Aids - Whats New?

AIDS - What\'s new ?

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Is the message getting through? We already know enough about AIDS

toprevent its spread, but ignorance, complacency, fear and bigotry

continue to stop many from taking adequate precautions to stop the

risk of getting the aids virus.

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 getting the AIDS message they just can\'t get the message

thought their minds. 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:

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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\'s that are 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:

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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 that imfect the blood cells. But being a

retrovirus, it has the rarecapacity 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. There for the HIV virus may

not produce illness until it\'s 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.)

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