Enteric viruses in the Danube river water and sludge.

A study of the viral pollution of the Roumanian course of the Danube river was carried out from 1972 to 1974. The presence of enteric viruses was investigated in 123 water samples, taken by the gauze swab method and in 116 sludge samples from the bottom of the river. The samples were collected from 20 sampling points along the river from Moldova Veche to Br?ila, in accordance with the water use and the main pollution sources. Viruses were recovered from 17.5% of the samples. The frequency of virus isolations from water samples was similar to that observed in sludge samples. Therefore, the viral pollution of the Romanian course of the Danube showed a low level in comparison with other rivers, though two concentration techniques into suckling mice and into tissue cultures, were used for each sample.     

Enteric viruses in molluscan shellfish

One hundred and thirty-seven bivalves were collected for environmental monitoring and the market; all the samples were analysed by RT-PCR test. Bacteriological counts meeting the European Union shellfish criteria were reached by 69.5% of all the samples, whereas the overall positive values for enteric virus presence were: 25.5%, 18.2%, 8.0% and 2.1% for Rotavirus, Astrovirus, Enteroviruses, Norovirus, respectively. Mussels appear to be the most contaminated bivalves, with 64.8% of positive samples, 55.7% and 22.7% respectively for clams and oysters, whereas in the bivalves collected for human consumption 50.7% were enteric virus positive, as compared to 56.4% of the samples collected for growing-area classification. The overall positive sample was 54.0%.     

Enteric viruses in HIV-related diarrhoea

HIV-related diarrhoea is an important cause of morbidity and mortality in HIV infection. Cytomegalovirus is a well-established cause of diarrhoea, but the role of other enteric viruses is less clear and will be discussed here. The clinical manifestations, disease mechanisms, diagnostic techniques and current treatments for the management of these infections are reviewed.     

Rapid detection of bacterial endotoxins in drinking water and renovated wastewater.

A pilot study was conducted to determine the feasibility of using the Limulus endotoxin assay to detect endotoxins in potable waters and from reclaimed advanced waste treatment (AWT) plant effluents. Water samples were tested using both Limulus lysates prepared in our laboratory and a commercial product, Difco Pyrotest. The Limulus assay procedure was easily adapted to the testing of water samples for endotoxin. Measured endotoxin concentrations varied from 0.78 ng/ml to 1,250 ng/ml. Levels of endotoxin were not predictable based on whether the water was drinking water or AWT water, i.e., some AWT water samples had less endotoxin activity than some samples of drinking water, and some AWT waters had greater endotoxin activity than drinking water. Only three of the water samples tested were free of any detectable endotoxin. Breakpoint chlorination procedures seemed to reduce measurable endotoxin content, whereas passage through activated carbon columns was associated with greater final endotoxin concentrations in test waters.     

Enteric viruses of humans and animals in aquatic environments: health risks, detection, and potential water quality assessment tools.

Waterborne enteric viruses threaten both human and animal health. These pathogens are host specific and cause a wide range of diseases and symptoms in humans or other animals. While considerable research has documented the risk of enteric viruses to human health from contact with contaminated water, the current bacterial indicator-based methods for evaluation of water quality are often ineffectual proxies for pathogenic viruses. Additionally, relatively little work has specifically investigated the risk of waterborne viruses to animal health, and this risk currently is not addressed by routine water quality assessments. Nonetheless, because of their host specificity, enteric viruses can fulfill a unique role both for assessing health risks and as measures of contamination source in a watershed, yet the use of animal, as well as human, host-specific viruses in determining sources of fecal pollution has received little attention. With improved molecular detection assays, viruses from key host groups can be targeted directly using PCR amplification or hybridization with a high level of sensitivity and specificity. A multispecies viral analysis would provide needed information for controlling pollution by source, determining human health risks based on assessments of human virus loading and exposure, and determining potential risks to production animal health and could indicate the potential for the presence of other zoonotic pathogens. While there is a need to better understand the prevalence and environmental distribution of nonhuman enteric viruses, the development of improved methods for specific and sensitive detection will facilitate the use of these microbes for library-independent source tracking and water quality assessment tools.     

Metagenomic analysis of viruses in reclaimed water

Reclaimed water use is an important component of sustainable water resource management. However, there are concerns regarding pathogen transport through this alternative water supply. This study characterized the viral community found in reclaimed water and compared it with viruses in potable water. Reclaimed water contained 1000-fold more virus-like particles than potable water, having approximately 10⁸ VLPs per millilitre. Metagenomic analyses revealed that most of the viruses in both reclaimed and potable water were novel. Bacteriophages dominated the DNA viral community in both reclaimed and potable water, but reclaimed water had a distinct phage community based on phage family distributions and host representation within each family. Eukaryotic viruses similar to plant pathogens and invertebrate picornaviruses dominated RNA metagenomic libraries. Established human pathogens were not detected in reclaimed water viral metagenomes, which contained a wealth of novel single-stranded DNA and RNA viruses related to plant, animal and insect viruses. Therefore, reclaimed water may play a role in the dissemination of highly stable viruses. Information regarding viruses present in reclaimed water but not in potable water can be used to identify new bioindicators of water quality. Future studies will need to investigate the infectivity and host range of these viruses to evaluate the impacts of reclaimed water use on human and ecosystem health.     

Enteric viruses evoke broad host immune responses resembling those elicited by the bacterial microbiome

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Psittacosis in Manitoba

Paired blood specimens submitted to the Virus Laboratory, between January and September 1970, from 200 patients with a lower respiratory tract infection were examined for antibodies to the psittacosis-human pneumonitis group antigen. A high static titre of antibodies was found in four patients and a rising titre in three. The illness varied in the seven patients, tending to be severe, chronic and recurrent. All patients recovered following a course of antibiotic therapy which was repeated in four; treatment tended to be inadequate since the diagnosis of psittacosis was made retrospectively. The likely source of the infection in four of the patients was budgerigars, in one it was pigeons, in one it was a canary as well as a pigeon, and in one the source was not identified. Two additional patients had a fairly high static titre of antibodies to the psittacosis-human pneumonitis antigen but were excluded from this report since they showed a diagnostic increase in antibodies to a respiratory virus during the course of their illness; both patients had an avian contact and are being followed up.     

水源中肠道病毒及胃肠炎病毒检测方法的研究进展及意义

人肠道病毒及胃肠炎病毒借助水体传播可能引起水源影响区域的疫情暴发.尤其对免疫力发育尚不完全的儿童和免疫缺陷人群,这些病毒感染可能会引起严重的临床症状和并发症.因此,做好水源中肠道病毒及胃肠炎病毒的检测和监测,将对这些病毒所致疾病的防范和控制有重要意义.本文综述了目前国内外针对水体中的病毒浓缩和检测所做的相关研究,包括从水样中浓缩、纯化病毒的不同方法及建立在分子生物学和细胞培养基础上的病原检测方法.这些研究为进一步建立行业标准和实验室检测规范提供了重要的参考和技术依据.     

Detection of enteric viruses in treated drinking water

The occurrence of viruses in conventionally treated drinking water derived from a heavily polluted source was evaluated by collecting and analyzing 38 large-volume (65- to 756-liter) samples of water from a 9 m3/s (205 X 10(6) gallons [776 X 10(6) liters] per day) water treatment plant. Samples of raw, clarified, filtered, and chlorinated finished water were concentrated by using the filter adsorption-elution technique. Of 23 samples of finished water, 19 (83%) contained viruses. None of the nine finished water samples collected during the dry season contained detectable total coliform bacteria. Seven of nine finished water samples collected during the dry season met turbidity, total coliform bacteria, and total residual chlorine standards. Of these, four contained virus. During the dry season the percent removals were 25 to 93% for enteric viruses, 89 to 100% for bacteria, and 81% for turbidity. During the rainy season the percent removals were 0 to 43% for enteric viruses, 80 to 96% for bacteria, and 63% for turbidity. None of the 14 finished water samples collected during the rainy season met turbidity standards, and all contained rotaviruses or enteroviruses.     

Roles of water molecules in bacteria and viruses

In addition to water, microbes mainly comprise lipids, carbohydrates, proteins and nucleic acids. Their structure and function singularly and conjointly is affected by water activity. Desiccation leads to dramatic lipid phase changes whereas carbohydrates, proteins and nucleic acids initially suffer spontaneous, reversible low activation energy Maillard reactions forming products that more slowly re-arrange, cross-link etc. to give non-native states. While initial products spontaneously may reverse to native states by raising water activity, later products only do so through energy consumption and enzymatic activity eg. repair. Yet, native states of lipid membranes and associated enzymes are required to generate energy. Consequently, good reserves of high energy compounds (e.g. ATP) and of membrane stabilisers (e.g. trehalose) may be expected to enhance survival following drying and rehydration (e.g. anhydrobiotic organisms).Presented at the Session Water in the Solar System and Its Role in Exobiology, during the 26th General Assembly of the European Geophysical Society, 22–26 April 1991 in Wiesbaden, Germany     

Stability of viruses in waste water sludge eluates

The survival of indigenous enteric viruses in samples of unconcentrated and concentrated waste water sludge eluates, which had been prepared using a combination beef extract elution - organic flocculation concentration procedure, was studied at 2, 23, and -70 degrees C. Changes of virus titer occurring in the samples were followed during an 84-day observation period, with rates of change then calculated by least-squares regression. Virus survival in both types of eluates was statistically dependent (p less than or equal to 0.05) upon storage temperature. Based upon the observed rates of inactivation the average times which would be required for a 90% decrease (one log10 unit) in virus titer for unconcentrated eluates are 27 days at 23 degrees C, 198 days at 2 degrees C, and 375 days at -70 degrees C. The calculated average times required for a 90% decrease in virus titer for concentrated eluates are 22 days at 23 degrees C, 132 days at 2 degrees C, and 246 days at -70 degrees C. In both types of eluates the rates of virus inactivation at 2 degrees C were statistically different from those observed at 23 degrees C, but not different from those observed at -70 degrees C. The three study temperatures were selected to approximate holding of samples in an air-conditioned room, fluid on wet ice (H2O), and frozen on dry ice (CO2).     

Adenovirus infections in Manitoba

This review of adenovirus infections in Manitoba over a five-year period is introduced with a brief presentation on the structure-function relationships of the adenoviruses. Extensive research has resulted in the accumulation of a great deal of basic information, far surpassing our knowledge about the infections that these viruses produce in man. More research is needed on the epidemiological and clinical aspects of these diseases, including methods for prevention and treatment, and earlier methods of diagnosis.Features of 216 adenovirus respiratory infections diagnosed from 1963 to 1967 are reviewed and presented. All infections were diagnosed by showing a four-fold or greater increase. In addition, an adenovirus was isolated from many of the infections. These infections occurred every year in substantial numbers and they were seen during each month of the year, although they were more frequent and severe in the winter. Infants and younger persons were often affected. The most severe disease was a pneumonitis which occurred mainly in infants. Associated symptoms usually arose from the gastrointestinal tract, and were sufficiently common to indicate that one should suspect an adenovirus infection when respiratory and gastrointestinal symptoms occur together in a child.The possible role of adenoviruses in the etiology of other than respiratory diseases is discussed and the features of 96 possible non-respiratory infections are presented. Further work will be required to establish a definite etiologic role of the adenoviruses in most of these infections.