HIV/AIDS PREVENTION, COULD THERE BE A BETTER WARNING TO MANKIND?

The preceding decade brought a new life-threatening disease into the vocabulary of every nation. AIDS (the acquired immune deficiency syndrome) is primarily transmitted as a venereal disease. First discovered in homosexual males, the syndrome has quickly spread encircling the world. Growing exponentially around our globe, this disease is caused by a virus called HIV (human immunodeficiency virus) and a similar virus is now found in cows (the bovine immunodeficiency virus). This article discusses some empirical pragmatically attested ways of preventing HIV transmission.

Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain infections and cancers. Initial infection may cause nonspecific febrile illness. Risk of subsequent manifestations related to immunodeficiency is proportional to the level of CD4+ lymphocytes. HIV can directly damage the brain, gonads, kidneys, and heart, causing cognitive impairment , hypogonadism, renal insufficiency, and cardiomyopathy. Manifestations range from asymptomatic carriage to AIDS, which is defined by serious opportunistic infections or cancers or a CD4 count of < 200/μL. HIV infection can be diagnosed by antibody, nucleic acid (HIV RNA), or antigen (p24) testing. Screening should be routinely offered to all adults and adolescents. Treatment aims to suppress HIV replication by using combinations of three (3) or more drugs that inhibit HIV enzymes; treatment can restore immune function in most patients if suppression of replication is sustained.

Transmission of HIV requires contact with body fluids—specifically blood, semen, vaginal secretions, breast milk, saliva, or exudates from wounds or skin and mucosal lesions that contain free HIV virions or infected cells. Transmission is more likely with the high levels of virions that are typical during primary infection, even when such infections are asymptomatic. Consequently, if everyone with a risk factor for HIV infection underwent prompt HIV testing, and if everyone identified as positive for HIV received ongoing antiretroviral therapy, then viremia could be suppressed to undetectable levels so that infectivity to others would be very low. Decreasing infectivity to near 0 by this strategy would markedly reduce the number of new infections. Infected persons could live a near normal lifespan on antiretroviral therapy. Transmission by saliva or droplets produced by coughing or sneezing, although conceivable, is extremely unlikely. HIV is not transmitted by casual nonsexual contact as may occur at work, school, or home. Transmission is usually by

• Direct transfer of genital, rectal or oral fluids through sexual intercourse

• Sharing of blood-contaminated needles
• Childbirth
• Breastfeeding
• Medical procedures (eg, transfusions, exposure to contaminated instruments)

APPROXIMATE RISK OF ACQUIRING HIV
Exposure
Approximate Risk
Vaginal Intercourse
0.1%
Anal Intercourse
1%
Percutaneous exposure (HCW)
0.3%
Needle Sharing (IVDU)
1%
MTCT
20-40%
Blood Transfusion (HIV-infected donor)
100%
(Semba RD, Tang AM. 1999)
Drug abusing men and women pick up the virus from contaminated needles. Many hemophiliacs have acquired the infection from blood product transfusions. Sporadic case reports of hospital workers and physicians have raised the spectrum of risky needle sticks, surgery, and invasive medical procedures. Gloves are mandated for medical contact with all body fluids (called universal precautions). Latex is not adequate protection, however. It frequently contains microscopic pores, and the virus can pass through easily.

From their first knowledge of AIDS, physicians in hospitals began to practice isolation precautions. Laws preserving the confidentiality of AIDS carriers , has lobbed the potential of risk avoidance or reduction by dentists, paramedics, physicians, and all health care providers, who may not even know their patient is carrying a virus. This has immensely affected the outcome of simple procedures that usually have good prognosis if handled prudently. Ignoring the consequence of doing certain procedures in an individual infected with the virus has resulted in jaw dropping complications that are difficult to manage.

This could be attributed to the fact that there is no universally accepted cure for HIV infections. Hence, most of the victims to HIV eventually develop full blown AIDS. This may develop in several ways. Sudden infection, with drug-resistant tuberculosis or pneumonia caused by an opportunistic germ such as Pneumocystis carinii . Unusual forms of cancer, such as Kaposi‘s sarcoma, Cervical cancer, throat cancer may appear. This directly reveals the devastation of the patient’s immune system. Lymphocyte counts are dangerously low; and the hapless patient must be supported with powerful and expensive drugs, usually for the rest of his life.

Sexual transmission: Sexual practices such as fellatio and cunnilingus appear to be relatively low risk but not absolutely safe. Risk does not increase significantly if semen or vaginal secretions are swallowed. However, open sores in the mouth may increase risk. The sexual practices with the highest risks are those that cause mucosal trauma, typically intercourse. Anal-receptive intercourse poses the highest risk. Mucous membrane inflammation facilitates HIV transmission; sexually transmitted diseases, such as gonorrhea, chlamydial infection, trichomoniasis, and especially those that cause ulceration (eg, chancroid, herpes, syphilis), increase the risk several fold.

In heterosexuals, the estimated risk per coital act is about 1/1000; however, risk is increased in early and advanced stages of HIV infection when HIV concentrations in plasma and genital fluids are higher, in younger people, and in people with ulcerative genital diseases. Circumcision seems to reduce the risk of males acquiring HIV infection by about 50% by removing the penile mucosa (underside of foreskin), which is more susceptible to HIV infection than the keratinized, stratified squamous epithelium that covers the rest of the penis. The penile skin (phallus) that is removed in circumcision has a lot of Langerhans cells that aids in HIV transmission as the virus has a high affinity to the mucosal epithelial surfaces found in this area which can become infected. Then, CD4+ T-lymphocytes that have surface receptors to which HIV can attach to promote entry into the cell. The infection extends to lymphoid tissues which contain follicular dendritic cells that can become infected and provide a reservoir for continuing infection of CD4+ T-lymphocytes.

Needle- and instrument-related transmission: Risk of transmission after skin penetration with a medical instrument contaminated with infected blood is on average about 1/300 without post-exposure antiretroviral prophylaxis. Immediate prophylaxis probably reduces risk to < 1/1500. Risk appears to be higher if the wound is deep or if blood is inoculated (eg, with a contaminated hollow-bore needle). Risk is also increased with hollow-bore needles and with punctures of arteries of veins compared with solid needles or other penetrating objects coated with blood because larger volumes of blood may be transferred. Thus, sharing needles that have entered the dsveins of other injection drug users is a very high risk activity.

Risk of transmission from infected health care practitioners who take appropriate precautions is unclear but appears minimal. In the 1980s,one documentation reviews that a dentist transmitted HIV to ≥ 6 of his patients by unknown means. However, extensive investigations of patients cared for by other HIV-infected physicians, including surgeons, have uncovered few other cases.

Postexposure prophylaxis (PEP): Potential consequences of exposure to HIV have prompted the development of policies and procedures, particularly preventive treatment, to decrease risk of infection to health care workers. Preventive treatment is indicated after penetrating injuries involving HIV-infected blood (usually needlesticks) or heavy exposure of mucous membranes (eye or mouth) to infected body fluids such as semen, vaginal fluids, or other body fluids containing blood (eg, amniotic fluid) . Risk of infection due to exposure to body fluids such as saliva, urine, or sweat is very low.

After initial exposure to blood, the exposed area is immediately cleaned with soap under running water for skin exposures and with antiseptic for puncture wounds. If mucous membranes are exposed, the area is flushed with large amounts of water.

The following are documented by Macallan DC. 1999;

• Type of exposure and time elapsed since exposure
• Clinical information (including risk factors and serologic tests for HIV) about the source patient for the exposure and the person exposed

Type of exposure is defined by

• Which body fluid was involved
• Whether exposure involved a penetrating injury (eg, needlestick, cut with sharp object) and how deep the injury was
• Whether the fluid had contact with nonintact skin (eg, abraded or chapped skin) or mucous membrane

Risk of infection is categorized as high or low:

• High: Involves a deep wound made by a hollow-bore needle with visible blood on it, direct exposure to a needle from a vein or an artery of the source patient, or mucocutaneous exposure with a large amount of blood from a high-risk source (viral load > 1500 copies/mL)
• Low: Involves a solid needle, superficial injury, or a low-risk source (viral load < 1500 copies/mL) and includes most mucocutaneous exposures

Risk of infection is about 0.3% (1:300) after a typical percutaneous exposure and about 0.09% (1:1100) after mucous membrane exposure, but these risks vary, reflecting the amount of HIV transferred to the person with the injury.

The source is qualified by whether it is known or unknown. If the source is unknown (eg, a needle on the street or in a sharps disposal container), risk should be assessed based on the circumstances of the exposure (eg, whether the exposure occurred in an area where injection drug use is prevalent, whether a needle discarded in a drug-treatment facility was used). If the source is known but HIV status is not, the source is assessed for HIV risk factors, and prophylaxis is considered

The goal is to start PEP as soon after exposure as possible if prophylaxis is warranted. CDC recommends providing PEP within 24 to 36 h after exposure; a longer interval after exposure requires the advice of an expert.

Use of PEP is determined by risk of infection; guidelines recommend antiretroviral therapy with 2 NRTIs (eg, ZDV plus 3TC) for low risk and the addition of one or more drugs (eg, 2 NRTIs plus a PI or an NNRTI) for high risk; drugs are given for 28 days. Nevirapine

is avoided because of the rare possibility of severe hepatitis. Although evidence is not conclusive, ZDV alone probably reduces risk of transmission after needlestick injuries by about 80%.

If the source's virus is known or suspected to be resistant to ≥ 1 drug, an expert in antiretroviral therapy and HIV transmission should be consulted. However, clinicians should not delay PEP pending expert consultation or drug susceptibility testing. Also, clinicians should provide immediate evaluation and face-to-face counseling and not delay follow-up care. The success of PEP has given light to possible prophylaxis in HIV prevention with some already existing anti-retro-viral drugs though the issue calls for a lot of debate.

Maternal transmission: HIV can be transmitted from mother to offspring transplacentally, perinatally, or via breast milk. Without treatment, risk of transmission at birth is about 25 to 35%. HIV is excreted in breast milk, and breastfeeding by untreated HIV-infected mothers may transmit HIV to about 10 to 15% of infants who had previously escaped infection. These rates can be reduced dramatically by treating HIV-positive mothers with antiretroviral drugs while they are pregnant, in labor, and breastfeeding. Because many HIV-positive pregnant women are treated or take prophylactic drugs, the incidence of AIDS in children is decreasing in many countries and 100% prevention of mother to child transmission is possible.

Transfusion- and transplant-related transmission: Screening of blood donors with tests for both antibody to HIV and HIV RNA has minimized risk of transmission via transfusion. Current risk of transmitting HIV via blood transfusion is probably < 1/2,000,000 per unit transfused in the US. However, in many developing countries, where blood and blood products are not screened for HIV, the risk of transfusion-transmitted HIV infection remains high.

Rarely, HIV has been transmitted via transplantation of organs from HIV-seropositive donors. Infection has developed in recipients of kidney, liver, heart, pancreas, bone, and skin—all of which contain blood—but screening for HIV greatly reduces risk of transmission. HIV transmission is even more unlikely from transplantation of cornea, ethanol-treated and lyophilized bone, fresh-frozen bone without marrow, lyophilized tendon or fascia, or lyophilized and irradiated dura mater. HIV transmission is possible via artificial insemination using sperm from HIV-positive donors but sperm washing from recent advancement has made it possible for this method to grant near 100% risk free of transmission of the virus.

To facilitate the realisation as to whether there could be any better warning to modern man, people living with HIV/AIDS should be put as an integral part of any nation’s response to the HIV/AIDS pandemic. There is a growing trend of money making voluntary organisations ignoring people living with the virus that need support. Further, support for HIV/AIDS programs is now dwindling at a time when a humongous score has been made in its prevention hence most projects have become a skeleton of the former self. As to those not yet infected by the virus, its high time we took responsibility of our sexuality and modified our behaviour to win this more than three decade old battle against the HIV/AIDS pandemic. If we continue operating with sleeping minds, our so called drug companies are going to continue benefiting from an increased HIV infected cases demanding for the supply of anti-retro viral drugs. The falling fortune in donor driven projects should now be a warning enough for people to realize their role in the prevention of the virus that is almost sending man into extinction.

Jones H. Munang’andu
Professional Scientific Medical Writer
Health commentator
Contact; Mobile 0966565670
Email; [email protected]
Skype; jones.muna