Diagnostic parameters and reliability of four rapid immunochromatographic tests for dengue 4

• Published in: The Brazilian journal of infectious diseases Vol. 24; no. 1; pp. 58 - 64
• Main Authors: Mata, Veronica Elizabeth, Passos, Sonia Regina Lambert, Santos, Maria Angelica Borges dos, Buonora, Sibelle Nogueira, de Andrade, Carlos Augusto Ferreira, Lima, Monique da Rocha Queiroz, Costa, Betina Moreira, Hökerberg, Yara Hahr Marques
• Format: Journal Article
• Language: English
• Published: Brazil Elsevier España, S.L.U 01-01-2020; Contexto; Elsevier; Brazilian Society of Infectious Diseases
• Subjects: Adult; Antigens; Brazil; Chromatography, Affinity - methods; Chromatography, Affinity - standards; Cross-Sectional Studies; Dengue; Dengue - diagnosis; Dengue - immunology; Dengue - virology; Dengue fever; Dengue virus; Dengue Virus - isolation & purification; Diagnosis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunochromatographic tests; INFECTIOUS DISEASES; Instrument industry (Equipment); Male; Middle Aged; Nurses; Observer Variation; Original; Polymerase chain reaction; Prejudice; Prospective Studies; Reference Standards; Reproducibility of Results; Reproducibility of tests; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Serogroup; Brazil; United States; Sensitivity and specificity; Reproducibility of tests; Immunochromatographic tests; Diagnosis; Dengue
• ISSN: 1413-8670; 1678-4391; 1678-4391
• DOI: 10.1016/j.bjid.2019.12.004

Although performance of rapid immunochromatographic tests (RITs) for dengue virus (DENV) serotypes 1, 2 and 3 is relatively settled, evidence on accuracy of RITs for DENV-4 are based on studies with small sample sizes and with discrepant results.
To assess accuracy and inter-observer agreement of RITs targeting dengue nonstructural protein-1 (NS1) antigen - Dengue NS1-Bioeasy™, Dengue NS1 Ag Strip-Bio-Rad™, IVB Dengue Ag NS1-Orangelife™ and Dengue NS1-K130-Bioclin™ in DENV-4 samples.
Study sample (n = 324) included adults presenting at an emergency unit in Rio de Janeiro, Brazil, with fever of ≤72 h and two or more dengue symptoms. A serum sample from each patient was tested by each RIT. A positive reverse-transcription polymerase chain reaction was considered as the reference standard for dengue diagnosis. The diagnostic parameters analyzed for each RIT were sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Each RIT was read by homogeneous (two junior nurses) or heterogeneous (one junior nurse and one senior biologist) pairs. Agreement was estimated by simple kappa with 95% confidence interval, positive (Ppos) and negative (Pneg) proportion concordance and prevalence and bias adjusted kappa, rated from poor (k < 0.0) to almost perfect (0.8 < k < 1.0), and perfect (k = 1).
NS1 RITs for DENV-4 diagnosis showed high specificity (95.9%–99.4%), but low sensitivity (14.7%–45.4%). Bioeasy™ had the best performance, with a positive likelihood ratio of 26.0 (95% CI: 8.4;81.0). Inter-observer agreement was almost perfect for all evaluated RITs. Mismatches in confirmed dengue were more common for the Bioclin™ (Ppos 88.3–90.0 %) and Orangelife™ (Ppos 91.7–94.1 %) tests.
For DENV-4, the tested RITs had high specificity, but lower sensitivity compared to published results for other serotypes. They should not be used for screening purposes. Different brands may have very different performances. This should be considered upon deciding of using RITs in DENV-4 outbreaks.