Environmental transmission of norovirus gastroenteritis

Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States.
Current opinion in virology 02/2012; 2(1):96-102. DOI: 10.1016/j.coviro.2011.11.005
Source: PubMed


The advent of molecular techniques and their increasingly widespread use in public health laboratories and research studies has transformed the understanding of the burden of norovirus. Norovirus is the most common cause of community-acquired diarrheal disease across all ages, the most common cause of outbreaks of gastroenteritis, and the most common cause of foodborne disease in the United States. They are a diverse group of single-stranded RNA viruses that are highly infectious and stable in the environment; both symptomatic and asymptomatic infections are common. Through shedding in feces and vomit, norovirus can be transmitted directly through an array of routes: person-to-person, food or the environment. The relative importance of environmental transmission of virus is yet to be fully quantified but is likely to be substantial and is an important feature that complicates control.

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Available from: Jan Vinjé, Oct 04, 2015
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    • "Norwalk virus (genus Norovirus) is a worldwide human health threat, which causes acute gastroenteritis , resulting in approximately 200,000 annual deaths (Patel et al., 2008). In the US alone, Norwalk virus infects approximately 21 million humans annually, resulting in 800 deaths (Lopman et al., 2012). Treatment of Norwalk virus is primarily limited to rehydration as there are no specific treatments or vaccines available (Iturriza-Gómara and Lopman, 2014). "
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    ABSTRACT: Norwalk virus causes severe gastroenteritis for which there is currently no specific anti-viral therapy. A stage of the infection process is uncoating of the protein capsid to expose the viral genome and allow for viral replication. A mechanical characterization of the Norwalk virus may provide important information relating to the mechanism of uncoating. The mechanical strength of the Norwalk virus has previously been investigated using atomic force microscopy (AFM) nanoindentation experiments. Those experiments cannot resolve specific molecular interactions, and therefore, we have employed a molecular modeling approach to gain insights into the potential uncoating mechanism of the Norwalk capsid. In this study, we perform simulated nanoindentation using a coarse-grained structure-based model, which provides an estimate of the spring constant in good agreement with the experimentally determined value. We further analyze the fracture mechanisms and determine weak interfaces in the capsid structure, which are potential sites to inhibit uncoating by stabilization of these weak interfaces. We conclude by identifying potential target sites at the junction of a weak protein-protein interface.
    Frontiers in Bioengineering and Biotechnology 08/2015; 3:103. DOI:10.3389/fbioe.2015.00103
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    • "Illnesses associated with adenoviruses range from acute respiratory disease, pneumonia, conjunctivitis, and gastroenteritis, all of which could potentially be transmitted environmentally through non-potable uses of harvested stormwater (Arnone and Walling, 2007). Noroviruses are frequently reported as the leading cause of viral gastroenteritis outbreaks worldwide, with some literature estimating that they account for ~50% of all gastroenteritis cases (Lopman et al., 2012; Patel et al., 2009). Direct measurements of viral concentration in stormwater, however, are sparse due to the difficulties facing the quantification technologies, which are often plagued by poor recoveries in environmental water and inhibitory effects of PCR used for detecting viral genomes (Rajal et al., 2007). "
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    ABSTRACT: Capturing stormwater is becoming a new standard for sustainable urban stormwater management, which can be used to supplement water supply portfolios in water-stressed cities. The key advantage of harvesting stormwater is to use low impact development (LID) systems for treatment to meet water quality requirement for non-potable uses. However, the lack of scientific studies to validate the safety of such practice has limited its adoption. Microbial hazards in stormwater, especially human viruses, represent the primary public health threat. Using adenovirus and norovirus as target pathogens, we investigated the viral health risk associated with a generic scenario of urban stormwater harvesting practice and its application for three non-potable uses: 1) toilet flushing, 2) showering, and 3) food-crop irrigation. The Quantitative Microbial Risk Assessment (QMRA) results showed that food-crop irrigation has the highest annual viral infection risk (median range: 6.8×10(-4)-9.7×10(-1) per-person-per-year or pppy), followed by showering (3.6×10(-7)-4.3×10(-2)pppy), and toilet flushing (1.1×10(-7)-1.3×10(-4)pppy). Disease burden of each stormwater use was ranked in the same order as its viral infection risk: food-crop irrigation>showering>toilet flushing. The median and 95th percentile risk values of toilet-flushing using treated stormwater are below U.S. EPA annual risk benchmark of ≤10(-4)pppy, whereas the disease burdens of both toilet-flushing and showering are within the WHO recommended disease burdens of ≤10(-6)DALYspppy. However, the acceptability of showering risk interpreted based on the U.S. EPA and WHO benchmarks is in disagreement. These results confirm the safety of stormwater application in toilet flushing, but call for further research to fill the data gaps in risk modeling as well as risk benchmarks. Copyright © 2015 Elsevier B.V. All rights reserved.
    Science of The Total Environment 02/2015; 523:95-108. DOI:10.1016/j.scitotenv.2015.03.077 · 4.10 Impact Factor
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    • "The viruses are transmitted mainly through the fecal-oral route, including consumption of contaminated food and water [2] [3] [4]. Yet, numerous outbreaks occurring in public settings, such as cruise ships, nursing homes, hospitals, and daycare centers, strongly indicate that food is rarely the main vehicle; rather, high persistence, infectivity, and transmissibility collectively implicate contaminated surfaces as a main reservoir for the spread of NoVs [5] [6] [7]. Currently, strict compliance with hygiene practices such as the use of chemical disinfectants and hand washing is recommended to break the cycle of NoV transmission by inactivating or physically removing the virus particles from fomites or hands [8]. "
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    ABSTRACT: We evaluated the virucidal efficacy of light-activated fluorinated TiO2 surface coatings on human norovirus and several surrogates (bacteriophage MS2, feline calicivirus (FCV), and murine norovirus (MNV)). Inactivation of viruses on surfaces exposed to a common fluorescent lamp was monitored and the effects of UVA intensity, temperature, and fluoride content were assessed. Destruction of RNA and capsid oxidation were evaluated for human norovirus inocula on the F-TiO2 surfaces, while contact with the F-TiO2 surface and exposure to residual UVA radiation of 10μWcm(-2) for 60min resulted in infectivity reductions for the norovirus surrogates of 2-3 log10. Infectivity reductions on pristine TiO2 surfaces in identical conditions were over 2 orders of magnitude lower. Under realistic room lighting conditions, MS2 infectivity declined below the lower detection limit after 12h. Reductions in RNA were generally low, with the exception of GII.4, while capsid protein oxidation likely played a larger role in infectivity loss. Inactivation of norovirus surrogates occurred significantly faster on F-TiO2 compared to pristine TiO2 surfaces. The material demonstrated antiviral action against human norovirus surrogates and was shown to effectively inhibit MS2 when exposed to residual UVA present in fluorescent room lighting conditions in a laboratory setting.
    Journal of Photochemistry and Photobiology B Biology 08/2014; 140C:315-320. DOI:10.1016/j.jphotobiol.2014.08.009 · 2.96 Impact Factor
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