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Best E, Parnell P, Couturier J, Barbut F, Le Bozec A, Arnoldo L, Madia A, Brusaferro S, Wilcox MH. Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study. J Hosp Infect 2018; 100:469-475. [PMID: 30006281 DOI: 10.1016/j.jhin.2018.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/04/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Hand hygiene is a fundamental component of infection prevention, but few studies have examined whether hand-drying method affects the risk of dissemination of potential pathogens. AIM To perform a multi-centre, internal-crossover study comparing bacterial contamination levels in washrooms with hand-drying by either paper towels (PT) or jet air dryer (JAD; Dyson). METHODS A total of 120 sampling sessions occurred over 12 weeks in each of three hospitals (UK, France, Italy). Bacteria were cultured from air, multiple surfaces, and dust. Washroom footfall (patients/visitors/staff) was monitored externally. FINDINGS Footfall was nine times higher in UK washrooms. Bacterial contamination was lower in PT versus JAD washrooms; contamination was similar in France and the UK, but markedly lower in Italian washrooms. Total bacterial recovery was significantly greater from JAD versus PT dispenser surfaces at all sites (median: 100-300 vs 0-10 cfu; all P < 0.0001). In the UK and France, significantly more bacteria were recovered from JAD washroom floors (median: 24 vs 191 cfu, P < 0.00001). UK meticillin-susceptible Staphylococcus aureus recovery was three times more frequent and six-fold higher for JAD vs PT surfaces (both P < 0.0001). UK meticillin-resistant S. aureus recovery was three times more frequent (21 vs 7 cfu) from JAD versus PT surfaces or floors. Significantly more enterococci and extended-spectrum β-lactamase (ESBL)-producing bacteria were recovered from UK JAD versus PT washroom floors (P < 0.0001). In France, ESBL-producing bacteria were recovered from dust twice as often during JAD versus PT use. CONCLUSION Multiple examples of significant differences in surface bacterial contamination, including by faecal and antibiotic-resistant bacteria, were observed, with higher levels in JAD versus PT washrooms. Hand-drying method affects the risk of (airborne) dissemination of bacteria in real-world settings.
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Affiliation(s)
- E Best
- Microbiology, Leeds Teaching Hospitals, Leeds, UK
| | - P Parnell
- Microbiology, Leeds Teaching Hospitals, Leeds, UK
| | - J Couturier
- CHU Saint Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - F Barbut
- CHU Saint Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - A Le Bozec
- CHU Saint Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - L Arnoldo
- Department of Medicine, University of Udine, Udine, Italy
| | - A Madia
- Department of Medicine, University of Udine, Udine, Italy
| | - S Brusaferro
- Department of Medicine, University of Udine, Udine, Italy
| | - M H Wilcox
- Microbiology, Leeds Teaching Hospitals, Leeds, UK; University of Leeds, Leeds, UK.
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Brisebois E, Veillette M, Dion-Dupont V, Lavoie J, Corbeil J, Culley A, Duchaine C. Human viral pathogens are pervasive in wastewater treatment center aerosols. J Environ Sci (China) 2018; 67:45-53. [PMID: 29778173 PMCID: PMC7128102 DOI: 10.1016/j.jes.2017.07.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/18/2017] [Accepted: 07/20/2017] [Indexed: 05/20/2023]
Abstract
Wastewater treatment center (WTC) workers may be vulnerable to diseases caused by viruses, such as the common cold, influenza and gastro-intestinal infections. Although there is a substantial body of literature characterizing the microbial community found in wastewater, only a few studies have characterized the viral component of WTC aerosols, despite the fact that most diseases affecting WTC workers are of viral origin and that some of these viruses are transmitted through the air. In this study, we evaluated in four WTCs the presence of 11 viral pathogens of particular concern in this milieu and used a metagenomic approach to characterize the total viral community in the air of one of those WTCs. The presence of viruses in aerosols in different locations of individual WTCs was evaluated and the results obtained with four commonly used air samplers were compared. We detected four of the eleven viruses tested, including human adenovirus (hAdV), rotavirus, hepatitis A virus (HAV) and Herpes Simplex virus type 1 (HSV1). The results of the metagenomic assay uncovered very few viral RNA sequences in WTC aerosols, however sequences from human DNA viruses were in much greater relative abundance.
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Affiliation(s)
- Evelyne Brisebois
- Université Laval, Pavillon Alexandre Vachon, 1045, ave de la Médecine, Québec, QC G1V0A6, Canada; CRIUCPQ, 2725, Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
| | - Marc Veillette
- CRIUCPQ, 2725, Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
| | - Vanessa Dion-Dupont
- Université Laval, Pavillon Alexandre Vachon, 1045, ave de la Médecine, Québec, QC G1V0A6, Canada; CRIUCPQ, 2725, Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
| | - Jacques Lavoie
- IRSST, 505 Boulevard de Maisonneuve O, Montréal, QC, H3A 3C2, Canada
| | - Jacques Corbeil
- CRCHU, 2705 Boulevard Laurier, RC-709, Québec, QC, G1V 4G2, Canada
| | - Alexander Culley
- Université Laval, Pavillon Alexandre Vachon, 1045, ave de la Médecine, Québec, QC G1V0A6, Canada
| | - Caroline Duchaine
- Université Laval, Pavillon Alexandre Vachon, 1045, ave de la Médecine, Québec, QC G1V0A6, Canada; CRIUCPQ, 2725, Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada.
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53
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Evaluation of hospital-grade disinfectants on viral deposition on surfaces after toilet flushing. Am J Infect Control 2018; 46:507-511. [PMID: 29305284 DOI: 10.1016/j.ajic.2017.11.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/03/2017] [Accepted: 11/03/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Past studies have shown that infectious aerosols created during toilet flushing result in surface contamination of the restroom. The goals of this study were to quantify viral contamination of surfaces in restrooms after flushing and the impact of disinfectants added to the toilet bowl prior to flushing on reducing surface contamination. METHODS The degree of contamination of surfaces in the restroom was assessed with and without the addition of coliphage MS2 to the toilet bowl before flushing. The bowl water and various surfaces in the restroom were subsequently tested for the presence of the virus. RESULTS The toilet bowl rim, toilet seat top, and toilet seat underside were contaminated in all trials without a disinfectant added to the bowl water before flushing. All disinfectants significantly reduced concentrations on surfaces when the contact time was ≥15 minutes. Hydrogen peroxide resulted in very little reduction of virus in the toilet bowl (<1 log10). Peracetic acid and quaternary ammonium had the greatest log reductions on virus in the organic matter in the toilet. CONCLUSIONS Toilet flushing resulted in extensive contamination of surfaces within the restroom. Addition of disinfectant to the toilet bowl prior to flushing reduced the level of contamination in the bowl and fomites after flushing.
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54
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Lei H, Li Y, Xiao S, Lin C, Norris SL, Wei D, Hu Z, Ji S. Routes of transmission of influenza A H1N1, SARS CoV, and norovirus in air cabin: Comparative analyses. INDOOR AIR 2018; 28:394-403. [PMID: 29244221 PMCID: PMC7165818 DOI: 10.1111/ina.12445] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 12/06/2017] [Indexed: 05/05/2023]
Abstract
Identifying the exact transmission route(s) of infectious diseases in indoor environments is a crucial step in developing effective intervention strategies. In this study, we proposed a comparative analysis approach and built a model to simulate outbreaks of 3 different in-flight infections in a similar cabin environment, that is, influenza A H1N1, severe acute respiratory syndrome (SARS) coronavirus (CoV), and norovirus. The simulation results seemed to suggest that the close contact route was probably the most significant route (contributes 70%, 95% confidence interval [CI]: 67%-72%) in the in-flight transmission of influenza A H1N1 transmission; as a result, passengers within 2 rows of the index case had a significantly higher infection risk than others in the outbreak (relative risk [RR]: 13.4, 95% CI: 1.5-121.2, P = .019). For SARS CoV, the airborne, close contact, and fomite routes contributed 21% (95% CI: 19%-23%), 29% (95% CI: 27%-31%), and 50% (95% CI: 48%-53%), respectively. For norovirus, the simulation results suggested that the fomite route played the dominant role (contributes 85%, 95% CI: 83%-87%) in most cases; as a result, passengers in aisle seats had a significantly higher infection risk than others (RR: 9.5, 95% CI: 1.2-77.4, P = .022). This work highlighted a method for using observed outbreak data to analyze the roles of different infection transmission routes.
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Affiliation(s)
- H. Lei
- Department of Mechanical EngineeringThe University of Hong KongPokfulamHong KongChina
| | - Y. Li
- Department of Mechanical EngineeringThe University of Hong KongPokfulamHong KongChina
| | - S. Xiao
- Department of Mechanical EngineeringThe University of Hong KongPokfulamHong KongChina
| | - C.‐H. Lin
- Environmental Control SystemsBoeing Commercial AirplanesEverettWAUSA
| | - S. L. Norris
- Environmental Control SystemsBoeing Commercial AirplanesEverettWAUSA
| | - D. Wei
- Boeing (China) Co. Ltd.BeijingChina
| | - Z. Hu
- Beijing Aeronautical Science & Technology Research Institute of COMACBeijingChina
| | - S. Ji
- Beijing Aeronautical Science & Technology Research Institute of COMACBeijingChina
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Miura F, Matsuyama R, Nishiura H. Estimating the Asymptomatic Ratio of Norovirus Infection During Foodborne Outbreaks With Laboratory Testing in Japan. J Epidemiol 2018; 28:382-387. [PMID: 29607886 PMCID: PMC6111106 DOI: 10.2188/jea.je20170040] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background Foodborne norovirus outbreak data in Japan from 2005–2006, involving virological surveillance of all symptomatic and asymptomatic individuals, were reanalyzed to estimate the asymptomatic ratio of norovirus infection along with the risk of infection and the probability of virus shedding. Methods Employing a statistical model that is considered to capture the data-generating process of the outbreak and virus surveillance, maximum likelihood estimation of the asymptomatic ratio was implemented. Results Assuming that all norovirus outbreaks (n = 55) were the result of random sampling from an identical distribution and ignoring genogroup and genotype specificities, the asymptomatic ratio was estimated at 32.1% (95% confidence interval [CI], 27.7–36.7). Although not significant, separate estimation of the asymptomatic ratio of the GII.4 genotype appeared to be greater than other genotypes and was estimated at 40.7% (95% CI, 32.8–49.0). Conclusion The present study offered the first explicit empirical estimates of the asymptomatic ratio of norovirus infection in natural infection settings. The estimate of about 30% was consistent with those derived from volunteer challenge studies. Practical difficulty in controlling GII.4 outbreaks was supported by the data, considering that a large estimate of the asymptomatic ratio was obtained for the GII.4 genotype.
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Affiliation(s)
- Fuminari Miura
- Graduate School of Medicine, Hokkaido University.,Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo
| | - Ryota Matsuyama
- Graduate School of Medicine, Hokkaido University.,CREST, Japan Science and Technology Agency
| | - Hiroshi Nishiura
- Graduate School of Medicine, Hokkaido University.,CREST, Japan Science and Technology Agency
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56
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Bing-Yuan, Zhang YH, Leung NH, Cowling BJ, Yang ZF. Role of viral bioaerosols in nosocomial infections and measures for prevention and control. JOURNAL OF AEROSOL SCIENCE 2018; 117:200-211. [PMID: 32226118 PMCID: PMC7094610 DOI: 10.1016/j.jaerosci.2017.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 09/21/2023]
Abstract
The presence of patients with diverse pathologies in hospitals results in an environment that can be rich in various microorganisms including respiratory and enteric viruses, leading to outbreaks in hospitals or spillover infections to the community. All hospital patients are at risk of nosocomial viral infections, but vulnerable groups such as older adults, children and immuno-compromised/-suppressed patients are at particular risk of severe outcomes including prolonged hospitalization or death. These pathogens could transmit through direct or indirect physical contact, droplets or aerosols, with increasing evidence suggesting the importance of aerosol transmission in nosocomial infections of respiratory and enteric viruses. Factors affecting the propensity to transmit and the severity of disease transmitted via the aerosol route include the biological characteristics affecting infectivity of the viruses and susceptibility of the host, the physical properties of aerosol particles, and the environmental stresses that alter these properties such as temperature and humidity. Non-specific systematic and individual-based interventions designed to mitigate the aerosol route are available although empirical evidence of their effectiveness in controlling transmission of respiratory and enteric viruses in healthcare settings are sparse. The relative importance of aerosol transmission in healthcare setting is still an on-going debate, with particular challenge being the recovery of infectious viral bioaerosols from real-life settings and the difficulty in delineating transmission events that may also be a result of other modes of transmission. For the prevention and control of nosocomial infections via the aerosol route, more research is needed on identifying settings, medical procedures or equipment that may be associated with an increased risk of aerosol transmission, including defining which procedures are aerosol-generating; and on the effectiveness of systematic interventions on aerosol transmission of respiratory and enteric viruses in healthcare settings.
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Affiliation(s)
- Bing-Yuan
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, No. 151, Yanjiangxi Road, Yuexiu District, Guangzhou, Guangdong 510120, China
- Department of Respiration, First People's Hospital of Yunnan Province, 157, Jinbi Road, Kunming, Yunnan 650032, China
| | - Yun-Hui Zhang
- Department of Respiration, First People's Hospital of Yunnan Province, 157, Jinbi Road, Kunming, Yunnan 650032, China
| | - Nancy H.L. Leung
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Patrick Manson Building (North Wing), 7 Sassoon Road, Pokfulam, Hong Kong SAR, China
| | - Benjamin J. Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Patrick Manson Building (North Wing), 7 Sassoon Road, Pokfulam, Hong Kong SAR, China
| | - Zi-Feng Yang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, No. 151, Yanjiangxi Road, Yuexiu District, Guangzhou, Guangdong 510120, China
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57
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McIntosh EDG. Healthcare-associated infections: potential for prevention through vaccination. Ther Adv Vaccines Immunother 2018; 6:19-27. [PMID: 29998218 PMCID: PMC5933536 DOI: 10.1177/2515135518763183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/06/2017] [Indexed: 01/06/2023] Open
Abstract
The challenge of healthcare-associated infections is compounded by the higher incidence of resistant organisms and the decreasing utility of antimicrobial agents. Historic and current vaccines have already contributed to reductions in healthcare-associated infections, and future vaccines have the potential to reduce these infections further. Through examples of bacterial and viral vaccines, this review will attempt to chart the way forward.
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58
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Lai ACK, Tan TF, Li WS, Ip DKM. Emission strength of airborne pathogens during toilet flushing. INDOOR AIR 2018; 28:73-79. [PMID: 28683156 PMCID: PMC7165531 DOI: 10.1111/ina.12406] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 07/01/2017] [Indexed: 05/04/2023]
Abstract
The flushing of toilets generates contaminated aerosols, the transmission of which may cause the spread of disease, particularly in the immunocompromised or the elderly. This study investigated the emission strength of three types of airborne bacteria, namely Staphylococcus epidermidis, Escherichia coli, and Pseudomonas alcaligenes, during toilet flushing in a custom-built toilet under a controlled environment. Flushing was activated by a flushometer operated at two pressure levels, 400 kPa (high pressure [HP]) and 200 kPa (low pressure [LP]), and by a water cistern tank placed 95 cm (high tank [HT]) and 46 cm (low tank [LT]) above the toilet seat. The pathogens emitted by the first flush were calculated, with the correlations between airborne pathogen emissions and droplet concentration (HP, r=0.944, P<.001; LP, r=0.803, P<.001, HT, r=0.885, P<.05) and bacterial size (HP, r=-0.919, P<.001; LP, r=-0.936, P<.001; HT, r=-0.967, P<.05) in the different conditions then tested. The emission strength in the HP condition was statistically greater than that in the LP condition, whereas the cistern tank system produced less emissions than the flushometer system, and tank height was not found to be a sensitive parameter.
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Affiliation(s)
- A. C. K. Lai
- Department of Architecture and Civil EngineeringCity University of Hong KongKowloonHong Kong
| | - T. F. Tan
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
| | - W. S. Li
- Queen Mary HospitalPokfulamHong Kong
- School of Public HealthThe University of Hong KongPokfulamHong Kong
| | - D. K. M. Ip
- School of Public HealthThe University of Hong KongPokfulamHong Kong
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59
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Xiao S, Tang JW, Li Y. Airborne or Fomite Transmission for Norovirus? A Case Study Revisited. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14121571. [PMID: 29240665 PMCID: PMC5750989 DOI: 10.3390/ijerph14121571] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 01/03/2023]
Abstract
Norovirus infection, a highly prevalent condition associated with a high rate of morbidity, comprises a significant health issue. Although norovirus transmission mainly occurs via the fecal-oral and vomit-oral routes, airborne transmission has been proposed in recent decades. This paper re-examines a previously described norovirus outbreak in a hotel restaurant wherein airborne transmission was originally inferred. Specifically, the original evidence that suggested airborne transmission was re-analyzed by exploring an alternative hypothesis: could this outbreak instead have occurred via fomite transmission? This re-analysis was based on whether fomite transmission could have yielded similar attack rate distribution patterns. Seven representative serving pathways used by waiters were considered, and the infection risk distributions of the alternative fomite transmission routes were predicted using a multi-agent model. These distributions were compared to the reported attack rate distribution in the original study using a least square methods approach. The results show that with some reasonable assumptions of human behavior patterns and parameter values, the attack rate distribution corresponded well with that of the infection risk via the fomite route. This finding offers an alternative interpretation of the transmission routes that underlay this particular norovirus outbreak and an important consideration in the development of infection control guidelines and the investigation of similar norovirus outbreaks in future.
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Affiliation(s)
- Shenglan Xiao
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
| | - Julian W Tang
- Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester LE1 7RH, UK.
- Infection, Immunity, Inflammation, University of Leicester, Leicester LE1 7RH, UK.
| | - Yuguo Li
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
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Abstract
Norovirus is the leading cause of acute gastroenteritis in the USA. Although secondary household transmission of norovirus is frequently reported in outbreaks, little is known about specific risk factors for susceptibility and infectiousness in the household. Three norovirus outbreaks were investigated and data were collected on individuals exposed in the primary outbreak setting and their household members. Potential individual- and household-level risk factors for susceptibility and infectiousness were assessed using univariate and multivariate generalised linear mixed models. In the univariate models, the secondary attack rate (SAR) was significantly higher when living in a household with two or more primary cases (incidence rate ratio (IRR) = 2·1; 95% confidence interval (CI) 1·37-3·29), more than one primary case with vomiting (IRR = 1·9; CI 1·11-3·37), and at least one primary case with diarrhoea (IRR = 3·0; CI 1·46-6·01). After controlling for other risk factors in the multivariate models, the SAR was significantly higher among those living in a household with two or more primary cases (adjusted IRR = 2·0; CI 1·17-3·47) and at least one primary case with diarrhoea (adjusted IRR = 2·8; CI 1·35-5·93). These findings underscore the importance of maintaining proper hygiene and isolating ill household members to prevent norovirus transmission in the household.
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61
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Mbareche H, Brisebois E, Veillette M, Duchaine C. Bioaerosol sampling and detection methods based on molecular approaches: No pain no gain. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:2095-2104. [PMID: 28558432 DOI: 10.1016/j.scitotenv.2017.05.076] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 05/23/2023]
Abstract
Bioaerosols are among the less studied particles in the environment. The lack of standardization in sampling procedures, difficulties related to the effect of sampling processes on the integrity of microorganisms, and challenges associated with the application of environmental microbiology analyses and molecular and culture methods frighten many young scientists. Every microorganism has its own particularities and acts differently when aerosolized in various conditions. Because the air is an extremely biologically diluted environment, it is necessary to concentrate its content before any analysis is performed. Challenges faced when applying molecular methods to air samples reveal the need for a better standardization of approaches for cell and nucleic acid recovery, the choice of genetic markers, and interpretation of data. This paper presents a few of the limits and difficulties tackled when molecular methods are applied to bioaerosols, suggests some improvements by specifying the critical stages that should be considered when studying the microbial ecology of bioaerosols, and provides thoughtful insights on how to overcome the challenges encountered.
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Affiliation(s)
- Hamza Mbareche
- Département de biochimie, microbiologie et bio-informatique, Faculté des sciences et de génie, Université Laval, Canada; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie, Université Laval, Canada.
| | - Evelyne Brisebois
- Département de biochimie, microbiologie et bio-informatique, Faculté des sciences et de génie, Université Laval, Canada; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie, Université Laval, Canada
| | - Marc Veillette
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie, Université Laval, Canada
| | - Caroline Duchaine
- Département de biochimie, microbiologie et bio-informatique, Faculté des sciences et de génie, Université Laval, Canada; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie, Université Laval, Canada.
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62
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Uhrbrand K, Koponen IK, Schultz AC, Madsen AM. Evaluation of air samplers and filter materials for collection and recovery of airborne norovirus. J Appl Microbiol 2017; 124:990-1000. [PMID: 28921812 DOI: 10.1111/jam.13588] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 11/27/2022]
Abstract
AIMS The aim of this study was to identify the most efficient sampling method for quantitative PCR-based detection of airborne human norovirus (NoV). METHODS AND RESULTS A comparative experiment was conducted in an aerosol chamber using aerosolized murine norovirus (MNV) as a surrogate for NoV. Sampling was performed using a nylon (NY) filter in conjunction with four kinds of personal samplers: Gesamtstaubprobenahme sampler (GSP), Triplex-cyclone sampler (TC), 3-piece closed-faced Millipore cassette (3P) and a 2-stage NIOSH cyclone sampler (NIO). In addition, sampling was performed using the GSP sampler with four different filter types: NY, polycarbonate (PC), polytetrafluoroethylene (PTFE) and gelatine (GEL). The sampling efficiency of MNV was significantly influenced by both sampler and filter type. The GSP sampler was found to give significantly (P < 0·05) higher recovery of aerosolized MNV than 3P and NIO. A higher recovery was also found for GSP compared with TC, albeit not significantly. Finally, recovery of aerosolized MNV was significantly (P < 0·05) higher using NY than PC, PTFE and GEL filters. CONCLUSIONS The GSP sampler combined with a nylon filter was found to be the best method for personal filter-based sampling of airborne NoV. SIGNIFICANCE AND IMPACT OF THE STUDY The identification of a suitable NoV air sampler is an important step towards studying the association between exposure to airborne NoV and infection.
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Affiliation(s)
- K Uhrbrand
- National Research Centre for the Working Environment, Copenhagen Ø, Denmark.,Division of Microbiology and Production, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - I K Koponen
- National Research Centre for the Working Environment, Copenhagen Ø, Denmark
| | - A C Schultz
- Division of Microbiology and Production, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - A M Madsen
- National Research Centre for the Working Environment, Copenhagen Ø, Denmark
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63
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Torremorell M, Alonso C, Davies PR, Raynor PC, Patnayak D, Torchetti M, McCluskey B. Investigation into the Airborne Dissemination of H5N2 Highly Pathogenic Avian Influenza Virus During the 2015 Spring Outbreaks in the Midwestern United States. Avian Dis 2017; 60:637-43. [PMID: 27610723 DOI: 10.1637/11395-021816-reg.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We investigated the plausibility of aerosol transmission of H5N2 highly pathogenic avian influenza (HPAI) virus during the 2015 spring outbreaks that occurred in the U.S. midwest. Air samples were collected inside and outside of infected turkey and layer facilities. Samples were tested to assess HPAI virus concentration (RNA copies/m(3) of air), virus viability, and virus distribution by particle size. HPAI virus RNA was detected inside and up to 1000 m from infected facilities. HPAI virus was isolated from air samples collected inside, immediately outside, up to 70 m from infected facilities, and in aerosol particles larger than 2.1 μm. Direct exposure to exhausted aerosols proved to be a significant source of environmental contamination. These findings demonstrate HPAI virus aerosolization from infected flocks, and that both the transport of infectious aerosolized particles and the deposition of particles on surfaces around infected premises represent a potential risk for the spread of HPAI.
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Affiliation(s)
- Montserrat Torremorell
- A Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, MN, 55108
| | - Carmen Alonso
- A Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, MN, 55108
| | - Peter R Davies
- A Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, MN, 55108
| | - Peter C Raynor
- B Division of Environmental Health Sciences, School of Public Health, University of Minnesota-Twin Cities, Saint Paul, MN 55455
| | - Devi Patnayak
- C Department of Veterinary Population Medicine, Veterinary Diagnostic Laboratory, University of Minnesota-Twin Cities, Saint Paul, MN 55108
| | - Mia Torchetti
- D United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Ames, IA 50010
| | - Brian McCluskey
- E United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Fort Collins, CO 80526
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Triadó-Margarit X, Veillette M, Duchaine C, Talbot M, Amato F, Minguillón MC, Martins V, de Miguel E, Casamayor EO, Moreno T. Bioaerosols in the Barcelona subway system. INDOOR AIR 2017; 27:564-575. [PMID: 27687789 DOI: 10.1111/ina.12343] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/23/2016] [Indexed: 05/22/2023]
Abstract
Subway systems worldwide transport more than 100 million people daily; therefore, air quality on station platforms and inside trains is an important urban air pollution issue. We examined the microbiological composition and abundance in space and time of bioaerosols collected in the Barcelona subway system during a cold period. Quantitative PCR was used to quantify total bacteria, Aspergillus fumigatus, influenza A and B, and rhinoviruses. Multitag 454 pyrosequencing of the 16S rRNA gene was used to assess bacterial community composition and biodiversity. The results showed low bioaerosol concentrations regarding the targeted microorganisms, although the bacterial bioburden was rather high (104 bacteria/m3 ). Airborne bacterial communities presented a high degree of overlap among the different subway environments sampled (inside trains, platforms, and lobbies) and were dominated by a few widespread taxa, with Methylobacterium being the most abundant genus. Human-related microbiota in sequence dataset and ascribed to potentially pathogenic bacteria were found in low proportion (maximum values below 2% of sequence readings) and evenly detected. Hence, no important biological exposure marker was detected in any of the sampled environments. Overall, we found that commuters are not the main source of bioaerosols in the Barcelona subway system.
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Affiliation(s)
- X Triadó-Margarit
- Centre for Advanced Studies of Blanes (CEAB), Spanish Research Council (CSIC), Blanes, Spain
| | - M Veillette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, QC, Canada
| | - C Duchaine
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, QC, Canada
| | - M Talbot
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, QC, Canada
| | - F Amato
- Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
| | - M C Minguillón
- Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
| | - V Martins
- Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
| | - E de Miguel
- Transports Metropolitans de Barcelona, TMB Santa Eulalia, Barcelona, Spain
| | - E O Casamayor
- Centre for Advanced Studies of Blanes (CEAB), Spanish Research Council (CSIC), Blanes, Spain
| | - T Moreno
- Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
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65
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de Graaf M, Villabruna N, Koopmans MP. Capturing norovirus transmission. Curr Opin Virol 2017; 22:64-70. [PMID: 28056379 DOI: 10.1016/j.coviro.2016.11.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 12/15/2022]
Abstract
Human norovirus is a leading cause of gastroenteritis and is efficiently transmitted between humans and around the globe. The burden of norovirus infections in the global community and in health-care settings warrant the availability of outbreak prevention strategies and control measures that are tailored to the pathogen, outbreak setting and population at risk. A better understanding of viral and host determinants of transmission would aid in developing and fine-tuning such efforts. Here, we describe mechanisms of transmission, available model systems for studying norovirus transmission and their strengths and weaknesses as well as future research strategies.
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Affiliation(s)
- Miranda de Graaf
- Department of Viroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands.
| | - Nele Villabruna
- Department of Viroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands
| | - Marion Pg Koopmans
- Department of Viroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands
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Characterization of Viral Exposures in United States Occupational Environments. EXPOSURE TO MICROBIOLOGICAL AGENTS IN INDOOR AND OCCUPATIONAL ENVIRONMENTS 2017. [PMCID: PMC7122517 DOI: 10.1007/978-3-319-61688-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Viruses are considered to be the most abundant biological particles and have the capability to infect all forms of life leading to a variety of diseases. American workers in specific occupational environments are threatened by viral exposures, highlighting the importance to recognize the type and risk of exposure, as well as the preventive measures that can be taken to reduce the risk of exposure. For example, healthcare workers can potentially be exposed to air and blood-borne pathogens, such as hepatitis and the human immunodeficiency virus. These types of exposures have led to the development of preventive equipment and regulations intended to reduce viral exposures in occupational settings. This chapter will discuss the characteristics of viruses and the occupationally relevant viruses of which people in varying occupations can potentially encounter. Regulatory guidelines and protective strategies will also be reviewed.
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67
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Turgeon N, Michel K, Ha TL, Robine E, Moineau S, Duchaine C. Resistance of Aerosolized Bacterial Viruses to Four Germicidal Products. PLoS One 2016; 11:e0168815. [PMID: 28030577 PMCID: PMC5193356 DOI: 10.1371/journal.pone.0168815] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/06/2016] [Indexed: 01/05/2023] Open
Abstract
Viral diseases can spread through a variety of routes including aerosols. Yet, limited data are available on the efficacy of aerosolized chemicals to reduce viral loads in the air. Bacteriophages (phages) are often used as surrogates for hazardous viruses in aerosol studies because they are inexpensive, easy to handle, and safe for laboratory workers. Moreover, several of these bacterial viruses display physical characteristics similar to pathogenic human and animal viruses, like morphological size, type of nucleic acids, capsid morphology, and the presence of an envelope. In this study, the efficacy of four chemicals was evaluated on four airborne phages at two different relative humidity levels. Non-tailed bacteriophages MS2 (single-stranded RNA), ϕ6 (double-stranded RNA, enveloped), PR772 (double-stranded DNA), and ϕX174 (single-stranded DNA) were first aerosolized in a 55L rotative environmental chamber at 19°C with 25% and 50% relative humidity. Then, hydrogen peroxide, Eugenol (phenylpropene used in commercial perfumes and flavorings), Mist® (automobile disinfectant containing Triethylene glycol), and Pledge® (multisurface disinfectant containing Isopropanol, n-Alkyl Dimethyl Benzyl Amonium Chlorides, and n-Alkyl Dimethyl Ethylbenzyl Ammonium Chloride) were nebulized with the phages using a separate nebulizer. Aerosols were maintained in suspension during 10 minutes, 1 hour, and 2 hours. Viral aerosols were sampled using an SKC BioSampler and samples were analyzed using qPCR and plaque assays. The resistance levels of the four phages varied depending on the relative humidity (RH) and germicidal products tested. Phage MS2 was the most stable airborne virus under the environmental conditions tested while phage PR772 was the least stable. Pledge® and Eugenol reduced the infectivity of all airborne phages tested. At 25% RH, Pledge® and Eugenol were more effective at reducing infectivity of RNA phages ϕ6 and MS2. At 50% RH, Pledge® was the most effective agent against phage MS2. These findings illustrate that various airborne viruses should be tested to demonstrate the effectiveness of germicidal treatments. This research also provides a set of parameters for testing germicidal products in large-scale settings to reduce the risk of virus transmission.
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Affiliation(s)
- Nathalie Turgeon
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec, Québec, Canada
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada
| | - Kevin Michel
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec, Québec, Canada
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada
| | - Thi-Lan Ha
- Centre Scientifique et Technique du Bâtiment, Champs-sur-Marne, Marne la Vallée cedex, France
| | - Enric Robine
- Centre Scientifique et Technique du Bâtiment, Champs-sur-Marne, Marne la Vallée cedex, France
| | - Sylvain Moineau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada
- Félix d’Hérelle Reference Center for Bacterial Viruses and GREB, Faculté de médecine dentaire, Université Laval, Québec, Québec, Canada
| | - Caroline Duchaine
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec, Québec, Canada
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada
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68
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Turgeon N, Toulouse MJ, Ho J, Li D, Duchaine C. Neuraminidase as an enzymatic marker for detecting airborne Influenza virus and other viruses. Can J Microbiol 2016; 63:119-128. [PMID: 27958763 DOI: 10.1139/cjm-2016-0450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Little information is available regarding the effectiveness of air samplers to collect viruses and regarding the effects of sampling processes on viral integrity. The neuraminidase enzyme is present on the surface of viruses that are of agricultural and medical importance. It has been demonstrated that viruses carrying this enzyme can be detected using commercial substrates without having to process the sample by methods such as RNA extraction. This project aims at evaluating the effects of 3 aerosol-sampling devices on the neuraminidase enzyme activity of airborne viruses. The purified neuraminidase enzymes from Clostridium perfringens, a strain of Influenza A (H1N1) virus, the FluMist influenza vaccine, and the Newcastle disease virus were used as models. The neuraminidase models were aerosolized in aerosol chambers and sampled with 3 different air samplers (SKC BioSampler, 3-piece cassettes with polycarbonate filters, and Coriolis μ) to assess the effect on neuraminidase enzyme activity. Our results demonstrated that Influenza virus and Newcastle disease virus neuraminidase enzymes are resistant to aerosolization and sampling with all air samplers tested. Moreover, we demonstrated that the enzymatic neuraminidase assay is as sensitive as RT-qPCR for detecting low concentrations of Influenza virus and Newcastle disease virus. Therefore, given the sensitivity of the assay and its compatibility with air sampling methods, viruses carrying the neuraminidase enzyme can be rapidly detected from air samples using neuraminidase activity assay without having to preprocess the samples.
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Affiliation(s)
- Nathalie Turgeon
- a Centre de recherche, Institut universitaire de cardiologie et de pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC G1V 4G5, Canada.,b Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
| | - Marie-Josée Toulouse
- a Centre de recherche, Institut universitaire de cardiologie et de pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC G1V 4G5, Canada.,b Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
| | - Jim Ho
- b Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
| | - Dongqing Li
- c Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Caroline Duchaine
- a Centre de recherche, Institut universitaire de cardiologie et de pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC G1V 4G5, Canada.,b Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
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69
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Duchaine C. Assessing microbial decontamination of indoor air with particular focus on human pathogenic viruses. Am J Infect Control 2016; 44:S121-6. [PMID: 27590696 PMCID: PMC7115274 DOI: 10.1016/j.ajic.2016.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 06/03/2016] [Indexed: 11/21/2022]
Abstract
Transmission of bacterial, fungal, and viral pathogens is of primary importance in public and occupational health and infection control. Although several standardized protocols have been proposed to target microbes on fomites through surface decontamination, use of microbicidal agents, and cleaning processes, only limited guidance is available on microbial decontamination of indoor air to reduce the risk of pathogen transmission between individuals. This article reviews the salient aspects of airborne transmission of infectious agents, exposure assessment, in vitro assessment of microbicidal agents, and processes for air decontamination for infection prevention and control. Laboratory-scale testing (eg, rotating chambers, wind tunnels) and promising field-scale methodologies to decontaminate indoor air are also presented. The potential of bacteriophages as potential surrogates for the study of airborne human pathogenic viruses is also discussed.
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Affiliation(s)
- Caroline Duchaine
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec City, QC, Canada.
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Abstract
ABSTRACT
Gastrointestinal infections in the immunocompromised host are caused by the common bacterial, viral, fungal, and parasitic agents that also cause infections in the immunocompetent host. Of special consideration is that immunocompromised patients may be at increased risk for infection or disease severity and by pathogens not seen in the competent host. This chapter reviews the various agents, risk factors, and diagnostic approaches to detect gastrointestinal infections in this patient population.
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Abstract
Among the wide variety of viral agents liable to be found as food contaminants, noroviruses and hepatitis A virus are responsible for most well characterized foodborne virus outbreaks. Additionally, hepatitis E virus has emerged as a potential zoonotic threat. Molecular methods, including an ISO standard, are available for norovirus and hepatitis A virus detection in foodstuffs, although the significance of genome copy detection with regard to the associated health risk is yet to be determined through viability assays. More precise and rapid methods for early foodborne outbreak investigation are being developed and they will need to be validated versus the ISO standard. In addition, protocols for next-generation sequencing characterization of outbreak-related samples must be developed, harmonized and validated as well.
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Affiliation(s)
- Albert Bosch
- Enteric Virus Group, Department of Microbiology, University of Barcelona, Avda Diagonal 643, 08028 Barcelona, Spain
- Nutrition and Food Safety Research Institute (INSA-UB), University of Barcelona, Avda Prat de la Riba 171, 08921 Santa Coloma de Gramanet, Spain
| | - Rosa M Pintó
- Enteric Virus Group, Department of Microbiology, University of Barcelona, Avda Diagonal 643, 08028 Barcelona, Spain
- Nutrition and Food Safety Research Institute (INSA-UB), University of Barcelona, Avda Prat de la Riba 171, 08921 Santa Coloma de Gramanet, Spain
| | - Susana Guix
- Enteric Virus Group, Department of Microbiology, University of Barcelona, Avda Diagonal 643, 08028 Barcelona, Spain
- Nutrition and Food Safety Research Institute (INSA-UB), University of Barcelona, Avda Prat de la Riba 171, 08921 Santa Coloma de Gramanet, Spain
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Rönnqvist M, Maunula L. Noroviruses on surfaces: detection, persistence, disinfection and role in environmental transmission. Future Virol 2016. [DOI: 10.2217/fvl-2015-0008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human noroviruses (HuNoVs), the most common cause of infectious nonbacterial gastroenteritis and the cause of numerous foodborne and hospital outbreaks, are easily transmitted from person-to-person. HuNoVs may persist on surfaces for long periods of time and may be transferred via hands, foods, fomites and air. In this review, studies on methods for detecting HuNoVs on environmental surfaces, such as swabbing, are presented. The review also focuses on recent studies on the efficiency of disinfectants for inactivating HuNoV or its surrogates, such as murine norovirus, on environmental surfaces and hands. Although HuNoV is probably more resistant than MuNoV, this study data adds to the understanding of HuNoV transmission routes and selection of tools for the prevention of HuNoV gastroenteritis outbreaks.
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Affiliation(s)
- Maria Rönnqvist
- Department of Food Hygiene & Environmental Health, Faculty of Veterinary Medicine, P.O. Box 66, 00014, University of Helsinki, Finland
- Finnish Food Safety Authority Evira, Mustialankatu 3, FI-00790 Helsinki, Finland
| | - Leena Maunula
- Department of Food Hygiene & Environmental Health, Faculty of Veterinary Medicine, P.O. Box 66, 00014, University of Helsinki, Finland
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Korte S, Pettke A, Kossow A, Mellmann A, Willems S, Kipp F. Norovirus outbreak management: how much cohorting is necessary? J Hosp Infect 2016; 92:259-62. [DOI: 10.1016/j.jhin.2015.10.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/22/2015] [Indexed: 11/29/2022]
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Tung-Thompson G, Libera DA, Koch KL, de los Reyes FL, Jaykus LA. Aerosolization of a Human Norovirus Surrogate, Bacteriophage MS2, during Simulated Vomiting. PLoS One 2015; 10:e0134277. [PMID: 26287612 PMCID: PMC4545942 DOI: 10.1371/journal.pone.0134277] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/21/2015] [Indexed: 12/28/2022] Open
Abstract
Human noroviruses (NoV) are the leading cause of acute gastroenteritis worldwide. Epidemiological studies of outbreaks have suggested that vomiting facilitates transmission of human NoV, but there have been no laboratory-based studies characterizing the degree of NoV release during a vomiting event. The purpose of this work was to demonstrate that virus aerosolization occurs in a simulated vomiting event, and to estimate the amount of virus that is released in those aerosols. A simulated vomiting device was constructed at one-quarter scale of the human body following similitude principles. Simulated vomitus matrices at low (6.24 mPa*s) and high (177.5 mPa*s) viscosities were inoculated with low (108 PFU/mL) and high (1010 PFU/mL) concentrations of bacteriophage MS2 and placed in the artificial "stomach" of the device, which was then subjected to scaled physiologically relevant pressures associated with vomiting. Bio aerosols were captured using an SKC Biosampler. In low viscosity artificial vomitus, there were notable differences between recovered aerosolized MS2 as a function of pressure (i.e., greater aerosolization with increased pressure), although this was not always statistically significant. This relationship disappeared when using high viscosity simulated vomitus. The amount of MS2 aerosolized as a percent of total virus "vomited" ranged from 7.2 x 10-5 to 2.67 x 10-2 (which corresponded to a range of 36 to 13,350 PFU total). To our knowledge, this is the first study to document and measure aerosolization of a NoV surrogate in a similitude-based physical model. This has implications for better understanding the transmission dynamics of human NoV and for risk modeling purposes, both of which can help in designing effective infection control measures.
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Affiliation(s)
- Grace Tung-Thompson
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Dominic A. Libera
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Kenneth L. Koch
- Section on Gastroenterology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, United States of America
| | - Francis L. de los Reyes
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Lee-Ann Jaykus
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
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Alonso C, Raynor PC, Davies PR, Torremorell M. Concentration, Size Distribution, and Infectivity of Airborne Particles Carrying Swine Viruses. PLoS One 2015; 10:e0135675. [PMID: 26287616 PMCID: PMC4545937 DOI: 10.1371/journal.pone.0135675] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 07/26/2015] [Indexed: 01/12/2023] Open
Abstract
When pathogens become airborne, they travel associated with particles of different size and composition. Particle size determines the distance across which pathogens can be transported, as well as the site of deposition and the survivability of the pathogen. Despite the importance of this information, the size distribution of particles bearing viruses emitted by infectious animals remains unknown. In this study we characterized the concentration and size distribution of inhalable particles that transport influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSV), and porcine epidemic diarrhea virus (PEDV) generated by acutely infected pigs and assessed virus viability for each particle size range. Aerosols from experimentally infected pigs were sampled for 24 days using an Andersen cascade impactor able to separate particles by size (ranging from 0.4 to 10 micrometer (μm) in diameter). Air samples collected for the first 9, 20 and the last 3 days of the study were analyzed for IAV, PRRSV and PEDV, respectively, using quantitative reverse transcription polymerase chain reaction (RT-PCR) and quantified as geometric mean copies/m3 within each size range. IAV was detected in all particle size ranges in quantities ranging from 5.5x102 (in particles ranging from 1.1 to 2.1μm) to 4.3x105 RNA copies/m3 in the largest particles (9.0–10.0μm). PRRSV was detected in all size ranges except particles between 0.7 and 2.1μm in quantities ranging from 6x102 (0.4–0.7μm) to 5.1x104 RNA copies/m3 (9.0–10.0μm). PEDV, an enteric virus, was detected in all particle sizes and in higher quantities than IAV and PRRSV (p < 0.0001) ranging from 1.3x106 (0.4–0.7μm) to 3.5x108 RNA copies/m3 (9.0–10.0μm). Infectious status was demonstrated for the 3 viruses, and in the case of IAV and PRRSV, viruses were isolated from particles larger than 2.1μm. In summary, our results indicated that airborne PEDV, IAV and PRRSV can be found in a wide range of particle sizes. However, virus viability is particle size dependent.
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Affiliation(s)
- Carmen Alonso
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, Minnesota, United States of America
| | - Peter C. Raynor
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota-Twin Cities, Saint Paul, Minnesota, United States of America
| | - Peter R. Davies
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, Minnesota, United States of America
| | - Montserrat Torremorell
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota-Twin Cities, Saint Paul, Minnesota, United States of America
- * E-mail:
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