Search

Your search keyword '"O'Hanlon, Simon"' showing total 25 results
Start Over Author "O'Hanlon, Simon" Search Limiters Full Text

Refine your results

more »

more »

more »

more »
25 results on '"O'Hanlon, Simon"'

1. Spatial and temporal distribution of onchocerciasis in West Africa, with particular reference to Ghana

Author

O'Hanlon, Simon, Basáñez, Maria-Gloria, Cheke, Robert, and Prichard, Roger

Subjects
614
Abstract

Background. Quantifying and predicting the effect of control interventions against infectious diseases requires knowledge about prevalence prior to the implementation of such control measures as well as knowledge of key parameters which affect model outcomes. Here is presented the first geostatistical map estimating the prevalence of human onchocerciasis in the former Onchocerciasis Control Programme in West Africa (OCP) before the initiation of vector control operations in 1975. The map is used to quantify the burden of onchocercal skin disease prior to interventions. The results of a socioeconomic survey investigating coverage and compliance to community-directed treatment with ivermectin are then presented. Methods and Findings. The OCP epidemiological database was investigated for spatial autocorrelation. A total of 737 village surveys had parasitological examinations conducted prior to the start of control. Using these 737 pre-control data points plus environmental covariates, a Bayesian model-based geostatistical (B-MBG) approach was used to generate a continuous surface (at a pixel resolution of 25km2) of microfilarial prevalence in West Africa prior to the commencement of the OCP. The mean Pearson’s correlation between observed prevalence and model-estimates of prevalence at hold-out locations was 0.693; mean prediction error was 0.77% and mean absolute prediction error was 12.2%. Within OCP boundaries, 17.8 million people were deemed to be at risk and 7.6 million infected in 1975 which is greater than previous estimates. The mean microfilarial prevalence across all countries was 45% (range: 2–90%). Conclusions and Significance. This is the first map of continuous onchocerciasis prevalence in West Africa, developed using robust geostatistical methods. Important environmental predictors of infection prevalence were identified and used in a model that out-performs those without spatial-random effects or environmental covariates. Our results may be compared with recent epidemiological mapping efforts to find areas of persisting transmission, informing feasibility of elimination with current and novel tools.

Published
2018
Full Text
View/download PDF

2. A Population-Based Study of the Incidence and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus Disease in San Francisco, 2004—2005

Author

Liu, Catherine, Graber, Christopher J., Karr, Michael, Diep, Binh An, Basuino, Li, Schwartz, Brian S., Enright, Mark C., O'Hanlon, Simon J., Thomas, Jonathon C., Perdreau-Remington, Francoise, Gordon, Shelley, Gunthorpe, Helen, Jacobs, Richard, Jensen, Peter, Leoung, Giffford, Rumack, James S., and Chambers, Henry F.

Published
2008
Full Text
View/download PDF

3. Chytridiomycosis Outbreak in a Chilean Giant Frog (Calyptocephalella gayi) Captive Breeding Program: Genomic Characterization and Pathological Findings

Author

Alvarado-Rybak, Mario, primary, Acuña, Paz, additional, Peñafiel-Ricaurte, Alexandra, additional, Sewell, Thomas R., additional, O'Hanlon, Simon J., additional, Fisher, Matthew C., additional, Valenzuela-Sánchez, Andres, additional, Cunningham, Andrew A., additional, and Azat, Claudio, additional

Published
2021
Full Text
View/download PDF

4. Discriminating lineages of Batrachochytrium dendrobatidis using quantitative PCR

Author

Ghosh, Pria, Verster, Ruhan, Sewell, Thomas R., O'Hanlon, Simon J., Brookes, Lola M., Rieux, Adrien, Garner, Trenton W. J., Weldon, Ché, Fisher, Matthew C., Ghosh, Pria, Verster, Ruhan, Sewell, Thomas R., O'Hanlon, Simon J., Brookes, Lola M., Rieux, Adrien, Garner, Trenton W. J., Weldon, Ché, and Fisher, Matthew C.

Abstract

The ability to detect and monitor infectious disease in a phylogenetically informative manner is critical for their management. Phylogenetically informative diagnostic tests enable patterns of pathogen introduction or changes in the distribution of genotypes to be measured, enabling research into the ecology of the pathogen. Batrachochytrium dendrobatidis (Bd), a causative agent of chytridiomycosis in amphibian populations, emerged worldwide in the 21st century and is composed of six lineages which are display varying levels of virulence in their hosts. Research into the distribution, ecology and pathogenicity of these lineages has been hampered by an inability to type lineage efficiently. Here, we describe a lineage-specific TaqMan qPCR assay that differentiates the two lineages of Bd most commonly associated with chytridiomycosis: BdGPL and BdCAPE. We demonstrate how this assay can be used for the surveillance of wild populations of amphibians in Southern Africa using skin swabs, tissue samples and cultured isolates.

Published
2021

5. Additional file 1: of Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns

Author

Cano, Jorge, Maria-Gloria Basáñez, O’Hanlon, Simon, Afework Tekle, Wanji, Samuel, Zouré, Honorat, Rebollo, Maria, and Pullan, Rachel

Abstract

Pan-African and country-specific (i.e. Cameroon and Democratic Republic of Congo) maps for lymphatic filariasis (LF); LF and onchocerciasis co-endemicity; LF, onchocerciasis and loiasis co-endemicity, and population estimates aggregated by African region. Text S1. Pan-African maps of lymphatic filariasis (LF). Figure S1. Pan-African map of LF endemicity at the level of implementation units (IU). Figure S2. Pan-African map of co-endemic areas for LF and onchocerciasis. Figure S3. Map of loiasis, LF and onchocerciasis co-endemicity in eastern Cameroon. Figure S4. Map of loiasis, LF and onchocerciasis co-endemicity in Oriental province, DRC. Table S1. Estimates of population living in endemic areas for lymphatic filariasis (LF) and/or onchocerciasis (oncho). Table S2. Population estimates for co-endemic areas of lymphatic filariasis, onchocerciasis and high prevalence of loiasis. (DOCX 2183 kb)

Published
2018
Full Text
View/download PDF

6. Development and worldwide use of non-lethal, and minimal population-level impact, protocols for the isolation of amphibian chytrid fungi

Author

Fisher, Matthew C., primary, Ghosh, Pria, additional, Shelton, Jennifer M. G., additional, Bates, Kieran, additional, Brookes, Lola, additional, Wierzbicki, Claudia, additional, Rosa, Gonçalo M., additional, Farrer, Rhys A., additional, Aanensen, David M., additional, Alvarado-Rybak, Mario, additional, Bataille, Arnaud, additional, Berger, Lee, additional, Böll, Susanne, additional, Bosch, Jaime, additional, Clare, Frances C., additional, A. Courtois, Elodie, additional, Crottini, Angelica, additional, Cunningham, Andrew A., additional, Doherty-Bone, Thomas M., additional, Gebresenbet, Fikirte, additional, Gower, David J., additional, Höglund, Jacob, additional, James, Timothy Y., additional, Jenkinson, Thomas S., additional, Kosch, Tiffany A., additional, Lambertini, Carolina, additional, Laurila, Anssi, additional, Lin, Chun-Fu, additional, Loyau, Adeline, additional, Martel, An, additional, Meurling, Sara, additional, Miaud, Claude, additional, Minting, Pete, additional, Ndriantsoa, Serge, additional, O’Hanlon, Simon J., additional, Pasmans, Frank, additional, Rakotonanahary, Tsanta, additional, Rabemananjara, Falitiana C. E., additional, Ribeiro, Luisa P., additional, Schmeller, Dirk S., additional, Schmidt, Benedikt R., additional, Skerratt, Lee, additional, Smith, Freya, additional, Soto-Azat, Claudio, additional, Tessa, Giulia, additional, Toledo, Luís Felipe, additional, Valenzuela-Sánchez, Andrés, additional, Verster, Ruhan, additional, Vörös, Judit, additional, Waldman, Bruce, additional, Webb, Rebecca J., additional, Weldon, Che, additional, Wombwell, Emma, additional, Zamudio, Kelly R., additional, Longcore, Joyce E., additional, and Garner, Trenton W. J., additional

Published
2018
Full Text
View/download PDF

7. Development and worldwide use of non-lethal, and minimal population-level impact, protocols for the isolation of amphibian chytrid fungi

Author

Fisher, Matthew C., Ghosh, Pria, Shelton, Jennifer M. G., Bates, Kieran, Brookes, Lola, Wierzbicki, Claudia, Rosa, Goncalo M., Farrer, Rhys A., Aanensen, David M., Alvarado-rybak, Mario, Bataille, Arnaud, Berger, Lee, Boell, Susanne, Bosch, Jaime, Clare, Frances C., Courtois, Elodie A., Crottini, Angelica, Cunningham, Andrew A., Doherty-bone, Thomas M., Gebresenbet, Fikirte, Gower, David J., Hoglund, Jacob, James, Timothy Y, Jenkinson, Thomas S., Kosch, Tiffany A., Lambertini, Carolina, Laurila, Anssi, Lin, Chun-fu, Loyau, Adeline, Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Ndriantsoa, Serge, O'Hanlon, Simon J., Pasmans, Frank, Rakotonanahary, Tsanta, Rabemananjara, Falitiana C. E., Ribeiro, Luisa P., Schmeller, Dirk S., Schmidt, Benedikt R., Skerratt, Lee, Smith, Freya, Soto-azat, Claudio, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-sanchez, Andres, Verster, Ruhan, Voeroes, Judit, Waldman, Bruce, Webb, Rebecca J., Weldon, Che, Wombwell, Emma, Zamudio, Kelly R., Longcore, Joyce E., Garner, Trenton W. J., Fisher, Matthew C., Ghosh, Pria, Shelton, Jennifer M. G., Bates, Kieran, Brookes, Lola, Wierzbicki, Claudia, Rosa, Goncalo M., Farrer, Rhys A., Aanensen, David M., Alvarado-rybak, Mario, Bataille, Arnaud, Berger, Lee, Boell, Susanne, Bosch, Jaime, Clare, Frances C., Courtois, Elodie A., Crottini, Angelica, Cunningham, Andrew A., Doherty-bone, Thomas M., Gebresenbet, Fikirte, Gower, David J., Hoglund, Jacob, James, Timothy Y, Jenkinson, Thomas S., Kosch, Tiffany A., Lambertini, Carolina, Laurila, Anssi, Lin, Chun-fu, Loyau, Adeline, Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Ndriantsoa, Serge, O'Hanlon, Simon J., Pasmans, Frank, Rakotonanahary, Tsanta, Rabemananjara, Falitiana C. E., Ribeiro, Luisa P., Schmeller, Dirk S., Schmidt, Benedikt R., Skerratt, Lee, Smith, Freya, Soto-azat, Claudio, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-sanchez, Andres, Verster, Ruhan, Voeroes, Judit, Waldman, Bruce, Webb, Rebecca J., Weldon, Che, Wombwell, Emma, Zamudio, Kelly R., Longcore, Joyce E., and Garner, Trenton W. J.

Abstract

Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating chytrids from infected animals to use toe clips and biopsies from toe webbing rather than euthanizing hosts, and distributed the protocol to researchers as part of the BiodivERsA project RACE; here called the RML protocol. In tandem, we developed a lethal procedure for isolating chytrids from tadpole mouthparts. Reviewing a database of use a decade after their inception, we find that these methods have been applied across 5 continents, 23 countries and in 62 amphibian species. Isolation of chytrids by the non-lethal RML protocol occured in 18% of attempts with 207 fungal isolates and three species of chytrid being recovered. Isolation of chytrids from tadpoles occured in 43% of attempts with 334 fungal isolates of one species (Batrachochytrium dendrobatidis) being recovered. Together, these methods have resulted in a significant reduction and refinement of our use of threatened amphibian species and have improved our ability to work with this group of emerging pathogens.

Published
2018
Full Text
View/download PDF

8. Recent Asian origin of chytrid fungi causing global amphibian declines

Author

O'Hanlon, Simon J., Rieux, Adrien, Farrer, Rhys A., Rosa, Goncalo M., Waldman, Bruce, Bataille, Arnaud, Kosch, Tiffany A., Murray, Kris A., Brankovics, Balazs, Fumagalli, Matteo, Martin, Michael D., Wales, Nathan, Alvarado-Rybak, Mario, Bates, Kieran A., Berger, Lee, Boell, Susanne, Brookes, Lola, Clare, Frances, Courtois, Elodie A., Cunningham, Andrew A., Doherty-Bone, Thomas M., Ghosh, Pria, Gower, David J., Hintz, William E., Höglund, Jacob, Jenkinson, Thomas S., Lin, Chun-Fu, Laurila, Anssi, Loyau, Adeline, Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Pasmans, Frank, Schmeller, Dirk S., Schmidt, Benedikt R., Shelton, Jennifer M. G., Skerratt, Lee F., Smith, Freya, Soto-Azat, Claudio, Spagnoletti, Matteo, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sanchez, Andres, Verster, Ruhan, Voros, Judit, Webb, Rebecca J., Wierzbicki, Claudia, Wombwell, Emma, Zamudio, Kelly R., Aanensen, David M., James, Timothy Y., Gilbert, M. Thomas P., Weldon, Che, Bosch, Jaime, Balloux, Francois, Garner, Trenton W. J., Fisher, Matthew C., O'Hanlon, Simon J., Rieux, Adrien, Farrer, Rhys A., Rosa, Goncalo M., Waldman, Bruce, Bataille, Arnaud, Kosch, Tiffany A., Murray, Kris A., Brankovics, Balazs, Fumagalli, Matteo, Martin, Michael D., Wales, Nathan, Alvarado-Rybak, Mario, Bates, Kieran A., Berger, Lee, Boell, Susanne, Brookes, Lola, Clare, Frances, Courtois, Elodie A., Cunningham, Andrew A., Doherty-Bone, Thomas M., Ghosh, Pria, Gower, David J., Hintz, William E., Höglund, Jacob, Jenkinson, Thomas S., Lin, Chun-Fu, Laurila, Anssi, Loyau, Adeline, Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Pasmans, Frank, Schmeller, Dirk S., Schmidt, Benedikt R., Shelton, Jennifer M. G., Skerratt, Lee F., Smith, Freya, Soto-Azat, Claudio, Spagnoletti, Matteo, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sanchez, Andres, Verster, Ruhan, Voros, Judit, Webb, Rebecca J., Wierzbicki, Claudia, Wombwell, Emma, Zamudio, Kelly R., Aanensen, David M., James, Timothy Y., Gilbert, M. Thomas P., Weldon, Che, Bosch, Jaime, Balloux, Francois, Garner, Trenton W. J., and Fisher, Matthew C.

Abstract

Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of themost devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide.

Published
2018
Full Text
View/download PDF

9. Recent Asian origin of chytrid fungi causing global amphibian declines

Author

Natural Environment Research Council (UK), Leverhulme Trust, Hungarian Scientific Research Fund, Hungarian Academy of Sciences, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Royal Geographical Society, National Research Foundation of Korea, Governo do Estado de São Paulo, Australian Research Council, Wolfson Foundation, Swedish Research Council, National Research Foundation (South Africa), Iranian National Science Foundation, Natural Sciences and Engineering Research Council of Canada, O’Hanlon, Simon J., Rieux, Adrien, Farrer, Rhys A., Rosa, Gonçalo M., Waldman, Bruce, Bataille, Arnaud, Kosch, Tiffany A., Murray, Kris A., Brankovics, Balázs, Fumagalli, Matteo, Martin, Michael D., Wales, Nathan, Alvarado-Rybak, Mario, Bates, Kieran A., Berger, Lee R., Böll, Susanne, Brookes, Lola, Clare, Frances C., Courtois, Elodie A., Cunningham, Andrew A., Doherty-Bone, Thomas M., Ghosh, Pria, Gower, David J., Hintz, William E., Höglund, Jacob, Jenkinson, Thomas S., Lin, Chun-Fu, Laurila, Anssi, Loyau, A., Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Pasmans, Frank, Schmeller, Dirk S., Schmidt, Benedikt R., Shelton, Jennifer M. G., Skerratt, Lee, Smith, Freya, Soto-Azat, Claudio, Spagnoletti, Matteo, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sánchez, Andrés, Verster, Ruhan, Vörös, Judit, Webb, Rebecca J., Wierzbicki, Claudia, Wombwell, Emma, Zamudio, Kelly R., Aanensen, David M., James, Timothy Y., Gilbert, M. Thomas P., Weldon, Ché, Bosch, Jaime, Balloux, François, Garner, Trenton W. J., Fisher, Matthew C., Natural Environment Research Council (UK), Leverhulme Trust, Hungarian Scientific Research Fund, Hungarian Academy of Sciences, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Royal Geographical Society, National Research Foundation of Korea, Governo do Estado de São Paulo, Australian Research Council, Wolfson Foundation, Swedish Research Council, National Research Foundation (South Africa), Iranian National Science Foundation, Natural Sciences and Engineering Research Council of Canada, O’Hanlon, Simon J., Rieux, Adrien, Farrer, Rhys A., Rosa, Gonçalo M., Waldman, Bruce, Bataille, Arnaud, Kosch, Tiffany A., Murray, Kris A., Brankovics, Balázs, Fumagalli, Matteo, Martin, Michael D., Wales, Nathan, Alvarado-Rybak, Mario, Bates, Kieran A., Berger, Lee R., Böll, Susanne, Brookes, Lola, Clare, Frances C., Courtois, Elodie A., Cunningham, Andrew A., Doherty-Bone, Thomas M., Ghosh, Pria, Gower, David J., Hintz, William E., Höglund, Jacob, Jenkinson, Thomas S., Lin, Chun-Fu, Laurila, Anssi, Loyau, A., Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Pasmans, Frank, Schmeller, Dirk S., Schmidt, Benedikt R., Shelton, Jennifer M. G., Skerratt, Lee, Smith, Freya, Soto-Azat, Claudio, Spagnoletti, Matteo, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sánchez, Andrés, Verster, Ruhan, Vörös, Judit, Webb, Rebecca J., Wierzbicki, Claudia, Wombwell, Emma, Zamudio, Kelly R., Aanensen, David M., James, Timothy Y., Gilbert, M. Thomas P., Weldon, Ché, Bosch, Jaime, Balloux, François, Garner, Trenton W. J., and Fisher, Matthew C.

Abstract

Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of the most devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide.

Published
2018

10. Development and worldwide use of non-lethal, and minimal population-level impact, protocols for the isolation of amphibian chytrid fungi

Author

Fundação para a Ciência e a Tecnologia (Portugal), Sao Paulo Research Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Royal Geographical Society, National Research Foundation of Korea, Leverhulme Trust, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Hungarian Academy of Sciences, Fisher, Matthew C., Ghosh, Pria, Shelton, Jennifer M. G., Bates, Kieran A., Brookes, Lola, Wierzbicki, Claudia, Rosa, Gonçalo M., Farrer, Rhys A., Aanensen, David M., Alvarado-Rybak, Mario, Bataille, Arnaud, Berger, Lee R., Böll, Susanne, Bosch, Jaime, Clare, Frances C., Courtois, Elodie A., Crottini, Angelica, Cunningham, Andrew A., Doherty-Bone, Thomas M., Gebresenbet, Fikirte, Gower, David J., Höglund, Jacob, James, Timothy Y., Jenkinson, Thomas S., Kosch, Tiffany A., Lambertini, Carolina, Laurila, Anssi, Lin, Chun-Fu, Loyau, A., Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Ndriantsoa, Serge, O’Hanlon, Simon, Pasmans, Frank, Rakotonanahary, Tsanta, Rabemananjara, Falitiana C. E., Ribeiro, Luisa P., Schmeller, Dirk S., Schmidt, Benedikt R., Skerratt, Lee, Smith, Freya, Soto-Azat, Claudio, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sánchez, Andrés, Verster, Ruhan, Vörös, Judit, Waldman, Bruce, Webb, Rebecca J., Weldon, Che, Wombwell, Emma, Zamudio, Kelly R., Longcore, Joyce E., Garner, Trenton W. J., Fundação para a Ciência e a Tecnologia (Portugal), Sao Paulo Research Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Royal Geographical Society, National Research Foundation of Korea, Leverhulme Trust, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Hungarian Academy of Sciences, Fisher, Matthew C., Ghosh, Pria, Shelton, Jennifer M. G., Bates, Kieran A., Brookes, Lola, Wierzbicki, Claudia, Rosa, Gonçalo M., Farrer, Rhys A., Aanensen, David M., Alvarado-Rybak, Mario, Bataille, Arnaud, Berger, Lee R., Böll, Susanne, Bosch, Jaime, Clare, Frances C., Courtois, Elodie A., Crottini, Angelica, Cunningham, Andrew A., Doherty-Bone, Thomas M., Gebresenbet, Fikirte, Gower, David J., Höglund, Jacob, James, Timothy Y., Jenkinson, Thomas S., Kosch, Tiffany A., Lambertini, Carolina, Laurila, Anssi, Lin, Chun-Fu, Loyau, A., Martel, An, Meurling, Sara, Miaud, Claude, Minting, Pete, Ndriantsoa, Serge, O’Hanlon, Simon, Pasmans, Frank, Rakotonanahary, Tsanta, Rabemananjara, Falitiana C. E., Ribeiro, Luisa P., Schmeller, Dirk S., Schmidt, Benedikt R., Skerratt, Lee, Smith, Freya, Soto-Azat, Claudio, Tessa, Giulia, Toledo, Luis Felipe, Valenzuela-Sánchez, Andrés, Verster, Ruhan, Vörös, Judit, Waldman, Bruce, Webb, Rebecca J., Weldon, Che, Wombwell, Emma, Zamudio, Kelly R., Longcore, Joyce E., and Garner, Trenton W. J.

Abstract

Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating chytrids from infected animals to use toe clips and biopsies from toe webbing rather than euthanizing hosts, and distributed the protocol to researchers as part of the BiodivERsA project RACE; here called the RML protocol. In tandem, we developed a lethal procedure for isolating chytrids from tadpole mouthparts. Reviewing a database of use a decade after their inception, we find that these methods have been applied across 5 continents, 23 countries and in 62 amphibian species. Isolation of chytrids by the non-lethal RML protocol occured in 18% of attempts with 207 fungal isolates and three species of chytrid being recovered. Isolation of chytrids from tadpoles occured in 43% of attempts with 334 fungal isolates of one species (Batrachochytrium dendrobatidis) being recovered. Together, these methods have resulted in a significant reduction and refinement of our use of threatened amphibian species and have improved our ability to work with this group of emerging pathogens.

Published
2018

11. Amphibian chytridiomycosis outbreak dynamics are linked with host skin bacterial community structure

Author

Bates, Kieran A., Clare, Frances C., O’Hanlon, Simon, Bosch, Jaime, Brookes, Lola, Hopkins, Kevin, McLaughlin, Emilia J., Daniel, Olivia, Garner, Trenton W. J., Fisher, Matthew C., Harrison, Xavier A., Bates, Kieran A., Clare, Frances C., O’Hanlon, Simon, Bosch, Jaime, Brookes, Lola, Hopkins, Kevin, McLaughlin, Emilia J., Daniel, Olivia, Garner, Trenton W. J., Fisher, Matthew C., and Harrison, Xavier A.

Abstract

Host-associated microbes are vital for combatting infections and maintaining health. In amphibians, certain skin-associated bacteria inhibit the fungal pathogen Batrachochytrium dendrobatidis (Bd), yet our understanding of host microbial ecology and its role in disease outbreaks is limited. We sampled skin-associated bacteria and Bd from Pyrenean midwife toad populations exhibiting enzootic or epizootic disease dynamics. We demonstrate that bacterial communities differ between life stages with few shared taxa, indicative of restructuring at metamorphosis. We detected a significant effect of infection history on metamorph skin microbiota, with reduced bacterial diversity in epizootic populations and differences in community structure and predicted function. Genome sequencing of Bd isolates supports a single introduction to the Pyrenees and reveals no association between pathogen genetics and epidemiological trends. Our findings provide an ecologically relevant insight into the microbial ecology of amphibian skin and highlight the relative importance of host microbiota and pathogen genetics in predicting disease outcome.

Published
2018

12. Spatial and temporal distribution of Onchocerciasis in West Africa with particular reference to Ghana

Author

O'Hanlon, Simon, Basáñez, Maria-Gloria, Cheke, Robert, Prichard, Roger, and Economic and Social Research Council (Great Britain)

Abstract

Background. Quantifying and predicting the effect of control interventions against infectious diseases requires knowledge about prevalence prior to the implementation of such control measures as well as knowledge of key parameters which affect model outcomes. Here is presented the first geostatistical map estimating the prevalence of human onchocerciasis in the former Onchocerciasis Control Programme in West Africa (OCP) before the initiation of vector control operations in 1975. The map is used to quantify the burden of onchocercal skin disease prior to interventions. The results of a socioeconomic survey investigating coverage and compliance to community-directed treatment with ivermectin are then presented. Methods and Findings. The OCP epidemiological database was investigated for spatial autocorrelation. A total of 737 village surveys had parasitological examinations conducted prior to the start of control. Using these 737 pre-control data points plus environmental covariates, a Bayesian model-based geostatistical (B-MBG) approach was used to generate a continuous surface (at a pixel resolution of 25km2) of microfilarial prevalence in West Africa prior to the commencement of the OCP. The mean Pearson’s correlation between observed prevalence and model-estimates of prevalence at hold-out locations was 0.693; mean prediction error was 0.77% and mean absolute prediction error was 12.2%. Within OCP boundaries, 17.8 million people were deemed to be at risk and 7.6 million infected in 1975 which is greater than previous estimates. The mean microfilarial prevalence across all countries was 45% (range: 2–90%). Conclusions and Significance. This is the first map of continuous onchocerciasis prevalence in West Africa, developed using robust geostatistical methods. Important environmental predictors of infection prevalence were identified and used in a model that out-performs those without spatial-random effects or environmental covariates. Our results may be compared with recent epidemiological mapping efforts to find areas of persisting transmission, informing feasibility of elimination with current and novel tools. Open Access

Published
2016

15. The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

Author

de Silva, Nilanthi, Hotez, Peter J., Alvarado, Miriam, Basáñez, María-Gloria, Bolliger, Ian, Bourne, Rupert R. A., Boussinesq, Michel, Brooker, Simon J., Brown, Ami S., Buckle, Geoffrey, Budke, Christine M., Carabin, Hélène, Coffeng, Luc E., Fèvre, Eric M., Fürst, Thomas, Halasa, Yara A., Jasrasaria, Rashmi, Johns, Nicole E., Keiser, Jennifer, King, Charles H., Lozano, Rafael, Murdoch, Michele E., O'Hanlon, Simon, Pion, Sébastien D. S., Pullan, Rachel L., Ramaiah, Kapa D., Roberts, Thomas, Shepard, Donald S., Smith, Jennifer L., Stolk, Wilma A., Undurraga, Eduardo A., Utzinger, Jürg, Wang, Mengru, Murray, Christopher J. L., and Naghavi, Mohsen

Published
2014

17. Genotypic Diversity Is Associated with Clinical Outcome and Phenotype in Cryptococcal Meningitis across Southern Africa

Author

Beale, Mathew A., primary, Sabiiti, Wilber, additional, Robertson, Emma J., additional, Fuentes-Cabrejo, Karen M., additional, O’Hanlon, Simon J., additional, Jarvis, Joseph N., additional, Loyse, Angela, additional, Meintjes, Graeme, additional, Harrison, Thomas S., additional, May, Robin C., additional, Fisher, Matthew C., additional, and Bicanic, Tihana, additional

Published
2015
Full Text
View/download PDF

18. The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

Author

Hotez, PJ, Alvarado, M, Basanez, MG, Bolliger, I, Bourne, R, Boussinesq, M, Brooker, SJ, Brown, AS, Buckle, G, Budke, CM, Carabin, H, Coffeng, Luc, Fevre, EM, Furst, T, Halasa, YA, Jasrasaria, R, Johns, NE, Keiser, J, King, CH, Lozano, R, Murdoch, ME, O'Hanlon, Simon, Pion, SDS, Pullan, RL, Ramaiah, KD, Roberts, T, Shepard, DS, Smith, JL, Stolk, Wilma, Undurraga, EA, Utzinger, J, Wang, MR, Murray, CJL, Naghavi, M, Hotez, PJ, Alvarado, M, Basanez, MG, Bolliger, I, Bourne, R, Boussinesq, M, Brooker, SJ, Brown, AS, Buckle, G, Budke, CM, Carabin, H, Coffeng, Luc, Fevre, EM, Furst, T, Halasa, YA, Jasrasaria, R, Johns, NE, Keiser, J, King, CH, Lozano, R, Murdoch, ME, O'Hanlon, Simon, Pion, SDS, Pullan, RL, Ramaiah, KD, Roberts, T, Shepard, DS, Smith, JL, Stolk, Wilma, Undurraga, EA, Utzinger, J, Wang, MR, Murray, CJL, and Naghavi, M

Published
2014

19. The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

Author

Hotez, Peter J., primary, Alvarado, Miriam, additional, Basáñez, María-Gloria, additional, Bolliger, Ian, additional, Bourne, Rupert, additional, Boussinesq, Michel, additional, Brooker, Simon J., additional, Brown, Ami Shah, additional, Buckle, Geoffrey, additional, Budke, Christine M., additional, Carabin, Hélène, additional, Coffeng, Luc E., additional, Fèvre, Eric M., additional, Fürst, Thomas, additional, Halasa, Yara A., additional, Jasrasaria, Rashmi, additional, Johns, Nicole E., additional, Keiser, Jennifer, additional, King, Charles H., additional, Lozano, Rafael, additional, Murdoch, Michele E., additional, O'Hanlon, Simon, additional, Pion, Sébastien D. S., additional, Pullan, Rachel L., additional, Ramaiah, Kapa D., additional, Roberts, Thomas, additional, Shepard, Donald S., additional, Smith, Jennifer L., additional, Stolk, Wilma A., additional, Undurraga, Eduardo A., additional, Utzinger, Jürg, additional, Wang, Mengru, additional, Murray, Christopher J. L., additional, and Naghavi, Mohsen, additional

Published
2014
Full Text
View/download PDF

21. Onchocerciasis: The Pre-control Association between Prevalence of Palpable Nodules and Skin Microfilariae

Author

Coffeng, Luc E., primary, Pion, Sébastien D. S., additional, O'Hanlon, Simon, additional, Cousens, Simon, additional, Abiose, Adenike O., additional, Fischer, Peter U., additional, Remme, Jan H. F., additional, Dadzie, K. Yankum, additional, Murdoch, Michele E., additional, de Vlas, Sake J., additional, Basáñez, María-Gloria, additional, Stolk, Wilma A., additional, and Boussinesq, Michel, additional

Published
2013
Full Text
View/download PDF

22. Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: The HARMONY collection

Author

Cookson, Barry, Robinson, Daniel Ashley, Monk, Alastair, Murchan, Stephen, Deplano, Ariane, De Ryck, Rafael, Struelens, Marc, Scheel, Christina, Fussing, Vivian, Salmenlinna, Saara, Vuopio-Varkila, Jaana, Cuny, Christina, Witte, Wolfgang, Tassios, Panayotis, Legakis, Nikolas, Van Leeuwen, Willem, Van Belkum, Alex, Vindel, Anna, Garaizar, Javier, Haeggman, Sara, Olsson-Liljequist, Barbro, Ransjo, Ulrika, Muller-Premru, Manica, Hryniewicz, Waleria, Rossney, Angela, O'Connell, Brian, Short, Benjamin, Thomas, Jonathan, O'Hanlon, Simon, Enright, Mark, Cookson, Barry, Robinson, Daniel Ashley, Monk, Alastair, Murchan, Stephen, Deplano, Ariane, De Ryck, Rafael, Struelens, Marc, Scheel, Christina, Fussing, Vivian, Salmenlinna, Saara, Vuopio-Varkila, Jaana, Cuny, Christina, Witte, Wolfgang, Tassios, Panayotis, Legakis, Nikolas, Van Leeuwen, Willem, Van Belkum, Alex, Vindel, Anna, Garaizar, Javier, Haeggman, Sara, Olsson-Liljequist, Barbro, Ransjo, Ulrika, Muller-Premru, Manica, Hryniewicz, Waleria, Rossney, Angela, O'Connell, Brian, Short, Benjamin, Thomas, Jonathan, O'Hanlon, Simon, and Enright, Mark

Abstract

SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2007

23. A Population‐Based Study of the Incidence and Molecular Epidemiology of Methicillin‐ResistantStaphylococcus aureusDisease in San Francisco, 2004–2005

Author

Liu, Catherine, primary, Graber, Christopher J., additional, Karr, Michael, additional, Diep, Binh An, additional, Basuino, Li, additional, Schwartz, Brian S., additional, Enright, Mark C., additional, O’Hanlon, Simon J., additional, Thomas, Jonathon C., additional, Perdreau‐Remington, Francoise, additional, Gordon, Shelley, additional, Gunthorpe, Helen, additional, Jacobs, Richard, additional, Jensen, Peter, additional, Leoung, Gifford, additional, Rumack, James S., additional, and Chambers, Henry F., additional

Published
2008
Full Text
View/download PDF

24. Evaluation of Molecular Typing Methods in Characterizing a European Collection of Epidemic Methicillin-Resistant Staphylococcus aureus Strains: the HARMONY Collection

Author

Cookson, Barry D., primary, Robinson, D. Ashley, additional, Monk, Alastair B., additional, Murchan, Stephen, additional, Deplano, Ariane, additional, de Ryck, Rafaël, additional, Struelens, Marc J., additional, Scheel, Christina, additional, Fussing, Vivian, additional, Salmenlinna, Saara, additional, Vuopio-Varkila, Jaana, additional, Cuny, Christina, additional, Witte, Wolfgang, additional, Tassios, Panayotis T., additional, Legakis, Nikolas J., additional, van Leeuwen, Willem, additional, van Belkum, Alex, additional, Vindel, Anna, additional, Garaizar, Javier, additional, Haeggman, Sara, additional, Olsson-Liljequist, Barbro, additional, Ransjo, Ulrika, additional, Muller-Premru, Manica, additional, Hryniewicz, Waleria, additional, Rossney, Angela, additional, O'Connell, Brian, additional, Short, Benjamin D., additional, Thomas, Jonathan, additional, O'Hanlon, Simon, additional, and Enright, Mark C., additional

Published
2007
Full Text
View/download PDF

25. Evaluation of Molecular Typing Methods in Characterizing a European Collection of Epidemic Methicillin-Resistant Staphylococcus aureusStrains: the HARMONY Collection

Author

Cookson, Barry D., Robinson, D. Ashley, Monk, Alastair B., Murchan, Stephen, Deplano, Ariane, de Ryck, Rafae¨l, Struelens, Marc J., Scheel, Christina, Fussing, Vivian, Salmenlinna, Saara, Vuopio-Varkila, Jaana, Cuny, Christina, Witte, Wolfgang, Tassios, Panayotis T., Legakis, Nikolas J., van Leeuwen, Willem, van Belkum, Alex, Vindel, Anna, Garaizar, Javier, Haeggman, Sara, Olsson-Liljequist, Barbro, Ransjo, Ulrika, Muller-Premru, Manica, Hryniewicz, Waleria, Rossney, Angela, O'Connell, Brian, Short, Benjamin D., Thomas, Jonathan, O'Hanlon, Simon, and Enright, Mark C.

Abstract

ABSTRACTWe analyzed a representative sample of methicillin-resistant Staphylococcus aureus(MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (=3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spaand clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mecgenes involved in methicillin resistance (SCCmec). A high level of discrimination was achieved using each of the three methodologies, with discriminatory indices between 89.5% and 91.9% with overlapping 95% confidence intervals. There was also a high level of concordance of groupings made using each method. MLST/SCCmectyping distinguished 10 groups containing at least two isolates, and these correspond to the majority of nosocomial MRSA clones described in the literature. PFGE and spatyping resolved 34 and 31 subtypes, respectively, within these 10 MRSA clones, with each subtype differing only slightly from the most common pattern using each method. The HARMONY group has found that the methods used in this study differ in their availability and affordability to European centers involved in MRSA surveillance. Here, we demonstrate that the integration of such technologies is achievable, although common protocols (such as we have developed for PFGE) may also be important, as is the use of centralized Internet sites to facilitate data analysis. PFGE and spa-typing data from analysis of MRSA isolates from the many centers that have access to the relevant equipment can be compared to reference patterns/sequences, and clonal designations can be made. In the majority of cases, these will correspond to those made by the (more expensive) method of choice—MLST/SCCmectyping—and these alternative methods can therefore be used as frontline typing systems for multicenter surveillance of MRSA.

Published
2007
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results