Public health risk of Giardia and Cryptosporidium posed by reintroduction of beavers into Scotland

Following publication of ‘Scottish Beaver Trial Independent Public Health Monitoring 2009-2014 Report and Recommendations’ (Mackie, 2014), two pieces of complementary work were undertaken in parallel to assess the potential contribution of reintroduced beavers in Scotland to the public health burden of disease attributed to Giardia spp. and Cryptosporidium spp. parasites. The first, a risk assessment, addressing the question ‘What is the likelihood that re-introduced beavers will have a significant impact on the contamination of drinking water supplies with Cryptosporidium parvum and Giardia lamblia?’ (Appendix 1), was conducted by Scottish Government’s Centre of Expertise on Animal Disease Outbreaks (EPIC). This reviewed evidence from data and publications across the world, as well as evidence from the beaver trial and SNH’s Tayside beaver reports, and used this to assess the likely additional contribution of beavers to the risk associated with exposure to these parasites in Scotland. The second, ‘What is the likelihood that beavers will be an important source of contamination of drinking water supplies with Cryptosporidium parvum and Giardia intestinalis?’ (Appendix 2), was prepared by Health Protection Scotland (HPS), Scottish Parasite Diagnostic Reference Laboratory (SPDL) and Drinking Water Quality Regulator for Scotland (DWQR). This reviewed the diagnostics, surveillance and epidemiology of these infections in people in Scotland

Public health risk of Giardia and Cryptosporidium posed by reintroduction of beavers into Scotland

Following publication of ‘Scottish Beaver Trial Independent Public Health Monitoring 2009-2014 Report and Recommendations’ (Mackie, 2014), two pieces of complementary work were undertaken in parallel to assess the potential contribution of reintroduced beavers in Scotland to the public health burden of disease attributed to Giardia spp. and Cryptosporidium spp. parasites. The first, a risk assessment, addressing the question ‘What is the likelihood that re-introduced beavers will have a significant impact on the contamination of drinking water supplies with Cryptosporidium parvum and Giardia lamblia?’ (Appendix 1), was conducted by Scottish Government’s Centre of Expertise on Animal Disease Outbreaks (EPIC). This reviewed evidence from data and publications across the world, as well as evidence from the beaver trial and SNH’s Tayside beaver reports, and used this to assess the likely additional contribution of beavers to the risk associated with exposure to these parasites in Scotland. The second, ‘What is the likelihood that beavers will be an important source of contamination of drinking water supplies with Cryptosporidium parvum and Giardia intestinalis?’ (Appendix 2), was prepared by Health Protection Scotland (HPS), Scottish Parasite Diagnostic Reference Laboratory (SPDL) and Drinking Water Quality Regulator for Scotland (DWQR). This reviewed the diagnostics, surveillance and epidemiology of these infections in people in Scotland

Assessing the likelihood of High Pathogenicity Avian Influenza incursion into the gamebird sector in Great Britain via designated hatcheries

The outbreaks of High Pathogenicity Avian Influenza (HPAI) in the United Kingdom in 2017 and 2021 had a substantial impact on the gamebird industry and highlighted to policymakers the importance of existing knowledge gaps for effective disease control. Despite the size of the industry, the impact of HPAI on the gamebird industry is not well-understood. To improve future disease preparedness, a veterinary risk assessment to explore the risk of HPAI incursion into the gamebird sector in Great Britain via a designated hatchery was commissioned by Scottish Government Animal Health and Welfare Division. Hatchery designation is a legal requirement for hatcheries located within disease control zones or that have business links to premises located in disease control zones to continue operating during an HPAI outbreak. Several risk pathways were identified, which involved various management procedures associated with egg production through to the delivery of day-old chicks. The overall likelihood of the HPAI virus introduction into a designated hatchery through hatching egg movement is considered to be low (high uncertainty). The overall likelihood of onward transmission of the HPAI virus into gamebird rearing sites from a designated hatchery through day-old chick movement is also considered to be low (medium uncertainty). These risk levels are based on the assumption that relevant control measures are observed, as enhanced biosecurity is one of the requirements for hatchery designation. However, high uncertainties and variabilities were identified in the level of compliance with these biosecurity measures. Factors increasing the likelihood level include management practices typical to this sector, such as having multiple egg production sites, raising birds at outdoor sites, catching birds from the wild for egg production, having various scale of satellite farms in various locations, importing eggs and day-old chicks from overseas, as well as the proximity of the game farm to the infected premise or to higher risk areas. This study offers evidence for policymakers to help develop criteria for hatchery designation and proposes important mitigation strategies for future disease outbreaks specific for the gamebird sector

A risk assessment of equine piroplasmosis entry, exposure and consequences in the UK

Background: Equine piroplasmosis (EP) is currently not endemic in the UK, despite a lack of formal surveillance and the presence of carrier horses in the equine population. Pathogen establishment would have significant welfare and economic impacts on the national equine industry, but the disease is often overlooked by UK practitioners. Objectives: To assess the risk of disease entry, exposure and consequences to the UK equine population. Study design: Qualitative risk assessment. Methods: A qualitative risk assessment was constructed utilising the current World Organisation for Animal Health (OIE) published framework for importation risk assessment, assessing the key areas of disease entry, exposure and consequences to the UK equine population. Results: The overall risk of EP entry to the UK via importation of infected equidae with acute disease is very low but considered medium with subclinical carrier animals. Entry via importation of ticks or the importation of blood is considered very low. The risk of EP exposure to susceptible equidae in the UK is considered low by the infection routes of tick-bites, contaminated needles and contaminated blood, but very high via transplacental transfer. However, the consequences of EP endemic establishment are considered of high significance to the UK equine industry. Main limitations: A lack of available numerical data for events and variables in disease import risk meant a qualitative assessment was the most practical method for this scenario. Conclusions: This risk assessment highlights that EP positive animals are able to enter and are currently present in the UK, and that conditions do exist that could allow forward transmission of the disease. It has highlighted a gap in existing policy where the UK falls behind OIE guidelines and has suggested steps to correct this discrepancy and improve national biosecurity

An Economic Evaluation of Preclinical Testing Strategies Compared to the Compulsory Scrapie Flock Scheme in the Control of Classical Scrapie

Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS). However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years). Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST) was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic). The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS

Extending the first-order post-Newtonian scheme in multiple systems to the second-order contributions to light propagation

In this paper, we extend the first-order post-Newtonian scheme in multiple systems presented by Damour-Soffel-Xu to the second-order contribution to light propagation without changing the virtueof the scheme on the linear partial differential equations of the potential and vector potential. The spatial components of the metric are extended to second order level both in a global coordinates ($q_{ij}/ c^4$) and a local coordinates ($Q_{ab}/ c^4$). The equations of $q_{ij}$ (or $Q_{ab}$) are obtained from the field equations.The relationship between $q_{ij}$ and $Q_{ab}$ are presented in this paper also. In special case of the solar system (isotropic condition is applied ($q_{ij} = \delta_{ij} q$)), we obtain the solution of $q$. Finally, a further extension of the second-order contributions in the parametrized post-Newtonian formalism is discussed.Comment: Latex2e; 6 pages PS fil

Summary of current knowledge of the size and spatial distribution of the horse population within Great Britain

<b>Background</b> Robust demographic information is important to understanding the risk of introduction and spread of exotic diseases as well as the development of effective disease control strategies, but is often based on datasets collected for other purposes. Thus, it is important to validate, or at least cross-reference these datasets to other sources to assess whether they are being used appropriately. The aim of this study was to use horse location data collected from different contributing industry sectors ("Stakeholder horse data") to calibrate the spatial distribution of horses as indicated by owner locations registered in the National Equine Database (the NED).<p></p> <b>Results</b> A conservative estimate for the accurately geo-located NED horse population within GB is approximately 840,000 horses. This is likely to be an underestimate because of the exclusion of horses due to age or location criteria. In both datasets, horse density was higher in England and Wales than in Scotland. The high density of horses located in urban areas as indicated in the NED is consistent with previous reports indicating that owner location cannot always be viewed as a direct substitute for horse location. Otherwise, at a regional resolution, there are few differences between the datasets. There are inevitable biases in the stakeholder data, and leisure horses that are unaffiliated to major stakeholders are not included in these data. Despite this, the similarity in distributions of these datasets is re-assuring, suggesting that there are few regional biases in the NED.<p></p> <b>Conclusions</b> Our analyses suggest that stakeholder data could be used to monitor possible changes in horse demographics. Given such changes in horse demographics and the advantages of stakeholder data (which include annual updates and accurate horse location), it may be appropriate to use these data for future disease modelling in conjunction with, if not in place of the NED

Risk-based evidence for animal health policy

No abstract available