GeneXpert HIV-1 quant assay, a new tool for scale up of viral load monitoring in the success of ART programme in India

Recent WHO guidelines identify virologic monitoring for diagnosing and confirming ART failure. In view of this, validation and scale up of point of care viral load technologies is essential in resource limited settings. A systematic validation of the GeneXpert® HIV-1 Quant assay (a point-of-care technology) in view of scaling up HIV-1 viral load in India to monitor the success of national ART programme was carried out. Two hundred nineteen plasma specimens falling in nine viral load ranges (5 L copies/ml) were tested by the Abbott m2000rt Real Time and GeneXpert HIV-1 Quant assays. Additionally, 20 seronegative; 16 stored specimens and 10 spiked controls were also tested. Statistical analysis was done using Stata/IC and sensitivity, specificity, PPV, NPV and %misclassification rates were calculated as per DHSs/AISs, WHO, NACO cut-offs for virological failure. The GeneXpert assay compared well with the Abbott assay with a higher sensitivity (97%), specificity (97-100%) and concordance (91.32%). The correlation between two assays (r = 0.886) was statistically significant (p