我国典型土壤对病毒等温静态吸附的数值模拟

通过室内等温静态批量平衡吸附实验,采用3种常见的等温线（Freundlich方程、Langmuir方程和Temkin方程）对2种病毒（MS2和X174）在2种处理（非灭菌和灭菌）条件下的6种土壤（红壤土、红粘土、乌栅土、黄泥土、沙质潮土和壤质潮土）中的吸附行为进行了回归拟合.实验结果和模拟结果均表明,土壤性质、病毒性质、土壤中的土著微生物对病毒在土壤中吸附行为均具有重要的影响.红粘土对MS2和X174的平均吸附比例几乎能达到100％,而2种潮土（沙质潮土和壤质潮土）相对较弱;总体来看土壤对X174的吸附能力高于MS2,但灭菌后的土壤对MS2的吸附能力却高于X174.在数值模拟中,Freundlich方程和Langmuir方程均具有理想的相关性.Freundlich方程能够表现出病毒浓度对其在土壤中吸附行为的影响;尽管Langmuir方程能够应用于土壤对病毒吸附能力的比较,但本研究中不能应用Langmuir方程来计算土壤对病毒的最大吸附量.     

Norovirus and Other Human Enteric Viruses in Moroccan Shellfish

The aim of this study was to evaluate the presence of human enteric viruses in shellfish collected along the Mediterranean Sea and Atlantic Coast of Morocco. A total of 77 samples were collected from areas potentially contaminated by human sewage. Noroviruses were detected in 30 % of samples, with an equal representation of GI and GII strains, but were much more frequently found in cockles or clams than in oysters. The method used, including extraction efficiency controls, allowed the quantification of virus concentration. As in previous reports, results showed levels of contamination between 100 and 1,000 copies/g of digestive tissues. Sapoviruses were detected in 13 % of samples mainly in oyster and clam samples. Hepatitis A virus was detected in two samples, with concentrations around 100 RNA copies/g of digestive tissues. Only two samples were contaminated with enterovirus and none with norovirus GIV or Aichi virus. This study highlights the interest of studying shellfish samples from different countries and different production areas. A better knowledge of shellfish contamination helps us to understand virus levels in shellfish and to improve shellfish safety, thus protecting consumers.     

Early invasive prenatal diagnosis in HBsAg-positive women

From 1982 to 1989, pregnant women in two large city hospitals in The Netherlands had serum samples screened for hepatitis B surface antigen (HBsAg). Infants of mothers found to be HBsAg-positive received hepatitis B immune globulin immediately after birth and hepatitis B vaccine in the first year of life. Blood samples of infants were regularly tested for HBsAg and antibodies directed against HBsAg. A retrospective analysis of the pregnancy outcome in HBsAg-positive women who had invasive tests for prenatal diagnosis was carried out to determine whether amniocentesis and chorionic villus sampling (CVS) are risk factors for the intrauterine transmission of the hepatitis B virus. Amniocentesis was carried out in 17 HBsAg-positive women and CVS in one case. Only two women were HBsAg- and HBeAg-positive. Prenatal diagnosis led to the termination of pregnancy for fetal chromosome abnormality in three cases. The remaining 15 pregnancies were uneventful; all infants were negative for HBsAg and developed an active immune response to the vaccine. These data suggest that amniocentesis in HBsAg-positive women constitutes a low risk for the intrauterine transmission of the hepatitis B virus, but definite conclusions in HBeAg-positive women cannot be drawn.     

紫外氯胺组合消毒供水系统中病毒微生物的分布特征

为研究紫外氯胺组合消毒对供水系统中病毒微生物的影响特性,以生产规模紫外氯胺组合消毒供水系统为研究对象,应用宏基因组技术对供水系统中病毒微生物的迁移变化、群落结构和病毒宿主进行了分析.结果表明,紫外氯胺组合消毒工艺能降低病毒物种数（6.13%）和基因丰度（51.97%）,但不能完全去除水中病毒微生物.对比美国环保署（USEPA）以培养法检测的水处理病毒去除率可达99%~99.99%,本研究利用宏基因组技术测得的总病毒去除率只有93.46%,以培养法检测水中病毒存在局限性.Caudovirales（有尾噬菌体目）是整个供水系统中最丰富病毒,对氯胺消毒都具有一定敏感性.Lentivirus（慢病毒属）作为能够感染人和脊椎动物的病毒,对紫外照射和氯胺消毒都具有强抵抗力.该供水系统中最大的病毒宿主是细菌（61.50%）.原水中病毒主要寄生在Synechococcus（聚球藻属）中;出厂水以及管网水中,优势病毒宿主均为Pseudomonas（假单胞菌属）;进入管网后,Pseudomonas aeruginosa（铜绿假单胞菌）宿主病毒基因丰度升高342.62%,应加强关注管网系统病毒微生物风险.紫外氯胺组合消毒工艺比单紫外消毒更有利于病毒宿主的去除（51.97%与0.79%）.     

Low Pathogenic Avian Influenza Viruses (H3N8, H5N6): In Vitro Influence of <Emphasis Type="SmallCaps">d</Emphasis>,<Emphasis Type="SmallCaps">l</Emphasis>-Lactic Acid and Sodium Chloride on Infectivity and Virus Persistence in Short Fermented Raw Poultry Sausage

Since highly pathogenic avian influenza virus H5N1 emerged in 1997, avian influenza is considered one of the most important infectious diseases globally. In respect of virus transmission to humans, the consumption of raw poultry products remains of serious concern. In this study, data about survival time and inactivation kinetics of two low pathogenic avian influenza virus (AIV) strains (H3N8, H5N6) in short fermented raw sausage were obtained. In addition, the impact of the preserving factors d,l-lactic acid and sodium chloride on virus infectivity was evaluated through in vitro studies. Virus infectivity was confirmed in embryonated chicken eggs. Inactivation of H3N8 was seen in d,l-lactic acid solutions (0.15 and 0.20%, pH 4.40–4.70 and pH 3.80–3.91) at both temperatures (20 vs. 4°C) during 3 days of exposure. However, infectious virus particles could still be detected after exposure to 0.1% d,l-lactic acid (pH 5.80–5.99). In all NaCl solutions (2, 6 and 12% w/v), infectivity of the H3N8 strain decreased steadily but reduction of the virus titre increased significantly with higher temperature. In raw sausages, decline in virus titre was observed for both strains during ripening and storage. Thereby, decline of virus infectivity was dependent on time and temperature with a more marked effect at higher temperatures (22 vs. 7°C). At refrigeration (7°C), both viruses maintained infectivity over 14 days. Results indicate that appropriate processing of short fermented raw poultry sausage is likely to reduce risk of virus exposure due to adequate inactivation of AIV during ripening and storage.     

Hepatologie Neuere Forschungsergebnisse in ihrer Bedeutung für das Verständnis von Leberkrankheiten

By two exemplary clinical situations — acute viral hepatitis, acute-phase reaction of the liver — the significance of basic research for the understanding of clinical phenomena and for the development of new diagnostic and therapeutic procedures is demonstrated. The very different phenomena following infection with the hepatitis-B-virus can be explained by the variation in the interactions of virus and liver cell, by the immune reaction of the host, and by mutants of the virus. The reaction of the liver to an extrahepatic infection is mediated by interleukin-6, and characterized by an alteration in protein metabolism. The synthesis of acute-phase proteins is increased. The proteins confine the local injury and establish the homeostasis of the organism.     

Virus Particle Detection by Convolutional Neural Network in Transmission Electron Microscopy Images

A new computational method for the detection of virus particles in transmission electron microscopy (TEM) images is presented. Our approach is to use a convolutional neural network that transforms a TEM image to a probabilistic map that indicates where virus particles exist in the image. Our proposed approach automatically and simultaneously learns both discriminative features and classifier for virus particle detection by machine learning, in contrast to existing methods that are based on handcrafted features that yield many false positives and require several postprocessing steps. The detection performance of the proposed method was assessed against a dataset of TEM images containing feline calicivirus particles and compared with several existing detection methods, and the state-of-the-art performance of the developed method for detecting virus was demonstrated. Since our method is based on supervised learning that requires both the input images and their corresponding annotations, it is basically used for detection of already-known viruses. However, the method is highly flexible, and the convolutional networks can adapt themselves to any virus particles by learning automatically from an annotated dataset.     

Internalisation of Enteric Viruses by Acanthamoeba castellanii, via Ingestion of Virus-Infected Mammalian Cells

The protozoan Acanthamoeba castellanii can inhabit various environments, including aquatic environments. After co-culture with mammalian cells which had been infected with coxsackievirus and rotavirus, virus was observed to have been internalised within the Acanthamoeba cells. No internalisation of freely-suspended virus was observed. The potential implications of virus internalisation of protozoa via infected mammalian cells, such as protection from disinfection, are discussed.     

Impact of an Alcohol-Based Hand Sanitizer Intervention on the Spread of Viruses in Homes

The objectives of this study were to determine the movement of a virus throughout a household and the impact of an alcohol-based hand sanitizer (ABHS) on reducing the movement and exposure of the virus to household members. Bacterial virus MS-2 was used as the surrogate for human enteric and respiratory viruses. Seven households with families having at least two children in the age range of 2–18 living in the home were used in this study. The hands of one adult family member were contaminated with 1 × 10⁸. MS-2 bacteriophage in each home. After 8 h, the hands of each family member (10 fingers) and 20 frequently touched fomites were sampled to determine baseline contamination without intervention. Within 8 h, MS-2 was detected on all of the family member’s hands and most of the fomites. The intervention consisted of providing the families in all selected homes with bottles of an ABHS, which were placed in the kitchen, bathrooms, and nurseries. Smaller individual bottles were provided for each family member greater than 12 years old to place in purses, pockets, backpacks, etc. The families were instructed to use the ABHS one time or three times during the day. For one and three uses, a statistically significant reduction of virus on un-inoculated and inoculated hands of ~99 % occurred within 8 h. Similar reductions occurred on fomites throughout the households (97–99 %). These results demonstrate that the use of an ABHS can significantly reduce transfer of a virus to the hands, and to the commonly touched surfaces within the household.     

Isolation and Genomic Sequence of Hepatitis A Virus from Mixed Frozen Berries in Italy

Hepatitis A virus (HAV) was detected in two samples of mixed frozen berries linked to Italian hepatitis A outbreak in April and September 2013. Both viruses were fully sequenced by next-generation sequencing and the genomes clustered with HAV complete genomes of sub-genotype IA with nucleotide identities of 95–97 %.     

Persistence of Hepatitis A Virus in Fresh Produce and Production Environments,and the Effect of Disinfection Procedures: A Review

Although information is limited, it is evident that prolonged persistence of infectious Hepatitis A virus (HAV) is a factor in the transmission of the virus via fresh produce. Consequently, data on persistence of the virus on produce, and in environments relevant to production, such as soils, water and surfaces, are required to fully understand the dynamics of transmission of HAV via foods. Furthermore, information on effective disinfection procedures is necessary to implement effective post-harvest control measures. This review summarises current information on HAV persistence in fresh produce and on relevant disinfection procedures. On vegetables, HAV can remain infectious for several days; on frozen berries, it can persist for several months. HAV can remain infectious on surfaces for months, depending on temperature and relative humidity, and can survive desiccation. It can survive for several hours on hands. Washing hands can remove the virus, but further data are required on the appropriate procedure. Chlorination is effective in water, but not when HAV is associated with foodstuffs. Bleach and other sodium hypochlorite disinfectants at high concentrations can reduce HAV on surfaces, but are not suitable for use on fresh produce. There is only limited information on the effects of heating regimes used in the food industry on HAV. HAV is resistant to mild pasteurisation. Some food components, e.g. fats and sugars, can increase the virus’ resistance to higher temperatures. HAV is completely eliminated by boiling. Quantitative prevalence data are needed to allow the setting of appropriate disinfection log reduction targets for fresh produce.     

Pre-harvest Viral Contamination of Crops Originating from Fecal Matter

Pre-harvest contamination of fresh produce and fruits is a possible route for viral transmission which should not be ignored. The contamination originates from viruses shed in human or animal fecal materials which eventually reach crops through many steps and hurdles, including spread of viruses into the agricultural environment through leakage of septic tanks/pipes or runoff from animal lagoons, virus survival during biosolids and manure treatment, virus survival and transport in soil and subsequent contamination of irrigation water, and virus transmission to crops through irrigation water, etc. Initially, large quantities of virus particles may be released from infected humans or animals, and then in the environment viruses are gradually inactivated under various natural conditions (e.g., temperature, water activity, microbial activities, etc.) and only a tiny portion of viruses may reach crops and cause the contamination. However, the fact that the infectious dose of some foodborne viruses is as low as 10–100 particles makes the pre-harvest contamination still a threat to human health. In the USA, the Environmental Protection Agency (USEPA) and United States Department of Agriculture (USDA) regulations and guidances on proper treatment and usage of manure and biosolids for agricultural purpose may largely reduce the release of viruses to the environment; however, pre-harvest viral contamination due to fecal matter is not completely avoidable. This review focuses on the current knowledge of pre-harvest viral contamination and describes the complex transmission process regarding the presence and survival of virus in soil and fecal material, the effect of different biosolids/manure treatment on virus inactivation, the transmission of virus from soil to water, the contamination of crops by irrigation water and survival of virus on crops.     

制药行业中污水处理技术及实践

采用物理灭活与生物处理相结合的废水处理技术对药厂污水进行处理,高温灭菌灭活了废水中的病毒、病菌等,生化处理化解污水中大分子的有机物.工程实践表明:两者相结合的处理方法,处理后的水质能够达到国家污水综合排放二级标准.     

两段回转窑焚烧炉处理医疗垃圾的实际应用

医疗垃圾是一种含有大量病菌、细菌及化学药剂的危险废物，它的随意排放和不当处理将造成严重的环境污染．危害人体健康。在此介绍了沈阳市拟建的医疗垃圾焚烧厂采用的两段回转窑焚烧炉处理技术的工艺流程、技术指标和设计要点。     

Use of ATP Readings to Predict a Successful Hygiene Intervention in the Workplace to Reduce the Spread of Viruses on Fomites

The purpose of this study was to validate the use of adenosine triphosphate (ATP) for evaluating hygiene intervention effectiveness in reducing viral dissemination in an office environment. The bacterial virus MS-2 was used to evaluate two scenarios, one where the hand of an individual was contaminated and another where a fomite was contaminated. MS-2 was selected as a model because its shape and size are similar to many human pathogenic viruses. Two separate experiments were conducted, one in which the entrance door push plate was inoculated and the other in which the hand of one selected employee was inoculated. In both scenarios, 54 selected surfaces in the office were tested to assess the dissemination of the virus within the office. Associated surface contamination was also measured employing an ATP meter. More than half of the tested hands and surfaces in the office were contaminated with MS-2 within 4 h. Next, an intervention was conducted, and each scenario was repeated. Half of the participating employees were provided hand sanitizer, facial tissues, and disinfecting wipes, and were instructed in their use. A significant (p < 0.05) reduction was observed in the number of surfaces contaminated with virus. This reduction in viral spread was evident from the results of both viral culture and the surface ATP measurements, although there was no direct correlation between ATP measurements with respect to viral concentration. Although ATP does not measure viruses, these results demonstrate that ATP measurements could be useful for evaluating the effectiveness of hygiene interventions aimed at preventing viral spread in the workplace.     

The Fate of Murine Norovirus and Hepatitis A Virus During Preparation of Fresh Produce by Cutting and Grating

Human noroviruses and hepatitis A virus (HAV) are commonly associated with outbreaks occurring in restaurant establishments and catered events. Food handlers are major contributing factors to foodborne illnesses initiated in the kitchen setting. In this study, transfer of HAV and murine norovirus (MNV-1), a human norovirus surrogate, between produce (cucumbers, strawberries, tomatoes, cantaloupes, carrots, and honeydew melons) and common kitchen utensils (graters and knives) was investigated. The extent of virus transfer to produce during utensil application, in the presence and the absence of food residue, and the impact of knife surface properties (sharp, dull, serrated) was also investigated. Transfer of MNV-1 and HAV from produce items, initially contaminated with ~5.5 log PFU, to knives and graters during application ranged from 0.9 to 5.1 log PFU. MNV-1 transfer to knives was the greatest for cucumbers, strawberries, and tomatoes, and the least for honeydew melons, while transfer of HAV to knives was greater for tomatoes and honeydew melons than strawberries, cantaloupes, and cucumbers. After preparation of a contaminated produce item, knife cross-contamination easily occurred as viruses were detected on almost all of the seven produce items successively prepared. Produce residues on utensils often resulted in less virus transfer when compared to utensils without residue accumulation. Knife surface properties did not impact virus transfer. The ease of virus transfer between produce and utensils demonstrated by the current study highlights the importance of efforts aimed toward preventing cross-contamination in the kitchen environment.     

Bayesian Modeling of Enteric Virus Density in Wastewater Using Left-Censored Data

Stochastic models are used to express pathogen density in environmental samples for performing microbial risk assessment with quantitative uncertainty. However, enteric virus density in water often falls below the quantification limit (non-detect) of the analytical methods employed, and it is always difficult to apply stochastic models to a dataset with a substantially high number of non-detects, i.e., left-censored data. We applied a Bayesian model that is able to model both the detected data (detects) and non-detects to simulated left-censored datasets of enteric virus density in wastewater. One hundred paired datasets were generated for each of the 39 combinations of a sample size and the number of detects, in which three sample sizes (12, 24, and 48) and the number of detects from 1 to 12, 24 and 48 were employed. The simulated observation data were assigned to one of two groups, i.e., detects and non-detects, by setting values on the limit of quantification to obtain the assumed number of detects for creating censored datasets. Then, the Bayesian model was applied to the censored datasets, and the estimated mean and standard deviation were compared to the true values by root mean square deviation. The difference between the true distribution and posterior predictive distribution was evaluated by Kullback–Leibler (KL) divergence, and it was found that the estimation accuracy was strongly affected by the number of detects. It is difficult to describe universal criteria to decide which level of accuracy is enough, but eight or more detects are required to accurately estimate the posterior predictive distributions when the sample size is 12, 24, or 48. The posterior predictive distribution of virus removal efficiency with a wastewater treatment unit process was obtained as the log ratio posterior distributions between the posterior predictive distributions of enteric viruses in untreated wastewater and treated wastewater. The KL divergence between the true distribution and posterior predictive distribution of virus removal efficiency also depends on the number of detects, and eight or more detects in a dataset of treated wastewater are required for its accurate estimation.