Stages of HIV Infection

When people get HIV and don't receive treatment, they will typically progress through three stages of disease. Medicine to treat HIV, known as antiretroviral therapy (ART), helps people at all stages of the disease if taken the right way, every day, and treatment can slow or prevent progression from one stage to the next. Treatment can also dramatically reduce the chance of transmitting HIV.

• Stage 1: Acute HIV infection
  Within 2 to 4 weeks after infection with HIV, people may experience a flu-like illness, which may last for a few weeks. This is the body's natural response to infection. When people have acute HIV infection, they have a large amount of virus in their blood and are very contagious. But people with acute infection are often unaware that they're infected because they may not feel sick right away or at all. To know whether someone has acute infection, either a fourth-generation or nucleic acid (NAT) test is necessary. If you think you have been exposed to HIV through sex or drug use and you have flu-like symptoms, seek medical care and ask for a test to diagnose acute infection.
• Stage 2: Clinical latency (HIV inactivity or dormancy)
  This period is sometimes called asymptomatic HIV infection or chronic HIV infection. During this phase, HIV is still active but reproduces at very low levels. People may not have any symptoms or get sick during this time. For people who aren't taking medicine to treat HIV, this period can last a decade or longer, but some may progress through this phase faster. People who are taking ART the right way, every day, may be in this stage for several decades. It's important to remember that you can still transmit HIV to others during this phase, although people who are on ART and stay virally suppressed are much less likely to transmit HIV than people who are not virally suppressed. At the end of this phase, your viral load starts to go up and your CD4 cell count begins to go down. + As this happens, you may begin to have symptoms as the virus levels increase in your body, and you move into Stage 3.

  CD4 cells activate the body's immune system to fight off infections. HIV attacks the body's CD4 cells so that the immune system is less able to fight off viruses or infections.

• Stage 3: Acquired immunodeficiency syndrome (AIDS)
  AIDS is the most severe phase of HIV infection. People with AIDS have such badly damaged immune systems that they get an increasing number of severe illnesses, called opportunistic illnesses. +

  Opportunistic illnesses are infections and infection-related cancers that are more common or more severe in people with HIV because their immune systems are damaged. Examples include Kaposi's sarcoma, lymphoma, tuberculosis, and pneumonia. More information on opportunistic infections and AIDS-related cancers can be found here.

Without treatment, people with AIDS typically survive about 3 years. Common symptoms of AIDS include chills, fever, sweats, swollen lymph glands, weakness, and weight loss. People are diagnosed with AIDS when their CD4 cell count drops below 200 cells/mm³ or if they develop certain opportunistic illnesses. People with AIDS can have a high viral load and be very infectious.