NS1-based tests with diagnostic utility for confirming dengue infection: a meta-analysis

Non-structural protein 1 (NS1)-based tests may offer a larger window of opportunity for dengue diagnosis and could constitute a very useful diagnostic tool. The aim of this study was to establish the overall accuracy of NS1-based tests for diagnosing dengue infection.

A meta-analysis was conducted including 18 studies published up to October 1, 2012 identified using PubMed, ISI Web of Science, Google Scholar, and the Chinese National Knowledge Infrastructure (CNKI) database.

For the single NS1-based tests - ELISA (Panbio Dengue Early ELISA Kit, Dengue NS1 Ag ELISA Kit, and Platelia Dengue NS1 Ag-ELISA Kit) and immunochromatography (Dengue NS1 Ag STRIP Kit and SD BIOLINE Dengue Duo Strip Kit) - the summarized sensitivities and specificities were 67% (95% confidence interval (CI) 59-74%) and 99% (95% CI 97-99%), and 71% (95% CI 61-79%) and 99% (95% CI 98-100%), respectively. The hierarchical summary receiver operating characteristics (HSROCs) were 0.92 and 0.96, respectively. For NS1 combined with an anti-dengue-specific IgM test, the summarized sensitivity, specificity, and HSROC were 83% (95% CI 68-92%), 86% (95% CI 79-91%), and 0.91 (95% CI 0.89-0.93), respectively. The accuracy for serotypes was 50.0-90.9% for DENV-1, 38.5-85.7% for DENV-2, 46.7-91.3% for DENV-3, and 21.7-87.0% for DENV-4.

These results support the use of single NS1-based tests; they have good diagnostic utility for confirming dengue and for distinguishing serotypes DENV-1 and 3 from DENV-2 and 4, while they can be used as a screening tool when combined with an IgM test. Moreover, the Dengue NS1 Ag STRIP Kit appears to be the best for confirming and serotyping dengue infection.