The episodic outbreak of COVID-19 due to SARS-CoV-2 is severely affecting the economy, and the global count of infected patients is increasing. The actual number of patients had been underestimated due to limited facilities for testing as well as asymptomatic nature of the expression of COVID-19 on individual basis. Tragically, for emerging economies with high population density, the situation has been more complex due to insufficient testing facilities for diagnosis of the disease. However, the recent reports about persistent shedding of viral RNA of SARS-CoV-2 in the human feces have created a possibility to track the prevalence and trends of the disease in communities, known as wastewater-based epidemiology (WBE). In this article, we highlight the current limitations and future prospects for WBE to manage pandemics.

A comprehensive understanding of the dynamic characteristics of geomorphological, ecological, and human systems is essential to explaining complex charland (mid-channel island) processes and crafting and implementing policy measures. This work demonstrates that the characteristics and outcomes of riparian hazards are determined by the interactive dynamics between hydrogeology and human conditions, which constitutes a novel contribution to the literature in this research area. We further contend that such dynamic social-ecological systems demand a flexible, adaptive management and planning approach. The present research has three key interdisciplinary objectives: (i) to analyze the salient features and characteristics of the geomorphological and riparian systems of the Bengal Delta; (ii) to analyze the evolutionary discourse of the legal systems concerning eroded (diluvion) and accreted (alluvion) land in Bangladesh; and (iii) to assess the characteristics of the coping and adaptation strategies employed by charland inhabitants. The findings of this research reveal that delta-building processes, which are characterized by dynamic shifts in the river channels, along with the erosion and accretion of charlands have made Bangladesh’s land and water systems very dynamic and unstable. The destabilization of these systems increases the inhabitants’ vulnerability to riparian hazards, which consistently results in the displacement of settlers and, consequently, a serious deterioration in their socioeconomic status. At present, Bangladesh does not have an effective institutional framework and structure for resettlement planning; therefore, the formulation of a comprehensive national resettlement policy with adequate flexibility to adapt to changing scenarios is urgently needed.

In the course of a COVID-19 pandemic, 0.33 million people got infected in Bangladesh, we made the first and successful attempt to detect SARS-CoV-2 viruses’ genetic material in the vicinity wastewaters of an isolation centre i.e. Shaheed Bhulu Stadium, situated at Noakhali. The idea was to understand the genetic loading variation, both temporal and distance-wise in the nearby wastewater drains when the number of infected COVID-19 patients is not varying much. Owing to the fact that isolation center, in general, always contained a constant number of 200 COVID-19 patients, the prime objective of the study was to check if several drains carrying RNA of coronavirus are actually getting diluted or accumulated along with the sewage network. Our finding suggested that while the temporal variation of the genetic load decreased in small drains over the span of 50 days, the main sewer exhibited accumulation of SARS-CoV-2 RNA. Other interesting finding displays that probably distance of sampling location in meters is not likely to have a significant impact on gene detection concentration, although the quantity of the RNA extracted in the downstream of the drain was higher. These findings are of immense value from the perspective of wastewater surveillance of COVID-19, as they largely imply that we do not need to monitor every wastewater system, and probably major drains monitoring may illustrate the city health. Perhaps, we are reporting the accumulation of SARS-CoV-2 genetic material along the sewer network i.e. from primary to tertiary drains. The study sought further data collection in this line to simulate conditions prevailed in the most of south Asian country and to shed further light on the temporal variation and decay/accumulation processes of the genetic load of the SARS-COV-2. HIGHLIGHTS: First detection report of SARS-CoV-2 RNA in the wastewaters of Bangladesh. We traced the genetic load in the vicinity of the isolation center with 200 COVID-19 patients. About 75% of positive samples were found during the monitoring period. Main sewer and canal exhibit temporal accumulation of genetic load of SARS-CoV-2 In general, shredding shows a variable trend during the sampling tenure.

The presence of SARS-CoV-2 genetic materials in wastewater has become a matter of grave for many countries of the world. Wastewater based epidemiology, in this context, emerged as an important tool in developed countries where proper sewage system is available. Due to the recent shift in the spread of the infection from urban to rural areas, it is now equally important to develop a similar mechanism for rural areas as well. Considering the urgency of the issue a study was conducted in 14 districts of Bangladesh and a total of 238 sewage samples were collected in two different periods from December 2020 to January 2021. We are the first to propose a surveillance system for both urban and rural areas where a proper sewage system is absent. Based on RT-PCR analysis of the water samples, in more than 92% of cases, we found the presence of the SARS-COV-2 gene (ORF1ab, N, and Internal Control-IC). The trend of Ct value varies for different study locations. The spread of genetic material for on-site (Δm = 0.0749) sanitation system was found more prominent than that of off-site sewage system (Δm = 0.0219); which indicated the shift of genetic material from urban to rural areas. Wastewater samples were also measured for physicochemical parameters, including pH (6.30 - 12.50) and temperature (22.10 - 32.60) ºC. The highest viral titer of 1975 copy/mL in sewage sample was observed in a sample collected from the isolation ward of the SARS-COV-2 hospital. Additionally, a correlation was found between bacterial load and SARS-CoV-2 genetic materials. The results indicated the association of increased Ct values with decreasing number of patients and vice versa. The findings reported in this paper contributed to the field of wastewater-based epidemiology dealing with SARS-COV-2 surveillance for developing countries where proper sewage system is absent and highlighting some of the challenges associated with this approach in such settings. Highlights Development of wastewater-based surveillance system based on on-site sanitation system for developing countries. Association of different environmental parameters with the presence of SARS CoV-2 genetic material in wastewater. Prediction of the viral concentration of sewage system using viral load and copy number parameter.