The novel SARS-CoV-2 pandemic: Possible environmental transmission, detection, persistence and fate during wastewater and water treatment

Abstract

The contagious SARS-CoV-2 virus responsible for COVID-19 disease has infected over 27 million people across the globe within a few months. While literature on SARS-CoV-2 indicates that its transmission may occur predominantly via aerosolization of virus-laden droplets, the possibility of alternate routes of transmission and reinfection through environmental factors require considerable scientific attention. This review aims to collate information on possible transmission routes of this virus, to ascertain its fate in the environment. Concomitant with the presence of SARS-CoV-2 viral RNA in faeces and saliva of infected patients, studies also indicated its occurrence in raw wastewater, primary sludge and river water. Therefore sewerage system could be a possible route of virus outbreak, a possible tool to assess viral community spread and future surveillance technique. Hence, this review looked into detection, occurrence and fate of SARS-CoV-2 during primary, secondary, and tertiary wastewater and water treatment processes based on published literature on SARS-CoV and other enveloped viruses. The review also highlights the need for focused research on occurrence and fate of SARS-CoV-2 in various environmental matrices. Utilization of this information in environmental transmission models developed for other enveloped and enteric viruses can facilitate risk assessment studies. Preliminary research efforts with SARS-CoV-2 and established scientific reports on other coronaviruses indicate that the threat of virus transmission from the aquatic environment may be currently non-existent. However, the presence of viral RNA in wastewater provides an early warning that highlights the need for effective sewage treatment to prevent a future outbreak of SARS-CoV-2.

SARS-CoV-2 tropism, entry, replication, and propagation: Considerations for drug discovery and development

“…While the mucosal surface is likely the entry site for SARS-CoV-2, examination of other tissues has revealed that high levels of ACE2/TMPRSS2 co-expression are present in the enterocytes of the ileum and colon, and the gut may have higher expression of these receptors than the lung [ 30 , 31 ]. The observation that some COVID-19 patients have gastrointestinal distress prior to developing respiratory symptoms as well as during disease progression may suggest a fecal–oral route of transmission [ 95 , 96 ]; evidence supporting this has been recently reviewed [ 97 , 98 ]. Similarly, gastrointestinal infection/distress was previously observed for the closely related SARS and MERS coronaviruses [ 99 , 100 ].…”

Monitoring the presence and persistence of SARS-CoV-2 in water-food-environmental compartments: State of the knowledge and research needs

“…The sludge has been found to harbor envelop virus due to the hydrophobic nature of the virus and organic matter present in the sludge, thereby making the magnitude of the virus concentration higher than those found in wastewater. This hydrophobic interaction has been reported to be largely responsible for virus attachment to solid materials like sludge ( Mohapatra et al, 2020 ). Chin et al (2020) also reported the persistence of SARS-CoV-2 on smooth surfaces, be it artificial or treated, such as plastic and steel than the rough surfaces such as paper, cloth, or wood.…”

Management of environmental health to prevent an outbreak of COVID-19

“…At low RH conditions, aerosols evaporate rapidly, droplet size decreases, and droplet virus particles can travel longer distances. 89 , 90 A recent study showed that due to high humidity, the SARS-CoV-2 virus might be rapidly inactivated due to the interaction of water with the lipid envelope. 91 Furthermore, at low RH, the nasal airway in humans dries out more so that the mucosal layer is less effective in trapping pathogens.…”