Aids - Whats New Essay

This essay has a total of 3459 words and 12 pages.

Aids - Whats 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
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
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