Dengue is one of the most important mosquito-borne viruses worldwide and causes significant disease burden in tropical and subtropical regions.dengue ns1 Early diagnosis of the disease significantly reduces associated morbidity and mortality.
The non-structural protein 1 (NS1) of the virus is a highly conserved target for serological diagnostic tests and can be measured in blood samples taken during the first 7 days of illness to indicate current or recent infection.dengue ns1 A positive NS1 test result meets the laboratory criteria for confirmation of a dengue case in the National Notifiable Diseases Surveillance System (NNDSS). There are several commercial NS1 ELISA tests available in the market and some public health and private laboratories use these kits. However, a negative NS1 result does not rule out a recent dengue virus infection, as the sensitivity and specificity of the tests may vary.
Our objective was to evaluate the performance of a bedside NS1 antigen rapid test in predicting the severity of dengue in patients admitted to hospital.dengue ns1 We recruited 186 patients hospitalized with dengue fever who underwent serum determination of NS1 on day 3-8 of their illness. Patients were grouped according to the occurrence of warning signs and/or severe dengue (defined as fluid leakage, bleeding manifestations or platelet count 25,000 cells/mm3). The bedside NS1 antigen rapid test had comparable sensitivity and specificity to the Panbio dengue early ELISA and SD Bioline Dengue Duo strip kit.
Serum NS1 antigen levels were higher in the group of patients that developed DHF compared to those who did not.dengue ns1 NS1 antigen levels also correlated with IL-10 production in monocytes. Dengue NS1 appears to contribute to the pathogenesis of DHF by inducing IL-10 production and possibly inducing apoptosis in T cells.
NS1 antigens do not correlate with viremia in the early phase of the infection, but the correlation becomes stronger during the second phase of the illness when the viremia reaches its peak.dengue ns1 Therefore, NS1 antigen detection during the early phase of the infection may be useful in identifying patients at risk for developing severe clinical disease, especially DHF.
The overall correct percentages for the NS1-based bedside rapid tests varied between 81% and 80%. However, these values were slightly lower than the percentages obtained by the Panbio dengue early ELISA or the SD Bioline NS1 Ag STRIP kit. This might be due to the fact that NS1 antigen does not change as rapidly as viremia during dengue infection. Nevertheless, NS1-based rapid tests can provide a larger window of opportunity for diagnosing dengue fever than the other existing tests and are recommended for point-of-care use.