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Compensatory density feedback of Oncomelania hupensis populations in two different environmental settings in China

Yang, G. J. and Zhou, X. N. and Sun, L. P. and Wu, F. and Zhong, B. and Qiu, D. C. and Utzinger, J. and Bradshaw, C. J.. (2011) Compensatory density feedback of Oncomelania hupensis populations in two different environmental settings in China. Parasites and Vectors, 4 (133).

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Official URL: http://edoc.unibas.ch/dok/A6002148

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Abstract

BACKGROUND: The most recent strategy for schistosomiasis control in the People's Republic of China aims to reduce the likelihood of environmental contamination of schistosome eggs. Despite considerable progress, it is believed that achievements would be further consolidated with additional intermediate host snail control measures. We provide an empirical framework for discerning the relative contribution of intrinsic effects (density feedback) from other extrinsic drivers of snail population dynamics.
METHODS: We set up experiments in two study locations to collect reproduction data of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. We applied a set of four population dynamic models that have been widely used to study phenomenological time-series data to examine the properties of demographic density feedback patterns from abundance data. We also contrasted the obtained results with the component feedback of density on survival rate to determine whether adult survival was the principal driver of the demographic feedback observed.
RESULTS: Demographic density feedback models (Ricker- and Gompertz-logistic) accounted for <99% of Akaike's information criterion model weight, with the Gompertz ranking highest in all O. hupensis population groups. We found some evidence for stronger compensatory feedback in the O. hupensis population from Sichuan compared to a Jiangsu population. Survival rates revealed strong component feedback, but the log-linear relationships (i.e. Gompertz) had less support in the demographic feedback analysis.
CONCLUSIONS: Our findings indicate that integrated schistosomiasis control measures must continue to reduce parasite abundance further because intermediate host snail populations tend to grow exponentially at low densities, especially O. hupensis populations in mountainous regions. We conclude that density feedback in adult survival is the principal component contribution to the demographic phenomenon observed in the population fitness (r)-abundance relationship.
Faculties and Departments:09 Associated Institutions > Swiss Tropical and Public Health Institute (Swiss TPH) > Department of Epidemiology and Public Health (EPH) > Eco System Health Sciences > Health Impact Assessment (Utzinger)
UniBasel Contributors:Utzinger, Jürg
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:BioMed Central
ISSN:1756-3305
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:16 Nov 2016 15:14
Deposited On:08 Nov 2012 16:20

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