What is HIV testing?

Updated: Sep 19, 2018
  • Author: David J Cennimo, MD, FAAP, FACP, AAHIVS; Chief Editor: Michael Stuart Bronze, MD  more...
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By the end of 2016, 36.7 million people were living with HIV infection, 30% of whom were unaware of their diagnosis. [1] Approximately 35.4 million deaths worldwide have been attributed to infection with human immunodeficiency virus (HIV) since the beginning of the HIV epidemic in the early 1980s. [2]  In the United States, by the end of 2015, the CDC estimated that 1.1 million persons aged 13 years or older were living with HIV infection. Of those, approximately 15% were unaware of their diagnosis. Approximately 39,000 people were newly diagnosed with HIV in 2015--differences within subpopulations illustrated in below—with a 5% decline in new diagnoses from 2011 to 2015. [3, 4]

Early diagnosis of HIV infection is of paramount importance, allowing health care providers an invaluable opportunity to prevent further transmission of the disease and to begin therapy, if warranted. Studies have also shown that infected persons who are aware of their positive HIV status decrease behaviors associated with transmission of the disease. [5, 6]  Furthermore, studies have also shown treatment of HIV infection can significantly lower the risk of transmission to sexual partners. The identification of persons living with HIV and their subsequent treatments is a cornerstone of the US strategy to prevent HIV infections; this strategy begins with testing. [7]  The diagnosis of HIV infection, as with any other diseases, should include a complete history and a detailed physical examination in order to reach an accurate interpretation of the information provided by laboratory data.

This article provides an overview of the available testing for the diagnosis of HIV infection. In order to adequately comprehend the scope of laboratory methods, a basic understanding of the structure of the HIV virion and its genome is necessary.

New HIV Diagnoses in the United States for the Mos New HIV Diagnoses in the United States for the Most-Affected Subpopulations, 2016. Courtesy of the CDC (Centers for Disease Control and Prevention. Estimated HIV incidence and prevalence in the United States, 2010–2015. HIV Surveillance Supplemental Report 2018;23(No. 1). Online at: http://www.cdc.gov/hiv/library/reports/hiv-surveillance.html. Published March 2018. Accessed Sept 10, 2018.)

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