Date Published: March 6, 2019
Publisher: Public Library of Science
Author(s): Mariana Kikuti, Jaqueline S. Cruz, Moreno S. Rodrigues, Aline S. Tavares, Igor A. D. Paploski, Monaise M. O. Silva, Perla M. Santana, Laura B. Tauro, Greice A. O. F. Silva, Gúbio S. Campos, Josélio M. G. Araújo, Uriel Kitron, Mitermayer G. Reis, Guilherme S. Ribeiro, Kwok Hung Chan.
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.
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.
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.
Dengue virus (DENV) is estimated to infect up to 390 million people each year, of which 96 million develop clinical disease . Symptomatic DENV infections may cause a wide spectrum of acute clinical manifestations, from self-limited, mild, and non-specific symptoms, such as fever, myalgia, and headache, to severe disease evolving with plasma leakage, hemorrhage, and eventually death . Thus, early diagnosis is critical to guide timely fluid replacement that can prevent disease complications and death .
In this study, we evaluated the diagnostic performance of the commercial SD BIOLINE Dengue Duo RDT among febrile patients from an outpatient health unit in a dengue endemic region, as well as among different control groups. Although the test presented good levels of specificity (88%– 96%), its overall sensitivity (combining positivity in either the NS1 or the IgM component) was not satisfactory (46.8%). This low sensitivity was associated with a suboptimal performance of both the NS1 and the IgM components of the test in detecting dengue cases early and late in the course of the disease, respectively.