IMMUNODEFICIENCY 1.2 Flashcards
ASSESSMENT AND DIAGNOSTIC METHODS-MEDICAL MANAGEMENT
ASSESSMENT AND DIAGNOSTIC METHODS
- Enzyme immunoassay (EIA)
- Western Blot
- Viral Load Test
- OraSure Saliva Test
- OraQuick Rapid HIV-1 antibody test
ASSESSMENT AND DIAGNOSTIC METHOD:
- Formerly enzyme-linked immunosorbent assay [ELISA]
- One of the most commonly used tests to screen for HIV antibodies. This test detects antibodies that the body produces in response to HIV infection
Enzyme Immunoassay (EIA)
ASSESSMENT AND DIAGNOSTIC METHOD:
- A blood sample is taken from the individual, and the test is performed in a laboratory. The test uses antigens from HIV to capture any antibodies present in the blood.
- If the test detects antibodies, it produces a positive result.
- However, because this is a screening test, any positive result must be confirmed by a more specific test, such as the Western blot assay.
Enzyme Immunoassay (EIA)
ASSESSMENT AND DIAGNOSTIC METHOD:
FALSE POSITIVE RESULT OF Enzyme Immunoassay (EIA)
- Cross-Reactivity
- Recent Vaccination
- Technical Errors
- Biological Factors
ASSESSMENT AND DIAGNOSTIC METHOD:
FALSE NEGATIVE RESULT OF Enzyme Immunoassay (EIA)
- Window Period
- Test Sensitivity
- Genetic Variants of HIV
FALSE POSITIVE RESULT:
Improper handling, contamination, or incorrect interpretation of the test results
Technical Errors
FALSE POSITIVE RESULT:
Can sometimes react with antibodies produced in response to other infections or conditions such as autoimmune disorders or other viral infections (EBV)
Cross-Reactivity
FALSE POSITIVE RESULT:
Rarely, individuals may naturally produce proteins that mimic HIV antibodies
Biological Factors
FALSE POSITIVE RESULT:
Can sometimes trigger the production of antibodies that cross-react with HIV antigens
Recent Vaccination
FALSE NEGATIVE RESULT:
The time between initial HIV infection and the point when the body produces enough antibodies to be detected by the EIA.
Window Period
FALSE NEGATIVE RESULT:
Antibody levels are very low in cases of early HIV infection and advanced HIV infection.
Test Sensitivity
ASSESSMENT AND DIAGNOSTIC METHODS:
- The confirmatory test for HIV.
- It is more specific than the EIA and is used to confirm the presence of HIV antibodies after a positive EIA test.
Western Blot
FALSE NEGATIVE RESULT:
Incorrect sample handling, dilution errors
Technical Errors
FALSE NEGATIVE RESULT:
While rare, certain genetic variants of HIV might not be detected by the antigens used in the standard EIA
Genetic Variants of HIV
ASSESSMENT AND DIAGNOSTIC METHODS:
Target Amplification Methods of Viral Load Test
- Polymerase Chain Reaction (PCR)
- Branched DNA (bDNA) Test