ABSTRACT
The most widely used invitro diagnostic qualitative screening method for dengue virus infection is the lateral flow immunoassay technique. Testing of dengue non-structural antigen NS1 offers specificity in determining the active infection while testing of IgM and IgG helps in differentiating the primary and secondary dengue infections. The ELISA functions as the golden standard for dengue testing and PCR credits for the most accurate determination tool at the genetic level. The RT-PCR endorsed NS1 gene and in ELISA or LFIA NS1 antigen is used as the marker owing to the specificity and lesser chances of mutation effects. This study evaluated the performance of AG-Q Dengue NS1 LFIA kit in comparison with RT-PCR quantification cycle (Cq) Values and ELISA NS1 quantitation. The study also focused on differentiating the samples among dengue serotypes using the RealStar Dengue Type RT-PCR Kit 1.0. Dengue serotype 2 is the prominent viral strain in Kerala region succeeded by serotype 3 and 1 with a prevalence rate of 64â¯%, 20â¯% and 6â¯% respectively. Dengue serotype 4 was not reported during this study period. 10â¯% co-infection with DENV 1 & DENV 2 was also reported. The AG-Q Dengue NS1 kit stood as efficient in screening by providing positive results with samples having RT-PCR Cq values up to 43 and ELISA NS1 quantification minimum of 14 Panbio units.
ABSTRACT
This study investigates the hydrogeochemistry of groundwater samples collected from the Shiriya River Basin (SRB), a tropical watershed located in Kasaragod, Kerala, southern India, with a special focus on trace elements. Fifty-four groundwater samples were collected from deep aquifers, which constitute weathered and fractured granitoids and mafic rocks, and the groundwater is tapped by bore wells from a fractured zone at a depth range of 60-100 m. Concentrations of Sr, Li, Ba, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Ag, Au, Te, Pb, Re, and PGEs in groundwater were determined by using Q-ICPMS. Out of the 25 analysed trace elements in groundwater, only Sr (489.6 µg/L), Ba (226 µg/L), Li (11.76 µg/L) Mn (396.8 µg/L), Ni (68 µg/L) and Fe (2438.5 µg/L) show anomalous values. The PGEs and the majority of trace elements show values within the permissible limit. Raman spectral studies reveal the presence of celsian in aquifer rocks and are the source of Ba in groundwater. Further, XRF data of the rocks show a high enrichment of Fe and Mn in mafic dyke, basalt, and syenite, and Ba and Sr in granite, pegmatite, and granitic gneiss. Therefore, this study proved that the source of these elements is geogenic, i.e., they are released from the crystalline aquifer through rock-water interaction under alkaline conditions. The results of this study show that the groundwater of the basin has enough metals such as Na, K, Mg, Ca, Mn, Fe, Co, Cu, and Zn, which are good for health. Nevertheless, a few metals (Fe, Mn, Ba, Sr, Li, Ni) that may exert toxic effects on humans are also present in the groundwater of the SRB. As groundwater is found to be a dependable source of drinking water in such watersheds, a comprehensive study on the hydrogeochemistry of all watersheds in tropical regions is recommended.
