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HIV Treatment

When to Start Antiretroviral Therapy

(Last updated 5/6/2014; last reviewed 5/6/2014)

Key Points

  • Antiretroviral therapy (ART) is the use of HIV medicines to treat HIV infection. ART is recommended for everyone infected with HIV. When to start ART, however, depends on a person’s unique needs and circumstances.
  • A person’s CD4 count is an important factor in the decision to start ART. A low or falling CD4 count indicates that HIV is advancing and damaging the immune system. A rapidly decreasing CD4 count increases the urgency to start ART.
  • The U.S. Department of Health and Human Services (HHS) provides guidelines on the use of HIV medicines to treat HIV infection. The HHS guidelines recommend ART for everyone infected with HIV, but the recommendation is strongest for those with CD4 counts less than 350 cells/mm3.
  • Regardless of CD4 count, there is greater urgency to start ART when a person has a high viral load or any of the following conditions: pregnancy, AIDS, and certain HIV-related illnesses and coinfections.  
  • ART is a life-long treatment that helps people with HIV live longer, healthier lives. But effective ART depends on adherence— taking HIV medicines every day and exactly as prescribed. Before starting ART, it’s important to address issues that can make adherence difficult.

When is it time to start treatment with HIV medicines?

Treatment with HIV medicines (called antiretroviral therapy or ART for short) is recommended for everyone infected with HIV. When to start ART, however, depends on a person’s unique needs and circumstances.

What factors influence the decision to start ART?

The following factors influence the decision to start ART:

  • A person’s CD4 count and other test results
  • Pregnancy
  • HIV-related illness or AIDS (AIDS is the most advanced stage of HIV infection.)
  • A person’s ability and willingness to commit to lifelong treatment with HIV medicines

Why is a person’s CD4 count an important factor in deciding when to start ART?

A CD4 count measures the number of CD4 cells in a sample of blood. CD4 cells are infection-fighting cells of the immune system. HIV attacks and destroys CD4 cells, making it hard for the body to fight off infection. A low or falling CD4 count indicates that HIV is advancing and damaging the immune system. 

The U.S. Department of Health and Human Services (HHS) provides guidelines on the use of HIV medicines to treat HIV infection. The HHS guidelines recommend ART for everyone with HIV, but the recommendation is strongest for those with CD4 counts less than 350 cells/mm3. (The CD4 count of a healthy person ranges from 500 to 1,200 cells/mm3.) If an HIV-infected person’s CD4 count is less than 200 cells/mm3 or falling rapidly, there is greater urgency to start ART. 

Once a person starts taking HIV medicines, an increasing CD4 count is a sign that the immune system is recovering.

What other factors increase the urgency to start ART?

Other factors that increase the urgency to start ART include high viral loads and conditions such as pregnancy, AIDS, and certain HIV-related illnesses and co-infections.

  • High viral loads
    An HIV viral load test measures the amount of HIV in a person’s blood. The urgency for ART increases when a person’s viral load is greater than 100,000 copies/mL.

  • Pregnancy
    Pregnant women with HIV should take HIV medicines to prevent mother-to-child transmission of HIV and to protect their own health. Women who are already taking HIV medicines when they become pregnant should continue taking HIV medicines throughout their pregnancies.

    Some women with HIV may not be taking HIV medicines when they become pregnant. In these cases, women who have a high viral load or symptoms of HIV infection should start taking HIV medicines as soon as possible in pregnancy. Women without symptoms of HIV infection and a high viral load may consider waiting until after the first trimester of pregnancy (12 weeks of pregnancy) to begin taking HIV medicines.

  • AIDS
    People whose HIV has advanced to AIDS urgently need to take HIV medicines. A diagnosis of AIDS is based on the following:
    • A CD4 count less than 200 cells/mm3
    • The presence of an AIDS-defining condition. AIDS-defining conditions are infections and cancers that are life-threatening when they develop in people with HIV. Certain forms of cervical cancer and tuberculosis are examples of AIDS-defining conditions.

  • HIV-related illnesses and co-infections  Some illnesses that develop in people infected with HIV increase the urgency for ART. These illnesses include HIV-related kidney disease and certain opportunistic infections (OIs). OIs are infections that develop more often or are more severe in people with weakened immune systems, such as people with HIV. 

    Coinfection is when a person has two or more infections at the same time. The urgency for ART is increased in individuals who are infected with HIV and hepatitis B or hepatitis C virus.


How does a person’s readiness to take HIV medicines every day affect the decision to start treatment?

ART is a life-long treatment that helps people with HIV live longer, healthier lives. But effective treatment depends on adherence—taking HIV medicines every day and exactly as prescribed. Before starting ART, it’s important to address issues that can make adherence difficult.

How can I learn more about factors that affect the decision to start ART?

 


This fact sheet is based on information from the following sources: