Continuing Pharmacy Education
What you need to know about…
AIDS was first reported in the United States in 1981 and has since become a major worldwide epidemic. AIDS is caused by the human immunodeficiency virus, or HIV. By killing or damaging cells of the body’s immune system, HIV progressively destroys the body’s ability to fight infections and certain cancers. People diagnosed with AIDS may get life-threatening diseases called opportunistic infections. These infections are caused by microbes such as viruses or bacteria that usually do not make healthy people sick.
Since 1981, more than 980,000 cases of AIDS have been reported in the United States to the Centers for Disease Control and Prevention (CDC). According to CDC, more than 1,000,000 Americans may be infected with HIV, one-quarter of whom are unaware of their infection. The epidemic is growing most rapidly among minority populations and is a leading killer of African-American males ages 25 to 44. According to CDC, AIDS affects nearly seven times more African Americans and three times more Hispanics than whites. In recent years, an increasing number of African-American women and children are being affected by HIV/AIDS.
What are HIV and AIDS?
HIV, or human immunodeficiency virus, is the virus that causes AIDS. HIV attacks the immune system by destroying CD4 positive (CD4+) T cells, a type of white blood cell that is vital to fighting off infection. The destruction of these cells leaves people infected with HIV vulnerable to other infections, diseases and other complications.
AIDS is the final stage of HIV infection. A person infected with HIV is diagnosed with AIDS when he or she has one or more opportunistic infections, such as pneumonia or tuberculosis, and has a dangerously low number of CD4+ T cells (less than 200 cells per cubic millimeter of blood).
How HIV causes AIDS
HIV destroys CD4 positive (CD4+) T cells, which are white blood cells crucial to maintaining the function of the human immune system. As HIV attacks these cells, the person infected with the virus is less equipped to fight off infection and disease, ultimately resulting in the development of AIDS.
Most people who are infected with HIV can carry the virus for years before developing any serious symptoms. But over time, HIV levels increase in the blood while the number of CD4+ T cells decline. Antiretroviral medicines can help reduce the amount of virus in the body, preserve CD4+ T cells and dramatically slow the destruction of the immune system.
People who are not infected with HIV and generally are in good health have roughly 800 to 1,200 CD4+ T cells per cubic millimeter (mm3) of blood. Some people who have been diagnosed with AIDS have fewer than 50 CD4+ T cells in their entire body.
About HIV Transmission
- HIV cannot survive for very long outside of the body
- HIV cannot be transmitted through routine daily activities such as using a toilet seat, sharing food utensils or drinking glasses, shaking hands, or through kissing.
- The virus can only be transmitted from person to person, not through animals or insect bites
- People infected with HIV who are taking antiretroviral therapy can still infect others through unprotected sex and needle-sharing
HIV Risk Factors
HIV is found in the blood, semen, or vaginal fluid of someone who is infected with the virus. You may be at increased risk of becoming infected with HIV if you
- Engage in anal, vaginal, or oral sex with men who have sex with men, multiple partners, or anonymous partners without using a condom
- Inject drugs or steroids where needles/syringes are shared
- Have a sexually transmitted infection, such as syphilis, genital herpes, chlamydia, gonorrhea, bacterial vaginosis, or trichomoniasis
- Have been diagnosed with hepatitis, tuberculosis, or malaria
- Exchange sex for drugs or money
- Are exposed to the virus as a fetus or infant before or during birth or through breastfeeding from a mother infected with HIV
- Received a blood transfusion or clotting factor in the United States anytime from 1978 to 1985
- Engage in unprotected sex with someone who has any of the risk factors listed above
In the first stages of HIV infection, most people will have very few, if any, symptoms. Within a month or two after infection, they may experience a flu-like illness, including:
- Enlarged lymph nodes in the neck and groin area
These symptoms usually disappear within a week to a month and are often mistaken for another viral infection, such as flu. However, during this period people are highly infectious because HIV is present in large quantities in genital fluids and blood. Some people infected with HIV may have more severe symptoms at first or symptoms that last a long time, while others may have no symptoms for 12 years or more.
During the late stages of HIV infection, the virus severely weakens the immune system, and people infected with the virus may have the following symptoms:
- Rapid weight loss
- Recurring fever or profuse night sweats
- Extreme and unexplained tiredness
- Prolonged swelling of the lymph glands in the armpits, groin, or neck
- Diarrhea that lasts for more than a week
- Sores of the mouth, anus, or genitals
- Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids
- Memory loss, depression, and other neurologic disorders.
Each of these symptoms can be related to other illnesses. The only way to find out if you are infected with HIV is to get tested.
Testing and Diagnosis
Routine HIV TestingOf the estimated 1.1 million Americans currently living with HIV, 21 percent do not know they are infected. People who have been infected recently with HIV often have few to no symptoms yet are extremely infectious and may unknowingly transmit the virus to others. Therefore, the Centers for Disease Control and Prevention (CDC) recommends HIV testing for adults, adolescents, and pregnant women during routine medical care.1Regular HIV screenings allow healthcare providers to identify people who are not aware that they are infected with HIV, so that they can be counseled on the need to avoid high-risk behaviors, instructed on safe-sex practices, and given information about starting antiretroviral therapy. HIV testing can also be performed anonymously if a person is concerned about confidentiality.
Types of HIV Tests
Healthcare providers can test a sample of blood to see if it contains human antibodies (disease-fighting proteins) specific to HIV. The two key types of HIV antibody tests are the enzyme-linked immunosorbent assay (ELISA) and the Western blot.
However, these antibody tests may not detect HIV antibodies in someone who has been recently infected with HIV (within 1 to 3 months of infection). In these situations, healthcare providers can test the blood for the presence of HIV genetic material. This test is extremely critical for identifying recently infected people who are at risk for unknowingly infecting others with HIV.
HIV Testing in Infants
CDC recommends that all pregnant women get tested for HIV before and/or during delivery. Knowing the HIV status of the mother allows physicians to prevent mother-to-child HIV transmission by providing antiretroviral treatment to both mothers infected with HIV and their newborn infants. However, it is difficult to determine if a baby born to a mother infected with HIV is actually infected because babies carry their mothers’ HIV antibodies for several months. Today, healthcare providers can conduct an HIV test for infants between ages 3 months and 15 months. Researchers are now evaluating several blood tests to determine which ones are suitable for testing babies younger than 3 months.
1Revised Recommendations for HIV Testing of Adults, Adolescents, and Pregnant Women in Health-Care Settings, September 2006.