Also Known As
HIV Nucleic Acid Amplification Test (NAAT or NAT): HIV by PCR
HIV RNA Test
Formal Name
Human Immunodeficiency Virus RNA, Quantitative
This article was last reviewed on
This article waslast modified on September 27, 2018.
At a Glance
Why Get Tested?

If you have been diagnosed with human immunodeficiency virus (HIV), initially to determine the status of the infection and subsequently to monitor the effectiveness of antiretroviral treatment

When To Get Tested?

When first diagnosed with HIV; 2 to 8 weeks after the start of therapy or therapy changes, then every 4 to 8 weeks until the viral load is not detectable; then every 3 to 4 months if you are on stable therapy and the virus remains suppressed; after two years of this, viral load testing frequency may be decreased to every 6 months.

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

None

You may be able to find your test results on your laboratory's website or patient portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab's website or portal, or contact your healthcare practitioner in order to obtain your test results.

Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.

If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.

Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called "normal" values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.

While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

For more information, please read the article Reference Ranges and What They Mean.

What is being tested?

Human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). This test measures the amount (viral load) of HIV genetic material (RNA) in the blood.

When a person is initially infected with HIV, the virus replicates — it produces more and more copies of itself. The main target of HIV is the CD4 cells, which are a type of white blood cell that fights infections. The virus enters the cells and uses them to replicate and spread throughout the body. It moves into the lymph nodes, spleen, and other parts of the body.

In the early stages of infection, there may not be any noticeable signs or symptoms of disease or only flu-like symptoms, although the virus is usually present in high amounts. Without treatment and even when there are no symptoms, the virus continues to replicate and the viral load will increase. HIV kills CD4 cells, so the number of CD4 cells will decrease as HIV infection progresses.

About 3-8 weeks after initial exposure to the virus, the person's immune system begins to produce HIV antibodies in response to the infection and suppresses the HIV viral load, decreasing it to a low level. Initial symptoms typically resolve, but the infection does not go away.

The only way to determine whether a person has been infected is through HIV testing. If not detected early and treated, an HIV infection may slowly degrade the immune system. After several years and without treatment, the immune system can become so weakened that the disease begins to affect the body's ability to fight infections and certain cancers. Symptoms of AIDS begin to appear at this stage as the body becomes more susceptible to infections with microorganisms such as tuberculosis and fungi or other diseases such as Kaposi's sarcoma.

When a person is diagnosed, antiretroviral treatments for HIV (also called highly active antiretroviral therapy or HAART) are initiated to suppress the amount of HIV virus present in the blood, limiting its ability to replicate and reducing the risk of progressing to AIDS. If a person with HIV discontinues treatment or if it loses its efficacy, then the person's HIV viral load can begin to increase again.

The HIV RNA test detects HIV virus genetic material and measures how many copies of HIV (viral load) are present in the blood at a particular time. It can track increases and decreases in HIV viral load and, in conjunction with a CD4 count, be used to evaluate treatment effectiveness.

How is the sample collected for testing?

A blood sample is drawn by needle from a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

Accordion Title
Common Questions
  • How is it used?

    The HIV viral load test is used initially, along with a CD4 count, to determine the status of HIV infection in a person diagnosed with the disease. The viral load is then used to monitor the effectiveness of antiretroviral treatment (ART) over time.

    HIV viral load testing measures the amount of HIV genetic material (RNA) in the blood and reports how many copies of the virus are present. Evidence shows that keeping the viral load at undetectable levels decreases an infected person's risk of progressing to AIDS and greatly improves long-term health.

    It is recommended that all individuals diagnosed with HIV infection receive antiretroviral treatment as soon as possible, including pregnant women. People typically take at least three drugs from two different classes in order to prevent or minimize virus replication and the emergence of drug-resistant strains. Combinations of three or more antiretroviral drugs are referred to as highly active antiretroviral therapy or HAART.

    The HIV viral load may also be used to help determine whether the virus infecting a person has become drug-resistant. If a person does not respond well to treatment and the amount of virus continues to increase, then the virus may be resistant to that particular ART. The person's treatment will then likely be modified.

    HIV viral load tests are most useful when they are compared with results obtained from earlier tests. They are used in combination with the CD4 count to monitor how effective ART is in suppressing the virus. CD4 cells are types of white blood cells that fight infection and play an important role in immune system function. They are the main target of HIV. The virus enters the cells and uses them to make copies of itself (replicate) and spread throughout the body. HIV kills CD4 cells as it replicates. If HIV is not detected early and treated, the viral load will increase and the number of CD4 cells will decrease.

  • When is it ordered?

    An HIV viral load test is typically ordered with a CD4 count when a person is first diagnosed with HIV infection as part of a baseline measurement. After the baseline, a viral load test will usually be ordered at intervals over time, depending on a few different factors.

    The following table summarizes recommendations* for the timing of viral load testing and CD4 counts:

    Clinical Status of Patient Viral Load CD4 Count
    When first diagnosed Test performed Test performed
    After initiating ART Within 2-4 weeks and then every 4-8 weeks until virus is suppressed (undetectable) 3 months later
    During the first 2 years of stable ART Every 3-4 months Every 3-6 months
    After 2 years of stable ART, virus undetectable, and CD4 greater than 300 cells/mm3 Can extend to every 6 months Annually; if CD4 consistently greater than 500 cells/mm3, monitoring is optional
    After changing ART due to side effects or simplifying drug regimen in a person with suppressed virus After 4-8 weeks, to confirm drug effectiveness Monitor according to prior CD4 count and the amount of time person has been on ART, as detailed above
    After changing ART due to increased viral load (treatment failure) Within 2-4 weeks and then every 4-8 weeks until virus undetectable Every 3-6 months
    While on ART and viral load is consistently greater than 200 copies/mL Every 3 months Every 3-6 months
    With new HIV symptoms or start of new treatment with interferon, corticosteroids or cancer drugs Every 3 months Perform test and monitor according to health status (e.g., new HIV symptoms, opportunistic infections)

    *Adapted from Guidelines for the Use of Antiretroviral Agents in HIV-1–Infected Adults and Adolescents, Table 4. Recommendations on the Indications and Frequency of Viral Load and CD4 Count Monitoring.

  • What does the test result mean?

    HIV viral load tests are reported as the number of HIV copies in a milliliter (copies/mL) of blood.

    If the viral load measurement is high, it generally indicates that HIV is present and replicating. Initial, untreated, and uncontrolled HIV viral loads can range as high as one million or more copies/mL.

    In someone who is receiving antiretroviral treatment (ART), a high viral load means that the treatment is not effective. People who do not respond to treatment will likely have their therapy changed. They should undergo HIV drug resistance testing to help in the selection of an alternative therapy.

    Viral loads that are consistently less than 200 copies/mL indicate that the virus is adequately suppressed and that the risk of disease progression is low. Nevertheless, an undetectable viral load in someone who has a diagnosed HIV infection does not mean that the person is cured; it means only that the level of HIV RNA is currently below the threshold needed for detection by the test.

    Changes in viral load can often be more important during HIV monitoring than a single test result. An increasing viral load indicates either that the infection is getting worse or that the virus has developed resistance to the drugs that are being used for therapy and are no longer effective. A decreasing viral load indicates improvement, treatment effectiveness, and suppression of the HIV infection.

  • Is there anything else I should know?

    Even when HIV is undetectable in the blood, it persists in cells and tissues throughout the body as "HIV provirus." HIV provirus refers to virus that has moved into the nucleus of cells and has become integrated with the DNA of the host cell. This is also called "HIV proviral DNA."

    There are several methods for testing viral load; results are not interchangeable, so it is important that the same method be used each time.

  • Will exercise, nutrition, and other lifestyle modifications help decrease my HIV viral load?

    There is no direct link between HIV viral load and exercise, nutrition, or other lifestyle factors. However, the Centers for Disease Control and Prevention (CDC) does suggest that if you eat healthy foods, you will stay strong and keep up your energy. More information about this is contained in the CDC brochure Living with HIV.

  • If I have undetectable HIV viral load, can I still spread the disease?

    Yes. Although having an undetectable viral load will decrease the chances of you spreading the disease to others, it can still happen. An undetectable viral load only means that there are too few copies of the virus present in the blood to be detected by the test. The virus can still be present in body fluids, such as semen and vaginal fluids, so you can still spread the virus if you have unprotected sex.

  • Can an HIV RNA test be used to screen for HIV?

    The recommended test for HIV screening is a combination test that detects HIV antibody and HIV antigen. By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. Most HIV screening tests detect only HIV antibody but are good options for screening because they may be available as rapid tests and at the point of care. If any of these screening tests are positive, they must be followed by another different antibody test. If the second test is positive, then HIV diagnosis is confirmed. If however, the first and second result do not match, then an HIV RNA test may be done to help establish a diagnosis.

    The recommended screening test for newborns, however, is an HIV RNA test (see Question 4).

  • Why is the HIV RNA test used to test newborns for HIV infection?

    Babies born to mothers infected with HIV are typically tested soon after birth (usually within one to four months) to help determine whether the mother has passed the infection to her baby. An HIV RNA test is performed in babies instead of standard screening HIV antibody tests because antibodies to HIV produced by the mother can cross the placenta and enter the baby's blood. If an HIV antibody test were to be performed on a baby, the result could be positive even though the baby is not infected with the virus.

    An infant with a positive HIV RNA test is likely infected with the virus. Repeat testing done on a second blood specimen is done to confirm the diagnosis. A negative HIV RNA test means that the baby is not infected (or may have been tested too soon after birth). If negative, the test is usually repeated when the infant is older than 1 month and again when the baby is older than 4 months. This may be necessary as the amount of virus may not be at a detectable level.

View Sources

Sources Used in Current Review

Okulicz, J. (2015 January 15, Updated). HIV in Primary Care. Medscape Drugs & Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/2061054-overview. Accessed on January 2016.

Vyas, J. (2015 May 12, Updated). HIV/AIDS. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000594.htm. Accessed on January 2016.

Reimer, L. and Slev, P. (2016 Jan, Updated). Human Immunodeficiency Virus – HIV. ARUP Consult. [On-line information]. Available online at http://www.arupconsult.com/Topics/HIV.html?client_ID=LTD. Accessed on January 2016.

Mayo Clinic Staff (2015 July). HIV/AIDS. Mayo Clinic [On-line information]. Available online at http://www.mayoclinic.org/diseases-conditions/hiv-aids/basics/definition/con-20013732. Accessed on January 2016.

Branson, B. et. al. (2014 June 27). Laboratory testing for the diagnosis of HIV infection : updated recommendations. CDC Stacks. [On-line information]. Available online at http://stacks.cdc.gov/view/cdc/23447. Accessed on January 2016.

Centers for Disease Control and Prevention (U.S.). (2014 June). New CDC recommendations for HIV testing in laboratories: a step-by-step account of the approach. CDC Stacks. [On-line information]. Available online at http://stacks.cdc.gov/view/cdc/23563. Accessed on January 2016.

Bennett, N. and Gilroy, S. (2015 Dec, Updated). HIV Disease. Medscape Drugs & Diseases. [On-line information]. Available online at http://emedicine.medscape.com/article/211316-overview. Accessed on January 2016.

(2015 April 8, Updated). Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. Available online at http://aidsinfo.nih.gov/contentfiles/lvguidelines/AdultandAdolescentGL.pdf. Accessed January 2016.

(May 1, 2014) Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents. Laboratory Testing, Plasma HIV-1 RNA (Viral Load) and CD4 Count Monitoring. Available online at https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescent-arv-guidelines/458/plasma-hiv-1-rna--viral-load--and-cd4-count-monitoring. Accessed January 2016.

(March 5, 2015) Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection. Diagnosis of HIV Infection in Infants and Children. Available online at https://aidsinfo.nih.gov/guidelines/html/2/pediatric-arv-guidelines/55/diagnosis-of-hiv-infection-in-infants-and-children. Accessed January 2016.

(Sep 3, 2015) AIDS.gov. What is viral load? Available online at https://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/understand-your-test-results/viral-load/. Accessed January 2016.

Sources Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

Janice K. Pinson MT, MBA. Molecular Business Strategies, Birmingham, MI.

Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp. 535-538.

Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Pp. 487-490.

Bennett, N. and Rose, F. (2008 October 22, Updated). HIV Disease. eMedicine [On-line information]. Available online at http://www.emedicine.com/med/TOPIC24.HTM. Accessed on 10/26/08.

Mayo Clinic Staff (2008 August 9). MayoClinic HIV/AIDS. MayoClinic.com [On-line information]. Available online at http://www.mayoclinic.com/health/hiv-aids/DS00005. Accessed on 10/30/08.

(2005 November, Revised). Human Immunodeficiency Virus (HIV) Introduction. Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec14/ch192/ch192a.html?qt=HIV&alt=sh. Accessed on 10/30/08.

(2008 September, Reviewed). Human Immunodeficiency Virus – HIV. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/InfectiousDz/Viruses/HIV.html. Accessed on 10/30/08.

(2006 September 22). Revised Recommendations for HIV Testing of Adults, Adolescents, and Pregnant Women in Health-Care Settings. CDC MMWR 55(RR14); 1-17 [On-line information]. Available online at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5514a1.htm. Accessed on 11/1/08.

(2008 September, Updated) HIV and Plasma Viral Load Testing. Familydoctor.org [On-line information]. Available online at http://familydoctor.org/online/famdocen/home/common/sexinfections/hiv/654.html. Accessed on 11/1/08.

(Updated January 9,2009) AVERT.org. HIV testing. Available online at http://www.avert.org/testing.htm. Accessed February 2009.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER and Bruns DE, eds. 4th ed. St. Louis, Missouri: Elsevier Saunders; 2006, Pp. 1567-1568.

(October 22, 2007) National Institute of Allergy and Infectious Diseases. HIV/AIDS. Available online at http://www3.niaid.nih.gov/topics/HIVAIDS/. Accessed February 2009.

Arup Laboratories. ArupConsult. Human Immunodeficiency Testing in Infants. PDF available for download at http://www.arupconsult.com/Algorithms/HIVInfants.pdf. Accessed February 2009.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson RA and Pincus MR, eds. Philadelphia: 2007, Pg. 989.

(Reviewed Oct 7, 2008) AIDS infonet.org. Fact sheet, Viral Load Tests. Available online at http://www.aidsinfonet.org/fact_sheets/view/125. Accessed February 2009.

(Updated 2011 January 10). Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents, Plasma HIV RNA Testing. AIDSinfo On-line information]. Available online through http://aidsinfo.nih.gov. Accessed February 2012.

Hillyard, D. et. al. (2011 November). Human Immunodeficiency Virus – HIV. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/HIV.html?client_ID=LTD. Accessed February 2012.

Bennett, N. (Updated 2011 July 14). Laboratory Assays in HIV Infection. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/1995114-overview#showall. Accessed February 2012.

Osterweil, N. (2012 January 12). Infectivity Rises with Plasma Viral Load. Medscape Medical News [On-line information]. Available online at http://www.medscape.com/viewarticle/756807. Accessed February 2012.

(© 1995-2012). Test ID: HIVQR, HIV-1 RNA Quantification with Reflex to HIV-1 Genotypic Drug Resistance Mutation Analysis, Plasma. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online through http://www.mayomedicallaboratories.com. Accessed February 2012.

Lowry, F. (2011 May 7). HIV Viral Load Detectable After Just 2 Days Without Meds. Medscape Medical News [On-line information]. Available online at http://www.medscape.com/viewarticle/743566. Accessed February 2012.

Delaney, K.P. et. al. Performance of an alternative laboratory-based algorithm for HIV diagnosis in a high-risk population J Clin Virol (2011), doi:10.1016/j.jcv.2011.09.013.

Masciotra, S. et. al. Evaluation of an alternative HIV diagnostic algorithm using specimens from seroconversion panels and persons with established HIV infections. J Clin Virol (2011), doi:10.1016/j.jcv.2011.09.011.

Wesolowski, L. et. al. Performance of an alternative laboratory-based algorithm for diagnosis of HIV infection utilizing a third generation immunoassay, a rpidrapid HIV-1/HIV-2 differentiation test and a DNA or RNA-based nucleic acid amplification test in persons with established HIV-1 infection and blood donors. J Clin Virol (2011), doi:1016/j.jcv.2011.09.026.

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 548-552.

Clarke, W., Editor (© 2011). Contemporary Practice in Clinical Chemistry 2nd Edition: AACC Press, Washington, DC. Pp 609-612.

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