The Distribution of Fecal Contamination in an Urbanized Tropical Lake and Incidence of Acute Diarrheal Disease

Aquatic ecosystems of tropical countries are vulnerable to fecal contamination that could cause spikes in the incidences of acute diarrheal disease (ADD) and challenge public health management systems. Vembanad lake, situated along the southwest coast of India, was monitored for one year (2018-2019). Escherichia coli, an indicator of fecal contamination, was prevalent in the lake throughout the year. Multiple antibiotic resistance among more than 50% of the E. coli isolates adds urgency to the need to control this contamination. The high abundance of E. coli and incidence of ADD were recorded during the early phase of the southwest monsoon (June-July), prior to the once-in-a-century floods that affected the region in the later phase (August). The extent of inundation in the low-lying areas peaked in August, but E. coli in the water peaked in July, suggesting that contamination occurred even prior to extreme flooding. During the COVID-19-related lockdown in March-May 2021, fecal contamination in the lake and incidence of ADD reached minimum values. These results indicate the need for improving sewage treatment facilities and city planning in flood-prone areas to avoid the mixing of septic sewage with natural waters during extreme climate events or even during the normal monsoon.

The Distribution of Fecal Contamination in an Urbanized Tropical Lake and Incidence of Acute Diarrheal Disease

Aquatic ecosystems of tropical countries are vulnerable to fecal contamination that could cause spikes in the incidences of acute diarrheal disease (ADD) and challenge public health management systems. Vembanad lake, situated along the southwest coast of India, was monitored for one year (2018-2019). Escherichia coli, an indicator of fecal contamination, was prevalent in the lake throughout the year. Multiple antibiotic resistance among more than 50% of the E. coli isolates adds urgency to the need to control this contamination. The high abundance of E. coli and incidence of ADD were recorded during the early phase of the southwest monsoon (June-July), prior to the once-in-a-century floods that affected the region in the later phase (August). The extent of inundation in the low-lying areas peaked in August, but E. coli in the water peaked in July, suggesting that contamination occurred even prior to extreme flooding. During the COVID-19-related lockdown in March-May 2021, fecal contamination in the lake and incidence of ADD reached minimum values. These results indicate the need for improving sewage treatment facilities and city planning in flood-prone areas to avoid the mixing of septic sewage with natural waters during extreme climate events or even during the normal monsoon. © 2023 American Chemical Society.

Role of pepper mild mottle virus as a tracking tool for fecal pollution in aquatic environments.

The plant pathogen pepper mild mottle virus (PMMoV) has recently been proposed as a water quality indicator, it is a RNA virus belonging to the genus Tobamovirus in the family Virgoviridae that causes harm to the pepper crops. After consuming processed food products containing infected peppers, such as hot sauces, PMMoV is excreted in high concentrations in feces; therefore, this is the most common RNA virus, constantly found in the feces of humans. The fecal-oral pathway is emerging as an environmental problem. The presence of high concentrations of pathogens associated with human excreta in environmental waters or water reuse supplies poses a threat to public health. Due to the difficulty in determining the presence of pathogens effectively in water, attempts to monitor microbial water quality often use surrogates or indicator organisms that can be easily detected; therefore, PMMoV is used as a viral surrogate in aquatic environment. This paper describes the incidence and persistence of PMMoV in aquatic environments and in waste treatment plants and its usefulness for quantifying virus reductions by advanced water treatment technologies. In recent research, SARS-CoV-2 was reported to be found in wastewater and utilized for the purpose of monitoring coronavirus illness outbreaks. Since PMMoV is readily identified in the human feces and can also serve as an indicator of human waste, the determined PMMoV concentrations may be utilized to give the normalized report of the SARS-CoV-2 concentration, so that, the amount of human waste found in the wastewater can be taken into consideration.

An Overview of Microbial Source Tracking Using Host-Specific Genetic Markers to Identify Origins of Fecal Contamination in Different Water Environments

Fecal contamination of water constitutes a serious health risk to humans and environmental ecosystems. This is mainly due to the fact that fecal material carries a variety of enteropathogens, which can enter and circulate in water bodies through fecal pollution. In this respect, the prompt identification of the polluting source(s) is pivotal to guiding appropriate target-specific remediation actions. Notably, microbial source tracking (MST) is widely applied to determine the host origin(s) contributing to fecal water pollution through the identification of zoogenic and/or anthropogenic sources of fecal environmental DNA (eDNA). A wide array of host-associated molecular markers have been developed and exploited for polluting source attribution in various aquatic ecosystems. This review is intended to provide the most up-to-date overview of genetic marker-based MST studies carried out in different water types, such as freshwaters (including surface and groundwaters) and seawaters (from coasts, beaches, lagoons, and estuaries), as well as drinking water systems. Focusing on the latest scientific progress/achievements, this work aims to gain updated knowledge on the applicability and robustness of using MST for water quality surveillance. Moreover, it also provides a future perspective on advancing MST applications for environmental research.

Groundwater contamination with the threat of COVID-19: Insights into CSR theory of Carroll's pyramid.

In this study, we elucidated the effect of sewage drain on groundwater contamination as including different contaminants, microbes, and pathogens, which deteriorating the groundwater by poor infiltration and seepage. This is getting severer in developing countries like India, Bangladesh, and Pakistan, where unprocessed effluent is discharged into the water bodies. This study was planned to elucidate the effect of sewage drain (based on distance 0-5, 5-10, 15-20, 20-25 m) from two different sewage drains to explain the different physiochemical, and biological parameters including total soluble solids (TSS), chloride, total dissolved solids (TDS), calcium, total hardness, magnesium, nitrate, chemical oxygen demand (COD), dissolved oxygen (D.O.), and biological oxygen demand (BOD). Drainage channel number-1 results showed that E. coli (positive), coliform count (22.75-48.66 /100 mL), and BOD (8-25.75 mgL-1) remained above the permissible limit of the World Health Organization (WHO). Besides, drainage channel number 2 results exposed that E. coli (positive), coliform count (17.7-47 /100 mL), and BOD (6.25-21.5 mg/ L) was not within the permissible limit of WHO. The presence of COVID-19 in the stool has been significantly reported in the literature. The presence of stool in sewage drain leading to groundwater contamination can be an emerging threat to water pollution and could lead to the spread of COVID-19. This study helps to minimize this threat with the help of corporate social responsibility (CSR). Because organizational responsibility towards its society is one of the critical factors to contain numerous issues related to the society.