——————-Is the message getting through? We already know enough about AIDS toprevent its spread, but ignorance, complacency, fear and bigotry continue tostop many from taking adequate precautions.
We know enough about how the infection is transmitted to protect ourselvesfrom it without resorting to such extremes as mandatory testing, enforcedquarantine or total celibacy. But too few people are heeding the AIDSmessage. Perhaps many simply don’t like or want to believe what they hear,preferring to think that AIDS “can’t happen to them. ” Experts repeatedlyremind us that infective agents do not discriminate, but can infect any andeveryone. Like other communicable diseases, AIDS can strike anyone.
It is notnecessarily confined to a few high-risk groups. We must all protect ourselvesfrom this infection and teach our children about it in time to take effectiveprecautions. Given the right measures, no one need get AIDS. The pandemic continues:———————–Many of us have forgotten about the virulence of widespread epidemics, suchas the 1917/18 influenza pandemic which killed over 21 million people,including 50,000 Canadians. Having been lulled into false security by modernantibiotics and vaccines about our ability to conquer infections, the Westernworld 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 as1968. ) The arrival of a new and lethal virus caught us off guard.
Researchsuggests that the agent responsible for AIDS probably dates from the 1950s,with a chance infection of humans by a modified Simian virus found in Africangreen monkeys. Whatever its origins, scientists surmise that the diseasespread from Africa to the Caribbean and Europe, then to the U. S. Currentestimates 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 virusthat invades white blood cells (lymphocytes) – especially T4-lymphocytes orT-helper cells – and certain other body cells, including the brain. In 1983and 1984, French and U. S. researchers independently identified the virusbelieved to cause AIDS as an unusual type of slow-acting retrovirus nowcalled “human immunodeficiency virus” or HIV.
Like other viruses, HIV isbasically a tiny package of genes. But being a retrovirus, it has the rarecapacity 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 ownenzyme, reverse transcriptase, to copy its genetic code into a DNA moleculewhich is then incorporated into the host’s DNA. The virus becomes an integralpart of the person’s body, and is subject to control mechanisms by which itcan be switched “on” or “off”.
But the viral DNA may sit hidden and inactivewithin 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 anysign of illness can unknowingly infect others. On average, the dormant virusseems to be triggered into action three to six years after first invadinghuman cells.
When switched on, viral replication may speed along, producingnew viruses that destroy fresh lymphocytes. As viral replication spreads, thelymphocyte destruction virtually sabotages the entire immune system. Inessence, HIV viruses do not kill people, they merely render the immune systemdefenceless against other “opportunistic: infections, e. g. yeast invasions,toxoplasmosis, cytomegalovirus and Epstein Barr infections, massive herpesinfections, special forms of pneumonia (Pneumocystis carinii – the killer inhalf of all AIDS patients), and otherwise rare malignant tumours (such asKaposi’s sarcoma.
)Cofactors may play a crucial contributory role:———————————————–What prompts the dormant viral genes suddenly to burst into action andstart destroying the immune system is one os the central unsolved challengesabout AIDS. Some scientists speculate that HIV replication may be set off bycofactors or transactivators that stimulate or disturb the immune system. Such triggers may be genetically determined proteins in someone’s system, orforeign 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 HIVreplication gets going, the lymphocyte destruction cripples the entire immunesystem. Recent British research suggest that some people may have a serumprotein that helps them resist HIV while others may have one that makes themgenetically more prone to it by facilitating viral penetration of T-helpercells.
Perhaps, says one expert, everybody exposed to HIV can becomeinfected, but whether or not the infection progresses to illness depends onmultiple immunogenic factors. Some may be lucky enough to have genes thatprotect 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. Thepresence of HIV antibodies thus does not confer immunity to AIDS, nor preventHIV transmission. Carriers may be able to infect others. The usual time takento test positive for HIV antibodies after exposure averages from four to sixweeks but can take over a year. Most experts agree that within six months allbut 10 per cent of HIV-infected people “seroconvert” and have detectableantibodies.
While HIV antibody tests can indicate infection, they are not foolproof. The ELISA is a good screening test that gives a few “false positives” andmore “false negatives” indicating that someone who is infected has not yetdeveloped identifiable antibodies. ) The more specific Western Blot test, doneto confirm a positive ELISA, is very accurate. However, absence of antibodiesdoesn’t guarantee freedom form HIV, as someone may be in the “window period”when, although already infected, they do not yet have measurable levels ofHIV antibodies. A seropositive result does not mean someone has AIDS; itmeans (s)he is carrying antibodies, may be infectious and may develop AIDS atsome future time.
As to how long seropositive persons remain infectious, theJune 1987 Third International Conference on AIDS was told to assume “FORLIFE”. What awaits HIV-carriers who test positive?:——————————————–On this issue of when those who test HIV positive will get AIDS, expertsthink that the fast track to AIDS is about two years after HIV infection; theslow route may be 10, 15, or more years until symptoms appear. Mostspecialists agree that it takes at least two years to show AIDS symptomsafter HIV infection, and that within ten years as many as 75 per cent ofthose infected may develop AIDS. A report from Atlanta’s CDC based on ananalysis of blood collected in San Francisco from 1978 to 1986, showed asteady increase with time in the rate of AIDS development among HIV-infectedpersons – 4 percent within three years; 14 percent after five years; 36percent after seven years. The realistic, albeit doomsday view is that 100percent 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 mainroute of HIV infection is via contaminated blood and shared IV needles. Sincethe concentration of virus is highest in semen and blood, the most commontransmission route is from man to man via anal intercourse, or man to womanvia 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 currentevidence implicates only semen, blood, vaginal secretions and possibly breastmilk in transmission. Pregnant mothers can pass the infection to theirbabies.
While breastfeeding is a rare and unproven transmission route, healthofficials suggest that seropositive mothers bottle feed their offspring. AIDS is not confined to male homosexuals and the high risk groups: Thereare now reports of heterosexual transmission – form IV drug users, hemo-philiacs or those infected by blood transfusion to sexual partners. There area few reported cases of AIDS heterosexually acquired from a single sexualencounter with a new, unknown mate. And there are three recent reports offemale-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 theinfection to the heterosexual population by sexual contact and transmissionfrom mother to child. Studies in Edinburgh, where 51 percent of drug usersare HIV-infected, show that providing clean needles isn’t enough to steminfection. Even given free disposable needles, many drug abusers preferredthe camaraderie of shared equipment. Only with added teaching programs andfree condom offers, are educational efforts likely to pay off. In New Jersey,offering free treatment coupons plus AIDS education brought 86 percent oflocal drug users to classes.
A San Francisco program issued pocket-sizecontainers of chlorine bleach to IVDAs with instructions on how to kill HIVviruses. The Toronto Addiction Research Foundation notes a similar demand forAIDS information. Risk of infection via blood transfusion very slight:—————————————————-Infection by blood transfusion is very rare in Canada today. As of November1985, the Red Cross, which supplies all blood and blood products to Canadianhospitals, had routinely tested all blood donations for the HIV antibody.
In1986, when we last discussed AIDS, the Red Cross reported the incidence ofHIV-positive blood samples as 25 in 100,000. Now, at the start of 1988, only10 per 100,000 blood samples are found to be infected – which, of course, arediscarded. Only a tiny fraction of HIV-positive blood (from HIV-infectedpeople who haven’t yet developed detectable antibodies) can now slip throughthe Red Cross screening procedure. The minimal risk is further decreased byscreening 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 feelcompelled by peer pressure to donate blood, total privacy to check the boxthat says “Do not use my blood for transfusion.
“As to banking one’s own blood, or autologous donations, the Red Crosspermits a few “medically suitable” people, referred by their physician, tostore their blood if they are likely to need blood transfusion in upcomingelective surgery. They can bank up to four units of blood, taken in the fiveweeks before surgery. Finally – it can be categorically stated – IT IS ABSOLUTELY IMPOSSIBLE TOGET AIDS BY GIVING BLOOD!!!Minimal risk to health care workers:————————————While health care personnel face a slight risk of HIV infection, all casesreported to date have been due to potentially avoidable mishaps or failure tofollow recommended precautions. Of thousands caring for AIDS patientsworldwide, only a tiny percentage has become infected, and so far no Canadianhealth personnel have become HIV-infected.
A survey done by the FederalCentre for AIDS (FCA) of 50 workers occupationally exposed to AIDS showedthat none became infected. A british hospital study on staff looking after400 AIDS patients over several years found none who became HIV-positive. Inone U. S. survey, 7 out of 2,500 health care workers seroconverted anddeveloped HIV antibodies all by potentially avoidable accidents such asneedle pricks, exposure to large amounts of blood, body fluids spattered intounprotected mouth, eyes or open sores.
The reported mishaps underscore theneed for rigorous, vigilant compliance with preventive guidelines. Universal body substance precautions (BSP) urged:————————————————-The newest guidelines suggest that every health care worker, includingdentists, should handle all blood and body fluids as if infectious. Testingall 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 falsesense of security. Rather than trying to identify infected persons, the CDCand Ottawa’s FCA now promote a philosophy that regards all patients aspotentially infected. (At Johns Hopkins in Baltimore, about six percent ofadmissions to the Traumatic Emergency Unit recently tested HIV-positive.
)Hospital and health care workers (including those caring for patients athome) are encouraged to “think AIDS” and protect themselves. All patientsshould 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 whenevergloves are removed), wearing masks, eye protection, plastic aprons and gownswhen appropriate. Taking such precautions will not only protect against AIDSbut also against more infectious agents such as hepatitis B and some hospitalacquired 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 tocatch.
One University of Toronto microbiologist speculates that those withhigh antibody counts are probably not very infectious. The most infectiousappear to be seemingly healthy persons carrying HIV without any sign ofdisease as yet. AIDS CANNOT BE PICKED UP CASUALLY via doorknobs, public washrooms, sharedschool books, communion coups, cutlery or even by food handlers with opencuts. A relatively weak virus, HIV is easily killed by a dilute 1 in 10solution of Javex/bleach, rubbing alcohol and other disinfectants. Even whereparents or caregivers have cleaned up HIV-infected blood, vomit or feces, HIVhas not been transmitted.
It is perfectly safe to share a kitchen, bathroom,schoolroom or workbench with HIV-infected individuals. But it is inadvisableto 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 TRANSMITAIDS. The rare exception might be direct blood-to-blood contact via cuts or woundsif infected blood (in considerable amounts) spills onto an open sore. Even insuch 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 thatthe AIDS virus cannot multiply or survive inside a mosquito. The infectionpattern in Africa – where children who are not sexually active might beexpected to have AIDS if mosquito bites were a real threat – shows no sign ofinsect transmission. Vaccines still a way off:————————-Scientists caution that a safe, effective vaccine against HIV may be atleast a decade away, mainly because, like the influenza virus, HIV mutates(changes structure) quickly, producing different strains. (Several differentHIV strains have already been isolated.
) An ideal vaccine must be able tostimulate neutralization of both “free” viruses and those hidden withinlymphocytes, such as T-helper cells. Researchers in various countries havedeveloped and are testing a few preliminary vaccines. One sub-unit vaccine,made from virus coat material (a glycoprotein) genetically cloned in aninsect virus (the baculovirus, which attacks moths and butterflies but nohumans) has been shown to stimulate an immune response in experimentalanimals. Another preliminary vaccine, produced by cloning modified Vacciniaviruses, containing a portion of HIV envelope, is about to enter clinicaltrials in New York. (It would be applies, like the old smallpox vaccine, intoa small scratch. ) But to date no vaccine tried in animals or humans has beenshown 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 ortest 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, despitea widespread demand for tests, especially among high-risk groups, a study inPittsburgh showed that 46 percent of a group of homosexual/bisexual mentested did not return for or want their antibody test results. Many healthexperts therefore believe that mandatory testing would be useless as HIVantibody tests only indicate exposure, not necessarily infectivity.
As oneUniversity of Toronto virologist puts it: “Widescale compulsory screening forHIV antibodies is not necessarily useful and will do nothing to promoteprevention or cure. What’s needed perhaps is more accurate knowledge aboutthe disease and more responsible behaviour rather than testing. “Those who should consider testing might include people known to be at highrisk and any who think they may have been HIV-infected or who wish to betested and have discussed it with their physician. What’s needed, as with anyinfectious disease, is not more testing buy more precautions againstinfection. Message clear but still largely unheeded:—————————————–Despite a veritable blitz of AIDS information, experts claim that too fewpeople are changing their lifestyles or behaviour sufficiently to protectthemselves from AIDS.
A recent Canadian poll revealed widespread ignorance ofthe fact that AIDS is primarily a sexually acquired infection, not caught bycasual touch. The survey showed that although sexual intercourse amongadolescents has risen steeply in the past 10 years, less than 25 percent ofthose 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 noguarantee) THAT YOUR SEX PARTNER IS HIV-FREE, USE A CONDOM (latex, not madeof animal material) plus a reliable spermicide (e. g.
one containing nonoxyl-9). Studies with infected haemophiliacs show that condom use by a regular sexpartner reduces infection risks, compared to unprotected sex. And regularcondom 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 outto young people at an early enough age for them to absorb it before becomingsexually active. Only by acting upon accurate AIDS information can peopleprotect themselves, their sex partners, families and ultimately society fromthis disease.
Protection the only answer:—————————The best way to avoid AIDS is to regard it as a highly lethal disease andpractice commonsense prevention. Avoiding infection is IN ONE’S OWN HANDS. People can protect themselves. To halt its spread, people are encouraged toobtain and apply accurate AIDS information to their living styles and sexualhabits 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 andwhen to communicate AIDS information – in the right way at “teachable”moments. Many Public Health Departments are now taking the lead indisseminating education about AIDS with largescale public awareness programs. What of the future?:——————–Many virologists believe that since antibiotics became available in thelate 1940s we have become too complacent about viral infections, no longertake communicable disease seriously, and have modern medical schools whichdevote few teaching hours to anti-infective strategies. In fact, we stillknow little about retroviruses such as HIV. Perhaps special virology researchcentres, like the Virus Research Institute proposed for the University ofToronto, will help to halt the tragic toll of AIDS and other as yet unknownviruses 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 anybodywho is suffering from the disease there is very little humour. The bestprevention is not the thought that “IT COULD NEVER HAPPEN TO ME”, if that wasso all the insurance companies would be out of business.The most reliable person to be put in-charge of preventing you for gettingAIDS is YOURSELF!!!!T A K EP R E V E N T I V EP R E C A U T I O N S ! !============================================================================Thanks to the University of Toronto Faculty of Medicine for the article.
