What is HIV/AIDS?
The virus that causes AIDS is called the Human Immunodeficiency Virus, or HIV. HIV attacks and kills important immune cells—cells that help you fight off diseases and infections. The cells HIV attacks are called “CD4+T cells.” By killing or damaging cells of the body's immune system, HIV progressively turns into AIDS and destroys the body's ability to fight infections and certain cancers.
AIDS is Acquired Immune Deficiency Syndrome, and is a disease that destroys the body’s immune system, leaving a person susceptible to life-threatening illnesses. A person is diagnosed with AIDS when there T-cell count drops below 200/mm3. People diagnosed with AIDS may get life-threatening diseases called opportunistic infections, which are caused by microbes such as viruses or bacteria that usually do not make healthy people sick.
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How is HIV Transmitted?
HIV/AIDS is passed from one person to another through blood-to-blood and sexual contact. The two most common ways HIV is spread is by having unprotected sex with an infected partner and among injection drug users by the sharing of needles or syringes contaminated with very small quantities of blood from someone infected with the virus.
In addition, 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.
There are no documented cases of HIV being transmitted by tears or saliva, but it is possible to be infected with HIV through oral sex or in rare cases through deep kissing, especially if you have open sores in your mouth or bleeding gums.
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What are the Symptoms of HIV?
The only way to know if you are infected is to be tested for HIV infection. Many people will not have any symptoms when they first become infected with HIV. Some people, however, will have a flu-like illness within a month or two after exposure to the virus. This illness may include
- Enlarged lymph nodes (glands of the immune system easily felt in the neck and groin)
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 (CD4+) cells found in the blood-the immune system's key infection fighters. 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
- Lack of energy
- Weight loss
- Frequent fevers and sweats
- Persistent or frequent yeast infections (oral or vaginal)
- Persistent skin rashes or flaky skin
- Pelvic inflammatory disease in women that does not respond to treatment
- Short-term memory loss
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.
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Approaches to Prevention
Because no vaccine for HIV is available, the only way to prevent infection by the virus is to avoid behaviors that put you at risk of infection, such as sharing needles and having unprotected sex. One of the challenges to preventing the spread of HIV/AIDS is that a quarter of the people infected with HIV do not know their status. The Centers for Disease Control and Prevention (CDC) is working to reduce barriers to early diagnosis of HIV infection and increase access to quality medical care, treatment, and ongoing prevention services for those with a diagnosis of HIV infection. The CDC’s initiative emphasizes the use of proven public health approaches to reduce the incidence and spread of disease and capitalizes on new rapid test technologies, interventions that bring persons unaware of their HIV status to HIV testing, and behavioral interventions that provide prevention skills to persons living with HIV.
The initiative consists of four key strategies:
- Make HIV testing a routine part of medical care;
- Implement new models for diagnosing HIV infections outside medical settings;
- Prevent new infections by working with HIV-infected persons and their partners
- Decrease perinatal HIV transmission
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