ABSTRACT
Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become a global public health problem. The real-time reverse transcription-polymerase chain reaction (RT-PCR) is the gold standard test for the detection of SARS-CoV-2. However, the assay requires hours to get the final results. Therefore, antigen-based rapid assays are being used extensively to reduce the time. We have evaluated the performance of the antigen-based rapid test for the detection of SARS-CoV-2 virus in comparison with RT-PCR. Materials and methods: Nasopharyngeal and throat swabs were collected from 366 suspected patients of COVID-19 visiting our institute and subjected to qualitative RT-PCR and antigen-based rapid assays to detect the presence of SARS-CoV-2 virus. The sensitivity and specificity of the antigen-based assay were calculated in comparison with RT-PCR. Results: Compared with RT-PCR, sensitivity and specificity of the antigen-based rapid assay were observed to be 70.5% and 98.6%, respectively, in comparison with RT-PCR. However, the sensitivity of antigen-based rapid assay varied significantly with decreasing viral load. The sensitivity of the rapid antigen assay was equivalent to RT-PCR (23/23, 100%) at a higher viral load (Ct value 15�). In contrast, the antigen assay could only detect 3/21 (14.28%) samples with Ct value >30. Conclusion: The antigen-based assay could assist in the rapid screening of a large population. However, the rapid antigen assay might not detect early stages of infection represented by low viral load. Therefore, the antigen-based assay could not replace RT-PCR testing. The study reiterates that all antigen-based negative tests should be confirmed by RT-PCR.
ABSTRACT
Aim: Arsenic concentration in groundwater above the acceptable level is of global concern due to its serious human health effects. Application of certain fungi, due to their amazing skill to remove arsenic from arsenic contaminated water has received attention in recent years. The main aim of this study was to isolate arsenic tolerant fungi from arsenic-contaminated groundwater and assess their ability for arsenic removal from the aquatic system in-vitro.Methodology: Fungi were isolated from arsenic-contaminated groundwater (44.9–161.1 mg l-1). An experiment on bioremediation/ removal of arsenic by selected highly arsenic tolerant fungi was conducted by culturing them in arsenic supplemented medium and measuring the arsenic contents in initial and after incubation with fungi using Hydride Generation Atomic Absorption Spectroscopy (HG-AAS) to find out the arsenic removal percentage. Results: In all, ten out of forty-five fungi obtained from highly arsenic-contaminated groundwater (44.9–161.1 mg l-1) were able to remove high arsenic contents (>80%) from liquid medium with >85% arsenite (by 6 fungal isolates) and >85% of arsenate (by 9 fungal isolates). In arsenic tolerance assay, all 10 test fungi grew readily in liquid medium enriched with either arsenate (10 and 20 g l-1) or arsenite (2 g l-1) under laboratory conditions (27±2°C). These fungi showed log phase between 5 to 10 days with stationary phase of 11-15 days. High arsenite concentration (4 g l-1) however, completely inhibited the growth of 50% of these fungal isolates. Five of these isolates showed high tolerance index pattern (0.97- 0.91) as compared to others (0.22–0.13). These fungi greatly altered the pH of arsenic supplemented liquid medium (10 mg l-1) as compared to the control when they were individually cultured. These arsenic tolerant fungal isolates may effectively be used for the bioremediation of arsenic from groundwater. Interpretation: The study suggested that 10 fungal isolates were able to tolerate high arsenic concentrations (20 g l-1 of arsenate and 2 g l-1 of arsenite) and were able to enhance arsenic removal (more than 80%) in liquid medium at neutral pH (7.0) and 27°C temperature.
Subject(s)
Cryptorchidism/pathology , Diagnosis, Differential , Hernia, Inguinal/congenital , Humans , Infant , Male , Testis/abnormalitiesABSTRACT
A retrospective study of two-weekly incidence of acute respiratory infections (ARI) in the under-five children of rural area of Alwar District (Rajasthan) based on the previous fourteen days' recall by the mothers was undertaken during December 1989 to assess the magnitude of the problem and its' risk factors. The two-weekly ARI incidence was reported to be 33 episodes per 100 under-fives. Mothers in higher socio-economic strata reported higher incidence of ARI for their children due to more accurate recall. Majority of ARI cases (76 per cent) were found to be of mild degree. 26 per cent of deaths in under-fives during the previous year were reported to be ARI-related. 50 per cent of ARI cases were left untreated. Among the treated group, private practitioners were found to be the main source of health care.