Test Guide - Quest Test Directory

New

HIV: Laboratory Testing for Screening, Diagnosis, and Management

This test guide provides an overview of the use of laboratory tests in the screening, diagnosis, and management of HIV based on clinical practice guidelines.

See also

Related tests (17)

Related guides (8)

Test guide list

Test Guide

HIV

Laboratory Testing for Screening, Diagnosis, and Management

Laboratory testing plays a central role in the spectrum of clinical care for patients with human immunodeficiency virus (HIV). This test guide provides an overview of the use of laboratory tests in the screening, diagnosis, and management of HIV based on clinical practice guidelines (Table 1).

Table 1. Clinical Practice Guidelines for Diagnosis and Management of HIV

Organization^a	Guideline title or page title	Guideline link
CDC	Guidelines and recommendations: HIV testing	CDC.gov/HIVpartners/PHP/Guidelines/Index.html#CDC_Generic_Section_1-HIV-testing (multiple downloadable guidelines)
DHHS	Federally approved clinical practice guidelines for HIV/AIDS	HIV/AIDS Treatment Guidelines \| Clinicalinfo.HIV.gov (multiple downloadable guidelines)
HIVMA/IDSA	Primary care guidance for providers of care for persons with human immunodeficiency virus: 2024 update by the HIV Medicine Association of the Infectious Diseases Society of America	IDSociety.org/Practice-Guideline/Primary-Care-Management-of-People-With-HIV/ (downloadable pdf)
USPSTF	Screening for HIV infection US Preventive Services Task Force Recommendation Statement	USPreventiveServicesTaskForce.org/USPSTF/Recommendation/Human-Immunodeficiency-Virus-HIV-Infection-Screening (downloadable pdf)

CDC, Centers for Disease Control and Prevention; DHHS, Department of Health and Human Services; HIVMA/IDSA, HIV Medicine Association of the Infectious Diseases Society of America; USPSTF, United States Preventive Services Task Force.
a	This listing is not intended to be comprehensive. Additional guideline statements for HIV are available from these and other organizations.

The information provided in this test guide is not intended as medical advice. A physician’s test selection and interpretation, diagnosis, and patient management decisions should be based on their education, clinical expertise, and assessment of the patient. For additional information on laboratory testing for HIV, please see the following educational guides available from Quest Diagnostics:

HIV-1/2 Antigen and Antibodies, Fourth Generation, With Reflexes (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TS_HIV4thGenScreen/)
HIV Pre-Exposure Prophylaxis (PrEP) (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TG_HIV_PrEP/)

Screening and diagnosis

Screening frequency recommendations

The Centers for Disease Control and Prevention (CDC) and the United States Preventive Services Task Force (USPSTF) provide screening recommendations for HIV (Table 2).^1-5The CDC’s recommendations on screening females and pregnant individuals for HIV are consistent with the American College of Obstetricians and Gynecologists (ACOG)’s recommendations.^1-3,5

Table 2. Recommendations for HIV Screening

Populations^a	Screening recommendations
Populations^a	USPSTF⁴	CDC^1-3,5
All individuals	At least once between 15-65 years of age	At least once between 13-64 years of age
Individuals at increased risk of HIV acquisition	Optimal frequency undetermined	At least annually
Pregnant individuals	Once for each pregnancy	Once at first prenatal visit If at increased risk of HIV acquisition, repeat during the third trimester

CDC, Centers for Disease Control and Prevention; HIV, human immunodeficiency virus; USPSTF, United States Preventive Services Task Force.
a	This is not intended as a comprehensive list of testing recommendations. Refer to guidelines for all current recommendations.

Screening and diagnostic testing

For screening and diagnosis, the CDC recommends HIV diagnostic testing based on fourth-generation antigen/antibody (Ag/Ab) combination assays, which simultaneously detect HIV-1 p24 Ag (acute phase before seroconversion) and HIV-1/HIV-2 Abs (after seroconversion). Repeatedly reactive specimens reflex to HIV-1/HIV-2 Ab differentiation for confirmation. If HIV is not confirmed by HIV-1/HIV-2 Ab differentiation, HIV-1/HIV-2 RNA qualitative real-time PCR testing is performed for final interpretation. Quest Diagnostics offers this testing as test code 91431 (Figure, Table 3).^6-8 For additional information, please see TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TS_HIV4thGenScreen/.

Figure. Reflex Pathway for the HIV-1/2 Antigen and Antibodies, Fourth Generation, With Reflexes Assay⁶

Table 3. Laboratory Tests Used for Screening and Diagnosis of HIV

Test code	Test name (component tests may be ordered separately)	Primary clinical use and/or differentiating factors
91431	HIV-1/2 Antigen and Antibodies, Fourth Generation, With Reflexes^a Includes HIV-1/2 antigen and antibody with reflex to HIV-1/2 antibody differentiation; if differentiation test is indeterminant or negative, reflex to HIV-1 and HIV-2 RNA, qualitative real-time PCR.	Screen for and confirm HIV-1 and HIV-2, including acute infection; uses “fourth-generation” screening immunoassay; reflexes are consistent with CDC HIV diagnostic algorithms^6,8
14312	HIV-1 and HIV-2 RNA, Qualitative Real-Time PCR	Detect HIV-1 and HIV-2, including acute infection; confirm HIV-1 and HIV-2 in individuals with repeatedly reactive initial results, including those with nonreactive HIV antibody–based supplemental test results; detect HIV-1 and HIV-2 in infants up to 18 months of age
8401	HIV-1 DNA, Qualitative, PCR	Detect HIV-1 in infants up to 18 months of age; qualitative HIV-1 DNA test detects HIV-1 proviral DNA

CDC, Centers for Disease Control and Prevention; HIV, human immunodeficiency virus; PCR, polymerase chain reaction.
a	a Reflex tests are performed at an additional charge and are associated with an additional CPT^® code or code(s).

For diagnosis and confirmation of HIV-1 and HIV-2 infections, Quest also offers PCR tests for infants (discussed in the following section), suspected acute infections, and for those with unclear or inconsistent Ag/Ab results (Table 3). For testing options for individuals starting or taking PrEP, please see TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TG_HIV_PrEP/.

Testing infants with perinatal HIV exposure

Ab-based testing is not appropriate in infants younger than 18 months because maternal Abs can cross the placenta and be detected in the infant after birth. In addition, testing for the p24 Ag is not recommended for infants owing to the assay’s low sensitivity relative to other virologic assays in the early months after birth.^9,10 Instead, HIV RNA or DNA PCR assays can be used for initial testing (Table 3). Positive results need to be confirmed with a repeat virologic test on a second specimen.^9,10 The Department of Health and Human Services (DHHS) provides recommendations for testing infants with perinatal HIV exposure (Table 4).^9,10

Table 4. Recommendations for Testing Infants With Perinatal HIV Exposure

Patient group^a	Testing age^9,10	Additional testing^9,10
All infants	At birth, 14-21 days, 1-2 months, and 4-6 months	Not routinely needed
Infants who are breastfed	At birth, 14-21 days, 1-2 months, and 4-6 months	At least every 3 months while breastfeeding At 4-6 weeks and 4-6 months after breastfeeding is discontinued
Infants who receive presumptive HIV therapy	At birth, 14-21 days, 1-2 months, and 4-6 months	At 2-6 weeks after ART is discontinued

ART, antiretroviral therapy; HIV, human immunodeficiency virus.
a	This is not intended as a comprehensive list of testing recommendations. Refer to guidelines for all current recommendations.

Management

This section provides a brief overview of laboratory evaluation in the management of HIV in conjunction with antiretroviral therapy (ART), which is recommended for all patients with HIV.^11,12

The HIV Medicine Association of the Infectious Diseases Society of America (HIVMA/IDSA) and the DHHS provide recommendations for ART-related testing in patients with HIV (Table 5).^11,12 Quest offers tests and panels that are consistent with this guidance to help assess disease status and select ART (Table 6), which are described here in detail. Quest also offers tests to monitor the general health of patients with HIV as well as screen for coinfection.

Table 5. Recommendations for ART-Related Testing in Patients with HIV

Laboratory evaluation^a	Test	Pre-ART^11,12	Post-ART initiation^11,12
Diagnosis confirmation	HIV antigen/antibody diagnostic algorithm	If no written diagnosis	No need to repeat
Disease status	CD4 count^b	At entry into care	Every 3-6 months for the first 2 years or if viremia detectable or if CD4 <300 cells/μL Every 12 months after 2 years if viral load undetectable and CD4 between 300-500 cells/μL Optional after 2 years if viral load undetectable and CD4 >500 cells/μL
Disease status	HIV viral load	At entry into care or when reengaging in care	At 2-4 weeks Every 4-8 weeks until viral suppression Every 3-4 months after viral suppression achieved Every 6 months after viral suppression >1 year
ART selection	Reverse transcriptase and protease genotyping	At entry into care or before ART initiation	If suboptimal virologic response or virologic failure
	Integrase genotyping	If transmitted resistance is a concern or if CAB-LA was used for PrEP	If virologic failure and history of INSTI use
	Tropism	If considering a CCR5 antagonist	Repeat before using a CCR5 antagonist or if virologic failure on a CCR5 antagonist
	HLA-B5701*	If considering abacavir	No need to repeat

ART, antiretroviral therapy; CAB-LA, long-acting cabotegravir; HIV, human immunodeficiency virus; INSTI, integrase strand transfer inhibitor; PrEP, pre-exposure prophylaxis.
a	This is not intended as a comprehensive list of testing recommendations. Refer to guidelines for all current recommendations.
a	CD4 percentage is recommended in addition to CD4 count at the entry of care.¹²

Table 6. Laboratory Tests Used in the Management of Patients With HIV

Test code	Test name (component tests may be ordered separately)	Primary clinical use and/or differentiating factors
Disease status
34471	HIV-1 RNA, Quantitative, PCR With Reflex to Genotype^a Includes reflex to HIV-1 genotype if HIV-1 RNA is ≥400 copies/mL.	Evaluate prognosis; assess effectiveness of ART and need to switch treatment regimen based on resistance to RTI and PI
40085	HIV-1 RNA, Quantitative, Real-Time PCR	Evaluate prognosis; monitor disease progression; assess effectiveness of ART and need to switch treatment regimen Reportable range: 20–10,000,000 HIV-1 RNA copies/mL
91691	HIV-1 RNA, Quantitative, Real-Time PCR With Reflex to Genotype (RTI, PI, Integrase)^a Includes reflex to HIV-1 genotype and HIV-1 integrase genotype if HIV-1 RNA is ≥400 copies/mL.	Evaluate prognosis; assess effectiveness of ART and need to switch treatment regimen based on resistance to RT, PI, and integrase inhibitors.
8360	Lymphocyte Subset Panel 5 Includes absolute lymphocyte count, absolute CD4, and percentage CD4.	Monitor urgency of therapy initiation; monitor cellular immunocompetence
ART selection
91299	HIV-1 Coreceptor Tropism, Proviral DNA^b	Evaluate eligibility for therapy with CCR5 antagonist (genotypic assay) in patients with low plasma viral load (<1,000 HIV-1 RNA copies/mL)
94014	HIV-1 Coreceptor Tropism, Ultradeep Sequencing^b	Evaluate eligibility for therapy with CCR5 antagonist (genotypic assay)
34949	HIV-1 Genotype^b	Detect mutations associated with resistance to RTI and PI
91692	HIV-1 Genotype (RTI, PI, Integrase Inhibitors)^b Includes HIV-1 genotype and HIV-1 integrase genotype.	Detect mutations associated with resistance to RTIs, PIs, and integrase inhibitors
94015	HIV-1 Genotype and Coreceptor Tropism, Ultradeep Sequencing^b	Detect mutations associated with resistance to RTI and PI; evaluate eligibility for therapy with CCR5 antagonist
16868	HIV-1 Integrase Genotype^b	Detect mutations associated with resistance to integrase inhibitors (raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir)
94810	HIV-1 Resistance and Coreceptor Tropism, Proviral DNA^b	Occasionallyc used; detect mutations associated with resistance to RTIs, PIs, and integrase inhibitors; evaluate eligibility for therapy with CCR5 antagonist in patients with undetectable or low plasma viral load (<1,000 HIV-1 RNA copies/mL)
94809	HIV-1 Resistance, Proviral DNA (Integrase Inhibitors)^b	Detect mutations associated with resistance to integrase inhibitors in patients with undetectable or low plasma viral load (<1,000 HIV-1 RNA copies/mL)
94808	HIV-1 Resistance, Proviral DNA (RT, PI Inhibitors)^b	Detect mutations associated with resistance to RTIs and PIs in patients with undetectable or low plasma viral load (<1,000 HIV-1 RNA copies/mL)
94807	HIV-1 Resistance, Proviral DNA (RTI, PI, Integrase Inhibitors)^b	Most commonly used; detect mutations associated with resistance to RTIs, PIs, and integrase inhibitors in patients with undetectable or low plasma viral load (<1,000 HIV-1 RNA copies/mL)
19774	HLA-B5701* Typing^d	Assess risk of abacavir hypersensitivity reaction

ART, antiretroviral therapy; HIV, human immunodeficiency virus; PCR, polymerase chain reaction; PI, protease inhibitor; RTI, reverse transcriptase inhibitor.
a	Reflex tests are performed at an additional charge and are associated with an additional CPT code or code(s).
b	This test was developed and its analytical performance characteristics have been determined by Quest. It has not been cleared or approved by the US Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
c	CCR5 antagonists are rarely prescribed.
d	Typing is performed by using allele-specific polymerase chain reaction (AS-PCR) with reflex to the FDA-cleared LABType^® SSO Kit. The AS-PCR portion of the test was developed and its performance characteristics have been determined by Quest.

In clinical practice, physicians select therapeutic regimens based on the patient's disease status, which includes immunological status, viral load, ART history, and resistance information as discussed below. Factors to consider other than resistance include potential metabolic toxicity, therapeutic failure due to poor adherence to the drug regimen, suboptimal therapy or drug bioavailability, and immunological decline.¹¹

Disease status testing

Lymphocyte subset testing (CD4 count)

The CD4+ T-cell (CD4) count is the most valuable indicator of immune status and the strongest predictor of disease progression and survival in patients with HIV.¹¹ CD4 counts should be measured in all patients with HIV at entry into care and every 3 to 6 months in patients who do not immediately begin ART.¹¹ Baseline CD4 counts provide an indication of the urgency of beginning ART and help determine whether to initiate prophylaxis for opportunistic infections.¹¹

CD4 counts can exhibit substantial variation and may be affected by medications, intercurrent illnesses, and other factors.^10,11 In these scenarios, CD4 cell percentages are less variable and may be more appropriate to assess immune status.¹¹ Quest offers a lymphocyte subset panel that includes both the CD4 count and CD4 percentage (test code 8360, Table 6). The trend in CD4 counts is more important than any single value; a 30% or greater change in the absolute CD4 count between tests, or a 3-percentage-point or greater change in the CD4 percentage, is considered clinically significant.¹¹

HIV-1 RNA, quantitative (viral load)

HIV-1 viral load is the primary marker of ART effectiveness. Before treatment initiation, the viral load provides information on the risk of disease progression, informs selection of an initial treatment regimen, and establishes a baseline for assessing treatment response.¹¹ After treatment is initiated, a primary goal is to decrease the viral load below the limits of detection (LODs) of the available assays within 24 weeks.¹¹ Thereafter, measuring viral load helps assess the continuing effectiveness of therapy. A viral load ≥200 copies/mL on 2 successive specimens indicates virologic failure.¹¹ The recommended frequency of viral load testing depends on the stage of disease management (Table 5).^11,12

Quest offers an FDA-cleared HIV-1 PCR assay for quantitation of HIV-1 RNA in blood plasma (test code 40085, Table 6). A change in viral load of 3-fold (0.5 log10 copies/mL) or greater is considered clinically significant.¹¹ Options for reflex testing to aid in ART selection are also available (test codes 34471 and 91691, Table 6).

ART selection

HIV-1 drug–resistance testing

The development of ART-resistant HIV variants is an important cause of virologic failure (ie, persistent viremia in the presence of drug treatment). Genotypic testing is the preferred resistance assay for selecting drug regimens when initiating ART or changing regimens because of virologic failure or suboptimal reduction in viral load.¹¹

Because drug-resistant HIV-1 variants can be transmitted and may affect response to the initial drug regimen, genotypic testing is recommended upon entry into care (Table 5).^11,12 If therapy is not begun soon thereafter, testing may be repeated before treatment initiation to guide selection of the starting regimen.^11,12 Genotypic testing is also generally recommended after the first or second treatment failure.^11,12

Genotypic testing should be performed on specimens obtained while the patient is still receiving a failing non–long-acting ART regimen or soon (<4 weeks) after discontinuation; otherwise, resistant variants may not be detected but may re-emerge if the drug is reinstated.^11,12 Patients receiving a failing long-acting ART regimen should receive resistance testing regardless of the time since discontinuation.¹¹ Therapy decisions should take into account the results of previous resistance testing.¹¹

Quest offers HIV RNA- and proviral DNA-based genotypic assays that identify mutations that may confer resistance to reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs) and/or integrase inhibitors.

HIV-1 RNA-based assay

Standard genotypic resistance tests measure viral RNA in plasma and are appropriate for patients with viremia. Quest offers the HIV-1 Genotype assay (test code 34949) that identifies current or evolving RTI- and PI-resistance–associated RNA mutations. Testing for mutations associated with integrase-inhibitor resistance is offered separately (test code 16868) or in a panel (test code 91692) with testing for RTI and PI-resistance mutations (Table 6). Quest employs a rules-based algorithm to interpret the results of this mutation analysis. Thus, predicted drug-resistance patterns are reported in addition to the actual mutations detected. The absence of resistance-associated mutations does not necessarily imply drug susceptibility; mutations in minor viral populations may not be detected but may become predominant in the future.

HIV-1 proviral DNA-based assay

Standard genotypic testing generally requires a plasma viral load of at least 500 to 1,000 HIV-1 RNA copies/mL.¹¹ For patients with low viral loads or for whom conventional genotypic testing is unsuccessful, testing can be performed on proviral HIV-1 DNA (using a new, separate whole blood specimen) rather than HIV-1 RNA, though results should be interpreted with caution since these assays may not detect all the previous resistance mutations.¹¹

Quest Diagnostics offers HIV-1 proviral DNA testing for multiple ART classes (test code 94807), including RTIs, PIs, and integrase inhibitors. RTI and PI testing (test code 94808) and integrase inhibitor testing (test code 94809) are also available separately (Table 6).

HIV-1 coreceptor tropism testing

HIV-1 coreceptor tropism testing is recommended to help determine patient eligibility before initiating treatment with CCR5 antagonists and for patients experiencing treatment failure on a CCR5 antagonist (Table 5).^11,12 Although guidelines consider phenotyping to be the preferred method for tropism testing because of its high sensitivity, genotypic tropism testing is a guideline-approved alternative because of its lower cost and faster analytical times.¹¹ The Quest genotypic tropism test (test code 94014, Table 6) is comparable to a high-sensitivity phenotypic test in distinguishing between virologic responders and nonresponders.¹³ This RNA-based assay detects HIV-1 envelope V3 variants associated with viral entry through CXCR4 and CCR5 coreceptors. It is also available in a panel with RTI and PI resistance testing (test code 94015, Table 6).

Standard genotypic tropism testing using RNA extracted from plasma generally requires a viral load of at least 1,000 HIV-1 RNA copies/mL. Patients with lower viral loads can be tested with a proviral HIV-1 DNA tropism assay (test code 91299, Table 6) using a whole-blood specimen rather than an HIV-1 RNA-based assay using plasma. In addition, Quest offers HIV-1 Resistance and Coreceptor Tropism, Proviral DNA (test code 94810, Table 6), which includes RTI, PI, integrase inhibitors, and tropism testing.

HLA-B*5701 typing

The nucleoside reverse transcriptase inhibitor abacavir is associated with an 8% risk of a hypersensitivity reaction.¹⁴ Susceptibility to this serious and sometimes fatal reaction has been associated with a specific human genetic variation known as HLA-B*5701. Patients should receive pharmacogenetic screening for HLA-B*5701 before initiating or reinitiating therapy with abacavir.^11,12,14 A negative result indicates that the patient is unlikely to have a hypersensitivity reaction to abacavir but does not rule out this possibility. A positive result indicates that alternatives to abacavir should be used for treatment because abacavir is contraindicated in HLA-B*5701-positivepatients.¹⁴ Quest offers the HLA-B*5701 Typing test (test code 19774) that uses PCR amplification followed by hybridization with sequence-specific oligonucleotide probes to detect the HLA-B*5701 allele (Table 6).

General health monitoring

With effective ART suppression, patients with HIV now tend to live near-normal lifespans. More emphasis is being given to routine screening, which includes initial evaluation of general health at entry into care and periodic monitoring thereafter. Laboratory evaluation usually includes complete blood count, chemistry tests, urinalysis, liver and kidney function, bone health, lipid profile, and markers of glucose intolerance and diabetes. Additional testing, including glucose-6-phosphate dehydrogenase, pregnancy status, testosterone, and cervical and/or anal cancer screening, is recommended for those with appropriate clinical indications.¹² Please see current guidelines for comprehensive monitoring recommendations^11,12 and refer to the Quest online Test Directory (TestDirectory.QuestDiagnostics.com) for testing options.

For additional information on laboratory testing for diabetes and chronic kidney disease, please see the following educational guides:

Laboratory Testing for Diabetes Diagnosis, Risk Assessment, and Management (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TG_Diabetes/)
Laboratory Testing for Chronic Kidney Disease Diagnosis and Management (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TG_CKD/)

Coinfection screening

Current guidelines recommend testing for several comorbid infectious diseases, including tuberculosis, viral hepatitis (A, B, and C), measles, trichomoniasis, varicella zoster virus, chlamydia, gonorrhea, and syphilis. Cryptococcal antigen and toxoplasma antibody tests are indicated in patients with symptoms or low CD4 counts.¹² Please see current guidelines for comprehensive monitoring recommendations^11,12 and refer to the Quest online Test Directory (TestDirectory.QuestDiagnostics.com) for testing options.

For additional information on laboratory testing for hepatitis and sexually transmitted infections, please see the following educational guides:

Viral Hepatitis: Laboratory Support for Diagnosis and Management (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/CF_ViralHepatitis/)
Measles (Rubeola) Virus, Qualitative Real-Time PCR, Nasopharyngeal/Throat (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/TS_Measles_RT_PCR/)
Sexually Transmitted Infections Associated With Urethritis, Cervicitis, and Pelvic Inflammatory Disease (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/CF_Urethritis_Cervicitis_PID/)
Syphilis: Laboratory Support for Screening, Diagnosis, and Monitoring (TestDirectory.QuestDiagnostics.com/Test/Test-Guides/CF_Syphilis/)

References

Centers for Disease Control and Prevention. Getting tested for HIV. Updated February 11, 2025. Accessed March 31, 2026. https://www.cdc.gov/hiv/testing/index.html
Committee on Gynecologic Practice. ACOG committee opinion number 596: routine human immunodeficiency virus screening. Obstet Gynecol. 2014;123(5):1137-1139. doi:10.1097/01.aog.0000446828.64137.50
Committee on Obstetric Practice HIV Expert Work Group. ACOG committee opinion number 752: prenatal and perinatal human immunodeficiency virus testing. Obstet Gynecol. 2018;132(3):e138-e142. doi:10.1097/aog.0000000000002825
US Preventive Services Task Force. Screening for HIV infection: US Preventive Services Task Force Recommendation Statement. JAMA. 2019;321(23):2326-2336. doi:10.1001/jama.2019.6587
Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. doi:10.15585/mmwr.rr7004a1
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Association of Public Health Laboratories. Technical update for HIV nucleic acid tests approved for diagnostic purposes. Published March 16, 2023. Accessed March 31, 2026. https://stacks.cdc.gov/view/cdc/129018
National Center for HIV/AIDS, Viral Hepatitis, and TB Prevention (US): Division of HIV/AIDS Prevention; Association of Public Health Laboratories. 2018 Quick reference guide: recommended laboratory HIV testing algorithm for serum or plasma specimens. Published January 2018. Accessed March 16, 2026. https://stacks.cdc.gov/view/cdc/50872
Branson BM, Owen SM, Wesolowski LG. Laboratory testing for the diagnosis of HIV infection: updated recommendations. Published June 27, 2014. Accessed March 28, 2026. https://stacks.cdc.gov/view/cdc/23447
Panel on Antiretroviral Therapy and Medical Management of Children Living With HIV. Guidelines for the use of antiretroviral agents in pediatric HIV infection. Published September 30, 2025. Accessed March 31, 2026. https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/pediatric-arv/guidelines-pediatric-arv.pdf
Panel on Treatment of HIV During Pregnancy and Prevention of Perinatal Transmission. Recommendations for the use of antiretroviral drugs during pregnancy and interventions to reduce perinatal HIV transmission in the United States. Published March 31, 2026. Accessed March 31, 2026. https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/perinatal-hiv/guidelines-perinatal.pdf
Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in adults and adolescents with HIV. Published September 25, 2025. Accessed March 31, 2026. https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/adult-adolescent-arv/guidelines-adult-adolescent-arv.pdf
Horberg M, Thompson M, Agwu A, et al. Primary care guidance for providers who care for persons with human immunodeficiency virus: 2024 update by the HIV Medicine Association of the Infectious Diseases Society of America. Clin Infect Dis. doi:10.1093/cid/ciae479
Kagan RM, Johnson EP, Siaw M, et al. A genotypic test for HIV-1 tropism combining Sanger sequencing with ultradeep sequencing predicts virologic response in treatment-experienced patients. PLoS ONE. 2012;7(9):e46334. doi:10.1371/journal.pone.0046334
ABACAVIR (abacavir tablet, film coated). Prescribing information. Aurobindo Pharma Limited; 2022.

Content reviewed 5/2026

top of page

Related tests (17)

94014 - HIV-1 Coreceptor Tropism, Ultradeep Sequencing

The use of CCR5 antagonists in patients harboring CXCR4(X4) or dual-mixed (DM) viruses has proven to be ineffective and leads to the emergence of X4 viruses as the predominant species in DM patients. In clinical trials, X4 virus was found in 55% of patients failing maraviroc therapy vs. only 9% of patients who experienced treatment failure in the placebo arm. The use of CCR5 antagonists, therefore, requires screening for viral tropism to exclude patients harboring X4 or DM virus. Detection of X4 virus prior to the initiation of therapy has been associated with a reduced response to maraviroc.
http://www.accessdata.fda.gov/drugsatfda_docs/label/2007/022128lbl.pdf

94015 - HIV-1 Genotype and Coreceptor Tropism, Ultradeep Sequencing

Select antiretroviral drug regimen for treating HIV-1 patients by assessing reverse transcriptase and protease inhibitor resistance, together with CCR5 antagonist eligibility.

91299 - HIV-1 Coreceptor Tropism, Proviral DNA

The use of CCR5 antagonists requires screening for viral tropism to exclude patients harboring X4 or D/M virus. HIV-1 Proviral DNA tropism test is useful for determination of viral tropism in patients with undetectable HIV-1 viral RNA (virologically suppressed).

8360 - Lymphocyte Subset Panel 5

This panel is used to measure CD4+ T cells (CD4) in the blood (absolute CD4 cell count, %CD4, absolute lymphocytes). The CD4+ T-cell (CD4) count is the most valuable indicator of immune status in HIV-infected individuals. This panel can be used to establish a baseline CD4 level and to monitor treatment progress. It can also be used to facilitate differential diagnoses between congenital and acquired immunodeficiency diseases [1].

A significant reduction in CD4 count can lead to opportunistic infections, and the CD4 cell count/percentage can he used to make decisions regarding opportunistic infection prophylaxis as per guidelines [1].

During the first 2 years of antiretroviral (ARV) therapy, CD4 levels should be tested every 3 to 6 months. Patients who develop viremia while on therapy or whose CD4 count stays below 300 cells/µL should also have their CD4 levels tested every 3 to 6 months. After 2 years of ARV therapy, with consistently suppressed viral load and a CD4 count of 300 to 500 cells/µL, CD4 counts should be tested every 12 months. Note that when CD4 counts are > 500 cells/ µL, CD4 testing is optional [1]. CD4 testing should also be conducted if therapy fails. Refer to current HIV management guidelines for further information on recommended testing frequency [1].

Reference
1. 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. https://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf. Updated July 10, 2019. Accessed November 10, 2019.

94809 - HIV-1 Resistance, Proviral DNA (Integrase Inhibitors)

This test utilizes PCR and next generation (ultra-deep) sequencing of proviral DNA to detect drug resistance mutations in the HIV-1 integrase gene. This information will assist clinicians considering a modification of the treatment regimens for virologically suppressed patients or for patients with a low viral load for whom an RNA resistance test was not successful.

94808 - HIV-1 Resistance, Proviral DNA (RT, PI Inhibitors)

This test utilizes PCR and next generation (ultra-deep) sequencing of proviral DNA to detect drug resistance mutations in the HIV-1 protease and reverse transcriptase genes. This information will assist clinicians considering a modification of the treatment regimens for virologically suppressed patients or for patients with a low viral load for whom an RNA resistance test was not successful.

91691 - HIV-1 RNA, Quantitative, Real-Time PCR with Reflex to Genotype (RTI, PI, Integrase)

Monitor viral load in HIV-1 patients undergoing antiretroviral therapy and automatically reflex to drug resistance testing for PR, RT and Integrase drugs in patients failing to achieve or maintain virologic suppression.

91692 - HIV-1 Genotype (RTI, PI, Integrase Inhibitors)

Identify drug resistance mutations in HIV-1 patients failing antiretroviral regimens containing RT, PR or Integrase inhibitors.
Identify transmitted drug resistance mutations in the RT, PR or integrase genes in treatment-naive patients prior to initiation of antiretroviral therapy.

94810 - HIV-1 Resistance and Coreceptor Tropism, Proviral DNA

This panel will assist clinicians to evaluate virologically suppressed patients for antiretroviral regimen modification when there is insufficient historical viral RNA resistance and viral tropism information. This test utilizes PCR and next generation (ultra-deep) sequencing of proviral DNA to detect drug resistance mutations in the HIV-1 protease, reverse transcriptase and integrase genes. As the CCR5 antagonist maraviroc may also be considered as a component of a new regimen, this panel includes the requisite tropism test performed on proviral DNA.

94807 - HIV-1 Resistance, Proviral DNA (RTI, PI, Integrase Inhibitors)

This test utilizes PCR and next generation (ultra-deep) sequencing of proviral DNA to detect drug resistance mutations in the HIV-1 protease, reverse transcriptase and integrase genes. This information will assist clinicians considering a modification of the treatment regimens for virologically suppressed patients or for patients with a low viral load for whom an RNA resistance test was not successful.

14312 - HIV-1 and HIV-2 RNA, Qualitative Real-Time PCR

This test is an in vitro nucleic acid amplification test (NAAT) for the qualitative detection of human immunodeficiency virus (HIV) types 1 and 2 RNA in human serum and plasma. The test is intended to be used as an aid in diagnosis of HIV-1 and 2 infections. In individuals without antibodies to HIV-1 or HIV-2, the presence of HIV-1 or 2 nucleic acid in the plasma or serum is indicative of acute infection. The HIV-1 and 2 Qualitative PCR may be used as part of a multi-step diagnostic algorithm to confirm the presence of HIV-1 or 2 infection in specimens reactive for HIV-1 and 2 antibodies or HIV antigen [1]. For infants with perinatal HIV exposure for whom HIV antigen/ antibody assays are not recommended, an HIV NAAT such as this test can aid in diagnosis [2].
This assay is not intended to be used for monitoring patient status, or for screening donors of blood, plasma, or human cells, tissues, and cellular and tissue-based products (HCT/Ps) for HIV.

1. Centers for Disease Control and Prevention. Clinical Testing Guidance for HIV. https://www.cdc.gov/hivnexus/hcp/diagnosis-testing/index.html
Published September 10, 2024. Accessed January 27, 2025.
2. Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection. HHS Panel on Antiretroviral Therapy and Medical Management of Children Living with HIV-A Working Group of the NIH Office of AIDS Research Advisory Council(OARAC). https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/pediatric-arv/guidelines-pediatric-arv.pdf

34471 - HIV-1 RNA, Quantitative, PCR with Reflex to Genotype

Measurement of HIV-1 plasma levels (viral load) provides a direct assessment of viremia and should be used in conjunction with CD4+ T-cell counts. HIV-1 RNA, quantitation is useful in patients to assess prognosis, monitor progression of HIV-1 infection, determine when to initiate therapy, and monitor the effectiveness of antiretroviral therapy.

8401 - HIV-1 DNA, Qualitative, PCR

HIV-1 DNA PCR is a sensitive method for detection of pro-viral DNA. It has been used in the management of perinatal HIV infection. HIV-1 RNA has recently been confirmed equally as sensitive and specific for this purpose.

34949 - HIV-1 Genotype

This test is intended for use in conjunction with clinical presentation and other laboratory markers of disease progress for the clinical management of HIV-1 infected patients. The test identifies drug resistance-associated mutations in the HIV-1 protease and reverse transcriptase genes. It can be used to predict antiretroviral drug resistance before initiation of therapy and in patients experiencing virologic failure while on therapy.

19774 - HLA-B*5701 Typing

Abacavir therapy for HIV treatment is associated with significant drug hypersensitivity in approximately 8% of recipients, with retrospective studies indicating a strong association with the HLA-B*5701 Allele. HLA-B*5701 typing can be used for genetic risk stratification prior to initiation of Abacavir therapy.

40085 - HIV-1 RNA, Quantitative, Real-Time PCR

This test is intended for use in conjunction with clinical presentation and other laboratory markers of disease progress for the clinical management of HIV-1 infected patients. The test can be used to assess patient prognosis by measuring the baseline HIV-1 RNA level or to monitor the effects of antiretroviral therapy by measuring changes in EDTA plasma HIV-1 RNA levels during the course of antiretroviral treatment.

91431 - HIV-1/2 Antigen and Antibodies, Fourth Generation, with Reflexes

This algorithm is used to help diagnose HIV-1 and HIV-2 infection, including acute infection, and to differentiate HIV-1 from HIV-2. It is consistent with the HIV diagnostic algorithm recommended by the Centers for Disease Control and Prevention [2]. It can be used in adults, including pregnant women, and in children 2 years or older.

This panel begins with an antigen/antibody assay that allows for detection of acute HIV-1 infection based on the presence of p24 antigen before seroconversion occurs, and HIV-1 and HIV-2 antibodies post-seroconversion. If the HIV-1/HIV-2 antigen/antibody test is positive, an antibody-differentiation test is done (at additional charge) to confirm infection and identify the presence of HIV-1 or HIV-2 specific antibodies. However, the HIV-1/HIV-2 differentiation test can be negative during acute infection (prior to development of specific antibodies). If the antibody-based HIV-1/HIV-2 supplemental test is negative, the specimen will be reflexed to the HIV-1 and HIV-2 RNA, Qualitative, Real-Time PCR test (at additional charge), which can detect the presence of HIV-1 and 2 RNA and identify patients with acute HIV-1 or 2 infection [1].

The United States Preventive Services Task Force (USPSTF) recommends HIV screening for all pregnant women, and for individuals between 15 and 65 years of age who live in regions with an HIV prevalence of >0.1% [2]. In addition, antigen/antibody-based HIV testing is recommended for high-risk individuals who want to begin pre-exposure prophylaxis (PrEP) therapy, because HIV-positive patients who start PrEP without knowing their HIV status face an elevated risk of antiretroviral resistance [3,4].

Because 40% of new HIV infections are transmitted unknowingly by people unaware of their HIV status, early diagnosis is important to reduce HIV transmission [5]. Antigen/antibody-based HIV screening assays have >99.7% sensitivity and >99.3% specificity for HIV infection and can identify most (>80%) acute infections that would otherwise require nucleic acid testing for detection [6,7].

References
1. Moyer V, USPTF. Ann Intern Med. 2013;159:51-60.
2. CDC. Clinical Testing Guidance for HIV. Clinical Testing Guidance for HIV | HIV Nexus | CDC. Published September 10, 2024. Accessed January 27, 2025.
3. CDC. Preventing HIV with PrEP. https://www.cdc.gov/hiv/prevention/prep.html?CDC_AAref_Val=https://www.cdc.gov/hiv/basics/prep.html. Published January 18, 2024. Accessed January 27, 2025.
4. Livant E, et al. J Clin Virol. 2017;94:15-21.
5. CDC. HIV testing. https://www.cdc.gov/hiv/testing/index.html. Published March 2019. Accessed May 20, 2019.
6. Nasrullah M, et al. AIDS. 2013;27:731-737.
7. Chavez P, et al. J Clin Virol. 2011;52(Suppl 1):S51-S55.

Related guides (8)

Syphilis: Laboratory Support for Screening, Diagnosis, and Monitoring

This Clinical Focus provides information about laboratory tests related to syphilis.

Laboratory Testing for Diabetes Diagnosis, Risk Assessment, and Management

This test guide discusses the use of laboratory tests for general screening and diagnosis of prediabetes and diabetes; it also provides additional information on diabetes risk assessment and monitoring glycemic control and complications in individuals with diabetes.

Laboratory Testing for Chronic Kidney Disease Diagnosis and Management

This test guide provides an overview of tests used to detect chronic kidney disease (CKD) in adults, as well as monitor CKD progression, comorbidities, complications, and response to therapy.

HIV Pre-Exposure Prophylaxis (PrEP): Laboratory Testing

This test guide is based on the Centers for Disease Control and Prevention guidelines for use of laboratory tests prior to and during pre-exposure prophylaxis (PrEP) for the prevention of HIV infection. Information that may help with timing and appropriate selection of laboratory tests is provided.

Sexually Transmitted Infections Associated With Urethritis, Cervicitis, and PID

This Clinical Focus covers laboratory tests that help diagnose, screen for, and manage sexually transmitted infections associated with urethritis, cervicitis, and PID.

Viral Hepatitis: Laboratory Support for Diagnosis and Management

This Clinical Focus provides information about laboratory tests related to hepatitis A, B, C, and D.

Measles (Rubeola) Virus, Qualitative Real-time PCR, Nasopharyngeal/Throat

This test is used to diagnose measles (rubeola) infection.

HIV-1/2 Antigen and Antibodies, Fourth Generation, With Reflexes

This test is used to screen for and diagnose HIV-1/HIV-2 infection (including acute infection) and to differentiate HIV-1 from HIV-2 infection.

Top of page

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The tests listed by specialty and category are a select group of tests offered. For a complete list of Quest Diagnostics tests, please adjust the filter options chosen, or refer to our Directory of Services.