title: Initial Accuracy of HIV Rapid Test Kits Stored in Suboptimal Conditions and Validity of Delayed Reading of Oral Fluid Tests.
abstract: OBJECTIVE
  To evaluate the effect of storing commonly used rapid diagnostic tests above manufacturer-recommended temperature (at 37°C), and the accuracy of delayed reading of oral fluid kits with relevance to HIV self-testing programmes.
  
  
  METHODS
  A quality assurance study of OraQuick (OraSure), Determine HIV 1/2™ (Alere) and Uni-Gold™ (Recombigen®).
  
  
  METHODS
  Consecutive adults (≥18y) attending Ndirande Health Centre in urban Blantyre, Malawi in January to April 2012 underwent HIV testing with two of each of the three rapid diagnostic test kits stored for 28 days at either 18°C (optimally-stored) or at 37°C (pre-incubated). Used OraQuick test kits were stored in a laboratory for delayed day 1 and subsequent monthly re-reading was undertaken for one year.
  
  
  RESULTS
  Of 378 individuals who underwent parallel testing, 5 (1.3%) were dropped from the final analysis due to discordant or missing reference standard results (optimally-stored Determine and Uni-Gold). Compared to the diagnostic reference standard, OraQuick had a sensitivity of 97.2% (95% CI: 93.6-99.6). There were 7 false negative results among all test kits stored at 37°C and three false negatives among optimally stored kits. Excellent agreement between pre-incubated tests and optimally-stored tests with Kappa values of 1.00 for Determine and Uni-Gold; and 0.97 (95% CI: 0.95; 1.00) for OraQuick were observed. There was high visual stability on re-reading of OraQuick, with only 1/375 pre-incubated and 1/371 optimally-stored OraQuick kits changing from the initial result over 12 months.
  
  
  CONCLUSIONS
  Erroneous results observed during HIV testing in low income settings are likely to be due to factors other than suboptimal storage conditions. Re-reading returned OraQuick kits may offer a convenient and accurate quality assurance approach, including in HIV self-testing programmes.
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: Augustine T
authors.initials: AT
authors.lastname: Choko
authors.affiliation: Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
authors.forename: Miriam
authors.initials: M
authors.lastname: Taegtmeyer
authors.affiliation: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.|Department of Clinical Research, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: MacPherson
authors.affiliation: Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
authors.forename: Derek
authors.initials: D
authors.lastname: Cocker
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: McEwen
authors.initials: M
authors.lastname: Khundi
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: Deus
authors.initials: D
authors.lastname: Thindwa
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: Rodrick S
authors.initials: RS
authors.lastname: Sambakunsi
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: Moses K
authors.initials: MK
authors.lastname: Kumwenda
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.
authors.forename: Kondwani
authors.initials: K
authors.lastname: Chiumya
authors.affiliation: Blantyre District Health Office, Ministry of Health, Blantyre, Malawi.
authors.forename: Owen
authors.initials: O
authors.lastname: Malema
authors.affiliation: Department of HIV, Ministry of Health, Lilongwe, Malawi.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Makombe
authors.affiliation: London School of Hygiene &Tropical Medicine, London, United Kingdom.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Webb
authors.affiliation: TB and HIV theme, Malawi Liverpool Wellcome Trust, Blantyre, Malawi.|London School of Hygiene &Tropical Medicine, London, United Kingdom.|College of Medicine, Blantyre, Malawi.
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Corbett
mesh_terms: D000328:Adult; D005260:Female; D006678:HIV / Q000145:classification / Q000235:genetics*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology*; D006801:Humans; D008297:Male; D008403:Mass Screening; D011933:Reagent Kits, Diagnostic / Q000592:standards; D015203:Reproducibility of Results; D012463:Saliva / Q000821:virology*; D012680:Sensitivity and Specificity; D057188:Workflow
chemical_list: D011933:Reagent Kits, Diagnostic