Materiały źródłowe

• #1 HIV/AIDS – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hiv-aids/diagnosis-treatment/drc-20373531

  HIV can be diagnosed through blood or saliva testing. Tests include: […] Antigen-antibody tests. These tests most often use blood from a vein. Antigens are substances on the HIV virus itself. They most often show up in the blood within a few weeks after being exposed to HIV. […] The immune system makes antibodies when it’s exposed to HIV. It can take weeks to months for antibodies to show up in blood. You may not show a positive result on an antigen-antibody test until 2 to 6 weeks after exposure to HIV. […] Antibody tests. These tests look for antibodies to HIV in blood or saliva. Most rapid HIV tests are antibody tests. This includes self-tests done at home. You may not show a positive result on an antibody test until 3 to 12 weeks after you’ve been exposed to HIV. […] Nucleic acid tests (NATs). These tests look for the virus in your blood, called viral load. They use blood from a vein.

• #1 Getting Tested for HIV | HIV | CDC

  https://www.cdc.gov/hiv/testing/index.html

  Everyone between the ages of 13 and 64 should get tested for HIV at least once. […] People with certain risk factors should get tested more often. […] The only way to know your HIV status is to get tested. […] If your test result is positive, you can take medicine to treat HIV to help you live a long, healthy life and protect others. […] If your test result is negative, you can take actions to prevent HIV. […] Pregnant people should get tested for HIV during each pregnancy. Testing pregnant people and treating those who have HIV is a highly effective way to prevent babies being born with HIV. […] There are three types of HIV tests: antibody tests, antigen/antibody tests, and nucleic acid tests (NAT). […] An antibody test looks for antibodies to HIV in your blood or oral fluid.

• #1 Diagnosis of HIV/AIDS – Wikipedia

  https://en.wikipedia.org/wiki/Diagnosis_of_HIV/AIDS

  HIV tests are used to detect the presence of the human immunodeficiency virus (HIV), the virus that causes HIV/AIDS, in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA. […] AIDS is diagnosed separately from HIV. […] The eclipse period is a variable period starting from HIV exposure in which no existing test can detect HIV. The median duration of the eclipse period in one study was 11.5 days. The window period is the time between HIV exposure and when an antibody or antigen test can detect HIV. The median window period for antibody/antigen testing is 18 days. Nucleic acid testing (NAT) further reduces this period to 11.5 days. […] All diagnostic tests have limitations, and sometimes their use may produce erroneous or questionable results. […] False positive: The test incorrectly indicates that HIV is present in a non-infected person.

• #1 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  Laboratory markers of HIV appear in a consistent sequence after infection occurs and delineate the period from initial exposure to established HIV. The Fiebig staging system defines 6 distinct stages of initial HIV infection that follow the eclipse phase, and these stages range from the emergence of HIV RNA to full Western blot reactivity. The CDC and Association of Public Health Laboratories (APHL) document have outlined the sequence of contemporary laboratory markers that turn positive following the acquisition of HIV. Following HIV acquisition, HIV RNA becomes detectable on standard laboratory tests approximately 10 days after infection. The next marker to appear is p24 antigen, which typically reaches detectable levels about 7 days after the emergence of HIV-1 RNA. […] The major tests used as screening tests for diagnosing HIV are HIV antigen-antibody laboratory-based tests, HIV antigen-antibody point-of-care tests, HIV antibody laboratory-based tests, and HIV antibody point-of-care tests. The HIV antigen-antibody laboratory-based immunoassays are the preferred screening tests for HIV. These immunoassays detect HIV-1 p24 (capsid) antigen and antibodies (IgM and IgG) to HIV-1 and HIV-2. All reactive HIV-1/2 antigen-antibody tests require confirmatory testing.

• #1 Getting Tested for HIV | HIV | CDC

  https://www.cdc.gov/hiv/testing/index.html

  An antigen/antibody test looks for both HIV antibodies and antigens. […] A NAT looks for the actual virus in the blood. […] If you use any type of antibody test and have a positive result, you will need a follow-up test to confirm your results. […] Testing positive for HIV does not mean you have AIDS (acquired immunodeficiency syndrome), the most advanced stage of HIV disease. However, HIV can lead to AIDS if a person with HIV does not get treatment or take care of their health. […] A negative result doesn’t necessarily mean that you don’t have HIV. That’s because of the window period. […] If you get an HIV test after a potential HIV exposure and the result is negative, get tested again after the window period for the type of test you took.

• #1 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  Diagnostic testing is the crucial first step in the HIV care continuum. Establishing a diagnosis of HIV has important implications for both HIV treatment and prevention. The CDC and the Association of Public Health Laboratories (APHL) released an HIV diagnostic algorithm to allow for more accurate diagnosis of acute HIV-1, improved ability to detect HIV type 2 (HIV-2), fewer indeterminate results, and faster turnaround time for completion of the testing algorithm. The HIV testing approach recommended by the CDC consists of initial screening with an HIV-1/2 antigen-antibody test, with follow-up testing of reactive samples using an HIV-1/HIV-2 differentiation antibody assay. Indeterminate or ambiguous results based on the initial HIV-1/2 antigen-antibody test and HIV-1/HIV-2 differentiation assay require further evaluation with an HIV nucleic acid test (NAT), such as an HIV-1 RNA PCR assay.

• #1 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  The CDC and APHL HIV testing algorithm utilizes an HIV-1/2 antigen-antibody immunoassay as the initial test, with positive test results followed by an HIV-1/2 differentiation assay. This HIV testing algorithm provides for a more accurate diagnosis of acute HIV-1, a more accurate diagnosis of HIV-2, fewer indeterminate results, and a faster turnaround time than previous approaches. […] A false-negative HIV test result refers to a negative HIV test result in a person who actually has HIV. A false-negative HIV antibody (or antigen-antibody) test result most often occurs when performing testing in a person with acute HIV, from laboratory error, or following receipt of potent antiretroviral therapy very early after HIV acquisition. A false-positive HIV test result is defined as a positive HIV test result in a person who does not have HIV.

• #1 HIV/AIDS – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hiv-aids/diagnosis-treatment/drc-20373531

  If you might have been exposed to HIV within the past few weeks, your healthcare professional may suggest NAT. NAT is the first test to become positive after exposure to HIV. […] Talk with your healthcare professional about which HIV test is right for you. If any of these tests are negative, you may need a follow-up test weeks to months later to confirm the results. […] If you’ve been diagnosed with HIV, find a specialist trained in diagnosing and treating HIV to help you: […] If you get a diagnosis of HIV/AIDS, tests can help your healthcare professional learn the stage of your disease and the best treatment, including: […] CD4 T cell count. CD4 T cells are white blood cells that HIV targets and destroys. Even if you have no symptoms, HIV infection becomes AIDS when your CD4 T cell count dips below 200.

• #1 HIV/AIDS – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hiv-aids/diagnosis-treatment/drc-20373531

  Viral load, also called HIV RNA. This test measures the amount of virus in your blood. After starting HIV treatment, the goal is to have a viral load so low that it doesn’t show up on the test, called undetectable. This greatly reduces your chances of opportunistic infection and other HIV-related complications. […] Medicine resistance. Some strains of HIV are resistant to medicines. This test helps your healthcare professional know if your form of the virus has resistance. This guides treatment decisions. […] Your healthcare professional also might order lab tests to check for other infections or complications, including: […] Your healthcare professional will watch your viral load and CD4 T cell counts to see your response to HIV treatment. The first check is at 4 to 6 weeks. After that, you see your health professional every 3 to 6 months. […] Treatment should lower your viral load so that can’t be found in the blood. That doesn’t mean your HIV is gone. Even if it can’t be found in the blood, HIV is still in your body.

• #1 HIV Infection and AIDS Workup: Approach Considerations, Screening for HIV Infection, CD4 T-cell Count

  https://emedicine.medscape.com/article/211316-workup

  Viral culture is expensive and time-consuming and is less sensitive in patients with low viral loads. […] Genotyping of viral DNA/RNA can guide therapy. […] Baseline studies for other infections that are important in the initial workup of a patient with newly diagnosed HIV infection include the following: Purified protein derivative (PPD) skin testing for tuberculosis or interferon gamma assay, Cytomegalovirus (CMV) testing, Syphilis testing, Rapid amplification testing for gonococcal and chlamydial infection, Hepatitis A, B, and C serology, Anti-Toxoplasma antibody, Ophthalmologic examination. […] Certain histologic findings are characteristic of various features of HIV infection and AIDS. […] The CDC classifies HIV infection into 3 categories, according to the presence of certain infections or diseases. […] Importantly, once an HIV infection has been staged into a higher clinical category, it remains in that category permanently.

• #1 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  The laboratory diagnosis of acute HIV-1 infection is most reliably made with a positive HIV RNA (or HIV-1 p24 antigen) with a concomitant negative HIV antibody assay. Use of HIV-1/2 antigen-antibody immunoassays will detect HIV about 17 days after HIV acquisition, which is significantly sooner than with HIV laboratory-based HIV antibody tests. […] The 2014 and 2018 HIV diagnostic algorithm improves the detection of HIV-2 by using an HIV-1/HIV-2 differentiation assay as the second step of the algorithm. Confirmation of HIV-2 infection can be challenging since HIV-1 RNA assays do not reliably detect or quantitate HIV-2. […] The use of multiple modalities for HIV testing and delivery of HIV test results has helped to optimize this process. Delivery of HIV test results by telephone has been found to be both effective and acceptable, and increases the number of people who receive their test results.

• #1 HIV testing and diagnosis insights | ViiV Healthcare

  https://viivhealthcare.com/about-hiv/hiv-testing-and-diagnosis/

  HIV testing is important because early detection and timely intervention are key in managing HIV effectively. During the initial phases, HIV may be symptomless or flu-like, making reliance on symptoms alone insufficient. These flu-like symptoms may include a fever (often accompanied with chills or night sweats), headaches, fatigue, swollen lymph nodes, and a persistent sore throat. A skin rash or muscle and joint pain may also become apparent, as well as weight loss, mouth ulcers, and diarrhoea. Clearly, these early HIV symptoms are also associated with other common illnesses and health conditions, so this emphasises why regular testing is so vital. […] HIV can be acquired through bodily fluids like blood and semen and is more easily transmitted in the early stages, making testing necessary not just for personal health but also to prevent unintentional transmission to others. Testing is the first step towards early diagnosis of HIV and guiding people living with HIV towards treatment.

• #1 LABORATORY METHODS FOR DIAGNOSIS OF HIV INFECTION IN INFANTS AND CHILDREN – WHO Recommendations on the Diagnosis of HIV Infection in Infants and Children – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK138552/

  Many methods for the detection of nucleic acids are available both commercially and non-commercially (in-house assays). […] WHO, through the WHO Prequalification of Diagnostics Programme, evaluates the performance of commercially available technologies including serological assays (EIAs and rapid tests), CD4 enumeration technologies and molecular technologies. […] Antibodies to HIV can be measured by a variety of techniques. […] However, because maternal HIV antibodies (immunoglobulin G [IgG]) are passively transferred across the placenta, HIV serological assays in infants are difficult to interpret. […] Most commercially available EIAs have a high sensitivity and specificity and are able to detect all subtypes of HIV-1 and HIV-2. […] A testing strategy describes generically a testing approach for specific needs (for example, transfusion and transplantation safety, surveillance, diagnosis of HIV infection [client-initiated or provider-initiated testing and counselling]), taking into consideration the presumed HIV prevalence in the population being tested.

• #1 Diagnosis of HIV Infection in Infants and Children | NIH

  https://clinicalinfo.hiv.gov/en/guidelines/perinatal/management-infants-diagnosis-hiv-infection-children

  Virologic assays (HIV RNA or HIV DNA nucleic acid tests [NATs]) that directly detect HIV must be used to diagnose HIV in infants and children aged 18 months with perinatal HIV exposure; HIV antibody and HIV antigen/antibody tests should not be used (AII). […] Plasma HIV RNA or cell-associated HIV DNA NATs are generally equally recommended (AII). […] An assay that detects HIV nonB subtype viruses or Group O infections (e.g., an HIV RNA NAT or a total DNA/RNA test) is recommended for use in infants and children who were born to birthing parents with known or suspected nonB subtype virus or Group O infections (AII). […] Virologic diagnostic testing using an HIV NAT is recommended for all infants with perinatal HIV exposure at the following ages: Birth (AII), 14 to 21 days (AII), 1 to 2 months (AII), 4 to 6 months (AII).

• #1 LABORATORY METHODS FOR DIAGNOSIS OF HIV INFECTION IN INFANTS AND CHILDREN – WHO Recommendations on the Diagnosis of HIV Infection in Infants and Children – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK138552/

  Blood (venous or capillary) must be drawn from the infant or young child for all methods of virological testing and serological assays. […] The time between specimen collection and testing can be important as viral nucleic acids may degrade over time, particularly if stored at high ambient temperature. […] Infants and children of HIV-infected mothers who continue to breastfeed are at ongoing risk for acquiring HIV infection and hence negative virological test results are difficult to interpret if the infant is still feeding. […] This is the same for all currently available methods of virological detection.

• #1 Screening and diagnostic testing for HIV infection in adults – UpToDate

  https://www.uptodate.com/contents/screening-and-diagnostic-testing-for-hiv-infection-in-adults

  Screening and diagnostic testing for HIV infection in adults […] Approximately 13 percent of persons with human immunodeficiency virus (HIV) in the United States remain unaware of their HIV status, leading to significant morbidity and risk of transmission to others. Improved access to HIV testing and new testing algorithms that enhance the detection of individuals with newly acquired infection can lead to increased access to antiretroviral therapy (ART), which can decrease the number of individuals who present with advanced immunocompromise and reduce transmission to others. Patients without other significant comorbidities who are treated before significant immunosuppression can expect a life expectancy approaching that of the general population. […] This topic will address screening and diagnostic testing for HIV in adults in clinical care settings.

• #1 HIV testing and diagnosis insights | ViiV Healthcare

  https://viivhealthcare.com/en-us/about-hiv/starting-your-journey/hiv-testing-and-diagnosis/

  It is generally advised that some people get tested more often (i.e. every 3 to 6 months). These include high-incidence groups, such as: MSM, PWID, those with a history of sexually transmitted infections (STIs), people who have sex without the use of prevention tools such as condoms, and those who have had sex with someone living with HIV with a detectable or unknown viral load. […] The World Health Organisation (WHO) states that people living with HIV who have an undetectable viral load, and take antiretroviral therapy (ART) as prescribed have zero risk of transmitting HIV to their sexual partner(s). […] HIV testing detects the virus before symptoms appear, or if you have a flu-like illness, a common reason for testing. Early diagnosis opposed to a late HIV diagnosis has many benefits; the sooner HIV treatment is started, the better the outcome.

• #1 HIV Testing | NIH

  https://hivinfo.nih.gov/understanding-hiv/fact-sheets/hiv-testing

  HIV testing can be confidential or anonymous. […] Your health care provider can give you an HIV test. If you feel apprehensive about talking to your personal physician or family doctor, HIV testing is also available at many hospitals, medical clinics, substance use programs, and community health centers.

• #1 False positive results on HIV tests | aidsmap

  https://www.aidsmap.com/about-hiv/false-positive-results-hiv-tests

  Tests always produce a small number of false positive results. […] In settings where very few people have HIV, a higher proportion of reactive results will be false positives. […] To ensure accurate diagnosis, a sequence of confirmatory tests is used to verify all reactive results. […] A diagnosis of HIV is never made on the basis of a single test result. […] A false positive is a test result that says a person has HIV when, in fact, they do not have it. […] This preliminary result must be verified with a series of confirmatory tests. […] If you have been tested in this way, with a sequence of confirmatory tests, and you have been told that you are HIV positive, you can be confident of the result. […] An HIV diagnosis is never made on the basis of a single test result. […] If that is the case, the confirmatory testing is essential.

• #1 HIV & AIDS: Causes, Symptoms, Treatment & Prevention

  https://my.clevelandclinic.org/health/diseases/4251-hiv-aids

  The goal of ART is to reduce HIV in the blood (viral load) to an amount that’s not detectable by an HIV test and to slow HIV’s weakening of your immune system. […] There is currently no cure for HIV, but there are many treatment options that can slow the progression of HIV significantly. […] If you’re diagnosed with HIV, it’s important to know that those living with HIV who follow treatment guidelines can live full lives for nearly as long as those without HIV. […] If you have a high CD4 count and an undetectable viral load within a year of starting treatment, research suggests you’ll have the best outcomes, as long as you continue your treatment plan. […] Left untreated, it can take about 10 years for HIV to advance to AIDS. […] Call your healthcare provider immediately if you think you’ve been exposed to HIV. […] It is important to begin treatment as soon as possible if you do have HIV.

• #2 HIV testing and diagnosis insights | ViiV Healthcare

  https://viivhealthcare.com/about-hiv/hiv-testing-and-diagnosis/

  HIV testing is important because early detection and timely intervention are key in managing HIV effectively. During the initial phases, HIV may be symptomless or flu-like, making reliance on symptoms alone insufficient. These flu-like symptoms may include a fever (often accompanied with chills or night sweats), headaches, fatigue, swollen lymph nodes, and a persistent sore throat. A skin rash or muscle and joint pain may also become apparent, as well as weight loss, mouth ulcers, and diarrhoea. Clearly, these early HIV symptoms are also associated with other common illnesses and health conditions, so this emphasises why regular testing is so vital. […] HIV can be acquired through bodily fluids like blood and semen and is more easily transmitted in the early stages, making testing necessary not just for personal health but also to prevent unintentional transmission to others. Testing is the first step towards early diagnosis of HIV and guiding people living with HIV towards treatment.

• #2 HIV Testing | NIH

  https://hivinfo.nih.gov/understanding-hiv/fact-sheets/hiv-testing

  Testing for HIV (human immunodeficiency virus) determines if a person has acquired HIV. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). AIDS is the most advanced stage of HIV infection. […] There are three types of tests used to diagnose HIV infection: antibody tests, antigen/antibody tests, and nucleic acid tests (NATs). […] A persons initial HIV test will usually be either an antibody test or an antigen/antibody test. NATs are not routinely used for HIV screening unless the person had a high-risk exposure or a possible exposure with early symptoms of HIV infection. […] When an HIV test is positive, a follow-up test will be conducted for confirmation. […] Talk to your health care provider who will determine your HIV risk factors and the best type of HIV test for you.

• #2 HIV Testing Overview

  https://www.hiv.gov/hiv-basics/hiv-testing/learn-about-hiv-testing/hiv-testing-overview

  There are three types of HIV tests: nucleic acid tests (NAT), antigen/antibody tests, and antibody tests, and they all have different window periods: […] A NAT can usually tell if you have HIV infection 10 to 33 days after exposure. […] An antigen/antibody test performed by a laboratory on blood from your vein can usually detect HIV infection 18 to 45 days after exposure. […] An antibody test can usually detect HIV infection 23 to 90 days after an exposure. […] If you get an HIV test after a potential HIV exposure and the result is negative, get tested again after the window period. […] As required by the Affordable Care Act, HIV screening is covered by health insurance without a co-pay.

• #2 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  Diagnostic testing is the crucial first step in the HIV care continuum. Establishing a diagnosis of HIV has important implications for both HIV treatment and prevention. The CDC and the Association of Public Health Laboratories (APHL) released an HIV diagnostic algorithm to allow for more accurate diagnosis of acute HIV-1, improved ability to detect HIV type 2 (HIV-2), fewer indeterminate results, and faster turnaround time for completion of the testing algorithm. The HIV testing approach recommended by the CDC consists of initial screening with an HIV-1/2 antigen-antibody test, with follow-up testing of reactive samples using an HIV-1/HIV-2 differentiation antibody assay. Indeterminate or ambiguous results based on the initial HIV-1/2 antigen-antibody test and HIV-1/HIV-2 differentiation assay require further evaluation with an HIV nucleic acid test (NAT), such as an HIV-1 RNA PCR assay.

• #2 HIV Testing: Types, How Often, What To Expect & Results

  https://my.clevelandclinic.org/health/diagnostics/4849-hiv-testing

  If you’re HIV-positive, your healthcare provider may order a NAT test to check your viral load, or how much of the virus is in your blood. […] The U.S. Preventive Services Task Force on HIV recommends that everyone between ages 15 to 65 take an HIV test at least once in their lifetimes. […] An HIV test is recommended during pregnancy and preferably given during the first trimester of pregnancy since HIV can be passed between the mother and fetus. […] An HIV test looks for evidence of HIV in your blood or oral fluid. […] If you test positive, your provider will do additional testing to confirm the results. The CDC recommends the following sequence of HIV tests: Test #1: An antigen/antibody test to check for HIV antigen p24 and HIV antibodies. […] This combination of testing is nearly 100% effective at diagnosing HIV.

• #2 HIV Tests: Diagnosis, Monitoring, and More

  https://www.healthline.com/health/hiv-aids/tests

  An HIV infection is now considered a manageable health condition, especially if treatment is sought early. […] If a person contracts HIV, early detection and treatment can help: improve their frame of mind; lower their risk of disease progression; prevent the development of stage 3 HIV, or AIDS. […] The life expectancy of people with an HIV diagnosis who start treatment early is the same as those without the virus. […] In 2012, the Food and Drug Administration (FDA) approved the OraQuick In-Home HIV Test. […] If a person thinks theyve contracted HIV, it can take anywhere from 1 to 6 months after transmission for a standard HIV test to produce positive results. […] According to Avert, third-generation HIV tests which are ELISA tests can only detect HIV 3 months after exposure to the virus.

• #2

  https://www.nhs.uk/conditions/hiv-and-aids/diagnosis/

  The only way to find out if you have HIV is to have an HIV test, as symptoms of HIV may not appear for many years. Anyone who thinks they could have HIV should get tested. […] Some HIV tests may need to be repeated 1-3 months after exposure to HIV infection, but you should not wait this long to seek help. […] There are 4 main types of HIV test: blood test where a sample of blood is taken in a clinic and sent for testing in a laboratory. Results are usually available on the same day or within a few days […] The blood test is the most accurate test and can normally give reliable results from 1 month after infection. […] For all these tests, a blood test should be carried out to confirm the result if the first test is positive. […] If you’re pregnant, you’ll be offered a blood test to check if you have HIV as part of routine antenatal screening.

• #2 Core Concepts – HIV Diagnostic Testing – Screening and Diagnosis – National HIV Curriculum

  https://www.hiv.uw.edu/go/screening-diagnosis/diagnostic-testing/core-concept/all

  The CDC and APHL HIV testing algorithm utilizes an HIV-1/2 antigen-antibody immunoassay as the initial test, with positive test results followed by an HIV-1/2 differentiation assay. This HIV testing algorithm provides for a more accurate diagnosis of acute HIV-1, a more accurate diagnosis of HIV-2, fewer indeterminate results, and a faster turnaround time than previous approaches. […] A false-negative HIV test result refers to a negative HIV test result in a person who actually has HIV. A false-negative HIV antibody (or antigen-antibody) test result most often occurs when performing testing in a person with acute HIV, from laboratory error, or following receipt of potent antiretroviral therapy very early after HIV acquisition. A false-positive HIV test result is defined as a positive HIV test result in a person who does not have HIV.

• #2 HIV Infection: Laboratory Testing for Diagnosis and Management | Test Guide | Quest Diagnostics HIV Infection: Laboratory Testing for Diagnosis and ManagementHIV Infection: Laboratory Testing for Diagnosis and Management

  https://testdirectory.questdiagnostics.com/test/test-guides/TG_HIV_Management/hiv-infection-laboratory-testing-for-diagnosis-and-management?p=r

  The 2014 HIV diagnostic testing algorithm recommended by the CDC is based on newer tests that are more sensitive for acute infection. The algorithm is designed to (1) detect acute infections more often; (2) reduce the frequency of indeterminate results on supplemental testing; and (3) differentiate HIV-1 and HIV-2 (HIV-1/2) antibodies. […] The “fourth-generation” testing algorithm begins with a screening test for HIV-1/2. The screening test of choice is a “fourth-generation” combination assay that detects HIV-1/2 antibodies and/or HIV-1 p24 antigen. HIV p24 antigen becomes detectable before seroconversion but rapidly disappears thereafter. Thus, the antigen component allows detection of infection during a portion of the pre-seroconversion window period, while the antibody component allows detection post-seroconversion. “Fourth-generation” assays can detect acute infection a median of 5 to 7 days before “third-generation” antibody-only detection assays. These antigen/antibody (Ag/Ab) combination assays have >99.7% sensitivity and >99.5% specificity for HIV infection and identify most (>80%) acute infections that would otherwise require nucleic acid testing for detection. Repeatedly reactive Ag/Ab screening assay results require confirmation with a supplemental antibody immunoassay that differentiates between HIV-1 and HIV-2 antibodies.

• #2 HIV/AIDS – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hiv-aids/diagnosis-treatment/drc-20373531

  Viral load, also called HIV RNA. This test measures the amount of virus in your blood. After starting HIV treatment, the goal is to have a viral load so low that it doesn’t show up on the test, called undetectable. This greatly reduces your chances of opportunistic infection and other HIV-related complications. […] Medicine resistance. Some strains of HIV are resistant to medicines. This test helps your healthcare professional know if your form of the virus has resistance. This guides treatment decisions. […] Your healthcare professional also might order lab tests to check for other infections or complications, including: […] Your healthcare professional will watch your viral load and CD4 T cell counts to see your response to HIV treatment. The first check is at 4 to 6 weeks. After that, you see your health professional every 3 to 6 months. […] Treatment should lower your viral load so that can’t be found in the blood. That doesn’t mean your HIV is gone. Even if it can’t be found in the blood, HIV is still in your body.

• #2 HIV Infection: Laboratory Testing for Diagnosis and Management | Test Guide | Quest Diagnostics HIV Infection: Laboratory Testing for Diagnosis and ManagementHIV Infection: Laboratory Testing for Diagnosis and Management

  https://testdirectory.questdiagnostics.com/test/test-guides/TG_HIV_Management/hiv-infection-laboratory-testing-for-diagnosis-and-management?p=r

  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 infection. CD4 counts should be measured in all patients with HIV infection at entry into care and every 3 to 6 months in patients who do not immediately begin ART. Baseline CD4 count provides an indication of the urgency of beginning ART and helps determine whether to initiate prophylaxis for opportunistic infections. […] 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. 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. Thereafter, measuring viral load helps assess the continuing effectiveness of therapy. A viral load ≥200 copies/mL on 2 successive specimens indicates antiviral virologic failure.

• #2 HIV Infection: Laboratory Testing for Diagnosis and Management | Test Guide | Quest Diagnostics HIV Infection: Laboratory Testing for Diagnosis and ManagementHIV Infection: Laboratory Testing for Diagnosis and Management

  https://testdirectory.questdiagnostics.com/test/test-guides/TG_HIV_Management/hiv-infection-laboratory-testing-for-diagnosis-and-management?p=r

  The development of drug-resistant HIV-1 variants is an important cause of virologic failure (ie, persistent viremia in the presence of drug treatment). Resistance assays are useful for selecting drug regimens when initiating ART or changing regimens because of virologic failure or suboptimal reduction in viral load. HIV drug resistance can be evaluated with genotypic or phenotypic testing. Regardless of the approach, resistance 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. [...] HIV-1 genotype testing 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.

• #2 Laboratory Tests and HIV: Entire Lession – HIV

  https://www.hiv.va.gov/patient/diagnosis/labtests-single-page.asp

  HIV viral load tests measure the amount of HIV in the blood. Lower levels are better than higher levels. The main goal of HIV drugs is to reduce the HIV viral load to an „undetectable” level, meaning that the HIV RNA is below the level that the test is able to count. […] This test determines whether the particular virus in your body is resistant to HIV medications. […] Therefore, resistance testing is performed upon diagnosis of HIV and if a medication regimen is no longer keeping the viral load suppressed. […] Tests for STDs, hepatitis B, and hepatitis C should be done at baseline. STD tests should be repeated at least once a year if you are sexually active and have had more than one sex partner since your last clinic visit. […] When you are diagnosed with HIV, your providers will check your blood to see if you have either active infection, protection from infection, or no protection from HBV. If you have protection from infection, great! There is nothing else to do. If you do not have protection, you will be offered the HBV vaccine to protect from future infection. If HBV is found in your bloodstream (i.e. active infection), you will be offered medication that can kill both HBV and HIV.

• #2 HIV Testing | NIH

  https://hivinfo.nih.gov/understanding-hiv/fact-sheets/hiv-testing

  HIV testing determines if a person has acquired HIV (human immunodeficiency virus). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). AIDS is the most advanced stage of HIV infection. […] HIV testing is important because it is estimated that 40% of new diagnoses of HIV are transmitted by people who are not aware of their HIV status. Knowing your HIV status can help keep you and others safe. Also, early and sustained HIV treatment will help you live a long and healthy life. […] The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 to 64 years of age get tested for HIV at least once as part of a routine health care exam, and that people at higher risk for HIV get tested more often. […] CDC recommends that all pregnant women get tested for HIV so that they can begin taking HIV medicines if they are HIV positive.

• #2 Screening and diagnostic testing for HIV infection in adults – UpToDate

  https://www.uptodate.com/contents/screening-and-diagnostic-testing-for-hiv-infection-in-adults

  HIV testing should be performed to diagnose HIV in patients with clinical signs and symptoms of acute or chronic infection as well as those with a possible exposure to HIV. Screening for persons who are asymptomatic should also be incorporated into routine care for all adolescents and adults. […] All patients with signs and symptoms of acute or chronic HIV infection should be tested. […] For patients presenting with clinical manifestations of acute HIV infection, testing for HIV ribonucleic acid (RNA) should be added to standard screening tests. A more detailed discussion of how to diagnose acute HIV is presented separately.

• #2 Diagnosis and Management of Acute HIV Infection – Clinical Guidelines Program

  https://www.hivguidelines.org/guideline/hiv-acute/

  The diagnosis of acute HIV infection requires a high degree of clinical awareness. The nonspecific signs and symptoms of acute HIV infection are often not recognized or attributed to another viral illness. […] Clinicians should always perform a plasma HIV RNA assay in conjunction with an Ag/Ab combination immunoassay when acute HIV is suspected. […] If a diagnosis of acute infection is made based on HIV RNA testing, clinicians should recommend ART initiation without waiting for serologic confirmation. […] Clinicians should recommend immediate ART initiation to all patients diagnosed with acute HIV infection. […] The urgency of ART initiation is even greater if the newly diagnosed patient is pregnant, has acute HIV infection, is aged 50 years, or has advanced disease. For these patients, every effort should be made to initiate ART immediately, ideally on the same day as diagnosis. […] When HIV infection is diagnosed, immediate linkage to care is essential; ART dramatically reduces HIV-related morbidity and mortality, and viral suppression prevents HIV transmission.

• #2 HIV testing and diagnosis insights | ViiV Healthcare

  https://viivhealthcare.com/en-us/about-hiv/starting-your-journey/hiv-testing-and-diagnosis/

  HIV testing is important because early detection and timely intervention are key in managing HIV effectively. During the initial phases, HIV may be symptomless or flu-like, making reliance on symptoms alone insufficient. These flu-like symptoms may include a fever (often accompanied with chills or night sweats), headaches, fatigue, swollen lymph nodes, and a persistent sore throat. A skin rash or muscle and joint pain may also become apparent, as well as weight loss, mouth ulcers, and diarrhoea. Clearly, these early HIV symptoms are also associated with other common illnesses and health conditions, so this emphasizes why regular testing is so vital. […] HIV can be acquired through bodily fluids like blood and semen and is more easily transmitted in the early stages, making testing necessary not just for personal health but also to prevent unintentional transmission to others. Testing is the first step towards early diagnosis of HIV and guiding people living with HIV towards treatment.

• #2 Diagnosis of HIV Infection in Infants and Children | NIH

  https://clinicalinfo.hiv.gov/en/guidelines/perinatal/management-infants-diagnosis-hiv-infection-children

  Virologic assays (HIV RNA or HIV DNA nucleic acid tests [NATs]) that directly detect HIV must be used to diagnose HIV in infants and children aged 18 months with perinatal HIV exposure; HIV antibody and HIV antigen/antibody tests should not be used (AII). […] Plasma HIV RNA or cell-associated HIV DNA NATs are generally equally recommended (AII). […] An assay that detects HIV nonB subtype viruses or Group O infections (e.g., an HIV RNA NAT or a total DNA/RNA test) is recommended for use in infants and children who were born to birthing parents with known or suspected nonB subtype virus or Group O infections (AII). […] Virologic diagnostic testing using an HIV NAT is recommended for all infants with perinatal HIV exposure at the following ages: Birth (AII), 14 to 21 days (AII), 1 to 2 months (AII), 4 to 6 months (AII).

• #2 HIV Infection: Laboratory Testing for Diagnosis and Management | Test Guide | Quest Diagnostics HIV Infection: Laboratory Testing for Diagnosis and ManagementHIV Infection: Laboratory Testing for Diagnosis and Management

  https://testdirectory.questdiagnostics.com/test/test-guides/TG_HIV_Management/hiv-infection-laboratory-testing-for-diagnosis-and-management?p=r

  Antibody-based testing is not appropriate in infants younger than 18 months, as maternal antibodies can cross the placenta and be detected in the infant after birth. In addition, testing for p24 antigen is not recommended for infants because it has low sensitivity relative to other virologic assays in the early months after birth. Instead, qualitative HIV-1 RNA or DNA PCR assays can be used for initial testing. For infants at risk of non-subtype B or Group O HIV-1 infection, an RNA or dual DNA/RNA assay should be used instead of a DNA assay. Positive results need to be confirmed with a repeat virologic test on a second specimen. […] This section provides a brief overview of tests used in the management of HIV infection in conjunction with ART, which is recommended for all patients with HIV infection.

• #2 Diagnosis of HIV Infection in Infants and Children | NIH

  https://clinicalinfo.hiv.gov/en/guidelines/perinatal/management-infants-diagnosis-hiv-infection-children

  For infants with perinatal HIV exposure who are being breastfed, virologic diagnostic testing is recommended at birth, 14 to 21 days, 1 to 2 months, and 4 to 6 months of age (AII). […] Age-appropriate HIV testing is also recommended for infants and children with signs and/or symptoms of HIV, even in the absence of documented or suspected HIV exposure (AII). […] For children aged 18 months, HIV antibody (or HIV antigen/antibody) tests are recommended for diagnostic testing (AII).

• #2 HIV testing for treatment and prevention | Labcorp

  https://www.labcorp.com/treatment-areas/virology-infectious-diseases/clinical-testing/hiv/hiv-screening-and-diagnosis

  Approximately 1.2 million people in the United States are infected with HIV. Approximately 13% of those with HIV infection are unaware of their diagnosis, contributing to transmission of HIV in approximately 40% of new infections. […] HIV testing is important for efforts aimed at treatment and prevention. […] The Centers for Disease Control (CDC) recommends HIV testing for all individuals between ages 13 and 64 at least once as part of standard health care. […] Annual screening is recommended for those persons with known or reported risk factors. […] All pregnant persons should be tested for HIV. […] CDC-recommended algorithm for laboratory diagnosis of HIV infection, including acute and primary infection. […] This test is intended for use as an aid in the diagnosis of HIV-1 or HIV-2 infection, including acute or primary infection. Presence of HIV-1 or HIV-2 RNA in the plasma of patients without antibodies to HIV-1 or HIV-2 is indicative of acute or primary HIV-1 or HIV-2 infection. […] This assay may also be used as an additional test, when it is reactive, to confirm HIV-1 infection in an individual whose specimen is repeatedly reactive for HIV-1 and/or HIV-2 antibodies. […] This test detects and quantitates HIV-1 in plasma.

• #2 HIV Symptoms Testing Prevention & Treatment | Freetesting HIV

  https://freetesting.hiv/about-hiv

  If there is a positive diagnosis of HIV after all three tests, you will be referred to a specialist HIV clinic to discuss your treatment options. […] If you are diagnosed with HIV, you will be prescribed antiretroviral medication. It works by stopping the virus from replicating. This protects your immune system from further damage and allows it to repair and strengthen itself. […] The goal of HIV treatment is to have an undetectable viral load. This means the level of the virus in your body has dropped so low that is can no longer be detected in a test. […] If you have been taking effective HIV treatment and your viral load tests have come back undetectable for more than 6 months, it means you cannot pass the virus on through sex. This is called undetectable equals untransmittable (U=U). […] Late diagnosis was 63% in heterosexual men and 50% in heterosexual women. Among gay and bisexual men it was 37%. Late diagnosis of HIV reduces the effectiveness of treatment, so it’s best to test early, and start treatment as soon as possible if you have a positive result.

• #2 HIV Testing Overview

  https://www.hiv.gov/hiv-basics/hiv-testing/learn-about-hiv-testing/hiv-testing-overview

  Knowing your HIV status helps you make healthy decisions to prevent getting or transmitting HIV. […] If you take a test in a health care setting or a lab, a health care provider or lab technician will take a sample of your blood or oral fluid. […] If your oral swab or finger prick test is positive, it will need to be followed up with a blood sample to confirm the results. […] If that confirmatory test result is positive, the lab will conduct follow-up tests. If you receive a positive test result, you can take medicine to treat HIV (called antiretroviral therapy or ART), which protects your health and prevents transmission to others. […] If your test result is positive, you should go to a health care provider or clinic for follow-up testing. […] No HIV test can detect HIV immediately after exposure, including a blood test.

• #2 False positive results on HIV tests | aidsmap

  https://www.aidsmap.com/about-hiv/false-positive-results-hiv-tests

  Tests always produce a small number of false positive results. […] In settings where very few people have HIV, a higher proportion of reactive results will be false positives. […] To ensure accurate diagnosis, a sequence of confirmatory tests is used to verify all reactive results. […] A diagnosis of HIV is never made on the basis of a single test result. […] A false positive is a test result that says a person has HIV when, in fact, they do not have it. […] This preliminary result must be verified with a series of confirmatory tests. […] If you have been tested in this way, with a sequence of confirmatory tests, and you have been told that you are HIV positive, you can be confident of the result. […] An HIV diagnosis is never made on the basis of a single test result. […] If that is the case, the confirmatory testing is essential.

• #2 Diagnosis of HIV/AIDS – Wikipedia

  https://en.wikipedia.org/wiki/Diagnosis_of_HIV/AIDS

  False negative: The test incorrectly indicates that HIV is absent in an infected person. […] Tests used for the diagnosis of HIV infection in a particular person require a high degree of both sensitivity and specificity. In the United States, this is achieved using an algorithm combining two tests for HIV antibodies. […] The combination of these two methods is highly accurate. […] The UNAIDS/WHO policy statement on HIV Testing states that conditions under which people undergo HIV testing must be anchored in a human rights approach that pays due respect to ethical principles. […] In the United States, one emerging standard of care is to screen all patients for HIV in all health care settings. […] HIV antibody tests are specifically designed for routine diagnostic testing of adults; these tests are inexpensive and extremely accurate.

• #2 Testing & Diagnostics

  https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/hiv/testing-diagnostics

  Monitoring of individuals on antiretroviral therapy is important to ensure treatment efficacy and improved health outcomes. Further, HIV treatment monitoring supports the third target of the United Nations 95-95-95 within which 95% of people living with HIV are virally suppressed. This includes the preferred method for treatment monitoring of viral load testing as well as CD4 testing to identify people living with advanced HIV disease. […] HIV drug resistance genotyping is the method of choice to detect the presence of drug resistance mutations through surveillance activities. WHO has developed guidance on methods for quality assurance of genotyping and criteria for HIV drug resistance assay validation.

• #2 HIV/AIDS Diagnosis | Stanford Health Care

  https://stanfordhealthcare.org/medical-conditions/sexual-and-reproductive-health/hiv-aids/diagnosis.html

  Medical experts recommend testing the blood of everyone diagnosed with HIV to look for this drug resistance. […] AIDS is the last and most severe stage of HIV infection. It is diagnosed if the results of your test show that you have: A CD4+ cell count of less than 200 cells per microliter (mcL) of blood.

• #2 HIV – Improving Treatment, Prevention, & Diagnosis

  https://www.gatesfoundation.org/our-work/programs/global-health/hiv

  Viral load testing—the measuring of HIV particles in the blood—can be critical to helping people living with HIV understand their health status and be motivated to continue treatment. […] We support the improved use of viral load testing, as well as the development of novel virus load testing systems, as a means of sustaining effective treatment. […] Several existing measures have proven effective in preventing HIV infection. […] They include voluntary medical male circumcision, condoms, and drugs that reduce the risk of acquiring the virus after exposure. […] New, more effective prevention methods are essential to reducing HIV transmission. […] We continue to invest in efforts to develop an HIV vaccine. […] While substantial progress has been made in increasing access to HIV treatment and new cases of HIV have declined substantially in some regions, controlling the epidemic will require improved efforts to increase the number of people living with HIV who know their status, as well as the effective use of better treatment and prevention measures.

• #3 Clinical Testing Guidance for HIV | HIV Nexus | CDC

  https://www.cdc.gov/hivnexus/hcp/diagnosis-testing/index.html

  CDC recommends all patients between the ages of 13 and 64 get tested for HIV at least once as part of routine health care. […] Use opt-out approach to remove stigma associated with HIV testing and foster earlier diagnosis and treatment. […] Diagnosing HIV quickly and linking people to treatment immediately are crucial steps to reducing new HIV infections. […] An HIV risk assessment should be included as part of routine primary care visits for all your sexually active patients. […] Routine, opt-out screening has proven to be highly effective because it removes the stigma associated with HIV testing, fosters earlier diagnosis and treatment, reduces chances of transmission, and is cost-effective. […] HIV testing laws vary from state to state. […] Three types of HIV tests are available.

• #3 HIV Testing | NIH

  https://hivinfo.nih.gov/understanding-hiv/fact-sheets/hiv-testing

  HIV testing determines if a person has acquired HIV (human immunodeficiency virus). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). AIDS is the most advanced stage of HIV infection. […] HIV testing is important because it is estimated that 40% of new diagnoses of HIV are transmitted by people who are not aware of their HIV status. Knowing your HIV status can help keep you and others safe. Also, early and sustained HIV treatment will help you live a long and healthy life. […] The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 to 64 years of age get tested for HIV at least once as part of a routine health care exam, and that people at higher risk for HIV get tested more often. […] CDC recommends that all pregnant women get tested for HIV so that they can begin taking HIV medicines if they are HIV positive.

• #3 HIV Tests: Diagnosis, Monitoring, and More

  https://www.healthline.com/health/hiv-aids/tests

  Fourth-generation HIV tests, which look for antibodies and the antigen p24, can detect HIV 18 to 45 days after transmission. […] According to the Centers for Disease Control and Prevention, 97 percent of people with HIV produce a detectable number of antibodies within 3 months. […] If a person thinks theyve been exposed to HIV, they should tell their healthcare professional. A viral load test that directly measures the virus can be used to detect whether someone has recently acquired HIV. […] If a person has received an HIV diagnosis, its important for them to monitor their condition on an ongoing basis. […] The two most common measures for assessing HIV transmission are CD4 count and viral load. […] If a persons CD4 count decreases to fewer than 200 cells per cubic millimeter of blood, theyll receive a diagnosis of stage 3 HIV, or AIDS.

• #3 HIV testing and diagnosis insights | ViiV Healthcare

  https://viivhealthcare.com/about-hiv/hiv-testing-and-diagnosis/

  It is generally advised that some people get tested more often (i.e. every 3 to 6 months). These include high-incidence groups, such as: MSM, PWID, those with a history of sexually transmitted infections (STIs), people who have sex without the use of prevention tools such as condoms, and those who have had sex with someone living with HIV with a detectable or unknown viral load. […] The World Health Organisation (WHO) states that people living with HIV who have an undetectable viral load, and take antiretroviral therapy (ART) as prescribed have zero risk of transmitting HIV to their sexual partner(s). […] HIV testing detects the virus before symptoms appear, or if you have a flu-like illness, a common reason for testing. Early diagnosis opposed to a late HIV diagnosis has many benefits; the sooner HIV treatment is started, the better the outcome.

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