protection, plastic aprons and gowns when
appropriate. Taking such precautions will not only protect against AIDS
but also against more infectious agents such as hepatitis B and some hospital
acquired infections. We are all being forced to remember stringent anti-
infection rules!
Absolutely no evidence of spread by casual
contact:
All the research to date points to the
fact that AIDS is not very easy to catch. One University of Toronto microbiologist
speculates that those with high antibody counts are probably not very infectious.
The most infectious appear to be seemingly healthy persons carrying HIV
without any sign of disease as yet.
AIDS CANNOT BE PICKED UP CASUALLY via doorknobs,
public washrooms, shared school books, communion coups, cutlery or even
by food handlers with open cuts. A relatively weak virus, HIV is easily
killed by a dilute 1 in 10 solution of Javex/bleach, rubbing alcohol and
other disinfectants. Even where parents or caregivers have cleaned up HIV-infected
blood, vomit or feces, HIV has not been transmitted. It is perfectly safe
to share a kitchen, bathroom, schoolroom or workbench with HIV-infected
individuals. But it is inadvisable to share toothbrushes, razors, acupuncture
needles, enema equip- ment or sharp gadgets, which could carry infected
blood through the skin.
ORDINARY, NONSEXUAL WORKPLACE AND CHILDHOOD
ACTIVITIES DON'T TRANSMIT AIDS. The rare exception might be direct blood-to-blood
contact via cuts or wounds if infected blood (in considerable amounts)
spills onto an open sore. Even in such cases a swab with dilute bleach
can kill HIV viruses.
Not spread by mosquitoes and other insects:
There's no evidence of HIV transmission
by insects. Researchers report that the AIDS virus cannot multiply or survive
inside a mosquito. The infection pattern in Africa - where children who
are not sexually active might be expected to have AIDS if mosquito bites
were a real threat - shows no sign of insect transmission.
Vaccines still a way off:
Scientists caution that a safe, effective
vaccine against HIV may be at least a decade away, mainly because, like
the influenza virus, HIV mutates (changes structure) quickly, producing
different strains. (Several different HIV strains have already been isolated.)
An ideal vaccine must be able to stimulate neutralization of both "free"
viruses and those hidden within lymphocytes, such as T-helper cells. Researchers
in various countries have developed and are testing a few preliminary vaccines.
One sub-unit vaccine, made from virus coat material (a glycoprotein) genetically
cloned in an insect virus (the baculovirus, which attacks moths and butterflies
but no humans) has been shown to stimulate an immune response in experimental
animals. Another preliminary vaccine, produced by cloning modified Vaccinia
viruses, containing a portion of HIV envelope, is about to enter clinical
trials in New York. (It would be applies, like the old smallpox vaccine,
into a small scratch.) But to date no vaccine tried in animals or humans
has been shown to prevent AIDS.
Testing no solution:
Large scale, screening of the public for
HIV antibodies offers little pro- tection because today's apparent negatives
can become infected tomorrow or test seropositive when antibodies develop
in those already harboring HIV. Reliance on tests could lull people into
false complacency. A "false nega- tive" result may fool someone into risky
sexual behaviour. Curiously, despite a widespread demand for tests, especially
among high-risk groups, a study in Pittsburgh showed that 46 percent of
a group of homosexual/bisexual men tested did not return for or want their
antibody test results. Many health experts therefore believe that mandatory
testing would be useless as HIV antibody tests only indicate exposure,
not necessarily infectivity. As one University of Toronto virologist puts
it:
"Widescale compulsory screening for HIV
antibodies is not necessarily useful and will do nothing to promote prevention
or cure. What's needed perhaps is more accurate knowledge about the disease
and more responsible behaviour rather than testing."
Those who should consider testing might
include people known to be at high risk and any who think they may have
been HIV-infected or who wish to be tested and have discussed it with their
physician. What's needed, as with any infectious disease, is not more testing
buy more precautions against infection.
Message clear but still largely unheeded:
Despite a veritable blitz of AIDS information,
experts claim that too few people are changing their lifestyles or behaviour
sufficiently to protect themselves from AIDS. A recent Canadian poll revealed
widespread ignorance of the fact that AIDS is primarily a sexually acquired
infection, not caught by casual touch. The survey showed that although
sexual intercourse among adolescents has risen steeply in the past 10 years,
less than 25 percent of those aged 18 to 34 have altered their sexual behaviour
to protect them- selves against AIDS, i.e. by consistent use of condoms
and spermicide.
THE CENTRAL MESSAGE IS CLEAR: UNLESS ABSOLUTELY
SURE (and monogamy is no guarantee) THAT YOUR SEX PARTNER IS HIV-FREE,
USE A CONDOM (latex, not made of animal material) plus a reliable spermicide
(e.g. one containing nonoxyl- 9). Studies with infected haemophiliacs show
that condom use by a regular sex partner reduces infection risks, compared
to unprotected sex. And regular condom use may bring the added reward of
preventing other sexually trans- mitted diseases such as gonorrhea and
chlamydia or unwanted pregnancy.
Many educators say that, by whatever means,
AIDS information must get out to young people at an early enough age for
them to absorb it before becoming sexually active. Only by acting upon
accurate AIDS information can people protect themselves, their sex partners,
families and ultimately society from this disease.
Protection the only answer:
The best way to avoid AIDS is to regard
it as a highly lethal disease and practice commonsense prevention. Avoiding
infection is IN ONE'S OWN HANDS. People can protect themselves. To halt
its spread, people are encouraged to obtain and apply accurate AIDS information
to their living styles and sexual habits in order to reduce the risk of
getting or transmitting the virus. Sadly, health promoters claim that "reaching
the many who don't want to know" is no easy task. Health promoters suggest
that educators must learn how and when to communicate AIDS information
- in the right way at "teachable" moments. Many Public Health Departments
are now taking the lead in disseminating education about AIDS with largescale
public awareness programs.
What of the future?:
Many virologists believe that since antibiotics
became available in the late 1940s we have become too complacent about
viral infections, no longer take communicable disease seriously, and have
modern medical schools which devote few teaching hours to anti-infective
strategies. In fact, we still know little about retroviruses such as HIV.
Perhaps special virology research centres, like the Virus Research Institute
proposed for the University of Toronto, will help to halt the tragic toll
of AIDS and other as yet unknown viruses waiting in the wings.
For more information on AIDS or aid for
AIDS call: local AIDS committees, Public Health Departments, or AIDS Hotlines
(in Toronto 392-AIDS.)
In everyday conversations, AIDS is usually
a source for humour. For anybody who is suffering from the disease there
is very little humour. The best prevention is not the thought that "IT
COULD NEVER HAPPEN TO ME", if that was so all the insurance companies would
be out of business.
The most reliable person to be put in-charge
of preventing you for getting AIDS is YOURSELF!!!!
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