?
-------------------
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 chromosomes (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, cerebrospinal 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,
hemophiliacs 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. ...