Background Rapid diagnosis tests (RDTs) are easy to carry out, provide fast results, and could potentially guide medical treatment decisions. We investigated the performance of a commercially available RDT, which simultaneously detects the non-structural 1 (NS1) dengue virus (DENV) antigen, and IgM and IgG DENV antibodies, using representative serum samples from individuals in a dengue endemic area in Salvador, Brazil. Methodology/Principal findings We evaluated the accuracy of the SD BIOLINE Dengue Duo RDT (Abbott, Santa Clara, USA; former Alere Inc, Waltham, USA) in a random collection of sera. Samples included acute-phase sera from 246 laboratory-confirmed dengue cases and 108 non-dengue febrile patients enrolled in a surveillance study for dengue detection, 73 healthy controls living in the same surveillance community, and 73 blood donors. RDT accuracy was blindly assessed based on the combined results for the NS1 and the IgM test components. The RDT sensitivity was 46.8% (38.6% for the NS1 component and 13.8% for the IgM component). Sensitivity was greater for samples obtained from patients with secondary DENV infections (49.8%) compared to primary infections (31.1%) (P: 0.02) and was also influenced by the result in the confirmatory dengue diagnostic test, ranging from 39.7% for samples of cases confirmed by IgM-ELISA seroconversion between paired samples to 90.4% for samples of cases confirmed by a positive NS1-ELISA. The RDT specificity was 94.4% for non-dengue febrile patients, 87.7% for the community healthy controls, and 95.9% for the blood donors. Conclusions/Significance The SD BIOLINE Dengue Duo RDT showed good specificities, but low sensitivity, suggesting that it may be more useful to rule in than to rule out a dengue diagnosis in dengue endemic regions.
Bibliographical noteFunding Information:
This study was supported by the Brazilian National Council for Scientific and Technological Development (grant 550160/2010-8 to MGR, grants 400830/2013-2 and 440891/2016-7 to GSR; and scholarships to IADP, MSR, LBT, UK, MGR, and GSR); the Bahia Foundation for Research Support (grant PNX0010/2011 to MGR, grants PPP0055/2011, JCB0020/2013, PET0026/ 2013, APP0044/2016, PET0022/2016 to GSR, and scholarship to MMOS and GAOFS); the Coordination for the Improvement of Higher Education Personnel, Brazilian Ministry of Education (grant 440891/2016-7, finance code 001 to GSR, and scholarship to MK), the Federal University of Bahia; and the Oswaldo Cruz Foundation (scholarship to MMOS, JSC and AST). The funding sources had no role in study design; in the collection, analysis and interpretation of data; in the writing of the paper; and in the decision to submit the article for publication. We would like to thank the technical staff who participated in study data collection and in sample processing. We would also like to thank the indispensable contributions to accomplish this work provided by the São Marcos Emergency Center staff, especially from Aurélio Nei and Celeste Moura; of the Pau da Lima Health District, Salvador Secretariat of Health; Pau da Lima community leaders and resident associations; and the State Blood Donation Center located in Salvador.