L Kelly

University of Strathclyde, Glasgow, Scotland, United Kingdom

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Publications (29)60.65 Total impact

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    ABSTRACT: AimsTo estimate qualitatively the probabilities of release (or entry) of Eurasian lineage H5N1 highly pathogenic avian influenza (HPAI) virus into Great Britain (GB), the Netherlands and Italy through selected higher risk species of migratory water bird. Methods and ResultsThe probabilities of one or more release events of H5N1 HPAI per year (prelease) were estimated qualitatively for 15 avian species, including swans, geese, ducks and gulls, by assessing the prevalence of H5N1 HPAI in different regions of the world (weighted to 2009) and estimates of the total numbers of birds migrating from each of those regions. The release assessment accommodated the migration times for each species in relation to the probabilities of their surviving infection and shedding virus on arrival. Although the predicted probabilities of release of H5N1 per individual bird per year were low, very low or negligible, prelease was high for a few species reflecting the high numbers of birds migrating from some regions. Values of prelease were generally higher for the Netherlands than for GB, while ducks and gulls from Africa presented higher probabilities to Italy compared to the Netherlands and GB. Conclusions Bird species with high values of prelease in GB, the Netherlands and Italy generally originate from within Europe based on data for global prevalence of H5N1 between 2003 and 2009 weighted to 2009. Potential long distance transfer of H5N1 HPAI from North Asia and Eurasia to GB, the Netherlands and Italy is limited to a few species and does not occur from South East Asia, an area where H5N1 is endemic. Significance and Impact of the StudyThe approach accommodates bio-geographic conditions and variability in the estimated worldwide prevalence of the virus. The outputs of this release assessment can be used to inform surveillance activities through focusing on certain species and migratory pathways.This article is protected by copyright. All rights reserved.
    Journal of Applied Microbiology 03/2014; · 2.20 Impact Factor
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    ABSTRACT: In recent years, several animal disease epidemics have occurred within the European Union (EU). At the 4th Annual Meeting of the EPIZONE network (7-10 June 2010, St. Malo, France), an interactive session was run to elicit the opinions of delegates on a pre-defined list of epidemic threats to the EU. Responses from over 190 delegates, to questions relating to impact and likelihood, were used to rank six virus groups with respect to their perceived threat now (2010) and in 2020. The combined opinions of all delegates suggested that, from the pre-selected list of virus groups, foot-and-mouth disease and influenza are currently of most concern. Delegates thought that influenza would be less of a threat and zoonotic arboviruses would be more of a threat in 2020. Although the virus group rankings should not be taken as definitive, the results could be used in conjunction with experimental and field data, by scientists, policy-makers and stakeholders when assessing and managing risks associated with these virus groups.
    Transboundary and Emerging Diseases 07/2012; · 2.10 Impact Factor
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    ABSTRACT: The goat population in Great Britain (GB), which is mostly oriented to milk production, is small compared to that in other European Union (EU) countries and contributes a very small fraction of the total livestock production. The recent confirmation and cull of scrapie-affected goat herds has raised the concern that the risk of re-introducing scrapie by mass restocking after the cull of a scrapie-affected herd, may not have been fully considered at the time of implementing statutory eradication measures. A conditional probability model has been developed to estimate the probability of introducing at least one animal infected with classical scrapie into a British goat herd under two scenarios: restocking over one year under normal operating conditions (Scenario 1); and restocking post a whole herd cull as part of the compulsory eradication measures (Scenario 2). Several of the parameters were based on expert opinion, as there is a paucity of data regarding goat industry norms for all sectors. Considering all herds, of which 99% have less than 100 animals, the probability of introduction is approximately 2 times higher for Scenario (2) than for Scenario (1). The risk of subsequently re-introducing the disease through the introduction of replacement stock is not insignificant, although it can be considered very low for the vast majority of herds (>99%). In the case of very large herds (>1000 heads), mass restocking would almost certainly reintroduce the disease since it would require purchases from a very large number of herds.
    Preventive Veterinary Medicine 06/2012; · 2.39 Impact Factor
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    ABSTRACT: To predict the risk of incursion of Crimean-Congo haemorrhagic fever virus (CCHFV) in livestock in Europe introduced through immature Hyalomma marginatum ticks on migratory birds under current conditions and in the decade 2075-2084 under a climate-change scenario. A spatial risk map of Europe comprising 14 282 grid cells (25 × 25 km) was constructed using three data sources: (i) ranges and abundances of four species of bird which migrate from sub-Saharan Africa to Europe each spring, namely Willow warbler (Phylloscopus trochilus), Northern wheatear (Oenanthe oenanthe), Tree pipit (Anthus trivialis) and Common quail (Coturnix coturnix); (ii) UK Met Office HadRM3 spring temperatures for prediction of moulting success of immature H. marginatum ticks and (iii) livestock densities. On average, the number of grid cells in Europe predicted to have at least one CCHFV incursion in livestock in spring was 1·04 per year for the decade 2005-2014 and 1·03 per year for the decade 2075-2084. In general with the assumed climate-change scenario, the risk increased in northern Europe but decreased in central and southern Europe, although there is considerable local variation in the trends. The absolute risk of incursion of CCHFV in livestock through ticks introduced by four abundant species of migratory bird (totalling 120 million individual birds) is very low. Climate change has opposing effects, increasing the success of the moult of the nymphal ticks into adults but decreasing the projected abundance of birds by 34% in this model. For Europe, climate change is not predicted to increase the overall risk of incursion of CCHFV in livestock through infected ticks introduced by these four migratory bird species.
    Journal of Applied Microbiology 11/2011; 112(2):246-57. · 2.20 Impact Factor
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    ABSTRACT: The monitoring and surveillance of animal diseases is becoming increasingly important to policy-makers in Great Britain particularly given recent incursions of avian influenza and the emergence of bovine spongiform encephalopathy. To meet this surveillance objective, data from British livestock is collected and analysed retrospectively on an ongoing basis. However, these data can also be analysed prospectively within an early detection system which raises alerts to significant increases in disease reporting soon after they occur in the field. The feasibility of such an approach has been examined previously for Salmonella. This paper applied the approach to a further subset of surveillance data to alert those monitoring disease to increases in potentially new and emerging diseases. Thus far, the analysis, conducted on a quarterly basis, has proved a useful additional tool in enhanced surveillance by raising alerts to significant increases in several syndromes in both sheep and cattle.
    Epidemiology and Infection 11/2010; 139(10):1476-85. · 2.87 Impact Factor
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    ABSTRACT: The antibiotic resistance profiles of 75 Campylobacter isolates of food and human clinical origin was determined by two agar diffusion susceptibility methods; disc diffusion and epsilometer-test (E-test). The most common therapeutic antimicrobials, erythromycin, ciprofloxacin and tetracycline were studied, along with chloramphenicol, ampicillin and naladixic acid. The resistance observed for each antimicrobial, as determined by both of methods, were statistically compared using Fisher two-tailed analysis. Of the six antimicrobials studied only two were shown to have statistically different patterns when resistance was compared by disc diffusion and E-test. The percentage of isolates resistant to clinically relevant antimicrobials using both techniques ranged from 6.6 to 21.3% for erythromycin, 25.3-26.6% for tetracycline and 33.3-36.0% for ciprofloxacin. The prevalence of multi-drug resistant (MDR) campylobacters (isolates resistant to 2 or more antimicrobials) for both disc diffusion and E-test was 44%. It can be concluded that, for four of the six antimicrobials assessed, antimicrobial resistance prevalences could be equally determined by either of the methods studied.
    Journal of microbiological methods 09/2009; 79(2):238-41. · 2.43 Impact Factor
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    ABSTRACT: Expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the European Union (EU) from five vector-borne viruses listed by the World Organization for Animal Health. It was predicted that climate change will increase the risk of incursions of African horse sickness virus (AHSV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV) into the EU from other parts of the world, with African swine fever virus (ASFV) and West Nile virus (WNV) being less affected. Currently the predicted risks of incursion were lowest for RVFV and highest for ASFV. Risks of incursion were considered for six routes of entry (namely vectors, livestock, meat products, wildlife, pets and people). Climate change was predicted to increase the risk of incursion from entry of vectors for all five viruses to some degree, the strongest effects being predicted for AHSV, CCHFV and WNV. This work will facilitate identification of appropriate risk management options in relation to adaptations to climate change.
    Epidemiology and Infection 08/2009; 138(2):214-25. · 2.87 Impact Factor
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    ABSTRACT: A quantitative model was constructed to estimate the probability that a serving of food containing eggs produced on the island of Ireland is contaminated with Salmonella spp. The model is based on the prevalence of contaminated eggs at the time of lay and a set of parameters which describe the pooling of eggs in the home and in catering situations. Both external and internal contamination of the eggs by Salmonella spp. was considered. The model estimates that there is a 90% chance that the probability of a serving of food being contaminated is between 0.0043% and 0.038%. Sensitivity analysis demonstrated that egg prevalence drives this low probability and that, at the current level of egg prevalence at the time of lay, pooling of eggs has a minor effect. These results indicate the importance of maintaining the low prevalence of contaminated eggs at the time of lay to minimise the risk of human cases of salmonellosis from consumption of eggs.
    International journal of food microbiology 08/2009; 135(3):187-92. · 3.01 Impact Factor
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    ABSTRACT: A qualitative exposure assessment for Salmonella in eggs produced on the island of Ireland was developed. The assessment was divided into three main modules (production and packing, distribution and storage, and preparation and consumption), and each of these stages into defined steps in the exposure pathway. In the production and packing stage the initial prevalences of Salmonella in the contents and on the shell of eggs were estimated to be negligible and low respectively. Numbers of Salmonella both in and on eggs were estimated to be low. At each subsequent step in the pathway, qualitative assessments were made of the impact of events on the probability and level of Salmonella contamination on the shells and in the contents of eggs. At the end of each module assessments were combined to give an overall probability and level of Salmonella contamination. In the first two modules the assessment focused on the effect of the duration and temperature of storage on yolk membrane integrity and the likelihood of shell penetration. During the final stage the influence of factors such as safe-handling procedures, pooling practices, consumption patterns and the effectiveness of cooking, on the prevalence and level of Salmonella contamination in a food item at time of consumption was assessed. The outcome of this assessment was an estimate of a low probability and level of Salmonella contamination of egg-containing foods, prepared with eggs produced on the island of Ireland.
    International Journal of Food Microbiology 06/2008; 125(3):308-19. · 3.43 Impact Factor
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    ABSTRACT: Following the emergence of Salmonella Enteritidis as a widespread contaminant of eggs and the role of eggs in the transmission of human salmonellosis, control measures were introduced to curb the spread of infection. Two approaches to Salmonella control are currently used by egg producers in Ireland, because Northern Ireland producers, like those in the rest of the United Kingdom, widely adopted a vaccination regime, whereas the Republic of Ireland does not permit vaccination but introduced controls based on routine monitoring for specific Salmonella serovars and subsequent culling of infected flocks. To compare the efficacy of these two approaches and determine the prevalence of salmonellae in eggs produced for retail sale in the island of Ireland, a major survey of approximately 30,000 grade A eggs was undertaken. Egg shells and contents were analyzed separately for salmonellae by procedures based on International Organization for Standardization methodology. The survey yielded only two positive samples, with Salmonella Infantis and Salmonella Montevideo isolated from shells; no egg contents yielded salmonellae. There was no statistically significant difference in the prevalence of salmonellae between eggs produced in Northern Ireland and those from the Republic of Ireland; hence, both regimes appeared to be equally effective in controlling salmonellae. The prevalence was also significantly lower than that found in a recent major United Kingdom survey. Hence, shell eggs produced in the island of Ireland are unlikely to be a source of human salmonellosis.
    Journal of food protection 06/2007; 70(5):1238-40. · 1.83 Impact Factor
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    The Veterinary record 06/2006; 158(20):694-5. · 1.80 Impact Factor
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    The Veterinary record 10/2005; 157(11):321-2. · 1.80 Impact Factor
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    ABSTRACT: Great Britain has been rabies-free since 1922, which is often considered to be in part due to the strict laws requiring that imported cats and dogs be vaccinated and quarantined for 6 months immediately on entry into the country. Except for two isolated incidents, this quarantine policy has contributed to ensuring that Great Britain has remained free of rabies. In 2000, amendments to the UK quarantine laws were made and the Pet Travel Scheme (PETS) was launched for companion animals traveling from European Union countries and rabies-free islands. Since its introduction, it has been proposed that other countries including North America should be included within the UK scheme. A quantitative risk assessment was developed to assist in the policy decision to amend the long-standing quarantine laws for dogs and cats from North America. It was determined that the risk of rabies entry is very low and is dependent on the level of compliance (i.e., legally conforming to all of the required regulations) with PETS and the number of pets imported. Assuming 100% compliance with PETS and the current level of importation of cats and dogs from North America, the annual probability of importing rabies is lower for animals traveling via PETS (7.22 x 10(-6), 95th percentile) than quarantine (1.01 x 10(-5), 95th percentile). These results, and other scientific evidence, directly informed the decision to expand the PETS scheme to North America as of December 2002.
    Risk Analysis 07/2005; 25(3):533-42. · 2.28 Impact Factor
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    ABSTRACT: The use of antibiotics for animal growth promotion has been controversial because of the potential transfer of antibiotic resistance from animals to humans. Such transfer could have severe public health implications in that treatment failures could result. We have followed a risk assessment approach to evaluate policy options for the streptogramin-class of antibiotics: virginiamycin, an animal growth promoter, and quinupristin/dalfopristin, a antibiotic used in humans. Under the assumption that resistance transfer is possible, models project a wide range of outcomes depending mainly on the basic reproductive number (R(0)) that determines the potential for person-to-person transmission. Counter-intuitively, the benefits of a ban on virginiamycin were highest for intermediate values of R(0), and lower for extremely high or low values of R(0).
    International Journal of Antimicrobial Agents 10/2004; 24(3):205-12. · 4.42 Impact Factor
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    ABSTRACT: The emergence of antimicrobial-resistant microorganisms in both humans and food animals is a growing concern. Debate has centred on links between antimicrobial use in the production of food animals and the emergence of resistant organisms in the human population. Consequently, microbial risk assessment (MRA) is being used to facilitate scientific investigations of the risks related to the food chain, including quantification of uncertainty and prioritization of control strategies. MRA is a scientific tool that can be used to evaluate the level of exposure and the subsequent risk to human health relating to a specific organism or particular type of resistance. This paper reviews the recent applications of MRA in the area of antimicrobial resistance, and in particular, it focuses on the methods, assumptions and data limitations. Since MRA outputs are dependent on the quality of data inputs used in their development, we aim to promote the generation of good quality data by describing the properties that data should ideally possess for MRA and by highlighting the benefit of data generation specifically for inclusion in MRAs.
    Journal of Antimicrobial Chemotherapy 07/2004; 53(6):906-17. · 5.34 Impact Factor
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    ABSTRACT: Great Britain (GB) has been "Officially Brucellosis Free" (OBF) since 1991; because this disease has both public-health and international-trade implications, it is in the country's interest to maintain this freedom. A quantitative risk-assessment model was developed to determine the annual risk of importing brucellosis-infected breeding cattle into GB from Northern Ireland and the Republic of Ireland. (These countries exported the largest number of cattle into GB and were not brucellosis free during the development of the assessment in 2000.) We predicted that we can expect to import brucellosis from Northern Ireland every 2.63 years (1.89, 4.17) and from the Republic of Ireland, every 3.23 years (2.13, 5.88). The estimates of risk are sensitive to the assumed proportion of animals missed during routine surveillance that originate from OBF herds and the uncertainty associated with the surveillance test sensitivities. As a result of the assessment, the Department for Environment, Food and Rural Affairs (Defra) introduced post-calving testing for all cattle imported into British herds.
    Preventive Veterinary Medicine 05/2004; 63(1-2):51-61. · 2.39 Impact Factor
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    ABSTRACT: Brucellosis is a widespread, economically devastating and highly infectious zoonosis. In cattle, infection predominantly is caused by Brucella abortus, and is usually detected in pregnant females through abortions. Great Britain (GB) has been declared free from brucellosis (officially brucellosis free (OBF)) since 1993 and as such is required by European Union (EU) regulations to test > or =20% of both beef and dairy cattle >24 months old routinely. Currently, however, GB serologically tests more cattle than required and the issue of reducing the level of testing has come under consideration. We developed a simulation model to determine the rate of spread of brucellosis under a variety of testing regimes. For dairy herds, we found that reducing the level of testing would have a major effect on the rate of spread of infection, should it be imported. For beef herds, reducing the level of testing would have much less effect. We also found that abortion notification is a very-important additional means of surveillance. As a result of our predictions, policy-makers decided not to reduce the level of testing and actively to promote abortion notification.
    Preventive Veterinary Medicine 04/2004; 63(1-2):63-73. · 2.39 Impact Factor
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    ABSTRACT: The risk of dispersing foot-and-mouth disease virus into the atmosphere, and spreading it to susceptible holdings as a result of burning large numbers of carcases together on open pyres, has been estimated for six selected pyres burned during the 2001 outbreak in the UK. The probability of an animal or holding becoming infected was dependent on the estimated level of exposure to the virus predicted from the concentrations of virus calculated by the Met Office, Bracknell. In general, the probability of infection per animal and per holding decreased as their distance from the pyre increased. In the case of two of the pyres, a holding under the pyre plumes became infected on a date consistent with when the pyre was lit. However, by calculating their estimated probability of infection from the pyres it was concluded that it was unlikely that in either case the pyre was the source of infection.
    The Veterinary record 03/2004; 154(6):161-5. · 1.80 Impact Factor
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    ABSTRACT: European directives require that all veterinary medicines be assessed to determine the harmful effects that their use may have on the environment. Fundamental to this assessment is the calculation of the predicted environmental concentration (PEC), which is dependent on the type of drug, its associated treatment characteristics, and the route by which residues enter the environment. Deterministic models for the calculation of the PEC have previously been presented. In this article, the inclusion of variability and uncertainty within such models is introduced. In particular, models for the calculation of the PEC for residues excreted directly onto pasture by grazing animals are considered and comparison of deterministic and stochastic results suggest that uncertainty and variability cannot be ignored.
    Risk Analysis 07/2003; 23(3):489-96. · 2.28 Impact Factor
  • PROCEEDINGS-SOCIETY FOR VETERINARY EPIDEMIOLOGY AND PREVENTIVE MEDICINE. 01/2003;