The Experts below are selected from a list of 744 Experts worldwide ranked by ideXlab platform
Charles P Gerba - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a disinfectant wipe intervention on Fomite to finger microbial transfer
Applied and Environmental Microbiology, 2014Co-Authors: Gerardo U Lopez, Charles P Gerba, Masaaki Kitajima, Aaron P Havas, Kelly A ReynoldsAbstract:Inanimate surfaces, or Fomites, can serve as routes of transmission of enteric and respiratory pathogens. No previous studies have evaluated the impact of surface disinfection on the level of pathogen transfer from Fomites to fingers. Thus, the present study investigated the change in microbial transfer from contaminated Fomites to fingers following disinfecting wipe use. Escherichia coli (10(8) to 10(9) CFU/ml), Staphylococcus aureus (10(9) CFU/ml), Bacillus thuringiensis spores (10(7) to 10(8) CFU/ml), and poliovirus 1 (10(8) PFU/ml) were seeded on ceramic tile, laminate, and granite in 10-μl drops and allowed to dry for 30 min at a relative humidity of 15 to 32%. The seeded Fomites were treated with a disinfectant wipe and allowed to dry for an additional 10 min. Fomite-to-finger transfer trials were conducted to measure concentrations of transferred microorganisms on the fingers after the disinfectant wipe intervention. The mean log10 reduction of the test microorganisms on Fomites by the disinfectant wipe treatment varied from 1.9 to 5.0, depending on the microorganism and the Fomite. Microbial transfer from disinfectant-wipe-treated Fomites was lower (up to <0.1% on average) than from nontreated surfaces (up to 36.3% on average, reported in our previous study) for all types of microorganisms and Fomites. This is the first study quantifying microbial transfer from contaminated Fomites to fingers after the use of disinfectant wipe intervention. The data generated in the present study can be used in quantitative microbial risk assessment models to predict the effect of disinfectant wipes in reducing microbial exposure.
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transfer efficiency of bacteria and viruses from porous and nonporous Fomites to fingers under different relative humidity conditions
Applied and Environmental Microbiology, 2013Co-Authors: Gerardo U Lopez, Charles P Gerba, Akrum H Tamimi, Masaaki Kitajima, Sheri L Maxwell, Joan B RoseAbstract:Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on Fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (Fomites). Nine Fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on Fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm2 of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with Fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from Fomite-transmitted human pathogens and the relative levels of exposure to different types of Fomites and microorganisms.
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land application of manure and class b biosolids an occupational and public quantitative microbial risk assessment
Journal of Environmental Quality, 2012Co-Authors: John P Brooks, Charles P Gerba, M R Mclaughlin, Ian L PepperAbstract:Land application is a practical use of municipal Class B biosolids and manure that also promotes soil fertility and productivity. To date, no study exists comparing biosolids to manure microbial risks. This study used quantitative microbial risk assessment to estimate pathogen risks from occupational and public exposures during scenarios involving Fomite, soil, crop, and aerosol exposures. Greatest one-time risks were from direct consumption of contaminated soil or exposure to Fomites, with one-time risks greater than 10. Recent contamination and high exposures doses increased most risks. and enteric viruses provided the greatest single risks for most scenarios, particularly in the short term. All pathogen risks were decreased with time, 1 d to14 mo between land application and exposure; decreases in risk were typically over six orders of magnitude beyond 30 d. Nearly all risks were reduced to below 10 when using a 4-mo harvest delay for crop consumption. Occupational, more direct risks were greater than indirect public risks, which often occur after time and dilution have reduced pathogen loads to tolerable levels. Comparison of risks by pathogen group confirmed greater bacterial risks from manure, whereas viral risks were exclusive to biosolids. A direct comparison of the two residual types showed that biosolids use had greater risk because of the high infectivity of viruses, whereas the presence of environmentally recalcitrant pathogens such as and maintained manure risk. Direct comparisons of shared pathogens resulted in greater manure risks. Overall, it appears that in the short term, risks were high for both types of residuals, but given treatment, attenuation, and dilution, risks can be reduced to near-insignificant levels. That being said, limited data sets, dose exposures, site-specific inactivation rates, pathogen spikes, environmental change, regrowth, and wildlife will increase risk and uncertainty and remain areas poorly understood.
Joan B Rose - One of the best experts on this subject based on the ideXlab platform.
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effect of surface sampling and recovery of viruses and non spore forming bacteria on a quantitative microbial risk assessment model for Fomites
Environmental Science & Technology, 2016Co-Authors: Mark H Weir, Tomoyuki Shibata, Yoshifumi Masago, Dena L Cologgi, Joan B RoseAbstract:Quantitative microbial risk assessment (QMRA) is a powerful decision analytics tool, yet it faces challenges when modeling health risks for the indoor environment. One limitation is uncertainty in Fomite recovery for evaluating the efficiency of decontamination. Addressing this data gap has become more important as a result of response and recovery from a potential malicious pathogen release. To develop more accurate QMRA models, recovery efficiency from non-porous Fomites (aluminum, ceramic, glass, plastic, steel, and wood laminate) was investigated. Fomite material, surface area (10, 100, and 900 cm2), recovery tool (swabs and wipes), initial concentration on the Fomites and eluent (polysorbate 80, trypticase soy broth, and beef extract) were evaluated in this research. Recovery was shown to be optimized using polysorbate 80, sampling with wipes, and sampling a surface area of 10–100 cm2. The QMRA model demonstrated, through a relative risk comparison, the need for recovery efficiency to be used in thes...
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Effect of Surface Sampling and Recovery of Viruses and Non-Spore-Forming Bacteria on a Quantitative Microbial Risk Assessment Model for Fomites
2016Co-Authors: Mark H Weir, Tomoyuki Shibata, Yoshifumi Masago, Dena L Cologgi, Joan B RoseAbstract:Quantitative microbial risk assessment (QMRA) is a powerful decision analytics tool, yet it faces challenges when modeling health risks for the indoor environment. One limitation is uncertainty in Fomite recovery for evaluating the efficiency of decontamination. Addressing this data gap has become more important as a result of response and recovery from a potential malicious pathogen release. To develop more accurate QMRA models, recovery efficiency from non-porous Fomites (aluminum, ceramic, glass, plastic, steel, and wood laminate) was investigated. Fomite material, surface area (10, 100, and 900 cm2), recovery tool (swabs and wipes), initial concentration on the Fomites and eluent (polysorbate 80, trypticase soy broth, and beef extract) were evaluated in this research. Recovery was shown to be optimized using polysorbate 80, sampling with wipes, and sampling a surface area of 10–100 cm2. The QMRA model demonstrated, through a relative risk comparison, the need for recovery efficiency to be used in these models to prevent underestimated risks
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transfer efficiency of bacteria and viruses from porous and nonporous Fomites to fingers under different relative humidity conditions
Applied and Environmental Microbiology, 2013Co-Authors: Gerardo U Lopez, Charles P Gerba, Akrum H Tamimi, Masaaki Kitajima, Sheri L Maxwell, Joan B RoseAbstract:Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on Fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (Fomites). Nine Fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on Fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm2 of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with Fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from Fomite-transmitted human pathogens and the relative levels of exposure to different types of Fomites and microorganisms.
Gerardo U Lopez - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a disinfectant wipe intervention on Fomite to finger microbial transfer
Applied and Environmental Microbiology, 2014Co-Authors: Gerardo U Lopez, Charles P Gerba, Masaaki Kitajima, Aaron P Havas, Kelly A ReynoldsAbstract:Inanimate surfaces, or Fomites, can serve as routes of transmission of enteric and respiratory pathogens. No previous studies have evaluated the impact of surface disinfection on the level of pathogen transfer from Fomites to fingers. Thus, the present study investigated the change in microbial transfer from contaminated Fomites to fingers following disinfecting wipe use. Escherichia coli (10(8) to 10(9) CFU/ml), Staphylococcus aureus (10(9) CFU/ml), Bacillus thuringiensis spores (10(7) to 10(8) CFU/ml), and poliovirus 1 (10(8) PFU/ml) were seeded on ceramic tile, laminate, and granite in 10-μl drops and allowed to dry for 30 min at a relative humidity of 15 to 32%. The seeded Fomites were treated with a disinfectant wipe and allowed to dry for an additional 10 min. Fomite-to-finger transfer trials were conducted to measure concentrations of transferred microorganisms on the fingers after the disinfectant wipe intervention. The mean log10 reduction of the test microorganisms on Fomites by the disinfectant wipe treatment varied from 1.9 to 5.0, depending on the microorganism and the Fomite. Microbial transfer from disinfectant-wipe-treated Fomites was lower (up to <0.1% on average) than from nontreated surfaces (up to 36.3% on average, reported in our previous study) for all types of microorganisms and Fomites. This is the first study quantifying microbial transfer from contaminated Fomites to fingers after the use of disinfectant wipe intervention. The data generated in the present study can be used in quantitative microbial risk assessment models to predict the effect of disinfectant wipes in reducing microbial exposure.
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transfer efficiency of bacteria and viruses from porous and nonporous Fomites to fingers under different relative humidity conditions
Applied and Environmental Microbiology, 2013Co-Authors: Gerardo U Lopez, Charles P Gerba, Akrum H Tamimi, Masaaki Kitajima, Sheri L Maxwell, Joan B RoseAbstract:Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on Fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (Fomites). Nine Fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on Fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm2 of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with Fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from Fomite-transmitted human pathogens and the relative levels of exposure to different types of Fomites and microorganisms.
Montserrat Torremorell - One of the best experts on this subject based on the ideXlab platform.
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Stability of Porcine Epidemic Diarrhea Virus on Fomite Materials at Different Temperatures
Veterinary Sciences, 2018Co-Authors: Venkatramana D. Krishna, Montserrat Torremorell, Sagar M Goyal, Maxim C.-j. CheeranAbstract:Indirect transmission of porcine epidemic diarrhea virus (PEDV) ensues when susceptible animals contact PEDV-contaminated Fomite materials. Although the survival of PEDV under various pHs and temperatures has been studied, virus stability on different Fomite surfaces under varying temperature conditions has not been explored. Hence, we evaluated the survival of PEDV on inanimate objects routinely used on swine farms such as styrofoam, rubber, plastic, coveralls, and other equipment. The titer of infectious PEDV at 4 °C decreased by only 1 to 2 log during the first 5 days, and the virus was recoverable for up to 15 days on Styrofoam, aluminum, Tyvek® coverall, cloth, and plastic. However, viral titers decreased precipitously when stored at room temperature; no virus was detectable after one day on all materials tested. A more sensitive immunoplaque assay was able to detect virus from Styrofoam, metal, and plastic at 20 days post application, representing a 3-log loss of input virus on Fomite materials. Recovery of infectious PEDV from Tyvek® coverall and rubber was above detection limit at 20 days. Our findings indicate that the type of Fomite material and temperatures impact PEDV stability, which is important in understanding the nuances of indirect transmission and epidemiology of PEDV.
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Evaluation of biosecurity measures to prevent indirect transmission of porcine epidemic diarrhea virus
BMC Veterinary Research, 2017Co-Authors: My Yang, Sagar M Goyal, Maxim C.-j. Cheeran, Montserrat TorremorellAbstract:Background The effectiveness of biosecurity methods to mitigate the transmission of porcine epidemic diarrhea virus (PEDV) via farm personnel or contaminated Fomites is poorly understood. This study was undertaken to evaluate the effectiveness of biosecurity procedures directed at minimizing transmission via personnel following different biosecurity protocols using a controlled experimental setting. Results PEDV RNA was detected from rectal swabs of experimentally infected (INF) and sentinel pigs by real-time reverse transcription polymerase chain reaction (rRT-PCR). Virus shedding in INF pigs peaked at 1 day post infection (dpi) and viral RNA levels remained elevated through 19 dpi. Sentinel pigs in the low biosecurity group (LB) became PEDV positive after the first movement of study personnel from the INF group. However, rectal swabs from pigs in the medium biosecurity (MB) and high biosecurity (HB) groups were negative during the 10 consecutive days of movements and remained negative through 24 days post movement (dpm) when the first trial was terminated. Viral RNA was detected at 1 dpm through 3 dpm from the personal protective equipment (PPE) of LB personnel. In addition, at 1 dpm, 2 hair/face swabs from MB personnel were positive; however, transmission of virus was not detected. All swabs of Fomite from the HB study personnel were negative. Conclusions These results indicate that indirect PEDV transmission through contaminated PPE occurs rapidly (within 24 h) under modeled conditions. Biosecurity procedures such as changing PPE, washing exposed skin areas, or taking a shower are recommended for pig production systems and appear to be an effective option for lowering the risk of PEDV transmission between groups of pigs.
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indirect transmission of influenza a virus between pig populations under two different biosecurity settings
PLOS ONE, 2013Co-Authors: Matt Allerson, Carol J Cardona, Montserrat TorremorellAbstract:Respiratory disease due to influenza virus is common in both human and swine populations around the world with multiple transmission routes capable of transmitting influenza virus, including indirect routes. The objective of this study was to evaluate the role of Fomites in influenza A virus (IAV) transmission between pig populations separated by two different biosecurity settings. Thirty-five pigs were divided into four experimental groups: 10 pigs (1 replicate) were assigned to the infected group (I), 10 pigs (2 replicates of 5 pigs) were assigned to the low biosecurity sentinel group (LB), 10 pigs (2 replicates of 5 pigs) were assigned to the medium biosecurity sentinel group (MB), and 5 pigs (1 replicate) were assigned to the negative control group (NC). Eight of 10 pigs in the infected group were inoculated with IAV and 36 hours following inoculation, personnel movement events took place in order to move potentially infectious clothing and personal protective equipment (PPE) to sentinel pig rooms. Following contact with the infected group, personnel moved to the MB group after designated hygiene measures while personnel moved directly to the LB group. Nasal swabs and blood samples were collected from pigs to assess IAV infection status and Fomites were sampled and tested via RRT-PCR. All experimentally inoculated pigs were infected with IAV and 11 of the 144 Fomite samples collected following contact with infected pigs were low level positive for IAV genome. One replicate of each sentinel groups LB and MB became infected with IAV and all five pigs were infected over time. This study provides evidence that Fomites can serve as an IAV transmission route from infected to sentinel pigs and highlights the need to focus on indirect routes as well as direct routes of transmission for IAV.
Ian L Pepper - One of the best experts on this subject based on the ideXlab platform.
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land application of manure and class b biosolids an occupational and public quantitative microbial risk assessment
Journal of Environmental Quality, 2012Co-Authors: John P Brooks, Charles P Gerba, M R Mclaughlin, Ian L PepperAbstract:Land application is a practical use of municipal Class B biosolids and manure that also promotes soil fertility and productivity. To date, no study exists comparing biosolids to manure microbial risks. This study used quantitative microbial risk assessment to estimate pathogen risks from occupational and public exposures during scenarios involving Fomite, soil, crop, and aerosol exposures. Greatest one-time risks were from direct consumption of contaminated soil or exposure to Fomites, with one-time risks greater than 10. Recent contamination and high exposures doses increased most risks. and enteric viruses provided the greatest single risks for most scenarios, particularly in the short term. All pathogen risks were decreased with time, 1 d to14 mo between land application and exposure; decreases in risk were typically over six orders of magnitude beyond 30 d. Nearly all risks were reduced to below 10 when using a 4-mo harvest delay for crop consumption. Occupational, more direct risks were greater than indirect public risks, which often occur after time and dilution have reduced pathogen loads to tolerable levels. Comparison of risks by pathogen group confirmed greater bacterial risks from manure, whereas viral risks were exclusive to biosolids. A direct comparison of the two residual types showed that biosolids use had greater risk because of the high infectivity of viruses, whereas the presence of environmentally recalcitrant pathogens such as and maintained manure risk. Direct comparisons of shared pathogens resulted in greater manure risks. Overall, it appears that in the short term, risks were high for both types of residuals, but given treatment, attenuation, and dilution, risks can be reduced to near-insignificant levels. That being said, limited data sets, dose exposures, site-specific inactivation rates, pathogen spikes, environmental change, regrowth, and wildlife will increase risk and uncertainty and remain areas poorly understood.