Test For HIV

Pretest Counselling & Informed Consent
  • Risk assessment & education focused on prevention should be done prior to & after receiving test results
  • The following information should be provided by health care providers when recommending HIV testing & counselling:
    • Reasons why HIV testing & counselling is being offered & their benefits & potential risks (eg discrimination, abandonment)
    • Services that are available, including ART, in either an HIV-positive or an HIV-negative test result
    • That the patient has a right to decline the test & that result will be treated w/ confidentiality; patient’s decision to decline should be noted in the medical record
    • In critically ill or unconscious patients where informed consent is not possible, permission should be sought from the patient’s next-of-kin, guardian or other caregiver; in the absence of such person, the health care provider should act according to the best interest of the patient
    • In case of an HIV-positive test result, disclosure to other persons who may be at risk of exposure to HIV should be encouraged
    • An opportunity for the patient to ask the health care provider questions

HIV Test
  • Choice of HIV test depends on various factors such as cost & availability of equipments or test kits, lab expertise, availability of staff, number of samples to be tested, collection & transport of samples, convenience, setting where testing will be performed, ability of the patients to come back for the results
  • Testing strategies are either done as:
    • Parallel testing: Recommended when using whole blood as samples; 2 tests are simultaneously done using assays based on different antigens; concordantly negative or positive results are reported as true negatives or positives, respectively
    • Serial testing: If the HIV antibody test is negative, it is reported as “negative”; if test result is positive, the specimen undergoes a second test using an antigen different from the first; a second positive result is considered a true positive
      • In low-prevalence setting where false positive results are likely, a third confirmatory test may be done 
      • Recommended due to its cheaper cost; a second test is only required for reactive initial test results
  • Rapid HIV tests
    • Eg OraQuick Rapid HIV-1/2 Antibody Test, Reveal G3 Rapid HIV-1 Antibody Test, Uni-Gold Recombigen HIV Test, Clearview HIV 1/2 Stat Pack, Clearview Complete HIV 1/2, Multispot HIV-1/HIV-2 Rapid Test
    • May either be done as serial or parallel testing
    • Provide accurate results w/in a much shorter time compared w/ traditional enzyme-linked immunosorbent assays (ELISA)
    • Advantages include visibility of the test & quick turn-around, testing can occur outside lab settings, does not require specialized equipment; however, trained lab supervisors are required to supervise & assure quality control
    • Are almost always serial in nature
    • Preferred method when large numbers of tests need to be performed (allows large numbers of samples to be tested efficiently at one time)
    • Disadvantages include longer time to assemble enough samples to make a test run, longer reporting time of the results (half day), precluding outpatients receiving the test result at the same visit, requires certified lab staff to manage the test procedure, report results & maintain equipment
  • Reactive ELISA or rapid test must be followed by a Western blot
  • Negative ELISA or rapid test or a reactive ELISA or rapid test w/ negative or indeterminate Western blot should be followed by a virologic test (ie p24 antigen or HIV RNA assay); a positive virologic test in this case, is consistent w/ acute HIV infection
  • If an acute HIV infection is diagnosed by a positive virologic test & preceded by a negative HIV antibody test, a confirmatory HIV antibody test should be performed over the next 3 months to confirm seroconversion

Post-Test Counseling

  • All individuals undergoing HIV testing should be counselled when their results are given, regardless of the test result
HIV-positive patients
  • Clearly inform the patient of the test result & allow him/her the time to consider it
  • Ensure that the patient understands the result & allow questions to be asked
  • Provide emotional support & crisis management
  • Discuss any immediate concerns & determine available & acceptable social network to offer support
  • Discuss treatment & follow-up services available, including care & support services, prevention of mother-to-child transmission
  • Provide information on prevention of HIV transmission (including provision of male & female condoms & guidance on their use) & relevant health preventive measures (eg good nutrition)
  • Notification, counselling & referral for HIV testing of partners & children
HIV-negative patients
  • Explanation of the test result, including information on the window period for the appearance of HIV antibodies & a recommendation to re-test in case of a recent exposure
  • Educate on methods of prevention of HIV transmission
  • Provision of male & female condoms & guidance on their use
  • Start ART to uninfected partner for prevention



History and Physical Examination
  • Signs, symptoms & lab findings of acute HIV infection w/ recent (w/in 2-6 weeks) high risk of exposure to HIV may include (but are not limited to):
    • Fever
    • Skin rash
    • Headache
    • Diarrhea
    • Myalgia, arthralgia
    • Lymphadenopathy
    • Oral ulcers
    • Leucopenia, thrombocytopenia
    • Elevated transaminase level
  • High-risk exposures include sexual contact w/ an HIV-infected person or w/ an individual at risk for HIV, sharing of injection drug use paraphernalia, contact w/ potentially infectious blood w/ mucous membranes or breaks in the skin

Laboratory Tests
  • HIV Antibody Testing
    • Done if no prior documentation is available or if HIV RNA is below the assay’s limit for detection
  • Plasma HIV RNA (viral load)
    • Most important indicator of initial or sustained response to ART
      • Should be measured in all HIV-infected patients upon start of care & therapy then on a regular basis thereafter
    • Pre-treatment viral load level is taken into consideration in selecting initial ARV regimen
      • Due to poorer responses in patients w/ high baseline viral load
    • Optimal viral suppression is generally defined as a viral load persistently below the level of detection (<20-75 copies/mL), depending on the assay used
    • Viral suppression is generally achieved in 12-24 weeks, provided patient is adherent to their ART regimen & does not develop resistance to the prescribed drugs
    • Early detection of virological failure allows better preservation of the efficacy of second-line regimens
    • In settings where resources are limited, measurement of plasma viral load is not required prior to initiation of ART 
    • Measurement is done:
      • After initiation of therapy because virologic failure w/in 2-4 weeks but not later than 8 weeks after treatment initiation or modification
      • Repeat viral load measurement at 4-8 weeks interval until the level falls below the assay's limit of detection
      • In virologically suppressed patients in whom ART was modified because of drug toxicity or for regimen simplification, measurement should be performed w/in 4-8 weeks after changing the therapy
      • Viral load test is repeated every 3-4 months or as clinically indicated in patients who are on stable & suppressive ARV regimen. It may be extended up to 6 months if the viral load was suppressed for >2 years & if the clinical & immunologic status are stable
      • Frequency of monitoring in patients w/ suboptimal response to ART will depend on the adherence & availability of other treatment options
  • CD4 T-cell count
    • Serves as a major indicator of immune function
    • One of the key factors in deciding whether to start ART & prophylaxis for opportunistic infections
    • Strongest predictor of subsequent disease progression & survival
    • An adequate CD4 response for most patients on ART is defined as an increase in CD4 count in the range of 50-150 cells/mm3 per year except in patients w/ a low starting CD4 count & in those w/ an advanced age who may show a blunted increase despite virologic suppression
    • Should be monitored every 3-4 months to determine when to initiate ART in untreated patients, evaluate immunologic response to ART & to determine the need for initiation or discontinuation of prophylaxis for opportunistic infections
    • In patients w/ consistently suppressed viral loads, CD4 count may be monitored every 6-12 months, unless there are changes in the clinical status of the patient
    • 3-6 months intervals was recommended in patients who fail to maintain viral suppression on ART & those who were already on ART for 2 years
  • CBC, transaminase levels, BUN, creatinine, hepatitis A, B & C serologies, urinalysis
  • Fasting blood sugar & lipid levels
  • HIV drug resistance testing should be done upon entry into care, regardless of whether ART will be started immediately or deferred
    • Genotypic testing is the preferred resistance testing to guide the selection of initial regimen in ART-naive patients
    • Helps in the selection of alternative regimens in patients who fail to achieve viral suppression
    • Is also performed when managing suboptimal viral load reduction
    • Should be done while the patient is taking ART regimen or w/in 4 weeks of treatment discontinuation
  • HLA-B *5701 screening
    • Recommended prior to initiating Abacavir-containing regimen to reduce the risk of hypersensitivity reaction
  • Pregnancy test: If patient will be started on Efavirenz
  • Coreceptor tropism assays are used whenever a CCR5 inhibitor (eg Maraviroc) is being considered
    • Also considered if patients exhibit virologic failure on Maraviroc or any CCR5 inhibitor
  • Other tests include tests for sexually transmitted infections & tests for determining risk of opportunistic infections

Clinical Staging of HIV Disease in Adults & Adolescents
  • HIV disease staging and classification systems are critical tools for providing clinicians and patients with important information about HIV disease stage and clinical management. Two major classification systems currently are in use: The U.S. Centers for Disease Control and Prevention (CDC) classification system and the World Health Organization (WHO) Clinical Staging and Disease Classification System
  • Assessment used where HIV infection has been confirmed by HIV antibody testing & serves to guide decisions on when to initiate ART
  • Clinical stage 1: Asymptomatic, persistent generalized lymphadenopathy
  • Clinical stage 2: Unexplained moderate weight loss (approx <10% of estimated or actual body wt), recurrent oral sores, angular cheilitis, pruritic papular lesions, seborrheic dermatitis, recurrent respiratory tract infections (eg tonsillitis, pharyngitis, otitis media, sinusitis), fungal nail infections, herpes zoster
  • Clinical stage 3: Unexplained severe weight loss (>10% of estimated or measured body wt), unexplained persistent fever (intermittent or constant) lasting for >1 month, unexplained diarrhea lasting for >1 month, unexplained neutropenia (< 0.5 x 109/L), anemia (<8 g/dL), &/or chronic thrombocytopenia (<50 x 109/L), oral hairy leukoplakia, persistent oral candidiasis, acute necrotizing stomatitis, gingivitis or periodontitis, pulmonary tuberculosis, severe bacterial infection (i.e pneumonia, empyema, meningitis, pyomyositis, bone & joint infection, bacteremia, severe pelvic inflammatory disease)
  • Clinical stage 4: HIV wasting syndrome, recurrent bacterial pneumonia, extrapulmonary tuberculosis, cytomegalovirus disease, Kaposi’s sarcoma, disseminated mycosis, recurrent septicemia, disseminated nontuberculous mycobacterial infection, lymphoma, progressive multifocal leukoencephalopathy, HIV encephalopathy, pneumocytis jirovecii, chronic herpes simplex (urolabial, genital, anorectal of >1mm or visceral at any site), esophageal candidiasis (trachea, bronchi & lungs), CNS toxoplasmosis, extrapulmonary cryptococcosis, including meningitis, chronic cryptosporidiosis, chronic isosporiasis, disseminated mycosis (histoplasmosis, coccidiomycosis) recurrent septicaemia (including nontyphoidal Salmonella), lymphoma (cerebral or B cell non-Hodgkin), invasive cervical carcinoma, atypical disseminated leishmaniasis and symptomatic HIV-associated nephropathy or HIV-associated cardiomyopathy