title: Clinical Evaluation of an Affordable Qualitative Viral Failure Assay for HIV Using Dried Blood Spots in Uganda.
abstract: 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 (VLref) 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 VLref 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 VLref. 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.
authors.affiliation: Joint Clinical Research Center, P.O. Box 10005, Kampala, Uganda.
authors.forename: Sheila N
authors.initials: SN
authors.lastname: Balinda
authors.affiliation: Amsterdam Institute for Global Health and Development, Department of Global Health, Academic medical Center, Trinity C Building, Pietersbergweg 17, 1105 BM, Amsterdam, the Netherlands.
authors.forename: Pascale
authors.initials: P
authors.lastname: Ondoa
authors.affiliation: Joint Clinical Research Center, P.O. Box 10005, Kampala, Uganda.
authors.forename: Ekwaro A
authors.initials: EA
authors.lastname: Obuku
authors.affiliation: PharmAccess International, Amsterdam, Trinity Building C Pietersbergweg 17, 1105 BM, Amsterdam, the Netherlands.
authors.forename: Aletta
authors.initials: A
authors.lastname: Kliphuis
authors.affiliation: Joint Clinical Research Center, P.O. Box 10005, Kampala, Uganda.
authors.forename: Isaac
authors.initials: I
authors.lastname: Egau
authors.affiliation: Wits Health Consortium, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa.
authors.forename: Michelle
authors.initials: M
authors.lastname: Bronze
authors.affiliation: Joint Clinical Research Center, P.O. Box 10005, Kampala, Uganda.
authors.forename: Lordwin
authors.initials: L
authors.lastname: Kasambula
authors.affiliation: University Medical Centre Utrecht, P.O. Box 80125, 3508 TC, Utrecht, the Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Schuurman
authors.affiliation: PharmAccess International, Amsterdam, Trinity Building C Pietersbergweg 17, 1105 BM, Amsterdam, the Netherlands.
authors.forename: Nicole
authors.initials: N
authors.lastname: Spieker
authors.affiliation: Amsterdam Institute for Global Health and Development, Department of Global Health, Academic medical Center, Trinity C Building, Pietersbergweg 17, 1105 BM, Amsterdam, the Netherlands.
authors.forename: Tobias F
authors.initials: TF
authors.lastname: Rinke de Wit
authors.affiliation: Joint Clinical Research Center, P.O. Box 10005, Kampala, Uganda.
authors.forename: Cissy
authors.initials: C
authors.lastname: Kityo
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000191:economics / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013048:Specimen Handling / Q000191:economics* / Q000379:methods; D014454:Uganda; D019562:Viral Load / Q000191:economics*; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents
references.citation: Croat Med J. 2003 Oct;44(5):639-50
references.pmid: 14515429
references.citation: AIDS. 2014 Mar;28 Suppl 2:S161-9
references.pmid: 24849476
references.citation: JAMA. 1998 Mar 11;279(10):756-61
references.pmid: 9508151
references.citation: Antivir Ther. 2009;14(5):619-29
references.pmid: 19704164
references.citation: Health Policy Plan. 2009 Nov;24(6):407-17
references.pmid: 19570773
references.citation: Lancet. 2010 Jan 30;375(9712):419-26
references.pmid: 20113826
references.citation: Health Policy Plan. 2010 Sep;25(5):363-71
references.pmid: 20472694
references.citation: Int J Epidemiol. 2012 Feb;41(1):43-54
references.pmid: 21071386
references.citation: Clin Infect Dis. 2012 Jun;54(11):1660-9
references.pmid: 22474222
references.citation: AIDS Res Hum Retroviruses. 2013 Jun;29(6):925-30
references.pmid: 23517497
references.citation: J Clin Microbiol. 2013 Jun;51(6):1757-61
references.pmid: 23536405
references.citation: J Clin Microbiol. 2013 Jun;51(6):1899-905
references.pmid: 23596235
references.citation: PLoS One. 2014;9(3):e86461
references.pmid: 24603442
references.citation: AIDS. 2014 Mar;28 Suppl 2:S151-60
references.pmid: 24849475
references.citation: Acad Emerg Med. 1996 Sep;3(9):895-900
references.pmid: 8870764