Human Immunodeficiency Virus (HIV) (cont.)
Eric S. Daar, MD
Dr. Daar received his undergraduate degree from UCLA and medical degree from Georgetown University School of Medicine. He completed an internship and residency in internal medicine at Cedars-Sinai Medical Center and his clinical and research fellowship in infectious diseases at Cedars-Sinai Medical Center and UCLA.
In this Article
- Human immunodeficiency virus (HIV) facts
- What is the history of HIV, and when was HIV discovered?
- What tests are used in the diagnosis of HIV?
- How is HIV spread (transmitted)?
- What are symptoms and signs of HIV infection and AIDS in men, women, and children?
- What happens after an exposure to the blood or genital secretions of an HIV-infected person?
- What laboratory tests are used to monitor HIV-infected people?
- What are HIV treatments and medications? What are the key principles in managing HIV infection?
- When should antiviral therapy be started?
- What is the initial therapy for HIV?
- What are nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs)?
- What are nonnucleoside analogue reverse transcriptase inhibitors (NNRTIs)?
- What are protease inhibitors?
- What are fusion inhibitors?
- What is a CCR5 antagonist?
- What is an integrase strand transfer inhibitor?
- What HIV drugs are in development?
- What are side effects of HIV therapy?
- What happens if the patient's viral load increases while on HIV therapy?
- What are the risks of missing doses or stopping antiviral therapy?
- Should patients with the flu- or mono-like illness of primary HIV infection be treated?
- What about treatment for HIV during pregnancy?
- What can be done for people who have severe immunosuppression?
- What is the future for HIV-infected individuals with regards to treatment simplification and cure research?
- What is in the future for preventing HIV transmission?
- HIV-AIDS Rxlist FAQs
- Find a local Infectious Disease Specialist in your town
How is HIV spread (transmitted)?
HIV is present to variable degrees in the blood and genital secretions of virtually all untreated individuals infected with HIV, regardless of whether or not they have symptoms. The spread of HIV can occur when these secretions come in contact with tissues such as those lining the vagina, anal area, mouth, eyes (the mucus membranes), or with a break in the skin, such as from a cut or puncture by a needle. The most common ways in which HIV is spreading throughout the world include sexual contact, sharing needles, and by transmission from infected mothers to their newborns during pregnancy, labor (the delivery process), or breastfeeding. (See the section below on treatment during pregnancy for a discussion on reducing the risk of transmission to the newborn.)
Sexual transmission of HIV has been described from men to men, men to women, women to men, and women to women through vaginal, anal, and oral sex. The best way to avoid sexual transmission is abstinence from sex until it is certain that both partners in a monogamous relationship are not HIV infected. Because the HIV antibody test can take weeks to turn positive after infection occurs, both partners would need to test negative for at least 12 and up to 24 weeks after their last potential exposure to HIV. If abstinence is out of the question, the next best method is the use of latex barriers. This involves placing a condom on the penis as soon as an erection is achieved in order to avoid exposure to pre-ejaculatory and ejaculatory fluids that contain infectious HIV. For oral sex, condoms should be used for fellatio (oral contact with the penis) and latex barriers (dental dams) for cunnilingus (oral contact with the vaginal area). A dental dam is any piece of latex that prevents vaginal secretions from coming in direct contact with the mouth. Although such dams occasionally can be purchased, they are most often created by cutting a square piece of latex from a condom.
The spread of HIV by exposure to infected blood usually results from sharing needles, as in those used for illicit drugs. HIV also can be spread by sharing needles for anabolic steroids to increase muscle, tattooing, and body piercing. To prevent the spread of HIV, as well as other diseases, including hepatitis, needles should never be shared. At the beginning of the HIV epidemic, many individuals acquired HIV infection from blood transfusions or blood products, such as those used for hemophiliacs. Currently, however, because blood is tested for both antibodies to HIV and the actual virus before transfusion, the risk of acquiring HIV from a blood transfusion in the United States is extremely small and is considered insignificant.
There is little evidence that HIV can be transferred by casual exposure, as might occur in a household setting. For example, unless there are open sores or blood in the mouth, kissing is generally considered not to be a risk factor for transmitting HIV. This is because saliva, in contrast to genital secretions, has been shown to contain very little HIV. Still, theoretical risks are associated with the sharing of toothbrushes and shaving razors because they can cause bleeding, and blood can contain large amounts of HIV. Consequently, these items should not be shared with infected people. Similarly, without sexual exposure or direct contact with blood, there is little if any risk of HIV contagion in the workplace or classroom.
Risk factors for acquiring HIV infection include increased amounts of virus in fluids and/or breaks in the skin or mucous membranes which also contain these fluids. The former primarily relates to the viral load in the infected person's blood and genital fluids. In fact, when the former is high, the latter usually is also quite elevated. This is in part why those on effective antiretroviral therapy are less likely to transmit the virus to their partners. With regard to disruption of mucous membranes and local trauma, this is often associated with the presence of other sexually transmitted diseases (for example, herpes and syphilis) or traumatic sexual activities. Another risk factor for HIV acquisition by a man is the presence of foreskin. This has most convincingly been demonstrated in high-risk heterosexual men in developing countries where the risk declines after adult male circumcision.
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