An integrated cell absorption process and quantitative PCR assay for the detection of the infectious virus in water

Evaluation and comparison of three virucidal agents on inactivation of Nipah virus

Modern human activity is profoundly changing our relationship with microorganisms with the startling rise in the rate of emerging infectious diseases. Nipah virus together with Ebola virus and SARS-CoV-2 are prominent examples. Since COVID-19 and the West African Ebola virus disease outbreak, different chemical disinfectants have been developed for preventing the direct spread of viruses and their efficacy has also been evaluated. However, there are currently no published efficacy studies for the chemical disinfection of Nipah virus. In this study, the virucidal efficacy of three disinfectants (Micro-Chem Plus detergent disinfectant cleaner, FWD and Medical EtOH) against Nipah virus was evaluated in quantitative suspension tests including. Our results showed that the > 4 log reduction achieved for all products in inactivating Nipah virus in 15 s. Even, 19% ethanol was able to inactivate Nipah virus when applied for at least 8 min contact time. Comparative analysis displayed virucidal efficacy of each of the evaluated disinfectants against SARS-CoV-2, Ebola virus and Nipah virus, with only minor differences in working concentrations and contact times required for complete inactivation. We expect that our study can assist in decontamination in healthcare settings and high level biosafety laboratories and can be beneficial to control for emerging enveloped viruses.

The occurrence and control of waterborne viruses in drinking water treatment: A review

As the coronavirus disease 2019 continues to spread globally, its culprit, the severe acute respiratory syndrome coronavirus 2 has been brought under scrutiny. In addition to inhalation transmission, the possible fecal-oral viral transmission via water/wastewater has also been brought under the spotlight, necessitating a timely global review on the current knowledge about waterborne viruses in drinking water treatment system - the very barrier that intercepts waterborne pathogens to terminal water users. In this article we reviewed the occurrence, concentration methods, and control strategies, also, treatment performance on waterborne viruses during drinking water treatment were summarized. Additionally, we emphasized the potential of applying the quantitative microbial risk assessment to guide drinking water treatment to mitigate the viral exposure risks, especially when the unregulated novel viral pathogens are of concern. This review paves road for better control of viruses at drinking water treatment plants to protect public health.

SARS-CoV-2 in environmental perspective: Occurrence, persistence, surveillance, inactivation and challenges

The unprecedented global spread of the severe acute respiratory syndrome (SARS) caused by SARS-CoV-2 is depicting the distressing pandemic consequence on human health, economy as well as ecosystem services. So far novel coronavirus (CoV) outbreaks were associated with SARS-CoV-2 (2019), middle east respiratory syndrome coronavirus (MERS-CoV, 2012), and SARS-CoV-1 (2003) events. CoV relates to the enveloped family of Betacoronavirus (βCoV) with positive-sense single-stranded RNA (+ssRNA). Knowing well the persistence, transmission, and spread of SARS-CoV-2 through proximity, the faecal-oral route is now emerging as a major environmental concern to community transmission. The replication and persistence of CoV in the gastrointestinal (GI) tract and shedding through stools is indicating a potential transmission route to the environment settings. Despite of the evidence, based on fewer reports on SARS-CoV-2 occurrence and persistence in wastewater/sewage/water, the transmission of the infective virus to the community is yet to be established. In this realm, this communication attempted to review the possible influx route of the enteric enveloped viral transmission in the environmental settings with reference to its occurrence, persistence, detection, and inactivation based on the published literature so far. The possibilities of airborne transmission through enteric virus-laden aerosols, environmental factors that may influence the viral transmission, and disinfection methods (conventional and emerging) as well as the inactivation mechanism with reference to the enveloped virus were reviewed. The need for wastewater epidemiology (WBE) studies for surveillance as well as for early warning signal was elaborated. This communication will provide a basis to understand the SARS-CoV-2 as well as other viruses in the context of the environmental engineering perspective to design effective strategies to counter the enteric virus transmission and also serves as a working paper for researchers, policy makers and regulators.

Viruses in wastewater: occurrence, abundance and detection methods

This paper presents an updated and comprehensive review on the different methods used for detection and quantification of viruses in wastewater treatment systems. The analysis of viability of viruses in wastewater and sludge is another thrust of this review. Recent studies have mostly focused on determining the abundance and diversity of viruses in wastewater influents, in samples from primary, secondary, and tertiary treatment stages, and in final effluents. A few studies have also examined the occurrence and diversity of viruses in raw and digested sludge samples. Recent efforts to improve efficiency of virus detection and quantification methods in the complex wastewater and sludge matrices are highlighted in this review. A summary and a detailed comparison of the pre-treatment methods that have been utilized for wastewater and sludge samples are also presented. The role of metagenomics or sequencing analysis in monitoring wastewater systems to predict disease outbreaks, to conduct public health surveillance, to assess the efficiency of existing treatment systems in virus removal, and to re-evaluate current regulations regarding pathogenic viruses in wastewater is discussed in this paper. Challenges and future perspectives in the detection of viruses, including emerging and newly emerged viruses such as the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in wastewater systems are discussed in this review.

Progress in the study of virus detection methods: The possibility of alternative methods to validate virus inactivation

Virus inactivation validation studies have been widely applied in the risk assessment of biogenic material-based medical products, such as biological products, animal tissue-derived biomaterials, and allogeneic biomaterials, to decrease the risk of virus transmission. Traditional virus detection methods in an inactivation validation study utilize cell culture as a tool to quantify the infectious virus by observing cytopathic effects (CPEs) after virus inactivation. However, this is susceptible to subjective factors because CPEs must be observed by experts under a microscope during virus titration. In addition, this method is costly and time- and labor-consuming. Molecular biological technologies such as quantitative polymerase chain reaction (qPCR) have been widely used for virus detection but cannot distinguish infectious and noninfectious viruses. Therefore, qPCR cannot be directly applied to virus inactivation validation studies. In this paper, methods to detect viruses and progress in the challenge of differentiating infectious and noninfectious viruses with the combination of pretreatment and qPCR techniques such as the integrated cell culture-qPCR (ICC-qPCR) method are reviewed. In addition, the advantages and disadvantages of each new method, as well as its prospect in virus inactivation validation studies, are discussed.