Detection and Phylogenetic Analysis of Hepatitis A Virus in the Wastewater Treatment Plant of Ekbatan Town in Tehran, Iran

Background: Limited sources of fresh water necessitate the application of health policies for treatment and decontamination of human sewage for further use. A wide variety of infectious agents, including bacteria, fungi, parasites, and viruses, can be found in sewage. Enteric viruses such as hepatitis A virus (HAV) can survive the current treatments and infect susceptible hosts. Objectives: This study aimed to evaluate the HAV contamination in human sewage before and after treatment in the wastewater treatment plant of Ekbatan town in Tehran, Iran, and analyze the phylogenetic properties of the identified viruses. Methods: Over a 12-month period, we collected the wastewater samples including influent, before chlorination, and effluent, from the wastewater treatment plant of Ekbatan town in Tehran, Iran. Ribonucleic acid (RNA) extraction, complementary deoxyribonucleic acid (cDNA) synthesis, and semi-nested polymerase chain reaction (PCR) were performed to identify HAV contamination. Phylogenetic analysis was performed to investigate subgenotypes of the virus. Results: HAV was detected in all influents and samples before chlorination, while the virus was detected in 50% of the effluent samples. All detected viruses belonged to subgenotype IB. Conclusions: Investigating the presence of HAV in sewage provides a general picture of the virus spread in the population of interest. HAV was detected in all influent samples, indicating that the infection is endemic in this area all year round. This also indicates the inability of the current treatment protocols in virus removal, which can be a threat to the public health.

Modeling on Wastewater Treatment Process in Saudi Arabia: a perspective of Covid-19

The novel coronavirus diseases (COVID-19) has resulted in an ongoing pandemic affecting the health system and devastating impact on global economy. The virus has been found in human feces, in sewage and in wastewater treatment plants. We highlight the transmission behavior, occurrence, and persistence of coronavirus in sewage and wastewater treatment plants. Our approach is to follow in the process of identifying a coronavirus hotspot through existing wastewater plants in major cities of Saudi Arabia. The mathematical distributions including log-normal distribution, Gaussian model and susceptible- exposed-infection-recovered- (SEIR) model are adopted to predict the coronavirus load in wastewater plants. This paper highlights not only the potential virus removal techniques from wastewater treatment plants but also to facilitate tracing of SARS-CoV-2 virus in human through wastewater treatment plants.

Filter made of cuprammonium regenerated cellulose for virus removal: a mini-review

In 1989, Asahi Kasei commercialized a porous hollow fiber membrane filter (Planova™) made of cuprammonium regenerated cellulose, making it possible for the first time in the world to “remove viruses from protein solutions by membrane filtration”. Planova has demonstrated its usefulness in separating proteins and viruses. Filters that remove viruses from protein solutions, i.e., virus removal filters (VFs), have become one of the critical modern technologies to assure viral safety of biological products. It has also become an indispensable technology for the future. The performance characteristics of VFs can be summarized in two points: 1) the virus removal performance increases as the virus diameter increases, and 2) the recovery rate of proteins with molecular weights greater than 10,000 exceeds the practical level. This paper outlines the emergence of VF and its essential roles in the purification process of biological products, requirements for VF, phase separation studies for cuprammonium cellulose solution, comparison between Planova and other regenerated cellulose flat membranes made from other cellulose solutions, and the development of Planova. The superior properties of Planova can be attributed to its highly interconnected three-dimensional network structure. Furthermore, future trends in the VF field, the subject of this review, are discussed.

The impact of heating, ventilation, and air conditioning design features on the transmission of viruses, including the 2019 novel coronavirus: a systematic review of ventilation and coronavirus

Aerosol transmission has been a pathway for virus spread for many viruses. Similarly, emerging evidence regarding SARS-CoV-2, and the resulting pandemic as declared by WHO in March 2020, determined aerosol transmission for SARS-CoV-2 to be significant. As such, public health officials and professionals have sought data regarding the effect of Heating, Ventilation, and Air Conditioning (HVAC) features to control and mitigate viruses, particularly coronaviruses. A systematic review was conducted using international standards to identify and comprehensively synthesize research examining the effectiveness of ventilation for mitigating transmission of coronaviruses. The results from 32 relevant studies showed that: increased ventilation rate was associated with decreased transmission, transmission probability/risk, infection probability/risk, droplet persistence, virus concentration, and increased virus removal and virus particle removal efficiency; increased ventilation rate decreased risk at longer exposure times; some ventilation was better than no ventilation; airflow patterns affected transmission; ventilation feature (e.g., supply/exhaust, fans) placement influenced particle distribution. Some studies provided qualitative recommendations; however, few provided specific quantitative ventilation parameters suggesting a significant gap in current research. Adapting HVAC ventilation systems to mitigate virus transmission is not a one-solution-fits-all approach but instead requires consideration of factors such as ventilation rate, airflow patterns, air balancing, occupancy, and feature placement.Practical ImplicationsIncreasing ventilation, whether through ventilation rates (ACH, m3/h, m3/min, L/min) or as determined by CO2 levels (ppm), is associated with decreased transmission, transmission probability/risk, infection probability/risk, droplet persistence, and virus concentration, and increased virus removal and efficiency of virus particle removal. As well, professionals should consider the fact that changing ventilation rate or using mixing ventilation is not always the only way to mitigate and control viruses as varying airflow patterns and the use of ventilation resulted in better outcomes than situations without ventilation. Practitioners also need to consider occupancy, ventilation feature (supply/exhaust and fans) placement, and exposure time in conjunction with both ventilation rates and airflow patterns. Some recommendations with quantified data were made, including using an air change rate of 9 h-1 for a hospital ward; waiting six air changes or 2.5 hours before allowing different individuals into an unfiltered office with ∼2 fresh air changes (FCH) and one air change for a high-efficiency MERV or HEPA filtered laboratory; and using a pressure difference between -2 and -25 Pa in negative pressure isolation spaces. Other recommendations for practice included using or increasing ventilation, introducing fresh air, using maximum supply rates, avoiding poorly ventilated spaces, assessing fan placement and potentially increasing ventilation locations, and employing ventilation testing and air balancing checks.

Virus Detection and Production of Virus Free Plant Materials from the Lily by Selecting Basal Filament Flower as Explants

Lilium is a perennial bulbous flower of Lily family Liliaceae, with high ornamental and economic value. However, Lily is vulnerable to virus infection, which seriously affects the yield and quality of Lily, and poses a great threat to the production, sales, especially export of Lily, and has caused huge economic losses to the related industries. Therefore, the research on lily virus removal methods and virus detection technology has important practical significance to improve the ornamental value and economic value of lily. In this study, the filaments of four susceptible lily varieties,' Valdisole' (A),'Adoration'(LA),' Ice Cube'(OT) and ‘Zantriana’ (O), were used as explants. The filaments of lily were divided into three parts, namely, top, middle, and base. In this paper, the virus detection of tissue culture seedlings induced by lily filaments was carried out by using DAS-ELISA and RT-PCR, and the removal effects of Cucumber mosaic virus,(CMV) and lily symptomless virus (LSV), two common viruses in lily, were explored, and the two detection technologies were compared. The results showed that the success rate of tissue culture seedlings induced by filament base was the highest, and CMV virus could be basically removed. RT-PCR detection is more sensitive than DAS-ELISA detection, but RT-PCR detection requires higher test conditions and technology. Therefore, appropriate virus detection methods can be selected according to actual conditions and severity.

The impact of heating, ventilation, and air conditioning design features on the transmission of viruses, including the 2019 novel coronavirus: a systematic review of filtration

Historically, viruses have demonstrated airborne transmission. Emerging evidence suggests the novel coronavirus (SARS-CoV-2) that causes COVID-19 may also spread by airborne transmission. This is more likely in indoor environments, particularly with poor ventilation. In the context of potential airborne transmission, a vital mitigation strategy for the built environment is heating, ventilation, and air conditioning (HVAC) systems. HVAC features could modify virus transmission potential. A systematic review following international standards was conducted to comprehensively identify and synthesize research examining the effectiveness of filters within HVAC systems in reducing virus transmission. Twenty-three relevant studies showed that: filtration was associated with decreased transmission; filters removed viruses from the air; increasing filter efficiency (efficiency of particle removal) was associated with decreased transmission, decreased infection risk, and increased viral filtration efficiency (efficiency of virus removal); increasing filter efficiency above MERV 13 was associated with limited benefit in further reduction of virus concentration and infection risk; and filters with the same efficiency rating from different companies showed variable performance. Increasing filter efficiency may mitigate virus transmission; however, improvement may be limited above MERV 13. Adapting HVAC systems to mitigate virus transmission requires a multi-factorial approach and filtration is one factor offering demonstrated potential for decreased transmission.

Chitosan Coagulation Pretreatment to Enhance Ceramic Water Filtration for Household Water Treatment

Viruses are major contributors to the annual 1.3 million deaths associated with the global burden of diarrheal disease morbidity and mortality. While household-level water treatment technologies reduce diarrheal illness, the majority of filtration technologies are ineffective in removing viruses due to their small size relative to filter pore size. In order to meet the WHO health-based tolerable risk target of 10−6 Disability Adjusted Life Years per person per year, a drinking water filter must achieve a 5 Log10 virus reduction. Ceramic pot water filters manufactured in developing countries typically achieve less than 1 Log10 virus reductions. In order to overcome the shortfall in virus removal efficiency in household water treatment filtration, we (1) evaluated the capacity of chitosan acetate and chitosan lactate, as a cationic coagulant pretreatment combined with ceramic water filtration to remove lab cultured and sewage derived viruses and bacteria in drinking waters, (2) optimized treatment conditions in waters of varying quality and (3) evaluated long-term continuous treatment over a 10-week experiment in surface waters. For each test condition, bacteria and virus concentrations were enumerated by culture methods for influent, controls, and treated effluent after chitosan pretreatment and ceramic water filtration. A > 5 Log10 reduction was achieved in treated effluent for E.coli, C. perfringens, sewage derived E. coli and total coliforms, MS2 coliphage, Qβ coliphage, ΦX174 coliphage, and sewage derived F+ and somatic coliphages.