Environmental surveillance of SARS-CoV-2 RNA in wastewater systems and related environments in Wuhan: April to May of 2020

Wastewater-based epidemiology(WBE) has emerged as an effective environmental surveillance tool in monitoring fecal-oral pathogen infections within a community. Congruently, SARS-Co V-2, the etiologic agent of COVID-19, has been demonstrated to infect the gastrointestinal tissues, and be shed in feces. In the present study, SARS-Co V-2 RNA was concentrated from wastewater, sludge, surface water, ground water, sediment, and soil samples of municipal and hospital wastewater systems and related envi...     

污水新型冠状病毒监测研究进展及启示

新冠肺炎疫情暴发以来,全球多个国家和地区频繁在污水中检测出新型冠状病毒核酸. 开展基于污水流行病学的污水新型冠状病毒监测,可作为人群新冠肺炎监测的重要补充,获得的核酸浓度数据和序列突变分析结果,可为新冠肺炎疫情早期预警、早期发现无症状感染者、评估感染规模、监测人群流行趋势、开展病毒溯源调查、制定防控政策等提供科学依据. 鉴于此,本文系统介绍了国内外污水中新型冠状病毒的来源及影响病毒存活的主要因素,归纳了常用的污水新型冠状病毒富集浓缩和核酸检测方法,概括了全球已开展的监测项目、进展及现存科学问题,指出了现有研究的局限性,包括缺乏污水中新型冠状病毒的分布特征及感染性研究、预测预警模型开发与应用不足等. 为我国下一阶段新冠肺炎疫情或者未来可能出现的突发重大疫情的精准防控提供借鉴与参考,提升我国应对传染病及非传染病的预测预警、流行规模评估及精准施策的能力.      

Environmental Surveillance of SARS-CoV-2 RNA in Wastewater and Groundwater in Quintana Roo,Mexico

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater has been reported as a result of fecal shedding of infected individuals. In this study, the occurrence of SARS-CoV-2 RNA was explored in primary-treated wastewater from two municipal wastewater treatment plants in Quintana Roo, Mexico, along with groundwater from sinkholes, a household well, and submarine groundwater discharges. Physicochemical variables were obtained in situ, and coliphage densities were determined. Three virus concentration methods based on adsorption-elution and sequential filtration were used followed by RNA isolation. Quantification of SARS-CoV-2 was done by RT-qPCR using the CDC 2020 assay, 2019-nCoV_N1 and 2019-nCoV_N2. The Pepper mild mottle virus, one of the most abundant RNA viruses in wastewater was quantified by RT-qPCR and compared to SARS-CoV-2 concentrations. The use of three combined virus concentration methods together with two qPCR assays allowed the detection of SARS-CoV-2 RNA in 58% of the wastewater samples analyzed, whereas none of the groundwater samples were positive for SARS-CoV-2 RNA. Concentrations of SARS-CoV-2 in wastewater were from 1.8 × 10³ to 7.5 × 10³ genome copies per liter (GC l⁻¹), using the N1 RT-qPCR assay, and from 2.4 × 10² to 5.9 × 10³ GC l⁻¹ using the N2 RT-qPCR assay. Based on PMMoV prevalence detected in all wastewater and groundwater samples tested, the three viral concentration methods used could be successfully applied for SARS-CoV-2 RNA detection in further studies. This study represents the first detection of SARS-CoV-2 RNA in wastewater in southeast Mexico and provides a baseline for developing a wastewater-based epidemiology approach in the area.

     

Mechanisms and evidence of vertical transmission of infections in pregnancy including SARS-CoV-2s

There remain unanswered questions concerning mother-to-child-transmission of SARS-CoV-2. Despite reports of neonatal COVID-19, SARS-CoV-2 has not been consistently isolated in perinatal samples, thus definitive proof of transplacental infection is still lacking. To address these questions, we assessed investigative tools used to confirm maternal-fetal infection and known protective mechanisms of the placental barrier that prevent transplacental pathogen migration. Forty studies of COVID-19 pregnancies reviewed suggest a lack of consensus on diagnostic strategy for congenital infection. Although real-time polymerase chain reaction of neonatal swabs was universally performed, a wide range of clinical samples was screened including vaginal secretions (22.5%), amniotic fluid (35%), breast milk (22.5%) and umbilical cord blood. Neonatal COVID-19 was reported in eight studies, two of which were based on the detection of SARS-CoV-2 IgM in neonatal blood. Histological examination demonstrated sparse viral particles, vascular malperfusion and inflammation in the placenta from pregnant women with COVID-19. The paucity of placental co-expression of ACE-2 and TMPRSS2, two receptors involved in cytoplasmic entry of SARS-CoV-2, may explain its relative insensitivity to transplacental infection. Viral interactions may utilise membrane receptors other than ACE-2 thus, tissue susceptibility may be broader than currently known. Further spatial-temporal studies are needed to determine the true potential for transplacental migration.     

Monitoring SARS-CoV-2 in the Wastewater and Rivers of Tapachula,a Migratory Hub in Southern Mexico

Food and Environmental Virology - The COVID-19 pandemic has been monitored by applying different strategies, including SARS-CoV-2 detection with clinical testing or through wastewater-based...     

A 1-Year Study on the Detection of Human Enteric Viruses in New Caledonia

Human enteric viruses occur in high concentrations in wastewater and can contaminate receiving environmental waters. Due to the lack of data on the prevalence of enteric viruses in New Caledonia, the presence and the concentrations of enteric viruses in wastewater and seawater were determined. Untreated wastewater and seawater samples were collected monthly for 1 year from a wastewater treatment plant (WWTP) and from the WWTP’s outlet, located directly on a popular recreational beach. Samples were tested for norovirus genogroups I and II (NoV GI and GII), astroviruses (AsV), sapoviruses (SaV), enteroviruses (EV), hepatitis A viruses (HAV), rotaviruses (RoV), human adenoviruses (HAdV) and human polyomaviruses (HPyV). To support these data, faecal samples from cases of gastroenteritis were tested for the first time for NoV and detected in the population. NoV GI, NoV GII, EV, SaV, HAdV and HPyV were detected in all wastewaters, RoV in 75 % and AsV in 67 %. HAV were not detected in wastewater. Overall, 92 % of seawater samples were positive for at least one virus. HPyV were detected most frequently in 92 % of samples and at concentrations up to 7.7 × 10³ genome copies/L. NoV GI, NoV GII, EV, SaV, RoV and HAdV were found in 33, 66, 41, 33, 16 and 66 % of seawater samples, respectively. AsV were not detected in seawater. This study reports for the first time the presence of NoV and other enteric viruses in New Caledonia and highlights the year-round presence of enteric viruses in the seawater of a popular beach.     

SARS-CoV-2 in the context of past coronaviruses epidemics: Consideration for prenatal care

Since December 2019, the novel SARS-CoV-2 outbreak has resulted in millions of cases and more than 200 000 deaths worldwide. The clinical course among nonpregnant women has been described, but data about potential risks for women and their fetus remain scarce. The SARS and MERS epidemics were responsible for miscarriages, adverse fetal and neonatal outcomes, and maternal deaths. For COVID-19 infection, only nine cases of maternal death have been reported as of 22 April 2020, and pregnant women seem to develop the same clinical presentation as the general population. However, severe maternal cases, as well as prematurity, fetal distress, and stillbirth among newborns have been reported. The SARS-CoV-2 pandemic greatly impacts prenatal management and surveillance and raise the need for clear unanimous guidelines. In this narrative review, we describe the current knowledge about coronaviruses (SARS, MERS, and SARS-CoV-2) risks and consequences on pregnancies, and we summarize available current candidate therapeutic options for pregnant women. Finally, we compare current guidance proposed by The Royal College of Obstetricians and Gynaecologists, The American College of Obstetricians and Gynecologists, and the World Health Organization to give an overview of prenatal management which should be utilized until future data appear.     

Quantification of viable bacteria in wastewater treatment plants by using propidium monoazide combined with quantitative PCR (PMA-qPCR)

The detection of viable bacteria in wastewater treatment plants(WWTPs) is very important for public health, as WWTPs are a medium with a high potential for waterborne disease transmission. The aim of this study was to use propidium monoazide(PMA) combined with the quantitative polymerase chain reaction(PMA-qPCR) to selectively detect and quantify viable bacteria cells in full-scale WWTPs in China. PMA was added to the concentrated WWTP samples at a final concentration of 100 μmol/L and the samples were incubated in the dark for 5 min, and then lighted for 4 min prior to DNA extraction and qPCR with specific primers for Escherichia coli and Enterococci, respectively. The results showed that PMA treatment removed more than 99% of DNA from non-viable cells in all the WWTP samples, while matrices in sludge samples markedly reduced the effectiveness of PMA treatment. Compared to qPCR, PMA-qPCR results were similar and highly linearly correlated to those obtained by culture assay, indicating that DNA from non-viable cells present in WWTP samples can be eliminated by PMA treatment, and that PMA-qPCR is a reliable method for detection of viable bacteria in environmental samples. This study demonstrated that PMA-qPCR is a rapid and selective detection method for viable bacteria in WWTP samples, and that WWTPs have an obvious function in removing both viable and non-viable bacteria. The results proved that PMA-qPCR is a promising detection method that has a high potential for application as a complementary method to the standard culture-based method in the future.     

One-year Surveillance of Human Enteric Viruses in Raw and Treated Wastewaters,Downstream River Waters,and Drinking Waters

Human enteric viruses are a major cause of waterborne diseases, and can be transmitted by contaminated water of all kinds, including drinking and recreational water. The objectives of the present study were to assess the occurrence of enteric viruses (enterovirus, norovirus, adenovirus, hepatitis A and E virus) in raw and treated wastewaters, in rivers receiving wastewater discharges, and in drinking waters. Wastewater treatment plants’ (WWTP) pathogen removal efficiencies by adenovirus quantitative real-time PCR and the presence of infectious enterovirus, by cell culture assays, in treated wastewaters and in surface waters were also evaluated. A total of 90 water samples were collected: raw and treated wastewaters (treated effluents and ultrafiltered water reused for industrial purposes), water from two rivers receiving treated discharges, and drinking water. Nested PCR assays were used for the identification of viral DNA/RNA, followed by direct amplicon sequencing. All raw sewage samples (21/21), 61.9 % of treated wastewater samples (13/21), and 25 % of ultrafiltered water samples (3/12) were contaminated with at least one viral family. Multiple virus families and genera were frequently detected. Mean positive PCRs per sample decreased significantly from raw to treated sewage and to ultrafiltered waters. Moreover, quantitative adenovirus data showed a reduction in excess of 99 % in viral genome copies following wastewater treatment. In surface waters, 78.6 % (22/28) of samples tested positive for one or more viruses by molecular methods, but enterovirus-specific infectivity assays did not reveal infectious particles in these samples. All drinking water samples tested negative for all viruses, demonstrating the effectiveness of treatment in removing viral pathogens from drinking water. Integrated strategies to manage water from all sources are crucial to ensure water quality.     

我国污水排放余氯限值规定及监测、控制方法研究进展

含氯消毒剂在我国污水处理过程中普遍使用,其在灭活病原微生物的同时会增加出水余氯浓度,对生态环境造成影响. 新冠肺炎疫情防控期间,含氯消毒剂的使用量大幅增加,余氯问题更加凸显. 为对我国水污染物排放标准中余氯限值的制定和修订提出可参考的建议,比较了国内外现有各类水污染物排放标准中的余氯限值,并总结分析余氯监测及控制方法的研究进展. 结果表明:①我国多项水污染物排放标准包含出水中余氯限值规定,如《医疗机构水污染物排放标准》规定采用氯化消毒的医院污水直接排放总余氯浓度应低于0.5 mg/L,北京、上海等地的地方污水综合排放标准规定直接排放的污水总余氯浓度应低于0.5 mg/L,但我国城镇污水处理厂消毒尾水中的余氯至今仍缺乏标准管控. ②我国余氯测定标准中规定的余氯监测方法为N,N-二乙基-1,4-苯二胺(DPD)滴定法和分光光度法,近年来余氯的仪器分析法和传感器法也得到迅速发展. ③余氯控制方法包括以二氧化硫和亚硫酸盐为脱氯剂的化学脱氯法、活性炭脱氯法和还原性金属材料脱氯法等. 因此,建议我国在未来城镇污水处理厂排放标准中考虑纳入余氯限值规定,并关注余氯监测及控制方法的发展与规范制定.