How can I...

What is HIV/AIDS?
The Human Immunodeficiency Virus, or HIV, is the virus that causes AIDS, the Acquired Immune Deficiency Syndrome. Over 1.1 million people in the United States are living with HIV, and almost a fifth (18.1%) of HIV infected Americans are unaware of their status. Although there have been major advances in the prevention and treatment of HIV, we continue to see too many new HIV infections and too many AIDS deaths. For these reasons, a general understanding of HIV is essential to public health.

How do people get HIV? 
It is important to recognize the main modes of HIV transmission. HIV can be passed from one person to another through bodily fluids such as blood, semen, vaginal fluids, and breast milk. Unprotected sex with an HIV infected person and direct contact with HIV-infected blood through shared injection equipment, open wounds, or mucous membranes (eyes, mouth, rectum, vagina) may lead to transmission. It is extremely unlikely for HIV infection to happen simply through brief contact between infectious bodily fluids and intact skin. The risk of HIV infection from any single sexual exposure is generally low, but receptive anal intercourse is the highest risk sexual activity, followed by receptive vaginal intercourse. Oral sex is very low risk, and HIV cannot be transmitted through saliva, sweat, or tears. 

How does HIV affect the body?
HIV infects cells of the human immune system, particularly a kind of white blood cell called the CD4 T-cell. These cells help in identifying and destroying harmful material in the body, including bacteria, viruses, parasites, and even some cancer cells. Over time, HIV infection destroys the CD4 cells, leading to a weakened immune system, certain kinds of infections, severe illness, and death. The infections are often called “opportunistic infections” (OIs) because they are rare or mild in healthy people but can take advantage of the opportunity provided by the HIV-weakened immune system and can be life threatening. The HIV virus can also damage tissue directly, causing neurologic disease, heart disease, and other problems.

The CD4 cell count (sometimes called a T-cell count) is a measure of the number of CD4 cells in one microliter of blood. People with HIV and their health care providers use the CD4 count to monitor the infection over time.

What are the stages of HIV? How long until progression to AIDS if left untreated?
The first stage of HIV infection is known as acute or primary infection. Most people will experience flu-like symptoms (fever, sore throat, rash, swollen glands) within a few weeks of contracting HIV, but sometimes these can be quite mild. In this stage, the virus spreads rapidly to immune cells throughout the body, especially in the lining of the gut. Large amounts of HIV can be detected in the blood initially, but eventually, the immune system responds and partially suppresses the virus. It can be difficult to detect HIV by blood tests in the first week or two of infection.

Following acute HIV infection, most people enter a period of clinical latency in which they have few or no symptoms. This period may last decades or only a few months, but most infected persons will progress to AIDS over several years. During clinical latency, the amount of virus in the blood often remains stable but detectable, and the CD4 count slowly declines from normal levels (above 500). In rare cases, the infected person’s immune system keeps the viral levels very low and the CD4 count does not drop, even without the use of medications.

If the CD4 count drops below 200 or if a HIV infected person develops one of several AIDS-defining conditions, this indicates progression to AIDS. The immune system is weakened and increasingly susceptible to OIs. Without any treatment, those persons with CD4 counts below 200 have a life expectancy of months to a few years. Once an OI is present in an AIDS patient, overall life expectancy without treatment drops to less than a year.

How can I learn my HIV status?
HIV is primarily spread by those unaware they have HIV, as they are less likely to take measures to protect their sex and injection drug use partners. Since many people feel healthy for years after contracting HIV, the only definitive way to know one’s HIV status is to get tested. Testing can be done by a medical provider or through an HIV testing program. Home test kits are now available, as well.

There are many very good HIV tests available that detect HIV-specific antibodies (part of the body’s response to many infections) or, in some cases, the virus itself. With advancements in the field of rapid HIV testing, it is possible to obtain preliminary results in as little as 20 minutes or less. Although HIV tests are very accurate, all HIV positive results must be confirmed by another test before a final diagnosis can be made.