Contamination with HIV antibody may be responsible for false positive results in specimens tested on automated platforms running HIV 4th generation assays in a region of high HIV prevalence
Fig 4
Western blots of selected specimens: negative, positive and low positive controls are labelled N, P and LP respectively.
Specimens of interest are labelled A to G. Specimens A, B and C were concordantly weakly positive on both serology assays and HIV viral loads were high. Their western blots were scored as positive (A) and indeterminate (B, C). Specimens D, E, F and G were also WB indeterminate, but RNA negative. A follow up specimen on D was antibody negative.