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Counseling and HIV Testing. HAIVN Harvard Medical School AIDS Initiatives in Vietnam. Learning Objectives. By the end of this session, participants will be able to: Explain the importance of HIV voluntary counseling and testing (VCT) List at least 3 HIV diagnostic testing
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Counseling and HIV Testing HAIVN Harvard Medical School AIDS Initiatives in Vietnam
Learning Objectives By the end of this session, participants will be able to: • Explain the importance of HIV voluntary counseling and testing (VCT) • List at least 3 HIV diagnostic testing • Describe the Vietnam MOH testing strategy
VCT Key Principles Voluntary: Client makes own decision whether to take HIV test Counseling: HIV testing always accompanied by HIV prevention counseling Testing: Test results must be provided in accordance with current MOH guidelines
Why is VCT Important ? VCT serves as an entry point for:
MOH Guidelines for VCT Pre-test session Post-test session HIV test • Provide: • test result • support around partner notification • emotional support • referrals • Discuss risk reduction plan • Assess client knowledge • Assess client risk • Create risk reduction plan with client • Prepare HIV test • Refer for services • Conduct HIV test • Done off-site in MOH approved labs • Client tries out risk reduction plan
HIV Testing and the “Window Period” Window period CD4 HIV Antibody Detectable antibody level Viral Load 1234567-12 1 2 3 4 5 6 7 8 9 10 11 12 13 Weeks Years
ELISA _ + _ + Positive Negative Read results immediately HIV Antibody Tests (1) “Rapid test” Western Blot _ +
HIV Antibody Tests (2) Rapid ELISA/Rapid EIA (“Rapid Tests”) • Results in 10 minutes to 2 hours using blood, urine or saliva • Extremely useful for immediate results • Many different tests are available with excellent sensitivity and specificity • Negative test can be reported as negative • Positive results must be confirmed with additional testing
HIV Antibody Tests (3) Western Blot Test (WB) • Used as a confirmatory test • Very specific for HIV • Samples that give a negative result are reported as negative
Direct HIV Tests (1) Polymerase Chain Reaction (PCR) • Detects HIV genetic material in blood • Positive within 1-2 weeks after infection • Babies born to HIV positive mothers may be tested by looking for HIV DNA • Can be used to diagnose acute HIV infection in adults during window period
Direct HIV Tests (2) Demonstration of viral antigen (p24 antigen) • Sometimes used to screen donated blood • Can also be used to test for HIV in individuals, mostly children • Detectable within 2-3 weeks after infection • Becomes negative after seroconversion and development of anti-p24 antibodies
Dry Blood Spot (DBS) Test (1) • DBS is used to facilitate testing of HIV DNA for the purposes of early infant HIV diagnosis • A DBS is a sample of whole blood collected on filter paper and dried • DBS can be stored and shipped to testing facilities • Using DBS, infants can be tested using PCR as early as 4-6 weeks of age.
MOH Testing Strategies(1) Strategy I: At blood banks • Positive test with one of these tests: ELISA, SERODIA, RAPID TEST. • If one simple positive screening test: reject for blood transfusion
MOH Testing Strategies (2) Strategy II: Routine screening in high prevalence areas • Two tests with different ELISA “format” • Positive result confirmed if both ELISAs tests positive.
MOH Testing Strategies (3) Strategy III: HIV diagnosis • Three tests with different ELISA “format” • Positive result confirmed if all 3 tests positive
Interpretation of HIV Test (1)Adults and Children > 18 Months
Interpretation of HIV Test (2)Children < 18 Months Confirmation of HIV infection requires: • Infants less than 9 months • Two positive PCR tests • Performed between 4-6 weeks, or ASAP • Breastfeeding stopped completely for more than 6 weeks • Infants between 9-18 months • Testing for antibody first • Confirmed with PCR test
Diagnosis of severe HIV / AIDS in infants <18 months • Positive result for HIV antibodies testing • One symptoms of clinical stage 4 • At least 2 of the 3 following symptoms: • Oral thrush (in > one month old child) • Severe pneumonia • Severe infections • Other factors: • Mother died of HIV-related disease • Mother has HIV/AIDS progression • CD4 percentage <20%
Key Points • HIV testing perform in any medical facility must be: • Voluntary and confidential • Including counseling before and after testing • Diagnosis of HIV is detected indirectly through the demonstration of virus-specific antibody: ELISA, rapid test, Western blot. • 3 positive tests needed to confirm HIV(Strategy III)
Thank you! Question?