Diagnostic utility of dengue NS1 antigen

Dengue is an acute febrile illness caused by dengue virus. It can result in a range of clinical manifestations from asymptomatic infection to dengue fever (DF) and the severe disease dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). Accurate and timely diagnosis of dengue virus is important for early detection of this infection. NS1 is a glycoprotein that is common to all dengue serotypes and can be used to detect primary and secondary infection in early stages; It can be detected in the serum as early as on day one of illness and persists upto 9-10 days. This article reviews the various NS1 antigen tests available. The overall sensitivities were 72.3% for the pan-E Early ELISA test, 83.6% for the Platelia™ NS1 kit, and 89.6% for the NS1 Ag Strip kit. Specificities were 100%, 98.7% and 99.1% for the PanBio kit, for the Platelia™ NS1 kit and for the NS1 Ag Strip, respectively, Positive predictive values were 98.3%, 99.5% and 100% for the Platelia™ NS1, NS1 Ag Strip and pan-E Early ELISA tests respectively. However, the pan-E Early ELISA showed the lowest negative predictive value (78.3%), followed by the Platelia™ NS1 test with 86.3% and the NS1 Ag Strip with 91.1%. Early diagnosis by detection of dengue virus NS1 antigen, will allow for considerable improvements in patient care. Specific and rapid diagnosis is essential in dengue fever cases, not only for the clinical management, but surveillance and containment of the disease.