Field Evaluation and Impact on Clinical Management of a Rapid Diagnostic Kit That Detects Dengue NS1, IgM and IgG

Abstract

BackgroundDengue diagnosis is complex and until recently only specialized laboratories were able to definitively confirm dengue infection. Rapid tests are now available commercially making biological diagnosis possible in the field. The aim of this study was to evaluate a combined dengue rapid test for the detection of NS1 and IgM/IgG antibodies. The evaluation was made prospectively in the field conditions and included the study of the impact of its use as a point-of-care test for case management as well as retrospectively against a panel of well-characterized samples in a reference laboratory.Methodology/Principal FindingsDuring the prospective study, 157 patients hospitalized for a suspicion of dengue were enrolled. In the hospital laboratories, the overall sensitivity, specificity, PPV and NPV of the NS1/IgM/IgG combination tests were 85.7%, 83.9%, 95.6% and 59.1% respectively, whereas they were 94,4%, 90.0%, 97.5% and 77.1% respectively in the national reference laboratory at Institut Pasteur in Cambodia. These results demonstrate that optimal performances require adequate training and quality assurance. The retrospective study showed that the sensitivity of the combined kit did not vary significantly between the serotypes and was not affected by the immune status or by the interval of time between onset of fever and sample collection. The analysis of the medical records indicates that the physicians did not take into consideration the results obtained with the rapid test including for care management and use of antibiotic therapy.ConclusionsIn the context of our prospective field study, we demonstrated that if the SD Bioline Dengue Duo kit is correctly used, a positive result highly suggests a dengue case but a negative result doesn't rule out a dengue infection. Nevertheless, Cambodian pediatricians in their daily practice relied on their clinical diagnosis and thus the false negative results obtained did not directly impact on the clinical management.

Evaluation of Commercially Available Assays for Diagnosis of Acute Dengue in Schoolchildren During an Epidemic Period in Medellin, Colombia

“…21,23 Guzman and others 8 also reported lower sensitivity of NS1 antigen detection in American countries (Nicaragua and Venezuela) compared with Asian countries. 8,24 The occurrence of secondary infections also seems to have an impact on the accuracy of IgM detection. Indeed, higher sensitivity of the anti-IgM SD Bioline Dengue Duo was evidenced in primary DENV infections compared with secondary infections.…”

“…Several studies evidenced that the diagnostic performances of different dengue diagnosis kits vary depending on geographical and temporal factors. 8,22,24,27 Thus, validation of those kits in one country should take into account 1) the epidemiological settings (endemic, epidemic, and hyperepidemic periods), 2) the genetic background and immunological status of studied population, the different phases of the dengue disease, and 3) the DENV serotypes and genotypes that are circulating in the area.…”

Comparison of a rapid immunochromatography assay with an enzyme linked immunosorbent assay (ELISA) for anti-dengue virus IgM detection

“…Thus a centrally validated (CDC) and widely accepted ELISA method is helpful for use as a comparator to assess rapid ICT assays. 12,13 Some studies have shown high rates of sensitivity and specificity for rapid ICT assays. 9 However, in the current study, the sensitivity and the NPV for anti-dengue virus IgM detection by the rapid ICT assay were comparatively lower than that of ELISA (Table 2) with the inference that this particular assay will give a high percentage of false negatives.…”

Emergence and Surveillance of Chikungunya

“…According to the special surveillance of Bsummer fevers^in Veneto region, Northern Italy, every febrile (≥38°C) traveller recently returned from endemic countries, after malaria and other obvious causes of fever have been ruled out, is considered as a possible case of DENV or CHIKV [88]. For DENV, RDT with good sensitivity and specificity are available [89]: in case of positivity, the patient is considered a probable case and samples are sent to a referral laboratory for confirmation (PCR and viral isolation). Unfortunately, an antigen RDT is not available for CHIKVand the sensitivity of RDT (for detection of IgM and IgG) is poor, especially during the first few days of fever.…”