|
_AIDS _
By: Anonymous
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!!!!
Word Count: 3367
|
