Quantitative microbial risk assessment of Salmonella and Enterococcus in Marina Reservoir and catchments

2015 ◽  
Vol 10 (3) ◽  
pp. 527-531 ◽  
Author(s):  
S. G. Goh ◽  
H. M. Fang ◽  
S. Y. Chang ◽  
Karina Y. H. Gin
Keyword(s):  
Risk Assessment ◽  
Environmental Protection Agency ◽  
The United States ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Simulation Techniques ◽  
Guideline Values ◽  
Microbial Risks

This study assesses the infection risks associated with non-swimming recreational activities in Marina Reservoir, Singapore. Apart from serving as a reservoir for potable water use, Marina Reservoir is also a place where various water recreations are carried out. Quantitative microbial risk assessment (QMRA) was applied to Marina Reservoir and its four main feeders. QMRA was performed based on the occurrence data of the potential pathogen, Salmonella spp. and bacteria indicator, Enterococcus spp. through Monte Carlo simulation techniques. The results suggest that microbial risks from Salmonella and Enterococcus at the reservoir were below the United States Environmental Protection Agency (USEPA) acceptable freshwater recreational illness rate of 0.8%. All upstream catchments showed acceptable microbial risks from Salmonella. However, the probability of gastrointestinal illness risks calculated for Enterococcus exceeded the USEPA guideline values in one of the upstream catchments, but far enough upstream from recreational areas that are used frequently.

Critical review of mathematical approaches for quantitative microbial risk assessment (QMRA) of Legionella in engineered water systems: research gaps and a new framework

2016 ◽  
Vol 2 (4) ◽  
pp. 599-613 ◽  
Author(s):  
K. A. Hamilton ◽  
C. N. Haas
Keyword(s):  
Risk Assessment ◽  
Disease Outbreaks ◽  
The United States ◽  
Water Systems ◽  
Quantitative Microbial Risk Assessment ◽  
Research Gaps ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Systems Research ◽  
New Framework

Legionellahas been identified as the responsible agent for two-thirds of waterborne disease outbreaks in the United States from 2011–2012.

scholarly journals Microbial risk assessment for recreational use of the Chicago Area Waterway System

2011 ◽  
Vol 9 (1) ◽  
pp. 169-186 ◽  
Author(s):  
G. Rijal ◽  
J. K. Tolson ◽  
C. Petropoulou ◽  
T. C. Granato ◽  
A. Glymph ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Environmental Protection Agency ◽  
Enteric Virus ◽  
Weather Conditions ◽  
The United States ◽  
Current Treatment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Chicago Area ◽  
Wet Weather

A microbial risk assessment was conducted to estimate the human health risks from incidental contact recreational activities such as canoeing, boating and fishing in the Chicago Area Waterway System (CAWS) receiving secondary treated, but non-disinfected, effluent from three municipal water reclamation plants. Actual concentrations of the pathogens (pathogenic E. coli [estimated], Giardia, Cryptosporidium, adenovirus, norovirus, enteric virus) detected from the waterway field data collection at locations upstream and downstream of the effluent outfall during dry and wet weather conditions within the recreation season were included in the risk assessment. The results under the current treatment scheme with no disinfection indicated that the total expected gastrointestinal illness (GI) rate per 1000 incidental contact recreational exposure events during combined weather (dry and wet) conditions ranged from 0.10 to 2.78 in the CAWS, which is below the eight illnesses per 1000 swimmers considered tolerable by the United States Environmental Protection Agency. Wet weather conditions contribute to elevated pathogen load to the CAWS; therefore this study determined that disinfecting the effluents of three major WRPs that discharge to the CAWS would result in an extremely small reduction in the aggregate recreation season risk to incidental contact recreators.

Quantitative microbial risk assessment (QMRA) to support decisions for water supply in affluent and developing countries

2019 ◽  
Vol 14 (3) ◽  
pp. 542-548 ◽  
Author(s):  
P. W. M. H. Smeets
Keyword(s):  
Risk Assessment ◽  
Developing Countries ◽  
Drinking Water ◽  
Water Supply ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
The Past ◽  
Relative Risks ◽  
Microbial Risks

Abstract Providing microbially safe water is a main goal of water supply to prevent endemic waterborne disease and outbreaks. Since increasing the level of safety requires resources, it is important to identify most relevant risks and efficient ways to reach health-based targets. Over the past decades, quantitative microbial risk assessment (QMRA) developed into a systematic, science-based approach to assess microbial risks through drinking water supply. In this study we present the QMRA approach and how it can be used to support decisions in both affluent and developing countries. This includes examples from the statutory QMRA in the Netherlands that led to efficient and effective improvements in water supply, not only in treatment, but also in monitoring and operation. In developing countries people often need to use various sources of drinking water. We will demonstrate how QMRA can help to improve insight in the relative risks of these routes and the effect of interventions.

scholarly journals Evaluating the Risk of Salmonellosis from Dry Roasted Sunflower Seeds

2019 ◽  
Vol 83 (1) ◽  
pp. 17-27 ◽  
Author(s):  
BALASUBRAHMANYAM KOTTAPALLI ◽  
STEPHANIE P. V. NGUYEN ◽  
KELLY DAWSON ◽  
KAITLYN CASULLI ◽  
CATE KNOCKENHAUER ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Water Activity ◽  
The United States ◽  
Arithmetic Mean ◽  
Assessment Model ◽  
Quantitative Microbial Risk Assessment ◽  
Sunflower Seeds ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Log Reduction

ABSTRACT Outbreaks and recalls related to nuts and seeds in the United States have increased recently, and 80% of these recalls are due to Salmonella. The U.S. Food and Drug Administration's Food Safety Modernization Act requires food manufacturers to implement risk-based preventive controls based on scientific and technical evidence. Data are limited on the inactivation of Salmonella during processing of saltwater brined in-shell sunflower seeds. The goal of this research was to validate the adequacy of roasting in controlling Salmonella during the production of sunflower seeds and to assess the resulting risk. Four Salmonella strains were inoculated onto sunflower seeds and processed to simulate commercial manufacturing. Seeds were tumbled and roasted at 225°F (107.2°C) and 275°F (135°C) for roasting times from 5 to 45 min. Regression models for Salmonella inactivation and water activity change were developed. The inactivation model predicted a 5-log reduction in Salmonella when sunflower seeds were roasted at 135°C for 19.2 min, with a corresponding water activity of ∼0.61. Roasted sunflower seeds are typically not saleable at water activities >0.6 due to quality issues. Saleable water activities (0.03 to 0.04) were only achieved when the sunflower seeds were roasted for 45 min at 135°C, which resulted in a >7-log reduction in Salmonella. A quantitative microbial risk assessment based on literature values, expert opinion, and the above-mentioned models was used to predict risk of salmonellosis from sunflower seeds. The quantitative microbial risk assessment model predicted an arithmetic mean probability of illness of 1.45E−07 per 28-g serving based on roasting at 135°C for 20 min and an arithmetic mean probability of illness of 5.46E−10 per serving based on roasting at 135°C for >45 min (i.e., saleable product process parameters). This study demonstrates that sunflower seeds roasted to saleable parameters should not represent a public health risk from potential presence of Salmonella.

Quantifying the Risk of Human Toxoplasma gondii Infection Due to Consumption of Domestically Produced Lamb in the United States

2016 ◽  
Vol 79 (7) ◽  
pp. 1181-1187 ◽  
Author(s):  
MIAO GUO ◽  
ABHINAV MISHRA ◽  
ROBERT L. BUCHANAN ◽  
JITENDER P. DUBEY ◽  
DOLORES E. HILL ◽  
...  
Keyword(s):  
Public Health ◽  
United States ◽  
Risk Assessment ◽  
Toxoplasma Gondii ◽  
The United States ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Public Health Burden ◽  
Health Burden

ABSTRACT Toxoplasma gondii is a prevalent protozoan parasite worldwide. Human toxoplasmosis is responsible for considerable morbidity and mortality in the United States, and meat products have been identified as an important source of T. gondii infections in humans. The goal of this study was to develop a farm-to-table quantitative microbial risk assessment model to predict the public health burden in the United States associated with consumption of U.S. domestically produced lamb. T. gondii prevalence in market lambs was pooled from the 2011 National Animal Health Monitoring System survey, and the concentration of the infectious life stage (bradyzoites) was calculated in the developed model. A log-linear regression and an exponential dose-response model were used to model the reduction of T. gondii during home cooking and to predict the probability of infection, respectively. The mean probability of infection per serving of lamb was estimated to be 1.5 cases per 100,000 servings, corresponding to ~6,300 new infections per year in the U.S. population. Based on the sensitivity analysis, we identified cooking as the most effective method to influence human health risk. This study provided a quantitative microbial risk assessment framework for T. gondii infection through consumption of lamb and quantified the infection risk and public health burden associated with lamb consumption.

scholarly journals Quantitative Microbial Risk Assessment of Drinking Water Quality to Predict the Risk of Waterborne Diseases in Primary-School Children

2020 ◽  
Vol 17 (8) ◽  
pp. 2774 ◽  
Author(s):  
Jamil Ahmed ◽  
Li Ping Wong ◽  
Yan Piaw Chua ◽  
Najeebullah Channa ◽  
Rasool Bux Mahar ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Primary School ◽  
School Children ◽  
Primary School Children ◽  
Quantitative Microbial Risk Assessment ◽  
Waterborne Diseases ◽  
Salmonella Spp ◽  
Microbial Risk Assessment ◽  
Microbial Risk

Primary-school children in low- and middle-income countries are often deprived of microbiologically safe water and sanitation, often resulting in a high prevalence of gastrointestinal diseases and poor school performance. We used Quantitative Microbial Risk Assessment (QMRA) to predict the probability of infection in schoolchildren due to consumption of unsafe school water. A multistage random-sampling technique was used to randomly select 425 primary schools from ten districts of Sindh, Pakistan, to produce a representative sample of the province. We characterized water supplies in selected schools. Microbiological testing of water resulted in inputs for the QMRA model, to estimate the risks of infections to schoolchildren. Groundwater (62%) and surface water (38%) were identified as two major sources of drinking water in the selected schools, presenting varying degrees of health risks. Around half of the drinking-water samples were contaminated with Escherichia coli (49%), Shigella spp. (63%), Salmonella spp. (53%), and Vibrio cholerae (49%). Southern Sindh was found to have the highest risk of infection and illness from Campylobacter and Rotavirus. Central and Northern Sindh had a comparatively lower risk of waterborne diseases. Schoolchildren of Karachi were estimated to have the highest probability of illness per year, due to Campylobacter (70%) and Rotavirus (22.6%). Pearson correlation was run to assess the relationship between selected pathogens. V. cholerae was correlated with Salmonella spp., Campylobacter, Rotavirus, and Salmonella spp. Overall, the risk of illness due to the bacterial infection (E. coli, Salmonella spp., V. cholerae, Shigella, and Campylobacter) was high. There is a dire need for management plans in the schools of Sindh, to halt the progression of waterborne diseases in school-going children.

Quantitative Microbial Risk Assessment of Antibacterial Hand Hygiene Products on Risk of Shigellosis

2014 ◽  
Vol 77 (4) ◽  
pp. 574-582 ◽  
Author(s):  
DONALD W. SCHAFFNER ◽  
JAMES P. BOWMAN ◽  
DONALD J. ENGLISH ◽  
GEORGE E. FISCHLER ◽  
JANICE L. FULS ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Hand Hygiene ◽  
Statistical Significance ◽  
Laboratory Data ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Log Reduction ◽  
Simulation Techniques ◽  
Simulation Scenario

There are conflicting reports on whether antibacterial hand hygiene products are more effective than nonantibacterial products in reducing bacteria on hands and preventing disease. This research used new laboratory data, together with simulation techniques, to compare the ability of nonantibacterial and antibacterial products to reduce shigellosis risk. One hundred sixty-three subjects were used to compare five different hand treatments: two nonantibacterial products and three antibacterial products, i.e., 0.46% triclosan, 4% chlorhexidine gluconate, or 62% ethyl alcohol. Hands were inoculated with 5.5 to 6 log CFU Shigella; the simulated food handlers then washed their hands with one of the five products before handling melon balls. Each simulation scenario represented an event in which 100 people would be exposed to Shigella from melon balls that had been handled by food workers with Shigella on their hands. Analysis of experimental data showed that the two nonantibacterial treatments produced about a 2-log reduction on hands. The three antibacterial treatments showed log reductions greater than 3 but less than 4 on hands. All three antibacterial treatments resulted in statistically significantly lower concentration on the melon balls relative to the nonantibacterial treatments. A simulation that assumed 1 million Shigella bacteria on the hands and the use of a nonantibacterial treatment predicted that 50 to 60 cases of shigellosis would result (of 100 exposed). Each of the antibacterial treatments was predicted to result in an appreciable number of simulations for which the number of illness cases would be 0, with the most common number of illness cases being 5 (of 100 exposed). These effects maintained statistical significance from 106 Shigella per hand down to as low as 100 Shigella per hand, with some evidence to support lower levels. This quantitative microbial risk assessment shows that antibacterial hand treatments can significantly reduce Shigella risk.

scholarly journals A Systematic Review of Beef Meat Quantitative Microbial Risk Assessment Models

2020 ◽  
Vol 17 (3) ◽  
pp. 688 ◽  
Author(s):  
Vincent Tesson ◽  
Michel Federighi ◽  
Enda Cummins ◽  
Juliana de Oliveira Mota ◽  
Sandrine Guillou ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Food Safety ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Beef Meat ◽  
Risk Assessment Models ◽  
Future Challenges ◽  
Meta Analyses

Each year in Europe, meat is associated with 2.3 million foodborne illnesses, with a high contribution from beef meat. Many of these illnesses are attributed to pathogenic bacterial contamination and inadequate operations leading to growth and/or insufficient inactivation occurring along the whole farm-to-fork chain. To ensure consumer health, decision-making processes in food safety rely on Quantitative Microbiological Risk Assessment (QMRA) with many applications in recent decades. The present study aims to conduct a critical analysis of beef QMRAs and to identify future challenges. A systematic approach, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was used to collate beef QMRA models, identify steps of the farm-to-fork chain considered, and analyze inputs and outputs included as well as modelling methods. A total of 2343 articles were collected and 67 were selected. These studies focused mainly on western countries and considered Escherichia coli (EHEC) and Salmonella spp. pathogens. Future challenges were identified and included the need of whole-chain assessments, centralization of data collection processes, and improvement of model interoperability through harmonization. The present analysis can serve as a source of data and information to inform QMRA framework for beef meat and will help the scientific community and food safety authorities to identify specific monitoring and research needs.

Modeling the Risk of Salmonellosis from Consumption of Peanuts in the United States

2019 ◽  
Vol 82 (4) ◽  
pp. 579-588 ◽  
Author(s):  
KAITLYN E. CASULLI ◽  
STEPHEN CALHOUN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
United States ◽  
Risk Assessment ◽  
Geometric Mean ◽  
The United States ◽  
Economic Losses ◽  
Quantitative Microbial Risk Assessment ◽  
Concentration Data ◽  
Modeling Tools ◽  
Microbial Risk Assessment ◽  
Microbial Risk

ABSTRACT Peanut products were the target of the largest food recall in United States history from 2008 to 2009, with more than 3,200 products implicated, economic losses estimated at $1 billion, and more than 700 reported illnesses and 9 deaths. Predictive modeling tools such as quantitative microbial risk assessment can be used to aid processors in making risk management decisions that may reduce the chances of foodborne illness, but published risk assessment for peanuts is not currently available. A quantitative microbial risk assessment was performed to quantify salmonellosis risk from consumption of peanuts in the United States. Prevalence and concentration data for Salmonella on raw, shelled peanuts were used in combination with probability distributions of simulated log reductions achieved during production steps before consumption. Data for time-temperature combinations used in each step were obtained from published literature, industry surveys, or expert opinion, and survival data were obtained from the literature. A beta-Poisson dose-response model was used to predict probability of illness from ingestion of Salmonella cells. The model predicted 14.2 (arithmetic mean) or 0.0123 (geometric mean) illnesses per year. Sensitivity analysis showed that thermal inactivation log reductions applied had the biggest impact on predicted salmonellosis risk, followed by consumer storage time, Salmonella starting concentration, Salmonella starting prevalence, and number of originally contaminated 25-g servings per originally positive 375-g sample. Scenario analysis showed that increasing log reduction variability increased mean salmonellosis risk. Removing the effect of storage on Salmonella survival increased the arithmetic and geometric means to 153 and 0.598 illnesses per year, respectively. This study indicated that the risk of salmonellosis from consumption of peanuts can be lowered by reducing field contamination, control of storage steps, and monitoring of appropriate critical limits in peanut roasting.

Enteric virus presence in green vegetables and associated irrigation waters in a rural area from Argentina. A quantitative microbial risk assessment

LWT ◽  
2021 ◽  
Vol 144 ◽  
pp. 111201 ◽  
Author(s):  
Prez Verónica Emilse ◽  
Victoria Matías ◽  
Martínez Laura Cecilia ◽  
Giordano Miguel Oscar ◽  
Masachessi Gisela ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Rural Area ◽  
Enteric Virus ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Irrigation Waters
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