Causes and Risk Factors of AIDS and HIV Infection

Causes and Risk Factors of AIDS and HIV Infection

AIDS is transmitted via three main routes:

• The most common mode of transmission is the transfer of body secretions through sexual contact. This is accomplished through exposure of mucous membranes of the rectum, vagina or mouth to blood, semen or vaginal secretions containing the HIV virus.
• Blood or blood products can transmit the virus, most often through the sharing of contaminated syringes and needles.
• HIV can be spread during pregnancy from mother to fetus.

You cannot get AIDS/HIV from touching someone or sharing items, such as cups or pencils, or through coughing and sneezing. Additionally, HIV is not spread through routine contact in restaurants, the workplace or school. However, sharing a razor does pose a small risk in that blood from a minor nick can be transmitted from one person to another.

Symptoms of AIDS and HIV Infection

Immediately following infection with HIV, most individuals develop a brief, nonspecific �viral illness� consisting of low grade fever, rash, muscle aches, headache and/or fatigue. Like any other viral illness, these symptoms resolve over a period of five to 10 days. Then for a period of several years (sometimes as long as several decades), people infected with HIV are asymptomatic (no symptoms). However, their immune system is gradually being destroyed by the virus. When this destruction has progressed to a critical point, symptoms of AIDS appear. These symptoms are as follows:

• extreme fatigue
• rapid weight loss from an unknown cause (more than 10 lbs. in two months for no reason)
• appearance of swollen or tender glands in the neck, armpits or groin, for no apparent reason, lasting for more than four weeks
• unexplained shortness of breath, frequently accompanied by a dry cough, not due to allergies or smoking
• persistent diarrhea
• intermittent high fever or soaking night sweats of unknown origin
• a marked change in an illness pattern, either in frequency, severity, or length of sickness
• appearance of one or more purple spots on the surface of the skin, inside the mouth, anus or nasal passages
• whitish coating on the tongue, throat or vagina
• forgetfulness, confusion and other signs of mental deterioration

It can take as short as a year to as long as 10 to 15 years to go from being infected with HIV to "full-blown" AIDS.

According to the Center for Disease Control and Prevention, a person is considered to have AIDS when they have a T cell count (also called CD4 cell count) of 200 or less (healthy T cell levels range from 500 to 1500) or they have an AIDS-defining condition. The AIDS-defining conditions are:

People who are not infected with HIV may also develop these diseases; the presence of any one of these conditions does not mean the person has AIDS. To be diagnosed with AIDS, a person must be infected with HIV.

Some people infected with HIV may develop a disease that is less serious than AIDS, referred to as AIDS Related Complex (ARC). ARC is a condition caused by the AIDS virus in which the patient tests positive for AIDS infection and has a specific set of clinical symptoms. However, ARC patients' symptoms are often less severe than those with classic AIDS because the degree of destruction of the immune system has not progressed as far as it has in patients with classic AIDS.

Symptoms of ARC may include loss of appetite, weight loss, fever, night sweats, skin rashes, diarrhea, tiredness, lack of resistance to infection or swollen lymph nodes.

Note: Not everyone who has been infected with HIV develops AIDS. Very rarely, some individuals can be infected with HIV yet maintain normal immune function and general good health even after 20 years of infection.

Diagnosis of AIDS and HIV Infection

Screening for HIV infection is most commonly done by testing blood for HIV antibodies. A newer test, the Orasure test, involves collecting secretions between the cheek and gum and evaluating them for HIV antibodies. Orasure is essentially as accurate as a blood test, and, because it doesn't involve a needle stick, it is favored by many individuals. Orasure is available through physicians� offices and many public health clinics. Finally, a new urine test available for screening, although if the test is positive, blood tests need to be performed for confirmation of the presence of HIV.

In 1996, a home HIV blood test (called Home Access) became available to the public. These home kits are available in pharmacies and by mail. The kit contains a few sharp tools called lancets, a piece of blotting paper marked with a unique identification number and a prepaid return envelope with a protective pouch. After pricking the finger with the lancet, a few drops of blood are blotted onto the paper, sealed into the envelope and sent to the address on the envelope. In about a week, the person calls a toll-free number to get the results of the test.

Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)

Delavirdine (Rescriptor, DLV) Pfizer

Efavirenz (Sustiva, EFV) Bristol-Myers Squibb

Nevirapine (Viramune, NVP) Boehringer Ingelheim

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

Abacavir (Ziagen, ABC) GlaxoSmithKline

Abacavir,Lamivudine, Zidovudine (Trizivir) GlaxoSmithKline

Didanosine (Videx, ddI, Videx EC) Bristol-Myers Squibb

Emtricitabine (Emtriva, FTC, Coviracil) Gilead Sciences

Lamivudine (Epivir, 3TC) GlaxoSmithKline

Lamivudine, Zidovudine (Combivir) GlaxoSmithKline

Stavudine ( Zerit, d4T) Bristol-Myers Squibb

Tenofovir DF (Viread, TDF) Gilead Sciences

Zalcitabine (Hivid, ddC) Hoffmann-La Roche

Atripla (tenofovir, emtricitabine, efavirenz) Gilead Sciences

Zidovudine (Retrovir, AZT, ZDV) GlaxoSmithKline

Protease Inhibitors (PIs)

Amprenavir (Agenerase, APV) GlaxoSmithKline, Vertex Pharmaceuticals

Atazanavir (Reyataz, ATV) Bristol-Myers Squibb

Fosamprenavir (Lexiva, FPV) GlaxoSmithKline, Vertex Pharmaceuticals

Indinavir (Crixivan, IDV) Merck

Lopinavir, Ritonavir (Kaletra, LPV/r) Abbott Laboratories

Nelfinavir (Viracept, NFV) Agouron Pharmaceuticals

Ritonavir (Norvir, RTV) Abbott Laboratories

Saquinavir (Fortovase, SQV) Invirase Hoffmann-La Roche

Tipranavir (Aptivus) Boehringer-Ingelheim

Darunavir (Prezista) Tibotec Therapeutics

Fusion Inhibitors

Enfuvirtide (Fuzeon, T-20) Hoffmann-La Roche, Trimeris