INTRODUCTION
No other word engenders as much fear, revulsion, despair and utter helplessness as AIDS. It is, in fact, rewriting medical history as humankind`s deadliest scourge. With 40 million deaths forecast in this millennium, statistics tell their own sordid tale.
The first recorded sample of HIV was discovered in 1959 in a blood specimen obtained at Leopoldville (now Kinshasa) in the Belgian Congo. This was the first known death chalked up by AIDS. The virus is thought to have originally affected chimpanzees. The crossover from animals to humans may have occurred in the 1950s through an accident or a bite.
Intermittently, other theories of its origins have been advanced. One theory, put forward by Bette Korber, traces the disease to a single viral ancestor that could have emerged between 1910 and 1950. Through an analysis done at the Los Alamos National Lab in New Mexico, Korber contends that the pandemic may have come from one or more infected humans around 1930.
Another highly controversial—but plausible—theory is that of American philosopher, Louis Pascal, first spelt out in 1987. All the early AIDS cases originated in the Central African states of Congo, Rwanda or Burundi. This belt was subjected to trials of a live polio vaccine on 300,000 men, women and children..
Pascal argued that the vaccine, which was grown in cultures obtained from chopped up chimpanzee kidneys, may have carried this virus. Polio researcher Dr Albert Sabin had reported that such a batch was contaminated by an unknown virus. In fact, monkeys harbor SIV or simian immunodeficiency virus (SV-40 to be more specific), which is thought to be the ancestor of HIV..
The first cases of AIDS were reported in the United States in 1981, amongst male homosexuals in Los Angeles and New York. Within two decades, up to 50 million may have been infected globally, approximately 22 million have succumbed and nearly 15,000 new infections are said to occur daily..
What Is Aids & HIV
HIV has two major categories: HIV-1 and HIV-2. HIV-1, which currently has about 10 subtypes, is most common worldwide and the only form found in the US. HIV-2 is less virulent and though currently confined to West Africa—it`s spreading.
The Human Immunodeficiency Virus (HIV) basically provokes an infection, which destroys the body`s immune system. And AIDS or Acquired Immune Deficiency Syndrome is the advanced stage of this disease, when the immune system becomes irreparably damaged, engendering multiple infections and cancers. A person is considered HIV positive when s/he tests positive for any of the 26 diseases (Kaposi`s sarcoma, lymphoma, pulmonary tuberculosis, recurrent pneumonia within a 12-month period, wasting syndrome and other indicators) that can easily invade the body during our immune system`s nonfunctionality.
On invading the body, the virus specifically attacks T-cells. A core part of the human defence system, they mobilize other cells to seek and destroy contagious foreign elements besides leading the immune system`s fight against infections. T-cells are targeted because the AIDS virus parasitizes the CD4 molecules on their surface.
With a protective outer shell of proteins and glyco-proteins, the AIDS virus contains genetic information on the inside. Although substantially smaller than the host T-cells—the virus reproduces by sponging off the host`s cellular resources! Our body fights back by producing up to two billion new T-cells to replace the infected ones, stabilizing the T-cell count temporarily. Yet from day one, the T-cells fight a losing battle.
The genetic information of the AIDS virus, which is encoded as RNA (ribonucleic acid), needs to be reverse transcripted—which the intruder accomplishes with the help of the host cell itself! The now legible DNA is thereafter randomly transferred into the nucleus. All this is accomplished barely a dozen hours following the infection. By this time, the aggressor begins to substantially weaken the host cell, which eventually dies, eroding the immune system and making the body vulnerable to diseases.
Although HIV targets T-cells and other cells in the body, it thrives mainly in the lymph nodes—another important part of the immune system. Each lymph node has a netlike structure inside it that acts as a protective filter by trapping virus and infected T-cells. But as healthy T-cells move through contaminated lymph nodes, they are infected by HIV. Particularly during the early stage of the disease, lymph nodes contain more infected cells than the blood.
Symptoms
In the early stages, a mild flu and swollen glands are typical. But the symptoms are often unmistakeable when full-blown AIDS develops. Loss of appetite, weight loss, constant fever, prolonged fatigue, diarrhea, constipation, changing bowel patterns, swollen glands, chills coupled with excessive sweating, especially at nights, lesions in the mouth, sore throat, persistent cough, shortness of breath, tumours, skin rashes, headaches, memory lapses, swelling in the joints, pain in various parts of the body, vision problems and a regular feeling of lethargy and ill health make up the litany of symptoms.
With immune systems out of kilter, HIV-positive persons are susceptible to several types of cancer, particularly Kaposi`s sarcoma (KS), an uncommon form that occurs under the skin and in the mucus membranes of the eyes, nose and mouth. Affected persons have lesions that appear as dark-coloured raised blotches. Though the lesions are painless, once KS spreads to the lungs, lymph nodes and digestive tract, the victim experiences difficulty in breathing, gastrointestinal bleeding and painful swelling around the lymph nodes, especially in the legs.
Modes Of Transmission
HIV is transmitted primarily by sex (anal, vaginal or oral sex with an infected partner), by injections (sharing contaminated needles for drug use or accidental piercing with a contaminated needle), or from infected mother to child through pregnancy or breast-feeding.
Infected semen and vaginal fluids, infected blood and blood products lead to the transmission of HIV. Drug abuse with unsterilized needles is another high-risk activity. Unprotected sex with multiple partners is the primary cause of infection. During unprotected sex, the infected fluid could enter the bloodstream through a tiny cut or a sore. Anal penetration has a higher risk of transmission, which is why a high percentage of homosexuals develop the disease. Bleeding during sex also raises the chances of infection. Therefore unprotected sex during menstrual periods and anal intercourse are best avoided.
An infected mother can also transmit the virus to her baby before or during birth or through breast milk. Although traces of HIV have been detected in body fluids (saliva, urine, faeces and tears) there is no evidence that HIV spreads through these fluids. Nor is it water-borne, air-borne or transmitted through mosquitoes and other insects.
Some HIV-infected patients progress to AIDS quickly while others can remain healthy for 10 years or more. Between initial infection and full-blown disease, a middle phase called symptomatic HIV infection, or AIDS-related complex (ARC), occurs, prompting symptoms such as weight loss, diarrhea, and swollen lymph glands.
Scientists have recently discovered clues to why some patients develop AIDS quickly. In a study published last March in the journal Science, National Cancer Institute researchers found that inherited genes may set the clock for AIDS progression. Certain gene patterns tend to stave off AIDS, while others promote it. The researchers say the study may help lead to an AIDS-preventive vaccine or improved therapies against the virus.
Gender Differences in the Risk of HIV Infection
HIV risk factors among injection drug users (IDUs) differ markedly by gender, according to a 10-year study funded by the National Institute on Drug Abuse (NIDA). A recent study by researchers at the Johns Hopkins University reported that while drug-related risk behaviors and homosexual activity are the most important predictors of HIV seroconversion among males, factors consistent with high-risk heterosexual activities are the main predictors among females. The findings, reported in the May 28 (2001) issue of the Archives of Internal Medicine, provide insight into the relationship between gender and high-risk sexual behaviors in the development of HIV infection.
"Early studies of injection drug users suggested that most HIV infections were due primarily to sharing needles," said NIDA Director Alan I. Leshner, Ph.D. "This study adds to the body of evidence that supports the need for gender-specific interventions in the treatment of that group of drug users."
Between 1988 and 1998, a team of researchers, led by Dr. Steffanie Strathdee at the Johns Hopkins University Bloomberg School of Public Health, examined both drug related and sexual risk factors for HIV transmission in a study of more than 1,800 injecting drug users in Baltimore, Maryland. Study participants were aged 18 or older, did not have an AIDS defining illness at enrollment, and reported a history of illicit injection drug use within the previous 10 years. Through semiannual interviews, researchers collected data on drug use history, sociodemographics, and drug use and sexual behavior within the last 6 months. Blood samples were also obtained at each study visit. Researchers used commercial HIV and antibody ELISA to identify those participants who had become HIV positive since their last visit.
Dr. Strathdee and her colleagues found that the greatest predictor for HIV seroconversion among both male and female IDUs was high-risk sexual behavior. Study findings revealed that male injection drug users who reported recent homosexual activity were four times more likely to become infected with HIV.
Among females, indicators of high-risk heterosexual activity outweighed needle-sharing behaviors as independent predictors of HIV seroconversion. HIV incidence was more than two times higher among women who reported recently having sex with another injection drug user.
Another common predictor of HIV seroconversion observed by researchers among both male and female IDUs was younger age. Investigators found that IDUs who were aged 30 or younger at enrollment were more than twice as likely to seroconvert than those aged 40 or older.
"This is consistent with several reports which indicate that younger IDUs are more likely to engage in needle sharing and other behaviors that place them at higher risk of acquiring HIV and hepatitis B or C viruses," stated Dr. Strathdee.
Prevention
While AIDS is a high-risk disease it can be prevented if proper precautions are taken and greater awareness meted out to those who are ignorant of the virus and its repercussions on the human body. Here we have listed a few measures which can be adopted by everyone inorder to stave off the insidious entry of HIV.
• Prevention is still the best bet. Promiscuous sexual behavior can leave a person highly susceptible to contracting the virus. Where abstinence is not possible, always use latex condoms. The female condom can also help protect both partners. Use only water-based lubricants. Oil lubricants (such as Vaseline) might even tear latex condoms. Use spermicidal (birth control) foams and jellies in addition to condoms. By themselves, spermicides may not be effective in preventing HIV.
• Avoid alcohol or drugs during sex, you might lose control of your senses and engage in unsafe sex. Stick to safer sex practices at all times and avoid having multiple partners. Practice monogamy. If this is a tall order, serial relationships are a lesser evil than multiple ones
• High-risk sexual behavior should be avoided at all costs. These include: oral genital sex involving contact with semen or vaginal fluids, oral anal sex, vaginal sex without a condom, anal sex sans a condom (active or passive), fisting or manual anal intercourse, the sharing of sex toys, using saliva for lubrication and blood contact of any kind during performance. If unable to resist oral sex, use a dental dam. If a woman is infected, avoid sex during the menses as menstrual blood is infectious
• For transfusions, use disposable syringes and needles. Ensure you get blood that is screened and certified as HIV-free. Better still, get blood from close family members rather than professional donors whose medical antecedents are nebulous
• The presence of sexually transmitted diseases (STDs) increases the risk of contracting HIV from an infected partner. STDs could cause breaks in the skin of the vagina, penis or anus permitting the virus to enter your bloodstream. If you ever contract an STD of any kind, ensure you get prompt treatment.
• The CDC recommends that an HIV-positive woman should not breast-feed her baby. The infant should be given AZT for the first several weeks to substantially reduce the risk of infection.
Myths & Facts
Say `AIDS` and dime-a-dozen misconceptions abound. The chart topper is that AIDS is supposedly a disease of gay men and intravenous drug users. The facts are otherwise. No doubt in the early years many HIV-positive cases were reported amongst the Western gay community. In recent years, however, prevalence rates among gays have leveled off. Instead, heterosexual transmission has been forging ahead of all other modes of transmission.
The AIDS virus is NOT contracted through touching, hugging, kissing, massage, sharing toilet seats, drinking or eating from utensils used by an infected person or any other mode of casual contact. Nor does working, socialising and living with infected people cause the disease.
Repeated sexual contact without proper precautions with an infected person, using an infected syringe, exposure to infected blood or sexual fluids are ways through which the disease can be transmitted.
Donating blood also does not run the risk of disease contraction since needles used for such purposes are always sterile. Since the AIDS virus is unable to survive outside the human body beyond a short duration, dried blood is not infectious For this reason, mosquitoes are incapable of transmitting HIV as the virus cannot replicate itself in the intestine of insects.
Although medical personnel are potentially at risk from infection, this is minimal if protective gear such as gloves, masks and goggles are always used when handling potentially infected material.
The Elusive Cure
The large-scale infections and deaths have spurred a spate of worldwide efforts for a cure. In the US, however, AIDS cases are said to be dropping and new infections leveling off. Mortality from AIDS is also dropping.
In the developing countries, though, the cases continue to rise alarmingly. Globally, three million died in the year 2000, with 5.3 million newly infected people, 95 percent of whom might die.
Many scientists, doctors and researchers contend that AIDS is not a new disease, having been around much longer than people believe. Dr. Robert Willner—author of Deadly Deception: The Proof That Sex and HIV Absolutely Do Not Cause AIDS—asserts that HIV is not the cause of AIDS. He claims that nearly 500 hundred top scientists of the world have challenged the hypothesis of Robert Gallo—who patented the HIV test the day after the AIDS virus was discovered—that HIV is the precursor of AIDS.
Besides other telling facts, the dissenters want to know how one can explain HIV-free AIDS cases, of which there are said to be nearly 5,000 on record.
Dr. Frank Shallenberger, a licensed medical and homeopathic practitioner, says that statistics are only a correlation—not a result—that HIV is one cause of AIDS, citing the fact that some AIDS victims do not have HIV antibodies. Dr. Shallenberger considers AIDS a multifactorial disease that strikes when the immune system is down.
The search for a cure, also brings to light other interesting facets. African chimpanzees have been harboring the simian equivalent of the AIDS virus for centuries, according to detailed studies conducted by researches at the University of Alabama in Birmingham. Why don`t the chimps succumb to the virus?
Says Dr. Anthony Fauci from the National Institutes of Health: "There must be something about the chimp`s immune system or some host defense system that is doing a very good job of containing the virus. If we find that out we may be able to extrapolate to humans."
Chimpanzees being the closest living relatives of humans, their DNA differs from human DNA by less than two percent. Adds Dr. Fauci: "It`s entirely conceivable that the very small genetic differences between the chimp and the human will explain why the chimpanzee does not get sick and the human does."
