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AIDS Overview |
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AIDS (acquired immunodeficiency syndrome) was first reported in the United States in 1981 and has since become a major worldwide epidemic. More than 1 million cases of AIDS have been reported in the United States since 1981. African Americans make up 50 percent and Hispanics represent 15 percent of all AIDS cases in the United States. AIDS is caused by HIV (human immunodeficiency virus). Approximately 40,000 new HIV infections occur each year in the United States, 70 percent of them among men and 30 percent among women. Of the new infections, approximately 40 percent are from male-to-male contact, 30 percent from heterosexual contact, and 25 percent from injection drug use. TRANSMISSIONHIV is spread most commonly by having unprotected sex with an infected partner. The virus can enter the body through the lining of the vagina, vulva, penis, rectum, or mouth during sex. Risky behavior HIV can infect anyone who practices risky behaviors such as
Infected blood HIV also is spread through contact with infected blood. Before donated blood was screened for evidence of HIV infection and before heat-treating techniques to destroy HIV in blood products were introduced, HIV was transmitted through transfusions of contaminated blood or blood components. Today, because of blood screening and heat treatment, the risk of getting HIV from such transfusions is extremely small. Contaminated needles HIV is frequently spread among injection drug users by the sharing of needles or syringes contaminated with very small quantities of blood from someone infected with the virus. It is rare, however, for a patient to give HIV to a health care worker or vice-versa by accidental sticks with contaminated needles or other medical instruments. Mother to child Women can transmit HIV to their babies during pregnancy or birth. Approximately one-quarter to one-third of all untreated pregnant women infected with HIV will pass the infection to their babies. HIV also can be spread to babies through the breast milk of mothers infected with the virus. If the mother takes certain drugs during pregnancy, she can significantly reduce the chances that her baby will get infected with HIV. If health care providers treat HIV-infected pregnant women and deliver their babies by cesarean section, the chances of the baby being infected can be reduced to a rate of 1 percent. HIV infection of newborns has been almost eradicated in the United States due to appropriate treatment. A study sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) in Uganda found a highly effective and safe drug for preventing transmission of HIV from an infected mother to her newborn. Independent studies have also confirmed this finding. This regimen is more affordable and practical than any other examined to date. Results from the study show that a single oral dose of the antiretroviral drug nevirapine (NVP) given to an HIV-infected woman in labor and another to her baby within 3 days of birth reduces the transmission rate of HIV by half compared with a similar short course of AZT (Azidothymidine). Saliva Although researchers have found HIV in the saliva of infected people, there is no evidence that the virus is spread by contact with saliva. Laboratory studies reveal that saliva has natural properties that limit the power of HIV to infect, and the amount of virus in saliva appears to be very low. Research studies of people infected with HIV have found no evidence that the virus is spread to others through saliva by kissing. The lining of the mouth, however, can be infected by HIV, and instances of HIV transmission through oral intercourse have been reported. Scientists have found no evidence that HIV is spread through sweat, tears, urine, or feces. Casual contact Studies of families of HIV-infected people have shown clearly that HIV is not spread through casual contact such as the sharing of food utensils, towels and bedding, swimming pools, telephones, or toilet seats. HIV is not spread by biting insects such as mosquitoes or bedbugs. Sexually transmitted infections If you have a sexually transmitted infection (STI) such as syphilis, genital herpes, chlamydial infection, gonorrhea, or bacterial vaginosis appears, you may be more susceptible to getting HIV infection during sex with infected partners.
EARLY SYMPTOMS OF HIV INFECTIONSome people who are infected with HIV may not have any symptoms for several years. Others may have a flu-like illness within a month or two after exposure to the virus. This illness may include
These symptoms usually disappear within a week to a month and are often mistaken for those of another viral infection. During this period, people are very infectious, and HIV is present in large quantities in genital fluids. More persistent or severe symptoms may not appear for 10 years or more after HIV first enters the body in adults, or within 2 years in children born with HIV infection. This period of "asymptomatic" infection varies greatly in each individual. Some people may begin to have symptoms within a few months, while others may be symptom-free for more than 10 years. Even during the asymptomatic period, the virus is actively multiplying, infecting, and killing cells of the immune system. The virus can also hide within infected cells and lay dormant. The most obvious effect of HIV infection is a decline in the number of CD4 positive T cells (more into). The virus slowly disables or destroys these cells without causing symptoms. As the immune system worsens, a variety of complications start to take over. For many people, the first signs of infection are large lymph nodes or "swollen glands" that may be enlarged for more than 3 months. Other symptoms often experienced months to years before the onset of AIDS include
Some people develop frequent and severe herpes infections that cause mouth, genital, or anal sores, or a painful nerve disease called shingles. Children may grow slowly or be sick a lot. TREATMENTWhen AIDS first surfaced in the United States, there were no medicines to combat the underlying immune deficiency and few treatments existed for the opportunistic diseases that resulted. Researchers, however, have developed drugs to fight both HIV infection and its associated infections and cancers. HIV infection The Food and Drug Administration (FDA) has approved a number of drugs for treating HIV infection. These drugs fall into three major classes: reverse transcriptase (RT) inhibitors, protease inhibitors and fusion inhibitors (more info). Opportunistic infections A number of available drugs help treat opportunistic infections. These drugs include
Cancers Health care providers use radiation, chemotherapy, or injections of alpha interferon (a genetically engineered protein that occurs naturally in the human body) to treat Kaposi's sarcoma or other cancers associated with HIV infection.
Reference: National Institute of Allergy and Infectious Diseases, USA.
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