Dr Nick Selemetas
Publications
Background Human, animal, and environmental health are increasingly threatened by the emergence and spread of antibiotic resistance. Inappropriate use of antibiotic treatments commonly contributes to this threat, but it is also becoming apparent that multiple, interconnected environmental factors can play a significant role. Thus, a One Health approach is required for a comprehensive understanding of the environmental dimensions of antibiotic resistance and inform science-based decisions and actions. The broad and multidisciplinary nature of the problem poses several open questions drawing upon a wide heterogeneous range of studies. Objective This study seeks to collect and catalogue the evidence of the potential effects of environmental factors on the abundance or detection of antibiotic resistance determinants in the outdoor environment, i.e., antibiotic resistant bacteria and mobile genetic elements carrying antibiotic resistance genes, and the effect on those caused by local environmental conditions of either natural or anthropogenic origin. Methods Here, we describe the protocol for a systematic evidence map to address this, which will be performed in adherence to best practice guidelines. We will search the literature from 1990 to present, using the following electronic databases: MEDLINE, Embase, and the Web of Science Core Collection as well as the grey literature. We shall include full-text, scientific articles published in English. Reviewers will work in pairs to screen title, abstract and keywords first and then full-text documents. Data extraction will adhere to a code book purposely designed. Risk of bias assessment will not be conducted as part of this SEM. We will combine tables, graphs, and other suitable visualisation techniques to compile a database i) of studies investigating the factors associated with the prevalence of antibiotic resistance in the environment and ii) map the distribution, network, cross-disciplinarity, impact and trends in the literature.
Fasciola hepatica infection challenges health, welfare and productivity of small ruminants throughout the world. The distribution of F. hepatica in sheep in Europe is usually scattered and studies are generally concerned with a single area making it difficult to compare results from different environments, climates and management regimes. In order to elucidate the current scenario in terms of prevalence and intensity of F. hepatica infection in sheep farms across Europe, a standardized cross-sectional survey was conducted in three pilot areas in Ireland, Switzerland and Italy, all part of the EU funded GLOWORM project. Two consecutive field surveys (in 2012 and 2013) were conducted in the three countries in the same period (August-October) in 361 sheep farms in total. Harmonized procedures (from farm to laboratory) based on pooled samples and the highly sensitive and accurate, diagnostic FLOTAC technique were used. The georeferenced parasitological results were modelled (at the pilot area level) following a Bayesian geostatistical approach with correction for preferential sampling and accounting for climatic and environmental covariates. The observed F. hepatica prevalence rates did not differ between the two study years in any of the three pilot areas, but they did vary between the countries showing high values in Ireland (61.6%) compared to Italy (7.9%) and Switzerland (4.0%). Spatial patterns of F. hepatica distribution were detected by the Bayesian geostatistical approach in Ireland with a high risk of infection in the south-western part of the pilot area there. The latent factor analysis highlighted the importance of year-to-year variation of mean temperature, rainfall and seasonality within a country, while long-term trends of temperature and rainfall dominated between countries with respect to prevalence of infection.
Haemonchus contortus is a species of gastrointestinal strongyles of primary concern for sheep. This highly pathogenic, blood-feeding helminth negatively influences animal health, welfare and productivity. In order to elucidate the current scenario in terms of prevalence and intensity of H. contortus infection in sheep farms across Europe, a standardized crosssectional survey was conducted in three pilot areas in Ireland, Switzerland and Italy, all part of the EU funded GLOWORM project. Two consecutive field surveys (in 2012 and 2013) were conducted in the three countries in the same period (August-October) in 259 sheep farms in total. Harmonized, diagnostic procedures (from farm to laboratory) based on pooled samples, the FLOTAC technique and coproculture were used. The georeferenced parasitological results were modelled (at the pilot area level) following a Bayesian geostatistical approach with correction for preferential sampling and accounting for climatic and environmental covariates. The observed H. contortus prevalence rates did vary between the countries showing high values in Switzerland (77%) and Italy (73%) compared to Ireland (4%). Spatial patterns of H. contortus distribution were detected in Switzerland and Italy with a north-south gradient. The latent factor analysis highlighted the importance of seasonality and annual cyclicity within country (particularly in southern Italy), while mean temperature and rainfall dominated between country variations in the prevalence of H. contortus infection.
Additional publications
Selemetas N., de Waal T. 2015. Detection of major climatic and environmental predictors of liver fluke exposure risk in Ireland using spatial cluster analysis. Veterinary Parasitology. doi:10.1016/j.vetpar.2015.02.029
Ducheyne E., Charlier J., Vercruysse J., Rinaldi L., Biggeri A., Demeler J., Brandt C., de Waal T., Selemetas N., Höglund J., Kaba J., Kowalczyk SJ., Hendrickx G. Modelling the spatial distribution of Fasciola hepatica in dairy cattle in Europe. Geospatial Health 9(2), 261-270
Rinaldi L., Biggeri A., Musella, V., de Waal T., Hertzberg H., Mavrot F., Torgerson PR., Selemetas N., Coll T., Bosco A., Grisotto L., Cringoli G., Catelan D. 2015. Sheep and Fasciola hepatica in Europe: the GLOWORM experience. Geospatial Health. 9(2), 309-317
Rinaldi L., Catelan D., Musella, V., Cecconi L., Hertzberg H., Torgerson PR., Mavrot F., de Waal T,., Selemetas N., Coll T., Bosco A., Biggeri A., Cringoli G. 2015. Haemonchus contortus: spatial risk distribution for infection in sheep in Europe. Geospatial Health. 9(2), 325-331
Selemetas N., Phelan P., O' Kiely P., de Waal T. 2015. Cluster analysis of fasciolosis in dairy cow herds in Munster province of Ireland and detection of major climatic and environmental predictors of the exposure risk. Geospatial Health 9(2), 271-279
Selemetas N., Ducheyne E., Phelan P., O' Kiely P., Hendrickx G., de Waal T. 2015. Spatial analysis and risk mapping of Fasciola hepatica infection in dairy herds in Ireland. Geospatial Health. 9(2), 281-291
Selemetas N., Phelan P., O' Kiely P., de Waal T. 2015. The effects of farm management practices on liver fluke prevalence and the current internal parasite control measures employed on Irish dairy farms. Veterinary Parasitology. 207, 228-240
Selemetas N., Phelan P., O' Kiely P., de Waal T. 2014. Weather and soil type affect incidence of fasciolosis in dairy cow herds. Veterinary Record 2014; 175:371 doi:10.1136/vr.102437