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Schaefer HR, Flannery BM, Crosby LM, Pouillot R, Farakos SMS, Van Doren JM, Dennis S, Fitzpatrick S, Middleton K. Reassessment of the cadmium toxicological reference value for use in human health assessments of foods. Regul Toxicol Pharmacol 2023; 144:105487. [PMID: 37640100 DOI: 10.1016/j.yrtph.2023.105487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/12/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023]
Abstract
The U.S. Food and Drug Administration (FDA) developed an oral toxicological reference value (TRV) for characterizing potential health concerns from dietary exposure to cadmium (Cd). The development of the TRV leveraged the FDA's previously published research including (1) a systematic review for adverse health effects associated with oral Cd exposure and (2) a human physiological based pharmacokinetic (PBPK) model adapted from Kjellstrom and Nordberg (1978) for use in reverse dosimetry applied to the U.S. population. Adverse effects of Cd on the bone and kidney are associated with similar points of departure (PODs) of approximately 0.50 μg Cd/g creatinine for females aged 50-60 based on available epidemiologic data. We also used the upper bound estimate of the renal cortical concentration (50 μg/g Cd) occurring in the U.S. population at 50 years of age as a POD. Based on the output from our reverse dosimetry PBPK Model, a range of 0.21-0.36 μg/kg bw/day was developed for the TRV. The animal data used for the animal TRV derivation (0.63-1.8 μg/kg bw/day) confirms biological plausibility for both the bone and kidney endpoints.
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Affiliation(s)
- Heather R Schaefer
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA.
| | - Brenna M Flannery
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | - Lynn M Crosby
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | | | | | - Jane M Van Doren
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | - Sherri Dennis
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | - Suzanne Fitzpatrick
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | - Karlyn Middleton
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, USA
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2
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Pang H, Pouillot R, Van Doren JM. Quantitative risk assessment-epidemic curve prediction model for leafy green outbreak investigation. Risk Anal 2023; 43:1713-1732. [PMID: 36513596 DOI: 10.1111/risa.14073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 10/13/2022] [Accepted: 10/20/2022] [Indexed: 06/17/2023]
Abstract
The objective of this study was to leverage quantitative risk assessment to investigate possible root cause(s) of foodborne illness outbreaks related to Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) infections in leafy greens in the United States. To this end, we developed the FDA leafy green quantitative risk assessment epidemic curve prediction model (FDA-LG QRA-EC) that simulated the lettuce supply chain. The model was used to predict the number of reported illnesses and the epidemic curve associated with lettuce contaminated with STEC O157 for a wide range of scenarios representing various contamination conditions and facility processing/sanitation practices. Model predictions were generated for fresh-cut and whole lettuce, quantifying the differing impacts of facility processing and home preparation on predicted illnesses. Our model revealed that the timespan (i.e., number of days with at least one reported illness) and the peak (i.e., day with the most predicted number of reported illnesses) of the epidemic curve of a STEC O157-lettuce outbreak were not strongly influenced by facility processing/sanitation practices and were indications of contamination pattern among incoming lettuce batches received by the facility or distribution center. Through comparisons with observed number of illnesses from recent STEC O157-lettuce outbreaks, the model identified contamination conditions on incoming lettuce heads that could result in an outbreak of similar size, which can be used to narrow down potential root cause hypotheses.
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Affiliation(s)
- Hao Pang
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Régis Pouillot
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Jane M Van Doren
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
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3
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Pouillot R, Santillana Farakos SM, Spungen J, Schaefer HR, Flannery BM, Van Doren JM. Corrigendum to "Cadmium physiologically based pharmacokinetic (PBPK) models for forward and reverse dosimetry: Review, evaluation, and adaptation to the U.S. population" [Toxicol. Lett. 367 (2022) 67-75]. Toxicol Lett 2023; 377:14-15. [PMID: 36764057 DOI: 10.1016/j.toxlet.2023.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Régis Pouillot
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Sofia M Santillana Farakos
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States.
| | - Judith Spungen
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Heather R Schaefer
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Brenna M Flannery
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Jane M Van Doren
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
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4
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Williams EN, Van Doren JM, Leonard CL, Datta AR. Prevalence of Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli, and Campylobacter spp. in raw milk in the United States between 2000 and 2019: A systematic review and meta-analysis. J Food Prot 2023; 86:100014. [PMID: 36916568 DOI: 10.1016/j.jfp.2022.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/22/2022] [Accepted: 11/13/2022] [Indexed: 01/13/2023]
Abstract
Raw (unpasteurized) milk is available for sale and direct human consumption within some states in the United States (US); it cannot be sold or distributed in interstate commerce. Raw milk may contain pathogenic microorganisms that, when consumed, may cause illness and sometimes may result in death. No comprehensive review for prevalence and levels of the major bacterial pathogens in raw milk in the US exists. The objective of the present research was to systematically review the scientific literature published from 2000 to 2019 to estimate the prevalence and levels of Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), and Campylobacter spp. in raw milk in the US. Peer-reviewed studies were retrieved systematically from PubMed®, Embase®, and Web of ScienceTM. The unique complete nonduplicate references were uploaded into the Health Assessment Work Collaborative (HAWC). Based on the selection criteria, twenty studies were included in the systematic review and meta-analysis. Comprehensive Meta-Analysis (CMA) was used for statistical analyses, specifically, random effects meta-analyses were used to synthesize raw bulk tank milk (BTM) and milk filters (MF) data. Data from studies using culture and non-culture-based detection methods were included. Forest plots generated in CMA (Biostat, Englewood, NJ) were used to visualize the results. The average prevalence (event rate) of L. monocytogenes, Salmonella spp., STEC, and Campylobacter spp. in raw BTM in the US was estimated at 4.3% (95% confidence intervals [CIs], 2.8-6.5%), 3.6% (95% CIs, 2.0-6.2%), 4.3% (95% CIs, 2.4-7.4%), and 6.0% (95% CIs, 3.2-10.9%), respectively. Estimated prevalence was generally larger in MF than in BTM. There was not enough data to perform a meta-analysis for the prevalence or levels of pathogens in raw milk from retail establishments or other milk categories.
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Affiliation(s)
- Elizabeth Noelia Williams
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740, USA.
| | - Jane M Van Doren
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740, USA
| | - Cynthia L Leonard
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740, USA
| | - Atin R Datta
- Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740, USA.
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5
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Mokhtari A, Pang H, Santillana Farakos S, McKenna C, Crowley C, Cranford V, Bowen A, Phillips S, Madad A, Obenhuber D, Van Doren JM. Leveraging risk assessment for foodborne outbreak investigations: The Quantitative Risk Assessment-Epidemic Curve Prediction Model. Risk Anal 2023; 43:324-338. [PMID: 35171502 DOI: 10.1111/risa.13896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Root cause analysis can be used in foodborne illness outbreak investigations to determine the underlying causes of an outbreak and to help identify actions that could be taken to prevent future outbreaks. We developed a new tool, the Quantitative Risk Assessment-Epidemic Curve Prediction Model (QRA-EC), to assist with these goals and applied it to a case study to investigate and illustrate the utility of leveraging quantitative risk assessment to provide unique insights for foodborne illness outbreak root cause analysis. We used a 2019 Salmonella outbreak linked to melons as a case study to demonstrate the utility of this model (Centers for Disease Control and Prevention [CDC], 2019). The model was used to evaluate the impact of various root cause hypotheses (representing different contamination sources and food safety system failures in the melon supply chain) on the predicted number and timeline of illnesses. The predicted number of illnesses varied by contamination source and was strongly impacted by the prevalence and level of Salmonella contamination on the surface/inside of whole melons and inside contamination niches on equipment surfaces. The timeline of illnesses was most strongly impacted by equipment sanitation efficacy for contamination niches. Evaluations of a wide range of scenarios representing various potential root causes enabled us to identify which hypotheses, were likely to result in an outbreak of similar size and illness timeline to the 2019 Salmonella melon outbreak. The QRA-EC framework can be adapted to accommodate any food-pathogen pairs to provide insights for foodborne outbreak investigations.
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Affiliation(s)
- Amir Mokhtari
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Hao Pang
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Sofia Santillana Farakos
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Crystal McKenna
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Cecilia Crowley
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Vanessa Cranford
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - April Bowen
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Sheena Phillips
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Asma Madad
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Donald Obenhuber
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
| | - Jane M Van Doren
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland, 20740, USA
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6
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Pouillot R, Santillana Farakos S, Van Doren JM. Modeling the risk of low bone mass and osteoporosis as a function of urinary cadmium in U.S adults aged 50-79 years. Environ Res 2022; 212:113315. [PMID: 35436451 DOI: 10.1016/j.envres.2022.113315] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/03/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
We developed an association model to estimate the risk of femoral neck low bone mass and osteoporosis from exposure to cadmium for women and men aged 50-79 in the U.S, as a function of the urinary cadmium (U-Cd) levels. We analyzed data from the NHANES 2005-2014 surveys and evaluated the relationship between U-Cd and femoral neck bone mineral density (BMD) using univariate and multivariate regression models with a combination of NHANES cycle, gender, age, smoking, race/ethnicity, height, body weight, body mass index, lean body mass, diabetes, kidney disease, physical activity, menopausal status, hormone replacement therapy, urinary lead, and prednisone intake as confounding variables. The regression coefficient between U-Cd and femoral neck BMD obtained with the best multivariate regression was used to develop an association model that can estimate the additional risk of low bone mass or osteoporosis in the population given a certain level of U-Cd. Results showed a linear relationship between U-Cd and BMD, conditional to body weight, where individuals with higher U-Cd had decreased BMD values. Our results do not support the hypothesis of a threshold for the effect of Cd on bone. Our model estimates that exposure to Cd results in an increase of 0.51 percentage points (CI95% 0.00, 0.92) of the population diagnosed with osteoporosis, compared to a theoretical absence of exposure. We estimate that 16% (CI95%: 0.00, 40%) of osteoporosis cases in the U.S. 50-79 aged population are a result of Cd exposure. This study presents the first continuous model estimating low bone mass and osteoporosis risk in the U.S. population given actual or potential changes in U-Cd levels. Our model will provide information to inform FDA's Closer to Zero initiative goal to reduce exposure to toxic elements.
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Affiliation(s)
- Régis Pouillot
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Sofia Santillana Farakos
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States.
| | - Jane M Van Doren
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
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7
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Pouillot R, Farakos SS, Spungen J, Schaefer HR, Flannery BM, Van Doren JM. Cadmium physiologically based pharmacokinetic (PBPK) models for forward and reverse dosimetry: Review, evaluation, and adaptation to the U.S. population. Toxicol Lett 2022; 367:67-75. [PMID: 35901988 DOI: 10.1016/j.toxlet.2022.07.812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/20/2022] [Accepted: 07/22/2022] [Indexed: 11/19/2022]
Abstract
The goal of this study was to assess a cadmium (Cd) physiologically based pharmacokinetic (PBPK) model to evaluate Cd toxicological reference values (e.g. reference dose, tolerable intake, minimum risk level) adapted to the U.S. population. We reviewed and evaluated previously published Cd PBPK models and developed further adaptations to the 1978 Kjellström and Nordberg (KN) model. Specifically, we propose adaptations with updated U.S.-specific bodyweight, kidney weight and creatinine excretion models by using NHANES data as well as a stochastic PBPK model that provides credible intervals of uncertainty around mean populational estimates. We provide our model review and adaptations as well as present estimates from the newly adapted models using observed U.S. urinary Cd values as a function of gender and age and given dietary exposure as evaluated from NHANES/WWEIA and U.S. Total Diet Study data. Results show all newly adapted models provide acceptable mean estimates of urinary Cd in the U.S. The stochastic model provides credible intervals to further inform regulatory decision making. Validation of the estimated K-Cd concentration values was not possible as data for a representative population was not available. We developed a web-based tool implementing these models and other potential adaptations to facilitate PBPK model estimate comparisons.
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Affiliation(s)
- Régis Pouillot
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Sofia Santillana Farakos
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States.
| | - Judith Spungen
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Heather R Schaefer
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Brenna M Flannery
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
| | - Jane M Van Doren
- Division of Risk and Decision Analysis, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States
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8
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Mokhtari A, Pang H, Santillana Farakos S, Davidson GR, Williams EN, Van Doren JM. Evaluation of Potential Impacts of Free Chlorine during Washing of Fresh-Cut Leafy Greens on Escherichia coli O157:H7 Cross-Contamination and Risk of Illness. Risk Anal 2022; 42:966-988. [PMID: 34528270 PMCID: PMC9544649 DOI: 10.1111/risa.13818] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/06/2021] [Accepted: 08/13/2021] [Indexed: 05/31/2023]
Abstract
Addition of chlorine-based antimicrobial substances to fresh-cut leafy green wash water is done to minimize microbial cross-contamination during processing. We developed the FDA Leafy Green Risk Assessment Model (FDA-LGRAM) to quantify the impact of free chlorine concentration in wash water during fresh-cut lettuce processing on the extent of water-mediated cross-contamination between shredded lettuce and the associated risk of illness due to exposure to Escherichia coli O157:H7. At different contamination prevalence and levels of E. coli O157:H7 on incoming lettuce heads, the model compared the predicted prevalence of contaminated fresh-cut lettuce packages and the risk of illness per serving between: (1) a scenario where fresh-cut lettuce was packaged without washing; and (2) scenarios involving washing fresh-cut lettuce with different levels of free chlorine (0 ppm, 5 ppm, 10 ppm, 15 ppm, and 20 ppm) prior to packaging. Our results indicate that the free chlorine level in wash water has a substantial impact on the predicted prevalence of contaminated fresh-cut lettuce packages and the risk of illness associated with E. coli O157:H7 in fresh-cut lettuce. Results showed that the required level of free chlorine that can minimize water-mediated cross-contamination and reduce the corresponding risk of illness depended on contamination prevalence and levels of E. coli O157:H7 on incoming lettuce heads. Our model also indicated that the pathogen inactivation rate in wash water via free chlorine was a key model parameter that had a significant impact on the extent of cross-contamination during washing and the predicted associated risk of illness.
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Affiliation(s)
- Amir Mokhtari
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
| | - Hao Pang
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
| | - Sofia Santillana Farakos
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
| | - Gordon R. Davidson
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
| | - Elizabeth Noelia Williams
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
| | - Jane M. Van Doren
- Food and Drug AdministrationCenter for Food Safety and Applied Nutrition5001 Campus DriveCollege ParkMaryland20740USA
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Pouillot R, Smith M, Van Doren JM, Catford A, Holtzman J, Calci KR, Edwards R, Goblick G, Roberts C, Stobo J, White J, Woods J, DePaola A, Buenaventura E, Burkhardt W. Risk Assessment of Norovirus Illness from Consumption of Raw Oysters in the United States and in Canada. Risk Anal 2022; 42:344-369. [PMID: 34121216 PMCID: PMC9291475 DOI: 10.1111/risa.13755] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 05/30/2023]
Abstract
Human norovirus (NoV) is the leading cause of foodborne illness in the United States and Canada. Bivalve molluscan shellfish is one commodity commonly identified as being a vector of NoV. Bivalve molluscan shellfish are grown in waters that may be affected by contamination events, tend to bioaccumulate viruses, and are frequently eaten raw. In an effort to better assess the elements that contribute to potential risk of NoV infection and illness from consumption of bivalve molluscan shellfish, the U.S. Department of Health and Human Services/Food and Drug Administration (FDA), Health Canada (HC), the Canadian Food Inspection Agency (CFIA), and Environment and Climate Change Canada (ECCC) collaborated to conduct a quantitative risk assessment for NoV in bivalve molluscan shellfish, notably oysters. This study describes the model and scenarios developed and results obtained to assess the risk of NoV infection and illness from consumption of raw oysters harvested from a quasi-steady-state situation. Among the many factors that influence the risk of NoV illness for raw oyster consumers, the concentrations of NoV in the influent (raw, untreated) and effluent (treated) of wastewater treatment plants (WWTP) were identified to be the most important. Thus, mitigation and control strategies that limit the influence from human waste (WWTP outfalls) in oyster growing areas have a major influence on the risk of illness from consumption of those oysters.
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Affiliation(s)
- Régis Pouillot
- U.S. Food and Drug Administration5001 Campus DriveCollege ParkMD20740USA
| | - Mark Smith
- Health Canada251 Sir Frederick Banting Driveway Tunney's Pasture, Mail Stop 2204EOttawaONK1A 0K9Canada
| | - Jane M. Van Doren
- U.S. Food and Drug Administration5001 Campus DriveCollege ParkMD20740USA
| | - Angela Catford
- Health Canada251 Sir Frederick Banting Driveway Tunney's Pasture, Mail Stop 2204EOttawaONK1A 0K9Canada
| | - Jennifer Holtzman
- Health Canada251 Sir Frederick Banting Driveway Tunney's Pasture, Mail Stop 2204EOttawaONK1A 0K9Canada
| | - Kevin R. Calci
- U.S. Food and Drug AdministrationGulf Coast Seafood LaboratoryDauphin IslandAL36528USA
| | - Robyn Edwards
- Canadian Food Inspection Agency1400 Merivale RoadOttawaONK1A 0Y9Canada
| | - Gregory Goblick
- U.S. Food and Drug AdministrationGulf Coast Seafood LaboratoryDauphin IslandAL36528USA
| | - Christopher Roberts
- Environment and Climate Change Canada45 Alderney Dr, 7th FloorDartmouthNSB2Y 2N6Canada
| | - Jeffrey Stobo
- Environment and Climate Change Canada45 Alderney Dr, 7th FloorDartmouthNSB2Y 2N6Canada
| | - John White
- Canadian Food Inspection Agency57 Central St., Suite 204SummersidePEC1N 3K9Canada
| | - Jacquelina Woods
- U.S. Food and Drug AdministrationGulf Coast Seafood LaboratoryDauphin IslandAL36528USA
| | - Angelo DePaola
- U.S. Food and Drug AdministrationGulf Coast Seafood LaboratoryDauphin IslandAL36528USA
| | - Enrico Buenaventura
- Health Canada251 Sir Frederick Banting Driveway Tunney's Pasture, Mail Stop 2204EOttawaONK1A 0K9Canada
| | - William Burkhardt
- U.S. Food and Drug AdministrationGulf Coast Seafood LaboratoryDauphin IslandAL36528USA
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Santillana Farakos SM, Pouillot R, Spungen J, Flannery B, Van Doren JM, Dennis S. Implementing a risk-risk analysis framework to evaluate the impact of food intake shifts on risk of illness: a case study with infant cereal. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2021; 38:718-730. [PMID: 33735599 DOI: 10.1080/19440049.2021.1885752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In food safety, process pathway risk assessments usually estimate the risk of illness from a single hazard and a single food and can inform food safety decisions and consumer advice. To evaluate the health impact of a potential change in diet, we need to understand not only the risk posed by the considered hazard and food but also the risk posed by the substitution food and other potential hazards. We developed a framework to provide decision-makers with a multi-faceted evaluation of the impact of dietary shifts on risk of illness. Our case study explored exposure to inorganic arsenic (iAs) and aflatoxins through consumption of infant cereals and the risk of developing lung, bladder and liver cancer over a lifetime. The estimated additional Disability-Adjusted Life Year (DALY) in the U.S. from exposure to iAs and aflatoxin based on available contamination and consumption patterns of infant rice and oat cereal is 4,921 (CI 90% 414; 9,071). If all infant cereal consumers shift intake (maintaining equivalent serving size and frequency) to only consuming infant rice cereal, the predicted DALY increases to 6,942 (CI 90% 326; 12,931). If all infant cereal consumers shift intake to only consuming infant oat cereal, the predicted DALY decreases to 1,513 (CI 90% 312; 3,356). Changes in contaminant concentrations or percent consumers, that could occur in the future, also significantly impact the predicted risk. Uncertainty in these risk predictions is primarily driven by the dose-response models. A risk-risk analysis framework provides decision-makers with a nuanced understanding of the public health impact of dietary changes and can be applied to other food safety and nutrition questions.
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Affiliation(s)
- Sofia M Santillana Farakos
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | | | - Judith Spungen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Brenna Flannery
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Jane M Van Doren
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Sherri Dennis
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
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Pang H, Mokhtari A, Chen Y, Oryang D, Ingram DT, Sharma M, Millner PD, Van Doren JM. A Predictive Model for Survival of Escherichia coli O157:H7 and Generic E. coli in Soil Amended with Untreated Animal Manure. Risk Anal 2020; 40:1367-1382. [PMID: 32378782 DOI: 10.1111/risa.13491] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/19/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
This study aimed at developing a predictive model that captures the influences of a variety of agricultural and environmental variables and is able to predict the concentrations of enteric bacteria in soil amended with untreated Biological Soil Amendments of Animal Origin (BSAAO) under dynamic conditions. We developed and validated a Random Forest model using data from a longitudinal field study conducted in mid-Atlantic United States investigating the survival of Escherichia coli O157:H7 and generic E. coli in soils amended with untreated dairy manure, horse manure, or poultry litter. Amendment type, days of rain since the previous sampling day, and soil moisture content were identified as the most influential agricultural and environmental variables impacting concentrations of viable E. coli O157:H7 and generic E. coli recovered from amended soils. Our model results also indicated that E. coli O157:H7 and generic E. coli declined at similar rates in amended soils under dynamic field conditions.The Random Forest model accurately predicted changes in viable E. coli concentrations over time under different agricultural and environmental conditions. Our model also accurately characterized the variability of E. coli concentration in amended soil over time by providing upper and lower prediction bound estimates. Cross-validation results indicated that our model can be potentially generalized to other geographic regions and incorporated into a risk assessment for evaluating the risks associated with application of untreated BSAAO. Our model can be validated for other regions and predictive performance also can be enhanced when data sets from additional geographic regions become available.
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Affiliation(s)
- Hao Pang
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Analytics and Outreach, College Park, MD, USA
- Joint Institute for Food Safety and Applied Nutrition, University of Maryland, College Park, MD, USA
| | - Amir Mokhtari
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Analytics and Outreach, College Park, MD, USA
- Booz Allen Hamilton, 4747 Bethesda Ave, Bethesda, MD, 20814, USA
| | - Yuhuan Chen
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Analytics and Outreach, College Park, MD, USA
| | - David Oryang
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Analytics and Outreach, College Park, MD, USA
| | - David T Ingram
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Food Safety, College Park, MD, USA
| | - Manan Sharma
- U.S. Department of Agriculture, Agricultural Research Service, Northeast Area, Beltsville Agricultural Research Center, Environmental Microbial and Food Safety Laboratory, Beltsville, MD, USA
| | - Patricia D Millner
- U.S. Department of Agriculture, Agricultural Research Service, Northeast Area, Beltsville Agricultural Research Center, Environmental Microbial and Food Safety Laboratory, Beltsville, MD, USA
| | - Jane M Van Doren
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Office of Analytics and Outreach, College Park, MD, USA
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12
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Chen Y, Chen Y, Pouillot R, Dennis S, Xian Z, Luchansky JB, Porto-Fett ACS, Lindsay JA, Hammack TS, Allard M, Van Doren JM, Brown EW. Genetic diversity and profiles of genes associated with virulence and stress resistance among isolates from the 2010-2013 interagency Listeria monocytogenes market basket survey. PLoS One 2020; 15:e0231393. [PMID: 32352974 PMCID: PMC7192433 DOI: 10.1371/journal.pone.0231393] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/23/2020] [Indexed: 12/15/2022] Open
Abstract
Whole genome sequencing (WGS) was performed on 201 Listeria monocytogenes isolates recovered from 102 of 27,389 refrigerated ready-to-eat (RTE) food samples purchased at retail in U.S. FoodNet sites as part of the 2010-2013 interagency L. monocytogenes Market Basket Survey (Lm MBS). Core genome multi-locus sequence typing (cgMLST) and in-silico analyses were conducted, and these data were analyzed with metadata for isolates from five food groups: produce, seafood, dairy, meat, and combination foods. Six of 201 isolates, from 3 samples, were subsequently confirmed as L. welshimeri. Three samples contained one isolate per sample; mmong the 96 samples that contained two isolates per sample, 3 samples each contained two different strains and 93 samples each contained duplicate isolates. After 93 duplicate isolates were removed, the remaining 102 isolates were delineated into 29 clonal complexes (CCs) or singletons based on their sequence type. The five most prevalent CCs were CC155, CC1, CC5, CC87, and CC321. The Shannon's diversity index for clones per food group ranged from 1.49 for dairy to 2.32 for produce isolates, which were not significantly different in pairwise comparisons. The most common molecular serogroup as determined by in-silico analysis was IIa (45.6%), followed by IIb (27.2%), IVb (20.4%), and IIc (4.9%). The proportions of isolates within lineages I, II, and III were 48.0%, 50.0% and 2.0%, respectively. Full-length inlA was present in 89.3% of isolates. Listeria pathogenicity island 3 (LIPI-3) and LIPI-4 were found in 51% and 30.6% of lineage I isolates, respectively. Stress survival islet 1 (SSI-1) was present in 34.7% of lineage I isolates, 80.4% of lineage II isolates and the 2 lineage III isolates; SSI-2 was present only in the CC121 isolate. Plasmids were found in 48% of isolates, including 24.5% of lineage I isolates and 72.5% of lineage II isolates. Among the plasmid-carrying isolates, 100% contained at least one cadmium resistance cassette and 89.8% contained bcrABC, involved in quaternary ammonium compound tolerance. Multiple clusters of isolates from different food samples were identified by cgMLST which, along with available metadata, could aid in the investigation of possible cross-contamination and persistence events.
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Affiliation(s)
- Yi Chen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Yuhuan Chen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Régis Pouillot
- Consultant, Buenos Aires, Argentina, United States of America
| | - Sherri Dennis
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Zhihan Xian
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - John B. Luchansky
- USDA Agricultural Research Service, Wyndmoor, Pennsylvania, United States of America
| | - Anna C. S. Porto-Fett
- USDA Agricultural Research Service, Wyndmoor, Pennsylvania, United States of America
| | - James A. Lindsay
- USDA Agricultural Research Service, Beltsville, Maryland, United States of America
| | - Thomas S. Hammack
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Marc Allard
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Jane M. Van Doren
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Eric W. Brown
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, United States of America
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13
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Abstract
We used an agent-based modeling (ABM) framework and developed a mathematical model to explain the complex dynamics of microbial persistence and spread within a food facility and to aid risk managers in identifying effective mitigation options. The model explicitly considered personal hygiene practices by food handlers as well as their activities and simulated a spatially explicit dynamic system representing complex interaction patterns among food handlers, facility environment, and foods. To demonstrate the utility of the model in a decision-making context, we created a hypothetical case study and used it to compare different risk mitigation strategies for reducing contamination and spread of Listeria monocytogenes in a food facility. Model results indicated that areas with no direct contact with foods (e.g., loading dock and restroom) can serve as contamination niches and recontaminate areas that have direct contact with food products. Furthermore, food handlers' behaviors, including, for example, hygiene and sanitation practices, can impact the persistence of microbial contamination in the facility environment and the spread of contamination to prepared foods. Using this case study, we also demonstrated benefits of an ABM framework for addressing food safety in a complex system in which emergent system-level responses are predicted using a bottom-up approach that observes individual agents (e.g., food handlers) and their behaviors. Our model can be applied to a wide variety of pathogens, food commodities, and activity patterns to evaluate efficacy of food-safety management practices and quantify contamination reductions associated with proposed mitigation strategies in food facilities.
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Affiliation(s)
- Amir Mokhtari
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Analytics and OutreachCollege ParkMDUSA
| | - Jane M. Van Doren
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Analytics and OutreachCollege ParkMDUSA
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14
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Pohl AM, Pouillot R, Bazaco MC, Wolpert BJ, Healy JM, Bruce BB, Laughlin ME, Hunter JC, Dunn JR, Hurd S, Rowlands JV, Saupe A, Vugia DJ, Van Doren JM. Differences Among Incidence Rates of Invasive Listeriosis in the U.S. FoodNet Population by Age, Sex, Race/Ethnicity, and Pregnancy Status, 2008-2016. Foodborne Pathog Dis 2019; 16:290-297. [PMID: 30735066 PMCID: PMC6482898 DOI: 10.1089/fpd.2018.2548] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a foodborne pathogen that disproportionally affects pregnant females, older adults, and immunocompromised individuals. Using U.S. Foodborne Diseases Active Surveillance Network (FoodNet) surveillance data, we examined listeriosis incidence rates and rate ratios (RRs) by age, sex, race/ethnicity, and pregnancy status across three periods from 2008 to 2016, as recent incidence trends in U.S. subgroups had not been evaluated. The invasive listeriosis annual incidence rate per 100,000 for 2008-2016 was 0.28 cases among the general population (excluding pregnant females), and 3.73 cases among pregnant females. For adults ≥70 years, the annual incidence rate per 100,000 was 1.33 cases. No significant change in estimated listeriosis incidence was found over the 2008-2016 period, except for a small, but significantly lower pregnancy-associated rate in 2011-2013 when compared with 2008-2010. Among the nonpregnancy-associated cases, RRs increased with age from 0.43 (95% confidence interval: 0.25-0.73) for 0- to 14-year olds to 44.9 (33.5-60.0) for ≥85-year olds, compared with 15- to 44-year olds. Males had an incidence of 1.28 (1.12-1.45) times that of females. Compared with non-Hispanic whites, the incidence was 1.57 (1.18-1.20) times higher among non-Hispanic Asians, 1.49 (1.22-1.83) among non-Hispanic blacks, and 1.73 (1.15-2.62) among Hispanics. Among females of childbearing age, non-Hispanic Asian females had 2.72 (1.51-4.89) and Hispanic females 3.13 (2.12-4.89) times higher incidence than non-Hispanic whites. We observed a higher percentage of deaths among older patient groups compared with 15- to 44-year olds. This study is the first characterizing higher RRs for listeriosis in the United States among non-Hispanic blacks and Asians compared with non-Hispanic whites. This information for public health risk managers may spur further research to understand if differences in listeriosis rates relate to differences in consumption patterns of foods with higher contamination levels, food handling practices, comorbidities, immunodeficiencies, health care access, or other factors.
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Affiliation(s)
- Aurelie M. Pohl
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland
| | - Régis Pouillot
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland
| | - Michael C. Bazaco
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland
| | - Beverly J. Wolpert
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland
| | - Jessica M. Healy
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Beau B. Bruce
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Mark E. Laughlin
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jennifer C. Hunter
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John R. Dunn
- Tennessee Department of Health, Nasvhille, Tennessee
| | - Sharon Hurd
- Connecticut Emerging Infections Program, Yale University School of Public Health, New Haven, Connecticut
| | | | - Amy Saupe
- Minnesota Department of Health, Saint Paul, Minnesota
| | - Duc J. Vugia
- California Department of Public Health, Sacramento, California
| | - Jane M. Van Doren
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland
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15
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Sanaa M, Pouillot R, Vega FG, Strain E, Van Doren JM. GenomeGraphR: A user-friendly open-source web application for foodborne pathogen whole genome sequencing data integration, analysis, and visualization. PLoS One 2019; 14:e0213039. [PMID: 30818354 PMCID: PMC6394949 DOI: 10.1371/journal.pone.0213039] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/13/2019] [Indexed: 11/18/2022] Open
Abstract
Food safety risk assessments and large-scale epidemiological investigations have the potential to provide better and new types of information when whole genome sequence (WGS) data are effectively integrated. Today, the NCBI Pathogen Detection database WGS collections have grown significantly through improvements in technology, coordination, and collaboration, such as the GenomeTrakr and PulseNet networks. However, high-quality genomic data is not often coupled with high-quality epidemiological or food chain metadata. We have created a set of tools for cleaning, curation, integration, analysis and visualization of microbial genome sequencing data. It has been tested using Salmonella enterica and Listeria monocytogenes data sets provided by NCBI Pathogen Detection (160,000 sequenced isolates in 2018). GenomeGraphR presents foodborne pathogen WGS data and associated curated metadata in a user-friendly interface that allows a user to query a variety of research questions such as, transmission sources and dynamics, global reach, and persistence of genotypes associated with contamination in the food supply and foodborne illness across time or space. The application is freely available (https://fda-riskmodels.foodrisk.org/genomegraphr/).
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Affiliation(s)
- Moez Sanaa
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, United States of America
| | - Régis Pouillot
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, United States of America
- * E-mail:
| | - Francisco Garcés Vega
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, United States of America
| | - Errol Strain
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, United States of America
| | - Jane M. Van Doren
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, United States of America
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16
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Chen Y, Pouillot R, Santillana Farakos SM, Duret S, Spungen J, Fu T, Shakir F, Homola PA, Dennis S, Van Doren JM. Risk Assessment of Salmonellosis from Consumption of Alfalfa Sprouts and Evaluation of the Public Health Impact of Sprout Seed Treatment and Spent Irrigation Water Testing. Risk Anal 2018; 38:1738-1757. [PMID: 29341180 PMCID: PMC6099441 DOI: 10.1111/risa.12964] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/13/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
We developed a risk assessment of human salmonellosis associated with consumption of alfalfa sprouts in the United States to evaluate the public health impact of applying treatments to seeds (0-5-log10 reduction in Salmonella) and testing spent irrigation water (SIW) during production. The risk model considered variability and uncertainty in Salmonella contamination in seeds, Salmonella growth and spread during sprout production, sprout consumption, and Salmonella dose response. Based on an estimated prevalence of 2.35% for 6.8 kg seed batches and without interventions, the model predicted 76,600 (95% confidence interval (CI) 15,400-248,000) cases/year. Risk reduction (by 5- to 7-fold) predicted from a 1-log10 seed treatment alone was comparable to SIW testing alone, and each additional 1-log10 seed treatment was predicted to provide a greater risk reduction than SIW testing. A 3-log10 or a 5-log10 seed treatment reduced the predicted cases/year to 139 (95% CI 33-448) or 1.4 (95% CI <1-4.5), respectively. Combined with SIW testing, a 3-log10 or 5-log10 seed treatment reduced the cases/year to 45 (95% CI 10-146) or <1 (95% CI <1-1.5), respectively. If the SIW coverage was less complete (i.e., less representative), a smaller risk reduction was predicted, e.g., a combined 3-log10 seed treatment and SIW testing with 20% coverage resulted in an estimated 92 (95% CI 22-298) cases/year. Analysis of alternative scenarios using different assumptions for key model inputs showed that the predicted relative risk reductions are robust. This risk assessment provides a comprehensive approach for evaluating the public health impact of various interventions in a sprout production system.
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Affiliation(s)
- Yuhuan Chen
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Régis Pouillot
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | | | - Steven Duret
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Judith Spungen
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Tong‐Jen Fu
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationBedford ParkILUSA
| | - Fazila Shakir
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Patricia A. Homola
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Sherri Dennis
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
| | - Jane M. Van Doren
- Center for Food Safety and Applied NutritionU.S. Food and Drug AdministrationCollege ParkMDUSA
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17
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Pouillot R, Klontz KC, Chen Y, Burall LS, Macarisin D, Doyle M, Bally KM, Strain E, Datta AR, Hammack TS, Van Doren JM. Infectious Dose of Listeria monocytogenes in Outbreak Linked to Ice Cream, United States, 2015. Emerg Infect Dis 2018; 22:2113-2119. [PMID: 27869595 PMCID: PMC5189132 DOI: 10.3201/eid2212.160165] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Listeriosis can occur in susceptible populations when products with low-level contamination are distributed widely. The relationship between the number of ingested Listeria monocytogenes cells in food and the likelihood of developing listeriosis is not well understood. Data from an outbreak of listeriosis linked to milkshakes made from ice cream produced in 1 factory showed that contaminated products were distributed widely to the public without any reported cases, except for 4 cases of severe illness in persons who were highly susceptible. The ingestion of high doses of L. monocytogenes by these patients infected through milkshakes was unlikely if possible additional contamination associated with the preparation of the milkshake is ruled out. This outbreak illustrated that the vast majority of the population did not become ill after ingesting a low level of L. monocytogenes but raises the question of listeriosis cases in highly susceptible persons after distribution of low-level contaminated products that did not support the growth of this pathogen.
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18
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Duret S, Pouillot R, Fanaselle W, Papafragkou E, Liggans G, Williams L, Van Doren JM. Quantitative Risk Assessment of Norovirus Transmission in Food Establishments: Evaluating the Impact of Intervention Strategies and Food Employee Behavior on the Risk Associated with Norovirus in Foods. Risk Anal 2017; 37:2080-2106. [PMID: 28247943 PMCID: PMC6032842 DOI: 10.1111/risa.12758] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/22/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
We developed a quantitative risk assessment model using a discrete event framework to quantify and study the risk associated with norovirus transmission to consumers through food contaminated by infected food employees in a retail food setting. This study focused on the impact of ill food workers experiencing symptoms of diarrhea and vomiting and potential control measures for the transmission of norovirus to foods. The model examined the behavior of food employees regarding exclusion from work while ill and after symptom resolution and preventive measures limiting food contamination during preparation. The mean numbers of infected customers estimated for 21 scenarios were compared to the estimate for a baseline scenario representing current practices. Results show that prevention strategies examined could not prevent norovirus transmission to food when a symptomatic employee was present in the food establishment. Compliance with exclusion from work of symptomatic food employees is thus critical, with an estimated range of 75-226% of the baseline mean for full to no compliance, respectively. Results also suggest that efficient handwashing, handwashing frequency associated with gloving compliance, and elimination of contact between hands, faucets, and door handles in restrooms reduced the mean number of infected customers to 58%, 62%, and 75% of the baseline, respectively. This study provides quantitative data to evaluate the relative efficacy of policy and practices at retail to reduce norovirus illnesses and provides new insights into the interactions and interplay of prevention strategies and compliance in reducing transmission of foodborne norovirus.
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Affiliation(s)
- Steven Duret
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Régis Pouillot
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Wendy Fanaselle
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Efstathia Papafragkou
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Girvin Liggans
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Laurie Williams
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
| | - Jane M. Van Doren
- U.S. Food and Drug AdministrationCenter for Food Safety and Applied NutritionCollege ParkMDUSA
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19
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Zhang G, Hu L, Pouillot R, Tatavarthy A, Doren JMV, Kleinmeier D, Ziobro GC, Melka D, Wang H, Brown EW, Strain E, Bunning VK, Musser SM, Hammack TS. Prevalence of Salmonella in 11 Spices Offered for Sale from Retail Establishments and in Imported Shipments Offered for Entry to the United States. J Food Prot 2017; 80:1791-1805. [PMID: 28981375 DOI: 10.4315/0362-028x.jfp-17-072] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/13/2017] [Indexed: 11/11/2022]
Abstract
The U.S. Food and Drug Administration conducted a survey to evaluate Salmonella prevalence and aerobic plate counts in packaged (dried) spices offered for sale at retail establishments in the United States. The study included 7,250 retail samples of 11 spice types that were collected during November 2013 to September 2014 and October 2014 to March 2015. No Salmonella-positive samples (based on analysis of 125 g) were found among retail samples of cumin seed (whole or ground), sesame seed (whole, not roasted or toasted, and not black), and white pepper (ground or cracked), for prevalence estimates of 0.00% with 95% Clopper and Pearson's confidence intervals of 0.00 to 0.67%, 0.00 to 0.70%, and 0.00 to 0.63%, respectively. Salmonella prevalence estimates (confidence intervals) for the other eight spice types were 0.19% (0.0048 to 1.1%) for basil leaf (whole, ground, crushed, or flakes), 0.24% (0.049 to 0.69%) for black pepper (whole, ground, or cracked), 0.56% (0.11 to 1.6%) for coriander seed (ground), 0.19% (0.0049 to 1.1%) for curry powder (ground mixture of spices), 0.49% (0.10 to 1.4%) for dehydrated garlic (powder, granules, or flakes), 0.15% (0.0038 to 0.83%) for oregano leaf (whole, ground, crushed, or flakes), 0.25% (0.03 to 0.88%) for paprika (ground or cracked), and 0.64% (0.17 to 1.6%) for red pepper (hot red pepper, e.g., chili, cayenne; ground, cracked, crushed, or flakes). Salmonella isolates were serotyped, and genomes were sequenced. Samples of these same 11 spice types were also examined from shipments of imported spices offered for entry to the United States from 1 October 2011 to 30 September 2015. Salmonella prevalence estimates (based on analysis of two 375-g composite samples) for shipments of imported spices were 1.7 to 18%. The Salmonella prevalence estimates for spices offered for sale at retail establishments for all of the spice types except dehydrated garlic and basil were significantly lower than estimates for shipments of imported spice offered for entry.
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Affiliation(s)
- Guodong Zhang
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Lijun Hu
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Régis Pouillot
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Aparna Tatavarthy
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Jane M Van Doren
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Daria Kleinmeier
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - George C Ziobro
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - David Melka
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Hua Wang
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Eric W Brown
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Errol Strain
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Vincent K Bunning
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Steven M Musser
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
| | - Thomas S Hammack
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.])
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20
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Abstract
Listeria monocytogenes is an important cause of foodborne illness hospitalization, fetal loss, and death in the United States. Listeriosis incidence rate varies significantly among population subgroups with pregnant women, older persons, and the Hispanic population having increased relative risks compared with the other subpopulations. Using estimated rates of listeriosis per subpopulation based on FoodNet data from 2004 to 2009, we evaluate the expected number of cases and incidence rates of listeriosis in the US population and the pregnant women subpopulation as the demographic composition changes over time with respect to ethnicity, pregnancy status, and age distribution. If the incidence rate per subpopulation is held constant, the overall US population listeriosis incidence rate would increase from 0.25 per 100,000 (95% confidence interval [CI]: 0.19-0.34) in 2010 to 0.28 (95% CI: 0.22-0.38) in 2020 and 0.32 (95% CI: 0.25-0.43) in 2030, because of the changes in the population structure. Similarly, the pregnancy-associated incidence rate is expected to increase from 4.0 per 100,000 pregnant women (95% CI: 2.5-6.5) in 2010 to 4.1 (95% CI: 2.6-6.7) in 2020 and 4.4 (95% CI: 2.7-7.2) in 2030 as the proportion of Hispanic pregnant women increases. We further estimate that a reduction of 12% in the exposure of the US population to L. monocytogenes would be needed to maintain a constant incidence rate from 2010 to 2020 (current trend), assuming infectivity (strain virulence distribution and individual susceptibility) is unchanged. To reduce the overall US population incidence rate by one-third (Healthy People 2020 goal) would require a reduction in exposure (or infectivity) to L. monocytogenes of 48% over the same time period. Reduction/elimination in exposure of pregnant and Hispanic subpopulations alone could not meet this target. This information may be useful in setting public health targets, developing risk management options, and in interpreting trends in the public health burden of foodborne listeriosis in the United States.
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Affiliation(s)
| | | | - Jane M. Van Doren
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland
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21
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Farakos SMS, Pouillot R, Johnson R, Spungen J, Son I, Anderson N, Davidson GR, Doren JMV. A Quantitative Assessment of the Risk of Human Salmonellosis Arising from the Consumption of Pecans in the United States. J Food Prot 2017; 80:1574-1591. [PMID: 28812908 DOI: 10.4315/0362-028x.jfp-16-511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A quantitative risk assessment was conducted to assess the risk of human salmonellosis acquired from consumption of pecans in the United States. The model considered the potential for Salmonella survival, growth, and recontamination of pecans from the sheller to the consumer, including steps such as immersion in water, drying, conditioning, cracking, partitioning, and storage. Five theoretical microbial reduction treatment levels (1 to 5 log CFU) were modeled. Data from the 2010 to 2013 surveys by the National Pecan Shellers Association were used for initial prevalence and contamination levels. The impacts of atypical situations in the pecan production system were also evaluated. Higher initial contamination levels, recontamination during processing, and a delay in drying postconditioning were the modeled atypical situations. The baseline model predicted a mean risk of salmonellosis in the United States from consumption of in-shell and shelled pecans processed by cold conditioning with no microbial reduction treatment and no further home cooking as 1 case per 775,193 servings (95% confidence interval [CI]: 1 case per 1,915,709 to 178,253 servings). This predicted risk per serving was estimated as a mean of 529 cases of salmonellosis per year (95% CI: 213 to 2,295 cases). Hot conditioning for shelled pecans and microbial reduction treatment of both shelled and in-shell pecans had a significant impact on the predicted mean risk of illness. Assuming 77% of the shelled pecans sold at retail (i.e., 80% of the retail supply) received hot conditioning, the mean estimated salmonellosis cases per year from consumption of in-shell and shelled pecans uncooked at home was 203 (95% CI: 81 to 882 cases) if no additional microbial reduction treatment were applied. The predicted risk of illness per serving was higher for all atypical situations modeled compared with the baseline model, and delay in drying had the greatest impact on risk.
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Affiliation(s)
- Sofia M Santillana Farakos
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Régis Pouillot
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Rhoma Johnson
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Judith Spungen
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Insook Son
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Nathan Anderson
- 2 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Bedford Park, Illinois 60501, USA
| | - Gordon R Davidson
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
| | - Jane M Van Doren
- 1 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740 (ORCID: http://orcid.org/0000-0002-6107-5212 [R.P.]); and
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22
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Farakos SMS, Pouillot R, Johnson R, Spungen J, Son I, Anderson N, Doren JMV. A Quantitative Assessment of the Risk of Human Salmonellosis Arising from the Consumption of Almonds in the United States: The Impact of Preventive Treatment Levels. J Food Prot 2017; 80:863-878. [PMID: 28414255 DOI: 10.4315/0362-028x.jfp-16-403] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/15/2016] [Indexed: 11/11/2022]
Abstract
The presence of Salmonella on almonds continues to result in product-related outbreaks and recalls in the United States. In this study, the impact of microbial reduction treatment levels (1 to 5 log CFU) on the risk of human salmonellosis from the consumption of almond kernels in the United States was evaluated. An exposure model, including major steps in almond processing, was used to estimate prevalence and levels of contamination of Salmonella on almonds at the point of consumption. A Salmonella dose-response model and consumption data for almonds in the United States were used to assess risk of illness per serving and per year, quantifying variability and uncertainty separately. A 3-log reduction treatment resulted in a predicted mean risk of illness of two cases per year for almonds consumed as a core product not cooked at home (95% confidence interval [CI], one to four cases), one case per year for almonds consumed as an ingredient not cooked at home (95% CI, one to two cases), and less than one case per year for almonds consumed as an ingredient cooked at home (95% CI, 7 × 10-7 to 3 × 10-6 cases). A minimum 4-log reduction treatment resulted in an estimated mean risk of illness below one case per year in the United States. This study also includes an assessment of the risk of human salmonellosis as a result of an exceptional situation, which results in higher risk estimates compared with the baseline model. The exceptional situations modeled posttreatment resulted in estimates of mean risk that were not significantly affected by treatment level. Sensitivity analysis results showed initial Salmonella contamination level to be the factor with the most impact on risk per serving estimates, given a certain treatment level. The risk assessment also includes a simulation of the events that occurred in 2001. Treatment levels with a minimum 4-log microbial reduction would have been sufficient to prevent the outbreak cases. The uncertainty range in the estimates indicates that additional information is needed to make more precise predictions of this specific outbreak event.
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Affiliation(s)
- Sofia M Santillana Farakos
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
| | - Régis Pouillot
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
| | - Rhoma Johnson
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
| | - Judith Spungen
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
| | - Insook Son
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
| | - Nathan Anderson
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Bedford Park, Illinois 60501, USA
| | - Jane M Van Doren
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740; and
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23
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Zhang G, Hu L, Melka D, Wang H, Laasri A, Brown EW, Strain E, Allard M, Bunning VK, Musser SM, Johnson R, Santillana Farakos S, Scott VN, Pouillot R, Doren JMV, Hammack TS. Prevalence of Salmonella in Cashews, Hazelnuts, Macadamia Nuts, Pecans, Pine Nuts, and Walnuts in the United States. J Food Prot 2017; 80:459-466. [PMID: 28207311 DOI: 10.4315/0362-028x.jfp-16-396] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nuts have been identified as a vector for salmonellosis. The objective of this project was to estimate the prevalence and contamination level of Salmonella in raw tree nuts (cashews, pecans, hazelnuts, macadamia nuts, pine nuts, and walnuts) at retail markets in the United States. A total of 3,656 samples of six types of tree nuts were collected from different types of retail stores and markets nationwide between October 2014 and October 2015. These samples were analyzed using a modified version of the Salmonella culture method from the U.S. Food and Drug Administration's Bacteriological Analytical Manual. Of the 3,656 samples collected and tested, 32 were culturally confirmed as containing Salmonella. These isolates represented 25 serotypes. Salmonella was not detected in pecans and in-shell hazelnuts. Salmonella prevalence estimates (and 95% confidence intervals) in cashews, shelled hazelnuts, pine nuts, walnuts, and macadamia nuts were 0.55% [0.15, 1.40], 0.35% [0.04, 1.20], 0.48% [0.10, 1.40], 1.20% [0.53, 2.40], and 4.20% [2.40, 6.90], respectively. The rates of Salmonella isolation from major or big chain supermarkets, small chain supermarkets, discount, variety, or drug stores, and online were 0.64% [0.38, 1.00], 1.60% [0.80, 2.90], 0.00% [0.00, 2.40], and 13.64% [2.90, 35.00], respectively (Cochran-Mantel-Haenszel test: P = 0.02). The rates of Salmonella isolation for conventional and organic nuts were not significantly different. Of the samples containing Salmonella, 60.7% had levels less than 0.003 most probable number (MPN)/g. The highest contamination level observed was 0.092 MPN/g. The prevalence and levels of Salmonella in these tree nut samples were comparable to those previously reported for similar foods.
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Affiliation(s)
- Guodong Zhang
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Lijun Hu
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - David Melka
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Hua Wang
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Anna Laasri
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Eric W Brown
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Errol Strain
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Marc Allard
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Vincent K Bunning
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Steven M Musser
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Rhoma Johnson
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Sofia Santillana Farakos
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Virginia N Scott
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Régis Pouillot
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Jane M Van Doren
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Thomas S Hammack
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, Maryland 20740, USA
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24
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Shappell NW, Shelver WL, Lupton SJ, Fanaselle W, Van Doren JM, Hakk H. Distribution of Animal Drugs among Curd, Whey, and Milk Protein Fractions in Spiked Skim Milk and Whey. J Agric Food Chem 2017; 65:938-949. [PMID: 28052193 DOI: 10.1021/acs.jafc.6b04258] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labeled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and thiabendazole were used to evaluate the distribution of animal drugs among rennet curd, whey, and protein fractions from skim cow milk. Our previous work reported the distribution of these same drugs between skim and fat fractions of milk. Drug distribution between curd and whey was significantly correlated (R2 = 0.70) to the drug's lipophilicity (log P), with improved correlation using log D (R2 = 0.95). Distribution of drugs was concentration independent over the range tested (20-2000 nM). With the exception of thiabendazole and ivermectin, more drug was associated with whey protein than casein on a nmol/g protein basis (oxytetracycline experiment not performed). These results provide insights into the distribution of animal drug residues, if present in cow milk, among milk fractions, with possible extrapolation to milk products.
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Affiliation(s)
- Nancy W Shappell
- USDA-ARS, Biosciences Research Laboratory , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Weilin L Shelver
- USDA-ARS, Biosciences Research Laboratory , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Sara J Lupton
- USDA-ARS, Biosciences Research Laboratory , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Wendy Fanaselle
- US-FDA, Center for Food Safety and Applied Nutrition , 5001 Campus Drive, College Park, Maryland 20740, United States
| | - Jane M Van Doren
- US-FDA, Center for Food Safety and Applied Nutrition , 5001 Campus Drive, College Park, Maryland 20740, United States
| | - Heldur Hakk
- USDA-ARS, Biosciences Research Laboratory , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
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25
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Chen Y, Pouillot R, S Burall L, Strain EA, Van Doren JM, De Jesus AJ, Laasri A, Wang H, Ali L, Tatavarthy A, Zhang G, Hu L, Day J, Sheth I, Kang J, Sahu S, Srinivasan D, Brown EW, Parish M, Zink DL, Datta AR, Hammack TS, Macarisin D. Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products. Int J Food Microbiol 2016; 241:15-22. [PMID: 27741432 DOI: 10.1016/j.ijfoodmicro.2016.09.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 07/11/2016] [Accepted: 09/24/2016] [Indexed: 11/25/2022]
Abstract
A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods.
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Affiliation(s)
- Yi Chen
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA.
| | - Régis Pouillot
- Office of Analytics and Outreach, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Laurel S Burall
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA
| | - Errol A Strain
- Office of Analytics and Outreach, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Jane M Van Doren
- Office of Analytics and Outreach, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Antonio J De Jesus
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Anna Laasri
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Hua Wang
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Laila Ali
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Aparna Tatavarthy
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Guodong Zhang
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Lijun Hu
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - James Day
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Ishani Sheth
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Jihun Kang
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA
| | - Surasri Sahu
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA
| | - Devayani Srinivasan
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA
| | - Eric W Brown
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Mickey Parish
- Office of the Center Director, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Donald L Zink
- Office of the Center Director, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Atin R Datta
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA
| | - Thomas S Hammack
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Dumitru Macarisin
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
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26
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Hakk H, Shappell NW, Lupton SJ, Shelver WL, Fanaselle W, Oryang D, Yeung CY, Hoelzer K, Ma Y, Gaalswyk D, Pouillot R, Van Doren JM. Distribution of Animal Drugs between Skim Milk and Milk Fat Fractions in Spiked Whole Milk: Understanding the Potential Impact on Commercial Milk Products. J Agric Food Chem 2016; 64:326-35. [PMID: 26652058 DOI: 10.1021/acs.jafc.5b04726] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Seven animal drugs [penicillin G (PENG), sulfadimethoxine (SDMX), oxytetracycline (OTET), erythromycin (ERY), ketoprofen (KETO), thiabendazole (THIA), and ivermectin (IVR)] were used to evaluate the drug distribution between milk fat and skim milk fractions of cow milk. More than 90% of the radioactivity was distributed into the skim milk fraction for ERY, KETO, OTET, PENG, and SDMX, approximately 80% for THIA, and 13% for IVR. The distribution of drug between milk fat and skim milk fractions was significantly correlated to the drug's lipophilicity (partition coefficient, log P, or distribution coefficient, log D, which includes ionization). Data were fit with linear mixed effects models; the best fit was obtained within this data set with log D versus observed drug distribution ratios. These candidate empirical models serve for assisting to predict the distribution and concentration of these drugs in a variety of milk and milk products.
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Affiliation(s)
- Heldur Hakk
- Biosciences Research Laboratory, U.S. Department of Agriculture Agricultural Research Services , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Nancy W Shappell
- Biosciences Research Laboratory, U.S. Department of Agriculture Agricultural Research Services , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Sara J Lupton
- Biosciences Research Laboratory, U.S. Department of Agriculture Agricultural Research Services , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Weilin L Shelver
- Biosciences Research Laboratory, U.S. Department of Agriculture Agricultural Research Services , 1605 Albrecht Boulevard, Fargo, North Dakota 58102-2765, United States
| | - Wendy Fanaselle
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - David Oryang
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Chi Yuen Yeung
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Karin Hoelzer
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Yinqing Ma
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Dennis Gaalswyk
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Régis Pouillot
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Jane M Van Doren
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
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27
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Van Doren JM, Blodgett RJ, Pouillot R, Westerman A, Kleinmeier D, Ziobro GC, Ma Y, Hammack TS, Gill V, Muckenfuss MF, Fabbri L. Prevalence, level and distribution of Salmonella in shipments of imported capsicum and sesame seed spice offered for entry to the United States: Observations and modeling results. Food Microbiol 2013; 36:149-60. [DOI: 10.1016/j.fm.2013.05.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 04/18/2013] [Accepted: 05/09/2013] [Indexed: 11/16/2022]
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Van Doren JM, Neil KP, Parish M, Gieraltowski L, Gould LH, Gombas KL. Foodborne illness outbreaks from microbial contaminants in spices, 1973–2010. Food Microbiol 2013; 36:456-64. [DOI: 10.1016/j.fm.2013.04.014] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Revised: 03/13/2013] [Accepted: 04/21/2013] [Indexed: 12/01/2022]
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Van Doren JM, Kleinmeier D, Hammack TS, Westerman A. Prevalence, serotype diversity, and antimicrobial resistance of Salmonella in imported shipments of spice offered for entry to the United States, FY2007–FY2009. Food Microbiol 2013; 34:239-51. [DOI: 10.1016/j.fm.2012.10.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 09/30/2012] [Accepted: 10/03/2012] [Indexed: 10/27/2022]
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30
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Miller TM, Friedman JF, Caples CM, Shuman NS, Van Doren JM, Bardaro MF, Nguyen P, Zweiben C, Campbell MJ, Viggiano AA. Electron attachment to sulfur oxyhalides: SOF2, SOCl2, SO2F2, SO2Cl2, and SO2FCl attachment rate coefficients, 300–900 K. J Chem Phys 2010; 132:214302. [DOI: 10.1063/1.3427527] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Van Doren JM, Condon LR, DeSouza-Goding A, Miller TM, Bopp JC, Viggiano AA. Electron affinity of trans-2-C4F8 from electron attachment-detachment kinetics. J Phys Chem A 2010; 114:1420-6. [PMID: 20020708 DOI: 10.1021/jp907154m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Electron attachment and detachment kinetics of 2-C(4)F(8) were studied over the temperature range 298-487 K with a flowing-afterglow Langmuir-probe apparatus. Only parent anions were formed in the attachment process throughout this temperature range. At the highest temperatures, thermal electron detachment of the parent anions is important. Analysis of the 2-C(4)F(8) gas showed an 82/18 mixture of trans/cis isomers. The kinetic data at the higher temperatures were used to determine the electron affinity EA(trans-2-C(4)F(8)) = 0.79 +/- 0.06 eV after making some reasonable assumptions. The same quantity was calculated using the G3(MP2) compound method, yielding 0.74 eV. The kinetic data were not sufficient to establish a reliable value for EA(cis-2-C(4)F(8)), but G3(MP2) calculations give a value 0.017 eV greater than that for trans-2-C(4)F(8). MP2 and density functional theory were used to study the structural properties of the neutral and anion isomers.
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Affiliation(s)
- Jane M Van Doren
- Department of Chemistry, College of the Holey Cross, Worcester, Massachusetts 01610-2395, USA.
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Van Doren JM, Miller TM, Viggiano AA. G3 and density functional theory investigations of the structures and energies of SFnCl (n=0–5) and their anions. J Chem Phys 2008; 128:094310. [DOI: 10.1063/1.2831770] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Van Doren JM, Miller TM, Viggiano AA, Španěl P, Smith D, Bopp JC, Troe J. Experimental and theoretical investigation of electron attachment to SF5Cl. J Chem Phys 2008; 128:094309. [DOI: 10.1063/1.2831767] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Van Doren JM, Hogan KB, Miller TM, Viggiano AA. Observation of dihalide elimination upon electron attachment to oxalyl chloride and oxalyl bromide, 300-550 K. J Chem Phys 2006; 124:184313. [PMID: 16709112 DOI: 10.1063/1.2196409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rate coefficients have been measured for electron attachment to oxalyl chloride [ClC(O)C(O)Cl] and oxalyl bromide [BrC(O)C(O)Br] in He gas at 133 Pa pressure over the temperature range of 300-550 K. With oxalyl chloride, the major ion product of attachment is Cl2(-) at all temperatures (66% at 300 K); its importance increases slightly as temperature increases. Two other product ions formed are Cl- (18% at 300 K) and the phosgene anion CCl2O- (16% at 300 K) and appear to arise from a common mechanism. With oxalyl bromide, the Br2(-) channel represents almost half of the ion product of attachment, independent of temperature. Br- accounts for the remainder. For oxalyl chloride, the attachment rate coefficient is small [(1.8 +/- 0.5) x 10(-8) cm3 s(-1) at 300 K], and increases with temperature. The attachment rate coefficient for oxalyl bromide [(1.3 +/- 0.4) x 10(-7) cm3 s(-1) at 300 K] is nearly collisional and increases only slightly with temperature. Stable parent anions C2Cl2O2(-) and C2Br2O2(-) and adduct anions Cl- (C2Cl2O2) and Br- (C2Br3O2) were observed but are not primary attachment products. G2 and G3 theories were applied to determine geometries of products and energetics of the electron attachment and ion-molecule reactions studied. Electron attachment to both oxalyl halide molecules leads to a shorter C-C bond and longer C-Cl bond in the anions formed. Trans and gauche conformers of the neutral and anionic oxalyl halide species have similar energies and are more stable than the cis conformer, which lies 100-200 meV higher in energy. For C2Cl2O2, C2Cl2O2(-), and C2Br2O2(-), the trans conformer is the most stable conformation. The calculations are ambiguous as to the oxalyl bromide geometry (trans or gauche), the result depending on the theoretical method and basis set. The cis conformers for C2Cl2O2 and C2Br2O2 are transition states. In contrast, the cis conformers of the anionic oxalyl halide molecules are stable, lying 131 meV above trans-C2Cl2O2(-) and 179 meV above trans-C2Br2O2(-). Chien et al. [J. Phys. Chem. A 103, 7918 (1999)] and Kim et al. [J. Chem. Phys. 122, 234313 (2005)] found that the potential energy surface for rotation about the C-C bond in C2Cl2O2 is "extremely flat." Our computational data indicate that the analogous torsional surfaces for C2Br2O2, C2Cl2O2(-), and C2Br2O2(-) are similarly flat. The electron affinity of oxalyl chloride, oxalyl bromide, and phosgene were calculated to be 1.91 eV (G3), and 2.00 eV (G2), and 1.17 eV (G3), respectively.
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Affiliation(s)
- Jane M Van Doren
- Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610-2395, USA.
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Van Doren JM, Friedman JF, Miller TM, Viggiano AA, Denifl S, Scheier P, Märk TD, Troe J. Electron attachment to POCl3: Measurement and theoretical analysis of rate constants and branching ratios as a function of gas pressure and temperature, electron temperature, and electron energy. J Chem Phys 2006; 124:124322. [PMID: 16599689 DOI: 10.1063/1.2176613] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Two experimental techniques, electron swarm and electron beam, have been applied to the problem of electron attachment to POCl3, with results indicating that there is a competition between dissociation of the resonant POCl3-* state and collisional stabilization of the parent anion. In the electron beam experiment at zero electron energy, the fragment ion POCl2- is the dominant ion product of attachment (96%), under single-collision conditions. Small amounts (approximately 2% each) of POCl3- and Cl- were observed. POCl3- and POCl2- ion products were observed only at zero electron energy, but higher-energy resonances were recorded for POCl-, Cl-, and Cl2- ion products. In the electron swarm experiment, which was carried out in 0.4-7 Torr of He buffer gas, the parent anion branching ratio increased significantly with pressure and decreased with temperature. The electron attachment rate constant at 297 K was measured to be (2.5+/-0.6)x10(-7) cm3 s(-1), with ion products POCl2- (71%) and POCl3- (29%) in 1 Torr of He gas. The rate constant decreased as the electron temperature was increased above 1500 K. Theory is developed for (a) the unimolecular dissociation of the nascent POCl3-* and (b) a stepladder collisional stabilization mechanism using the average energy transferred per collision as a parameter. These ideas were then used to model the experimental data. The modeling showed that D0 o(Cl-POCl2-) and EA(POCl3) must be the same within +/-0.03 eV.
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Affiliation(s)
- Jane M Van Doren
- Department of Chemistry, Holy Cross College, Worcester, Massachusetts 01610-2195, USA
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Van Doren JM, Kerr DM, Miller TM, Viggiano AA. Electron attachment and detachment, and the electron affinities of C5F5N and C5HF4N. J Chem Phys 2005; 123:114303. [PMID: 16392555 DOI: 10.1063/1.2032967] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rate constants have been measured for electron attachment to C5F5N (297-433 K) and to 2, 3, 5, 6-C5HF4N (303 K) using a flowing-afterglow Langmuir-probe apparatus (at a He gas pressure of 133 Pa). In both cases only the parent anion was formed in the attachment process. The attachment rate constants measured at room temperature are 1.8 +/- 0.5 X 10(-7) and 7 +/- 3 X 10(-10) cm(-3) s(-1), respectively. Rate constants were also measured for thermal electron detachment from the parent anions of these molecules. For C5F5N- detachment is negligible at room temperature, but increases to 2530 +/- 890 s(-1) at 433 K. For 2, 3, 5, 6-C5HF4N-, the detachment rate at 303 K was 520 +/- 180 s(-1). The attachment/detachment equilibrium yielded experimental electron affinities EA(C5F5N)=0.70 +/- 0.05 eV and EA(2, 3, 5, 6-C5HF4N)=0.40 +/- 0.08 eV. Electronic structure calculations were carried out for these molecules and related C5HxF5-xN using density-functional theory and the G3(MP2)//B3LYP compound method. The EAs are found to decrease by 0.25 eV, on average, with each F substitution by H. The calculated EAs are in good agreement with the present experimental results.
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Affiliation(s)
- Jane M Van Doren
- Department of Chemistry, College of the Holy Cross, Worcester, MA 01610-2395, USA.
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Miller TM, Viggiano AA, Friedman JF, Van Doren JM. Electron attachment and detachment: Electron affinities of isomers of trifluoromethylbenzonitrile. J Chem Phys 2004; 121:9993-8. [PMID: 15549874 DOI: 10.1063/1.1806418] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rate constants for electron attachment to the three isomers of trifluoromethylbenzonitrile [(CF(3))(CN)C(6)H(4), or TFMBN] were measured over the temperature range of 303-463 K in a 133-Pa He buffer gas, using a flowing-afterglow Langmuir-probe apparatus. At 303 K, the measured attachment rate constants are 9.0 x 10(-8) (o-TFMBN), 5.5 x 10(-8) (m-TFMBN), and 8.9 x 10(-8) cm(3) s(-1) (p-TFMBN), estimated accurate to +/-25%. The attachment process formed only the parent anion in all three cases. Thermal electron detachment was observed for all three anion isomers, and rate constants for this reverse process were also measured. From the attachment and detachment results, the electron affinities of the three isomers of TFMBN were determined to be 0.70(o-TFMBN), 0.67(m-TFMBN), and 0.83 eV (p-TFMBN), all +/-0.05 eV. G3(MP2) [Gaussian-3 calculations with reduced Møller-Plesset orders (MP2)] calculations were carried out for the neutrals and anions. Electron affinities derived from these calculations are in good agreement with the experimental values.
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Affiliation(s)
- Thomas M Miller
- Air Force Research Laboratory, Space Vehicles Directorate, Hanscom Air Force Base, Bedford, Massachusetts 01731-3010, USA.
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Van Doren JM, Miller TM, Williams S, Viggiano AA. Direct measurement of the thermal rate coefficient for electron attachment to ozone in the gas phase, 300-550 K: implications for the ionosphere. Phys Rev Lett 2003; 91:223201. [PMID: 14683234 DOI: 10.1103/physrevlett.91.223201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2003] [Indexed: 05/24/2023]
Abstract
Attachment of thermal electrons to O3 was studied in 133 Pa He between 300-550 K; the process is extremely inefficient. The rate coefficient increases sharply with temperature from 0.9 to 5 x 10(-11) cm(3) s(-1) (+/-30%) and comparison to kinetic energy measurements suggests internal energy can drive the reaction. These determinations account for competing processes of diffusion, recombination, and electron detachment reactions, and imply that no significant zero-energy resonance cross section exists, contradicting recent electron-beam results that call for substantial revision of ionospheric models.
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Affiliation(s)
- Jane M Van Doren
- Department of Chemistry, College of the Holy Cross, Worcester, MA 01610-2395, USA
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Van Doren JM, Barlow SE, DePuy CH, Bierbaum VM. Tandem flowing afterglow-selected ion flow tube and its application to the thermal energy reactions of 18O-. J Am Chem Soc 2002. [DOI: 10.1021/ja00248a057] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Van Doren JM, Viggiano AA, Morris RA. Rate Enhancement of the Reaction of HCl with ClONO2 by Ions: Implications for the Mechanisms of Stratospherically Important Heterogeneous Reactions. J Am Chem Soc 2002. [DOI: 10.1021/ja00094a069] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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DePuy CH, Van Doren JM, Gronert S, Kass SR, Motell EL, Ellison GB, Bierbaum VM. Gas-phase negative-ion chemistry of diazomethane. J Org Chem 2002. [DOI: 10.1021/jo00269a020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Worsnop DR, Zahniser MS, Kolb CE, Gardner JA, Watson LR, Van Doren JM, Jayne JT, Davidovits P. The temperature dependence of mass accommodation of sulfur dioxide and hydrogen peroxide on aqueous surfaces. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100340a027] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kass SR, Filley J, Van Doren JM, DePuy CH. Nitrous oxide in gas-phase ion-molecule chemistry: a versatile reagent for the determination of carbanion structure. J Am Chem Soc 2002. [DOI: 10.1021/ja00271a011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Van Doren JM, Watson LR, Davidovits P, Worsnop DR, Zahniser MS, Kolb CE. Temperature dependence of the uptake coefficients of nitric acid, hydrochloric acid and nitrogen oxide (N2O5) by water droplets. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100371a009] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Barlow SE, Van Doren JM, Bierbaum VM. The gas phase displacement reaction of chloride ion with methyl chloride as a function of kinetic energy. J Am Chem Soc 2002. [DOI: 10.1021/ja00229a064] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Morris RA, Viggiano AA, Van Doren JM, Paulson JF. Chemistry of H2O+ (oxoniumyl) with tetrafluoroethene, hexafluoroethane, and CF3X (X = F, Cl, Br, I). ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100186a050] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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