Ask the Experts - Use of Rapid HIV Test to Determine Need for PEP?
Ask the Experts - Use of Rapid HIV Test to Determine Need for PEP?
What role, if any, does the rapid HIV antibody test have in a protocol for postexposure treatment of needlestick or other significant exposures to body fluids from HIV-infected patients? Is it worth delaying the initiation of therapy until the results of that test are available?
The newer rapid HIV antibody (SUDS) test takes only 10 minutes to complete, by using serum or plasma. These tests depend on an antigen/antibody reaction. Only one test has been approved, but several others are in development, and home testing based on a salivary transudate or finger stick may ultimately be possible.
These tests are currently being explored for use in a variety of settings. For example, because 25% of people do not follow-up on traditional tests, it might be sensible to offer immediate preliminary results in clinic settings or at home. But the wisdom of providing information in this manner has not been established. The rapid test is also being used to help direct preventive therapy: specifically, to examine test samples involved in occupational exposure to preclude HIV contamination, or to identify HIV-positive mothers at the time of delivery, or to identify HIV in a patient with an acute illness (eg, opportunistic infection) that might be related to unrecognized HIV infection.
Although these tests have excellent sensitivity and specificity, false-positive and -negative results are possible. As the prevalence of HIV in the population decreases, a larger number of false-positive tests will be reported. Accordingly, positive tests must be confirmed. False negative tests become a consideration in clinical situations where very early infection or HIV-2 infection (neither of which would be detected) are suspected.
Given the speed with which results are available, the SUDS test should probably be used to direct PEP after a needle stick. A negative result can be used to preclude postexposure prophylaxis, unless the clinical history related to the sample or the exposure suggests a reason that the SUDS test might fail to detect HIV.
What role, if any, does the rapid HIV antibody test have in a protocol for postexposure treatment of needlestick or other significant exposures to body fluids from HIV-infected patients? Is it worth delaying the initiation of therapy until the results of that test are available?
The newer rapid HIV antibody (SUDS) test takes only 10 minutes to complete, by using serum or plasma. These tests depend on an antigen/antibody reaction. Only one test has been approved, but several others are in development, and home testing based on a salivary transudate or finger stick may ultimately be possible.
These tests are currently being explored for use in a variety of settings. For example, because 25% of people do not follow-up on traditional tests, it might be sensible to offer immediate preliminary results in clinic settings or at home. But the wisdom of providing information in this manner has not been established. The rapid test is also being used to help direct preventive therapy: specifically, to examine test samples involved in occupational exposure to preclude HIV contamination, or to identify HIV-positive mothers at the time of delivery, or to identify HIV in a patient with an acute illness (eg, opportunistic infection) that might be related to unrecognized HIV infection.
Although these tests have excellent sensitivity and specificity, false-positive and -negative results are possible. As the prevalence of HIV in the population decreases, a larger number of false-positive tests will be reported. Accordingly, positive tests must be confirmed. False negative tests become a consideration in clinical situations where very early infection or HIV-2 infection (neither of which would be detected) are suspected.
Given the speed with which results are available, the SUDS test should probably be used to direct PEP after a needle stick. A negative result can be used to preclude postexposure prophylaxis, unless the clinical history related to the sample or the exposure suggests a reason that the SUDS test might fail to detect HIV.