HIV/AIDS Program
How is HIV transmitted?
HIV is transmitted when infected blood, semen, vaginal fluids, organs, or breast milk enter another person's body. This most often occurs during unprotected sex or during injection drug use (when needles are shared). Anyone who is infected with HIV can transmit it, whether or not they appear sick, have an AIDS diagnosis, or are taking effective treatment for their infection. Although effective treatment greatly reduces the amount of virus in a person's body, often virus remains in the semen and other sexual fluids, making the person still infectious. Infected women who become pregnant can transmit HIV to their newborns and are much more likely to do so if they are not treated effectively. Thus, it is now being recommended that every pregnant woman be tested for HIV, regardless of their risk profile.
Requires:
| 1) |
Infected body fluid: |
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Blood, semen, vaginal secretions and breast milk
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| 2) |
Entry to the body: |
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Mucous membrane -- anal, oral or vaginal sex |
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Blood to blood -- needle or broken skin |
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Perinatal -- in utero, during birth, breastfeeding |
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HIV is spread in the following ways:
- Unprotected sexual intercourse.
HIV can enter the body during sex through the mucous membranes of the anus, vagina, penis (urethra), or mouth; AND through cuts, sores, and abrasions on the skin. With each of these practices, the receptive partner (vagina, anus, mouth) is at somewhat greatest risk
- Oral sex.
The risk of becoming infected with HIV through unprotected (without a condom) oral sex (without a condom) is lower than that of unprotected anal or vaginal sex. However, even a lower risk activity can become an important way people get infected if it is done often enough. A recent study found that 7.8% (8 of 102) of recently infected men who have sex with men in San Francisco were probably infected through oral sex. Oral sex is reported as a more frequent activity than anal sex and is almost never protected by condoms. And because many people (especially youth) do not associate oral sex with risk, oral sex is more likely to be unprotected than anal or vaginal sex.
- Injection drug use.
Using shared, unsterile needles and syringes carries a high risk of HIV transmission. Sharing drug injection equipment (such as cookers, cottons, and water for mixing) can also transmit HIV. After use, small amounts of blood can remain in the used needles, syringes, cookers, and cottons. Blood may also remain in the water used for mixing drugs. This remaining blood can enter the body of the next user when any of these items are shared. If this blood is HIV infected, transmission can easily occur.
Sharing other types of needles also may transmit HIV and other germs. These types of needles include those used to inject steroids and those used for tattooing or piercing. Tattoos and piercings should be done by a qualified technician who uses only sterile equipment.
- From an infected mother to her infant.
HIV can be transmitted from mother to child during pregnancy, more often during birth, or through breast-feeding. Before treatment with AZT became a routine recommendation for women near the end of their pregnancy and children following birth, about 1 in 4 or 5 babies born to HIV-infected women became infected. Now, when treatment is taken, the HIV transmission rate from a mother to her baby is greatly reduced. Consequently, all pregnant women should see their doctor, be tested for HIV, and obtain recommended treatment.
HIV is rarely transmitted in the following ways:
- Blood transfusions and organ transplants.
The risk of acquiring HIV from a blood transfusion today is estimated to be 1 out of 600,000 transfusions. The risk of acquiring HIV from an organ transplantation is probably similar; however, with newly effective treatments for HIV some people who might otherwise die from immediate lack of an organ may prefer an HIV-infected one. Before 1985, there were no tests to screen blood and organ donations for HIV. Today, blood and organ banks screen out most potential donors at risk for HIV infection in advance. They then do extensive testing on specimens of blood, blood products, and organs for HIV and other blood-borne germs.
- The health care setting.
There is a very small, but real, risk of health care workers getting HIV from patients as a result of needle stick accidents and other substantial blood exposures. The risk of patients getting infected from health care workers is also very small. A largeseries of studies of HIV-infected surgeons and dentists have not shown any transmissions to patients. Nonetheless, seven patients may have become infected from a dentist with AIDS in Florida, and several other transmissions of HIV (and of hepatitis B & C viruses) have been traced to surgeons.
- Mosquitoes.
There is no evidence of HIV transmission through insects--even in areas where there are many cases of AIDS and large populations of insects such as mosquitoes.
When an insect bites a person, it does not inject its own or a previous victim's blood into the new victim. Rather, it injects saliva. Such diseases as yellow fever and malaria are transmitted through the saliva of specific species of mosquitoes. However, HIV lives for only a short time inside an insect and, unlike organisms that are transmitted via insect bites, HIV does not reproduce (and, therefore, cannot survive) in insects.
- Casual contact.
HIV is not spread by casual contact. It dies quickly outside the body and is easily killed by soap and by common disinfectants such as bleach. Additionally, if the blood is dry, the virus is definitely dead.
There is no risk of HIV infection from:
- donating blood
- mosquito bites
- toilet seats
- shaking hands
- hugging
- sharing eating utensils food or objects handled by people with HIV or AIDS
- spending time in the same house, business, or public place with a person with HIV/AIDS.
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