Modeling the die-off of E. coli and Ascaris in wastewater-irrigated vegetables: implications for microbial health risk reduction associated with irrigation cessation

Seidu, Razak; Sjølander, Ingrid; Abubakari, Amina; Amoah, Isaac Dennis; Larbi, John Asiedu; Stenström, Thor Axel

doi:10.2166/wst.2013.335

Cited by 17 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All enteric pathogens of viral, bacterial and parasitic (helminthic and protozoan) origins can be found in wastewater; and can be transmitted to farmers using the wastewater for irrigation, consumers of wastewater-irrigated vegetables and communities close to wastewater irrigated fields [5]. Several studies have shown a significant relationship between Ascaris infection and exposure to wastewater (either treated or untreated) [6,7,8]. This is because soil transmitted helminths (STHs) (such as Ascaris ) can survive for long periods of time under severe adverse environmental conditions [9] contributing to their high risk of infection.…”

Section: Introductionmentioning

confidence: 99%

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

et al. 2016

Self Cite

View full text Add to dashboard Cite

Wastewater irrigation is associated with several benefits but can also lead to significant health risks. The health risk for contracting infections from Soil Transmitted Helminths (STHs) among farmers has mainly been assessed indirectly through measured quantities in the wastewater or on the crops alone and only on a limited scale through epidemiological assessments. In this study we broadened the concept of infection risks in the exposure assessments by measurements of the concentration of STHs both in wastewater used for irrigation and the soil, as well as the actual load of STHs ova in the stool of farmers and their family members (165 and 127 in the wet and dry seasons respectively) and a control group of non-farmers (100 and 52 in the wet and dry seasons, respectively). Odds ratios were calculated for exposure and non-exposure to wastewater irrigation. The results obtained indicate positive correlation between STH concentrations in irrigation water/soil and STHs ova as measured in the stool of the exposed farmer population. The correlations are based on reinfection during a 3 months period after prior confirmed deworming. Farmers and family members exposed to irrigation water were three times more likely as compared to the control group of non-farmers to be infected with Ascaris (OR = 3.9, 95% CI, 1.15–13.86) and hookworm (OR = 3.07, 95% CI, 0.87–10.82). This study therefore contributes to the evidence-based conclusion that wastewater irrigation contributes to a higher incidence of STHs infection for farmers exposed annually, with higher odds of infection in the wet season.

show abstract

Section: Introductionmentioning

confidence: 99%

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, simple first‐order (single‐phase) die‐off is probably not accurate as most soil and subsurface environments are highly heterogeneous and because of the potential for long‐term survival of persistent subpopulations and/or re‐growth in the environment (Bradford and others ). As such, biphasic survival kinetics have been observed in both water (Easton and others ; Ahmed and others ) and fresh produce production environment (Petterson and others ; Seidu and others ). In biphasic decay kinetics an initial rapid decay is noted, often followed by an attenuated, slower decay.…”

Section: Resultsmentioning

confidence: 96%

“… Diallo and others () Seidu and others () Barker and others (); Ottoson and others () Bastos and others (); Domenech and others (); Mara and others (); Rodriguez and others (); Or Oron and others (); Van Ginneken and Oron () …”

Section: Resultsmentioning

confidence: 99%

“…In biphasic decay kinetics an initial rapid decay is noted, often followed by an attenuated, slower decay. The inclusion of the possibility of a biphasic decay in QMRA is important as the survival of pathogens, and hence the predicted infection risk, can be significantly underestimated if the presence of a persistent subpopulation of the microorganisms is not considered (Petterson and Ashbolt ; Seidu and others ).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Zero Risk Does Not Exist: Lessons Learned from Microbial Risk Assessment Related to Use of Water and Safety of Fresh Produce

Keuckelaere

Jacxsens

Amoah

et al. 2015

Comp Rev Food Sci Food Safe

View full text Add to dashboard Cite

Risk assessments related to use of water and safety of fresh produce originate from both water and food microbiology studies. Although the set-up and methodology of risk assessment in these 2 disciplines may differ, analysis of the current literature reveals some common outcomes. Most of these studies from the water perspective focus on enteric virus risks, largely because of their anticipated high concentrations in untreated wastewater and their resistance to common wastewater treatments. Risk assessment studies from the food perspective, instead, focus mainly on bacterial pathogens such as Salmonella and pathogenic Escherichia coli. Few site-specific data points were available for most of these microbial risk assessments, meaning that many assumptions were necessary, which are repeated in many studies. Specific parameters lacking hard data included rates of pathogen transfer from irrigation water to crops, pathogen penetration, and survival in or on food crops. Data on these factors have been investigated over the last decade and this should improve the reliability of future microbial risk estimates. However, the sheer number of different foodstuffs and pathogens, combined with water sources and irrigation practices, means that developing risk models that can span the breadth of fresh produce safety will be a considerable challenge. The new approach using microbial risk assessment is objective and evidence-based and leads to more flexibility and enables more tailored risk management practices and guidelines. Drawbacks are, however, capacity and knowledge to perform the microbial risk assessment and the need for data and preferably data of the specific region.Keywords: fruits and vegetables, health risk, mitigation strategies, quantitative microbial risk assessment, water Practical Application: This manuscripts intends to give an extensive overview of approaches and challenges of past and future quantitative microbial risk assessment studies in the fresh produce chain related to the use of water in order to aid further research efforts in this area.

show abstract

“…The duration and temperature conditions of storage between purchase and consumption can play a role in potential survival, decline, or growth of certain pathogens on fresh-cut produce and will influence the outcome of microbiological risk assessments (7,17,45) for leafy greens in various distribution chains. The behavior of pathogens on fresh produce has been investigated using laboratory experiments and modelling (e.g., Escherichia coli 0157:H 7, Salmonella, and Listeria monocytogenes on leafy greens (23,32) and fresh-cut iceberg lettuce (28)) and real-life experiments (42,48).…”

Section: Consumption Data Expressed As Acute Intakementioning

confidence: 99%

Belgian and Spanish Consumption Data and Consumer Handling Practices for Fresh Fruits and Vegetables Useful for Further Microbiological and Chemical Exposure Assessment

Jacxsens

Ibañez

Gómez‐López

et al. 2015

Journal of Food Protection

View full text Add to dashboard Cite

A consumer survey was organized in Spain and Belgium to obtain consumption data and to gain insight into consumer handling practices for fresh vegetables consumed raw or minimally processed (i.e., heads of leafy greens, bell peppers, tomatoes, fresh herbs, and precut and packed leafy greens) and fruits to be consumed without peeling (i.e., apples, grapes, strawberries, raspberries, other berries, fresh juices, and precut mixed fruit). This information can be used for microbiological and/or chemical food safety research. After extensive cleanup of rough databases for missing and extreme values and age correction, information from 583 respondents from Spain and 1,605 respondents from Belgium (18 to 65 years of age) was retained. Daily intake (grams per day) was calculated taking into account frequency and seasonality of consumption, and distributions were obtained that can be used in quantitative risk assessment for chemical hazards with chronic effects on human health. Data also were recalculated to obtain discrete distributions of consumption per portion and the corresponding frequency of consumption, which can be used in acute microbiological risk assessment or outbreak investigations. The ranked median daily consumption of fruits and vegetables was similar in Spain and Belgium: apple > strawberry > grapes > strawberries and raspberries; and tomatoes > leafy greens > bell peppers > fresh herbs. However, vegetable consumption was higher (in terms of both portion and frequency of consumption) in Spain than in Belgium, whereas the opposite was found for fruit consumption. Regarding consumer handling practices related to storage time and method, Belgian consumers less frequently stored their fresh produce in a refrigerator and did so for shorter times compared with Spanish consumers. Washing practices for lettuce heads and packed leafy greens also were different. The survey revealed differences between these two countries in consumption and consumer handling practices, which can have an impact on outcomes of future microbiological or chemical risk assessment studies.

show abstract

Modeling the die-off of E. coli and Ascaris in wastewater-irrigated vegetables: implications for microbial health risk reduction associated with irrigation cessation

Cited by 17 publications

References 0 publications

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

Zero Risk Does Not Exist: Lessons Learned from Microbial Risk Assessment Related to Use of Water and Safety of Fresh Produce

Belgian and Spanish Consumption Data and Consumer Handling Practices for Fresh Fruits and Vegetables Useful for Further Microbiological and Chemical Exposure Assessment

Contact Info

Product

Resources

About