Predictive modelling and risk assessment of BSE: a review

Cummins, Enda; Grace, Patrick M.; McDonnell, Kevin; Ward, Shane; Fry, D. J.

doi:10.1080/13669870152023809

Cited by 14 publications

(14 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although this methodology has been successful in describing and predicting the number of vCJD incidents, uncertainties remain about the distribution of incubation periods and the dependence on exposure to infectious material. In addition, extensive studies on BSE risk assessment have been conducted to assess the inherent risk of vCJD in humans, especially in the lower‐BSE‐prevalence EU countries . Other studies relating vCJD risk to dietary consumption of BSE‐contaminated meat products have been limited to indirect calculation of human hID 50 (i.e., the amount of exposure required for the risk of 50% human infection) through animal bioassay experiments and assumptions about cross‐species barriers .…”

Section: Introductionmentioning

confidence: 99%

“…In addition, extensive studies on BSE risk assessment have been conducted to assess the inherent risk of vCJD in humans, especially in the lower-BSE-prevalence EU countries. (14)(15)(16)(17)(18)(19) Other studies relating vCJD risk to dietary consumption of BSE-contaminated meat products have been limited to indirect calculation of human hID 50 (i.e., the amount of exposure required for the risk of 50% human infection) through animal bioassay experiments and assumptions about crossspecies barriers. (14,(20)(21)(22) No direct assessment of the relationship between human exposure and vCJD risk has been performed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Consumption of Bovine Spongiform Encephalopathy (BSE) Contaminated Beef and the Risk of Variant Creutzfeldt‐Jakob Disease

Chen

Wang

2013

Risk Analysis

View full text Add to dashboard Cite

To date, the variant Creutzfeldt-Jakob disease (vCJD) risk assessments that have been performed have primarily focused on predicting future vCJD cases in the United Kingdom, which underwent a bovine spongiform encephalopathy (BSE) epidemic between 1980 and 1996. Surveillance of potential BSE cases was also used to assess vCJD risk, especially in other BSE-prevalent EU countries. However, little is known about the vCJD risk for uninfected individuals who accidentally consume BSE-contaminated meat products in or imported from a country with prevalent BSE. In this article, taking into account the biological mechanism of abnormal prion PrP(res) aggregation in the brain, the probability of exposure, and the expected amount of ingested infectivity, we establish a stochastic mean exponential growth model of lifetime exposure through dietary intake. Given the findings that BSE agents behave similarly in humans and macaques, we obtained parameter estimates from experimental macaque data. We then estimated the accumulation of abnormal prions to assess lifetime risk of developing clinical signs of vCJD. Based on the observed number of vCJD cases and the estimated number of exposed individuals during the BSE epidemic period from 1980 to 1996 in the United Kingdom, an exposure threshold hypothesis is proposed. Given the age-specific risk of infection, the hypothesis explains the observations very well from an extreme-value distribution fitting of the estimated BSE infectivity exposure. The current BSE statistics in the United Kingdom are provided as an example.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Consumption of Bovine Spongiform Encephalopathy (BSE) Contaminated Beef and the Risk of Variant Creutzfeldt‐Jakob Disease

Chen

Wang

2013

Risk Analysis

View full text Add to dashboard Cite

show abstract

“…The basic reproduction ratio, R o , which was used in the model to quantify the internal stability of the cattle system, was obtained using a calculation method developed by de Koeijer et al ( 36 ) Cummins ( 43 ) has reviewed a number of calculation methods that could be used alternatively. A simpler approach could be based on the semi‐quantitative assessment used for the GBR, as was done for Sweden.…”

Section: Discussionmentioning

confidence: 99%

“…(41) When detailed Norwegian surveillance results in [2001][2002][2003][2004] were analyzed in combination with demographic information about the national cattle population, the BSurvE model estimated a prevalence of infection of zero with an upper 95% confidence interval of 63 per million cattle. (42) Interestingly, the low age at slaughter of Norwegian cattle has a reducing effect on the risk of BSE, since total infectiousness of infected cattle increases with time (see Cummins (43) for review). However, when surveillance data are analyzed with the BSurvE, which takes into account the probability of detecting disease in the tested animals, the young age of the cattle population reduces the value of performed tests, since the agent is less likely to be found in young individuals.…”

Section: Discussionmentioning

confidence: 99%

Quantitative Risk Assessment for Bovine Spongiform Encephalopathy in Low‐ or Zero‐Prevalence Countries: The Example of Norway

Høgåsen

Koeijer²

2007

Risk Analysis

View full text Add to dashboard Cite

A predictive case-cohort model is applied to Norwegian data to analyze the interaction between challenge and stability factors for bovine spongiform encephalopathy (BSE) during the period 1980-2010. For each year, the BSE risk in cattle is estimated as the expected number of cases. The age distribution of expected cases as well as the relative impact of different challenges is estimated. The model consists of a simple, transparent, and practical deterministic spreadsheet calculation model, in which the following country-specific inputs are entered: (i) annual imports of live cattle and meat and bone meal, (ii) age distribution of native cattle, and (iii) estimated annual basic reproduction ratio (R(0)) for BSE. Results for Norway indicate that the highest risk of BSE cases was in 1989, when a total BSE risk of 0.13 cases per year was expected. After that date, the year-to-year decrease in risk ranged between 3% and 47%, except for a secondary peak in 1994 at 0.06 cases per year. The primary peak was almost entirely (99%) attributable to the importation of 11 cattle from the United Kingdom between 1982 and 1986. The secondary peak, in 1994, originated mainly from the recycling of the U.K. imported cattle (92%). In 2006, the remaining risk was 0.0003 cases per year, or 0.001 per million cows per year, with a maximal age-specific incidence of 0.03 cases per million per year in 10-year-old cattle. Only 15% of the cases were expected in imported cattle. The probability of having zero cases in Norway in 2006 was estimated to be 99.97%. The model and results are compared to previous risk assessments of Norway by the EU.

show abstract

“…However, the risks to humans associated with the combustion of tallow need to be quantified by using a risk assessment. Many elements of risk assessment relating to BSE have been reviewed elsewhere (Cummins et al 2001).…”

Section: Combustion Of Srm-derived Tallow In Irelandmentioning

confidence: 99%

Human Risks from the Combustion of SRM-Derived Tallow in Ireland

Cummins

Colgan

Grace

et al. 2002

Human and Ecological Risk Assessment: An International Journal

Self Cite

View full text Add to dashboard Cite

The identification of meat and bone meal (MBM) as a significant factor in the spread of bovine spongiform encephalopathy (BSE) has resulted in the introduction of restrictions on the use and movement of MBM and tallow. This has led to a requirement for alternative uses for these products. This paper reports on a risk assessment performed on the use of tallow as a fuel oil extender in diesel engines. With up to 4000 tonnes of tallow being produced each year in Ireland, combustion with energy recovery represents a viable, cost-efficient utilization route. A stochastic (Latin Hypercube sampling) simulation model was developed to assess the infectivity risk to humans associated with potential airborne exposure to the combustion products when using tallow as a combustion fuel in diesel engines. The model simulates the potential infectivity pathways that tallow follows, including its production from animals with potentially subclinical BSE and processing the tallow with segregation and heat treatments. The model uses probability distributions for the most important input parameters. The assessment takes into account a number of epidemiological parameters that include tissue infectivity, species barrier, disease incidence, and heat inactivation. Two scenarios, reflecting the infectivity risk in different animal tissues defined by the European Commissions Scientific Steering Committee (SSC), were performed. It is seen from the model results that the risk of a human contracting variant Creutzfeldt-Jakob Disease (vCJD) from potential airborne exposure to BSE, resulting from the combustion of tallow, is extremely small even when model uncertainty is taken into account (mean individual risk values ranging from to 10-7.23 per year/person). The risks are a number of Cummins et al.orders of magnitude less than the sporadic annual incidence level of CreutzfeldtJakob Disease (CJD) in Europe (approximately ) .

show abstract

Predictive modelling and risk assessment of BSE: a review

Cited by 14 publications

References 18 publications

Consumption of Bovine Spongiform Encephalopathy (BSE) Contaminated Beef and the Risk of Variant Creutzfeldt‐Jakob Disease

Consumption of Bovine Spongiform Encephalopathy (BSE) Contaminated Beef and the Risk of Variant Creutzfeldt‐Jakob Disease

Quantitative Risk Assessment for Bovine Spongiform Encephalopathy in Low‐ or Zero‐Prevalence Countries: The Example of Norway

Human Risks from the Combustion of SRM-Derived Tallow in Ireland

Contact Info

Product

Resources

About