Association of SARS-CoV-2 presence in sewage with public adherence to precautionary measures and reported COVID-19 prevalence in Tehran.

Compared to the growing body of literature on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection and quantification in sewage, there are limited studies reporting on correlations between the viral loads in sewage and the prevalence of infected patients. The present work is a part of the regular monitoring effort for SARS-CoV-2 in wastewater influents from seven wastewater treatment plants (WWTPs) in Tehran, Iran, starting from late September 2020 until early April 2021. These facilities cover ~64% of the metropolis serving >5000,000 M individuals. The study set out to track the trends in the prevalence of COVID-19 in the community using wastewater based epidemiology (WBE) and to investigate whether these measurements correlate with officially reported infections in the population. Composite sewage samples collected over 16 h were enriched by polyethylene glycol precipitation and the corresponding threshold cycle (Ct) profiles for CDC 'N' and 'ORF1ab' assays were derived through real time RT-qPCR. Monte Carlo simulation model was employed to provide estimates of the disease prevalence in the study area. RNA from SARS-CoV-2 was detectable in 100% ('N' assay) and 81% ('ORF1ab' assay) of totally 91 sewage samples, with viral loads ranging from 40 to 45,000 gene copies/L. The outbreak of COVID-19 positively correlated (R2 = 0.80) with the measured viral load in sewage samples. Furthermore, sewage SARS-CoV-2 RNA loads preceded infections in the population by 1 to 2 days, which were in line with public adherence with and support for government instructions to contain the pandemic. Given the transient presence of human host-restricted infections such as SARS-CoV-2, these results provide evidence for assessment of the effectiveness of coordinated efforts that specifically address public health responses based on wastewater-based disease surveillance against not only COVID-19 but also for future infectious outbreaks.

Bidirectional association between COVID-19 and the environment: A systematic review.

The global crisis caused by SARS-CoV-2 (COVID-19) affected economics, social affairs, and the environment, not to mention public health. It is estimated that near 82% of the SARS-CoV-2 genome is similar to the severe acute respiratory syndrome. The purpose of the review is to highlight how the virus is impacted by the environment and how the virus has impacted the environment. This review was based on an electronic search of the literature in the Scopus, Science Direct, and PubMed database published from December 2019 to July 2020 using combinations of the following keywords: SARS-CoV-2 transmission, COVID-19 transmission, coronavirus transmission, waterborne, wastewater, airborne, solid waste, fomites, and fecal-oral transmission. Studies suggest the thermal properties of ambient air, as well as relative humidity, may affect the transmissibility and viability of the virus. Samples taken from the wastewater collection network were detected contaminated with the novel coronavirus; consequently, there is a concern of its transmission via an urban sewer system. There are concerns about the efficacy of the wastewater treatment plant disinfection process as the last chance to inactivate the virus. Handling solid waste also requires an utmost caution as it may contain infectious masks, etc. Following the PRISMA approach, among all reviewed studies, more than 36% of them were directly or indirectly related to the indoor and outdoor environment, 16% to meteorological factors, 11% to wastewater, 14% to fomites, 8% to water, 9% to solid waste, and 6% to the secondary environment. The still growing body of literature on COVID-19 and air, suggests the importance of SARS-CoV-2 transmission via air and indoor air quality, especially during lockdown interventions. Environmental conditions are found to be a factor in transmitting the virus beyond geographical borders. Accordingly, countries need to pay extra attention to sustainable development themes and goals.

Removal of Cefixime from Water Using Rice Starch by Response Surface Methodology.

BACKGROUND: Remaining pharmaceutical compounds cause environmental pollution. Therefore, refining these compounds has become a major challenge. In this study, the function of eliminating Cefixime (CFX) using rice starch was evaluated under controlled conditions. METHODS: Response Surface Methodology (RSM) was used to design, analyze, and optimize experiments, and the interaction between four variables including pH (3-9), rice starch dose (0-300 mg/L), CFX initial concentration (0-16 mg/L) and time (20-120 min) was investigated on CFX removal. RESULTS: The optimum pH, starch dose, initial concentration and time were 4.5, 225 mg/L, 7.9 mg/L and 95 min, respectively. The maximum efficiency of CFX removal was 70.22%. According to RSM, this study follows a quadratic model (R2=0.954). CONCLUSION: Rice starch has been successful in removing CFX from the aqueous solution. Therefore, it is recommended to utilize this process to remove CFX from aqueous solutions.

Monitoring and comparison of antibiotic resistant bacteria and their resistance genes in municipal and hospital wastewaters.

BACKGROUND: Human exposure to antibiotic resistant bacteria (ARB) is a public health concern which could occur in a number of ways. Wastewaters seem to play an important role in the dissemination of bacteria and antibiotic resistant genes (ARGs) in our environment. The aim of this study was to evaluate the occurrence of three groups of ARB and their resistance genes in hospital and municipal wastewaters (MWs) as possible sources. METHODS: A total of 66 samples were collected from raw MWs and hospital wastewaters (HWs) and final effluents of related wastewater treatment plants (WWTPs). Samples were analyzed for the detection of three groups of ARB including gentamicin (GM), chloramphenicol (CHL) and ceftazidime resistant bacteria and their ARGs (aac (3)-1, cmlA1 and ctx-m-32, respectively). RESULTS: The mean concentration of GM, CHL and ceftazidime resistant bacteria in raw wastewater samples was 1.24 × 10(7), 3.29 × 10(7) and 5.54 × 10(7) colony forming unit/100 ml, respectively. There is a variation in prevalence of different groups of ARB in MWs and HWs. All WWTPs decreased the concentration of ARB. However, high concentration of ARB was found in the final effluent of WWTPs. Similar to ARB, different groups of ARGs were found frequently in both MWs and HWs. All genes also detected with a relative high frequency in effluent samples of MWs WWTPs. CONCLUSIONS: Discharge of final effluent from conventional WWTPs is a potential route for dissemination of ARB and ARGs into the natural environment and poses a hazard to environmental and public health.