Friday, December 12, 2008

Acquired Immunodeficiency Syndrome (AIDS) and Human Immunodeficiency Virus (HIV)

Definition
Acquired immunodeficiency syndrome (AIDS) is an illness that weakens the body's immune system. The immune systems of people with AIDS are not able to fight off certain infections and cancers.

Causes
AIDS is caused by the human immunodeficiency virus (HIV), which destroys important immune system cells. HIV is spread through contact with HIV-infected blood or other body fluids including semen, vaginal fluid, and breast milk.
HIV is spread through:
• Sexual contact with an HIV-infected person, especially intercourse or anal sex
• Transfer of HIV from a mother to child during pregnancy, childbirth, or breastfeeding
• Being pricked by an HIV-contaminated needle
• Blood transfusion with HIV-infected blood (rare today, due to testing of all donated blood for HIV infection beginning in 1985)
Rarely, HIV can be spread through:
• Blood from an HIV-infected person getting into an open wound of another person
• Being bitten by someone infected with HIV
• Sharing personal hygiene items with an HIV-infected person (razors, toothbrushes, etc)
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors include:
• Multiple sexual partners
• Sharing needles for injecting drugs
• Regular exposure to HIV-contaminated blood or other body fluids (a concern for healthcare workers)
• Infant born to an HIV-infected mother
• Receiving donor blood products, tissue, organs, or artificial insemination
• Immigrants from geographic locations with high numbers of AIDS patients (east central Africa and Haiti)
• Sexual relationship with a high-risk individual or a partner already infected with HIV
Symptoms
HIV may not cause symptoms for a number of years.
Early symptoms that you may experience a month or two after becoming infected may last a couple of weeks. These include:
• Rapid weight loss
• Dry cough
• Sore throat
• Recurring fever
• Night sweats
• Extreme, unexplained fatigue
• Swollen lymph nodes in armpits, neck, or groin
• White spots on the tongue or in the mouth or throat
• Headache
• Discomfort from light
• Rash
• Depression
• Irritable mood
• Memory loss or other neurological disorder
After these initial symptoms are gone, there may be no symptoms for months to years. Then, the following symptoms may occur over the course of 1-3 years:
• Swollen lymph glands all over the body
• Fungal infections of the mouth, fingernails, toes
• Repeated vaginal infections (yeast and Trichomonas)
• Development of lots of warts
• Exacerbations of prior conditions, such as eczema, psoriasis, herpes infection
• Shingles
• Night sweats
• Weight loss
• Chronic diarrhea
Once HIV has progressed to AIDS, the immune system has become quite weakened. Opportunistic infections are infections that people with a normal immune system don't usually get. These infections occur in patients with AIDS because the immune system isn't able to fight them off. Examples of opportunistic infections and other complications of AIDS include:
• Thrush (an overgrowth of yeast)
• Pneumonia (particularly Pneumocystis carinii pneumonia)
• Invasive fungal infections (resulting in brain and/or lung infections)
• Toxoplasmosis infection
• Tuberculosis
• Viral brain infection
• Kaposi's sarcoma
• Lymphoma
• Cervical cancer
• Eye disease due to cytomegalovirus infection
• Intestinal infections, especially due to Shigella, Salmonella, and Campylobacter
• Severe weight loss (wasting syndrome)
• Severe skin rashes
• Reactions to medications
• Psychiatric problems, including depression and dementia
Diagnosis
The doctor will ask about your symptoms, medical history, and risk factors, and perform a physical exam.
A blood test called an ELISA test is used to detect HIV infection. If an ELISA test is positive, the Western blot blood test is usually done to confirm the diagnosis. The ELISA test may be negative if you were infected with HIV recently. Many people (95%) will have a positive test within three months. Most people (99%) will have a positive test within six months. If an ELISA test is negative, but you think you may have HIV, you should be tested again in 1-3 months.
Treatment
With medication, the development of AIDS can be prevented, delayed, or controlled in many people infected with HIV.
Drugs That Fight HIV
These drugs are often given in combination, referred to popularly as "AIDS cocktails." They include:
Nucleoside reverse transcriptase inhibitors:
• AZT (zidovudine or ZDV)
• ddC (zalcitabine)
• ddI (dideoxyinosine)
• d4T (stavudine)
• 3TC (lamivudine)
• Emtricitabine (Emtriva)
• Tenofovir (Viread)
Non-nucleoside reverse transriptase inhibitors:
• Delvaridine (Rescriptor)
• Nevirapine (Viramune)
• Efravirenz (Sustiva)
Protease inhibitors:
• Ritonavir (norvir)
• Saquinivir (invirase)
• Indinavir (crixivan)
• Amprenivir (Agenerase)
• Nelfinavir (Viracept)
• Lopinavir (Kaletra)
Drugs That Fight AIDS-related Infections and Cancers
People who have developed AIDS are treated with numerous drugs that help prevent:
• Pneumonia
• Thrush
• Repeated herpes infections
• Toxoplasmic brain infections
Prevention
To prevent becoming infected with HIV:
• Abstain from sex or use a male latex condom. This includes intercourse and any other sexual acts that result in the exchange of bodily fluids.
• Do not share needles for drug injection.
• Limit your number of sexual partners.
• Avoid sexual partners who are HIV-infected or injection drug users.
• Avoid receiving transfusion of unscreened blood products.
• If you are a healthcare worker:
o Wear latex gloves and facial masks during all procedures.
o Carefully handle and properly dispose of needles.
o Carefully follow universal precautions (a detailed list of how to handle such things as needles and other biohazard materials).
• If you live in a household with an HIV-infected person:
o Wear latex gloves if handling HIV-infected bodily fluids.
o Cover all cuts and sores (yours and the HIV-infected person's) with bandages.
o Do not share any personal hygiene items (razors, toothbrushes, etc).
o Carefully handle and properly dispose of needles used for medication.
In addition, three recent trials involving over 11,000 Africans found that circumcised men were significantly less likely to develop HIV infection compared to uncircumcised men. While this finding has less relevance in the US, where most men are already circumcised and the risk of HIV is far lower, it is still important to consider that circumcision can apparently reduce the risk of HIV transmission.*
To prevent spreading HIV to others if you are HIV infected:
• Abstain from sex or use a male latex condom. This includes intercourse and any other sexual acts that result in the exchange of bodily fluids.
• Inform former or potential sexual partners.
• Do not donate blood or organs.
• Try not to get pregnant. If you are sexually active, ask for professional advice about contraception.
• If you have a baby, do not breastfeed.