False-positive HIV DNA PCR testing of infants : implications in a changing epidemic
Date
2012-03
Authors
Feucht, Ute
Forsyth, Brian
Kruger, Mariana
Journal Title
Journal ISSN
Volume Title
Publisher
Health and Medical Publishing Group (HMPG)
Abstract
Aim. To examine false-positive HIV DNA polymerase chain reaction (PCR) test results in children, and the potential implications for the paediatric HIV epidemic in sub-Saharan Africa. Methods. A review was done of records over a 6-year period of children less than 18 months old at an HIV treatment site in South Africa, to evaluate those with an initial 'false'-positive HIV DNA PCR result, but later proven to be HIV-uninfected with HIV DNA PCR and/or quantitative HIV RNA PCR tests. We calculated the influence of changing HIV transmission rates on predictive values (PV) of HIV DNA PCR tests in a hypothetical population of all HIV-exposed infants over a 1-year period. (Positive PV: proportion of individuals with a positive test with disease; negative PV: proportion of individuals with negative test and no disease). Results. Of 718 children, 40 with an initial positive HIV DNA PCR test were subsequently proven to be HIV-uninfected, resulting in a positive PV of 94.4%. Most (75%) uninfected children had PMTCT interventions and were asymptomatic or mildly symptomatic (77.5%). Calculations using a test specificity of 99.4%, as reported previously, show a decrease in positive PV using a single-test strategy from 98.6% at 30% HIV transmission rate, to 94.8% at 10% transmission, to 62.5% at 1% transmission. Reduction in test specificity further decreases positive PV at low transmission rates. Conclusion. Decreasing mother-to-child HIV transmission rates reduce the positive predictive value of a single HIV DNA PCR test result, necessitating adaptations to diagnostic algorithms to avoid misdiagnosis and inappropriate treatment, especially with early initiation of antiretroviral therapy in asymptomatic infants.
Description
The original publication is available at http://www.samj.org.za
Keywords
HIV infections -- Prevention -- Sub-Saharan Africa, HIV positive children -- Treatment -- Sub-Saharan Africa, Diagnostic error -- Complications, HIV infections in children -- Diagnosis -- Complications
Citation
Feucht, U., Forsyth, B. & Kruger, M. 2012. False-positive HIV DNA PCR testing of infants : implications in a changing epidemic. South African Medical Journal, 102(3):149-152.