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Appears in Collections:Biological and Environmental Sciences Journal Articles
Peer Review Status: Refereed
Title: Pangloss revisited: A critique of the dilution effect and the biodiversity-buffers-disease paradigm
Author(s): Randolph, Sarah E
Dobson, Andrew
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Keywords: dilution effect
community structure
disease risk
vector-borne diseases
rodent-borne infections
Issue Date: Jun-2012
Date Deposited: 12-Nov-2013
Citation: Randolph SE & Dobson A (2012) Pangloss revisited: A critique of the dilution effect and the biodiversity-buffers-disease paradigm. Parasitology, 139 (7), pp. 847-863.
Abstract: The twin concepts of zooprophylaxis and the dilution effect originated with vector-borne diseases (malaria), were driven forward by studies on Lyme borreliosis and have now developed into the mantra "biodiversity protects against disease". The basic idea is that by diluting the assemblage of transmission-competent hosts with non-competent hosts, the probability of vectors feeding on transmission-competent hosts is reduced and so the abundance of infected vectors is lowered. The same principle has recently been applied to other infectious disease systems - tick-borne, insect-borne, indirectly transmitted via intermediate hosts, directly transmitted. It is claimed that the presence of extra species of various sorts, acting through a variety of distinct mechanisms, causes the prevalence of infectious agents to decrease. Examination of the theoretical and empirical evidence for this hypothesis reveals that it applies only in certain circumstances even amongst tick-borne diseases, and even less often if considering the correct metric - abundance rather than prevalence of infected vectors. Whether dilution or amplification occurs depends more on specific community composition than on biodiversity per se. We warn against raising a straw man, an untenable argument easily dismantled and dismissed. The intrinsic value of protecting biodiversity and ecosystem function outweighs this questionable utilitarian justification.
DOI Link: 10.1017/S0031182012000200
Rights: Publisher policy allows this work to be made available in this repository. Published in Parasitology / Volume 139 / Issue 07 / June 2012, pp 847-863 Copyright © Cambridge University Press 2012. The original publication is available at:

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