Open AccessClinical Evaluation of an Affordable Qualitative Viral Failure Assay for HIV Using Dried Blood Spots in Uganda
Author(s) -
Sheila N. Balinda,
Pascale Ondoa,
Ekwaro A. Obuku,
Aletta Kliphuis,
Isaac Egau,
Michelle Bronze,
Lordwin Kasambula,
Rob Schuurman,
Nicole Spieker,
Tobias F. Rinke de Wit,
Cissy Kityo
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0145110
Subject(s) - viral load , dried blood spot , medicine , dried blood , antiretroviral therapy , human immunodeficiency virus (hiv) , virology , biology , chemistry , chromatography , genetics
Background WHO recommends regular viral load (VL) monitoring of patients on antiretroviral therapy (ART) for timely detection of virological failure, prevention of acquired HIV drug resistance (HIVDR) and avoiding unnecessary switching to second-line ART. However, the cost and complexity of routine VL testing remains prohibitive in most resource limited settings (RLS). We evaluated a simple, low–cost, qualitative viral–failure assay (VFA) on dried blood spots (DBS) in three clinical settings in Uganda. Methods We conducted a cross–sectional diagnostic accuracy study in three HIV/AIDS treatment centres at the Joint Clinical Research Centre in Uganda. The VFA employs semi-quantitative detection of HIV–1 RNA amplified from the LTR gene. We used paired dry blood spot (DBS) and plasma with the COBASAmpliPrep/COBASTaqMan, Roche version 2 (VL ref ) as the reference assay. We used the VFA at two thresholds of viral load, (>5,000 or >1,000 copies/ml). Results 496 paired VFA and VL ref results were available for comparative analysis. Overall, VFA demonstrated 78.4% sensitivity, (95% CI: 69.7%–87.1%), 93% specificity (95% CI: 89.7%–96.4%), 89.3% accuracy (95% CI: 85%–92%) and an agreement kappa = 0.72 as compared to the VL ref . The predictive values of positivity and negativity among patients on ART for >12 months were 72.7% and 99.3%, respectively. Conclusions VFA allowed 89% of correct classification of VF. Only 11% of the patients were misclassified with the potential of unnecessary or late switch to second–line ART. Our findings present an opportunity to roll out simple and affordable VL monitoring for HIV–1 treatment in RLS.