Community diversity reduces Schistosoma mansoni transmission, host pathology and human infection risk
- 20 January 2009
- journal article
- Published by The Royal Society in Proceedings. Biological sciences
- Vol. 276 (1662), 1657-1663
- https://doi.org/10.1098/rspb.2008.1718
Abstract
Global biodiversity loss and disease emergence are two of the most challenging issues confronting science and society. Recently, observed linkages between species-loss and vector-borne infections suggest that biodiversity may help reduce pathogenic infections in humans and wildlife, but the mechanisms underlying this relationship and its applicability to a broader range of pathogens have remained speculative. Here, we experimentally evaluated the effects of host community structure on transmission of the human pathogen, Schistosoma mansoni, which alternates between snail intermediate hosts and vertebrate definitive hosts. By manipulating parasite exposure and community diversity, we show that heterospecific communities cause a 25-50 per cent reduction in infection among snail hosts (Biomphalaria glabrata). Infected snails raised alongside non-host snails (Lymnaea or Helisoma sp.) also produced 60-80 per cent fewer cercariae, suggesting that diverse communities could reduce human infection risk. Because focal host density was held constant during experiments, decreases in transmission resulted entirely from diversity-mediated pathways. Finally, the decrease in infection in mixed-species communities led to an increase in reproductive output by hosts, representing a novel example of parasite-mediated facilitation. Our results underscore the significance of community structure on transmission of complex life-cycle pathogens, and we emphasize enhanced integration between ecological and parasitological research on the diversity-disease relationship.This publication has 33 references indexed in Scilit:
- Diversity and disease: community structure drives parasite transmission and host fitnessEcology Letters, 2008
- Increased Avian Diversity Is Associated with Lower Incidence of Human West Nile Infection: Observation of the Dilution EffectPLOS ONE, 2008
- The role of biotic factors in the transmission of free-living endohelminth stagesParasitology, 2008
- Schistosomiasis and water resources development: systematic review, meta-analysis, and estimates of people at riskThe Lancet Infectious Diseases, 2006
- Sacred Cows and Sympathetic Squirrels: The Importance of Biological Diversity to Human HealthPLoS Medicine, 2006
- COMMUNITY DISASSEMBLY, BIODIVERSITY LOSS, AND THE EROSION OF AN ECOSYSTEM SERVICEEcology, 2003
- Age/size- and time-specific effects of Schistosoma mansoni on energy allocation patterns of its snail host Biomphalaria glabrataOecologia, 1997
- Decoy effect and host infection by miracidia within snail communitiesParasitology, 1993
- INFLUENCE OF NON-TARGET MOLLUSCS ON THE GROWTH OF BIOMPHALARIA GLABRATA INFECTED WITH SCHISTOSOMA MANSONI: CORRELATION BETWEEN GROWTH AND CERCARIAL PRODUCTIONJournal of Molluscan Studies, 1991
- Transmission of Schistosoma mansoni from man to snail: laboratory studies on the influence of snail and miracidial densities on transmission successParasitology, 1982