Author:
Minchella D. J.,Loverde P. T.
Abstract
SUMMARYA method of interrupting the life-cycle of the human blood fluke Schistosoma by increasing the proportion of genetically insusceptible intermediate host snails in natural populations was first proposed nearly 25 years ago. The method assumes that insusceptible snails will be at a selective advantage over susceptible snails when the schistosome parasite is present, and therefore natural selection will act to increase the proportion of alleles for insusceptibility. A major objection to the proposed technique is ‘If insusceptible snails are at a selective advantage, then why are they not predominant in natural populations that transmit disease?’ One explanation of this paradox is that insusceptibility may be associated with a disadvantageous character or a physiological defect. This study tests this hypothesis by measuring the relative reproductive success of susceptible and insusceptible snails under controlled conditions. Results indicate that insusceptible (unsuitable) snails are negatively affected in the presence of either susceptible snails or schistosome parasites. Furthermore, in the presence of both susceptible snails and schistosome parasites, insusceptible snails are selectively disadvantaged compared to susceptible snails. These results obtained under laboratory-controlled conditions suggest a plausible answer as to why insusceptible snails are not predominant in natural populations that transmit disease.
Publisher
Cambridge University Press (CUP)
Subject
Infectious Diseases,Animal Science and Zoology,Parasitology
Reference24 articles.
1. The Transmission of Human Bilharziasis in Sierra Leone, with an Account of the Life-Cycle of the Schistosomes Concerned,S. MansoniandS. Haematobium
2. Compatibility and host–parasite relationships between species of the genus Bulinus (Basommatophora: Planorbidae) and an Egyptian strain of Schistosoma haematobium (Trematoda: Digenea);Lo;Malacologia,1972
3. Variations in infectivity for Biomphalaria glabrata in strains of Schistosoma mansoni from the same geographical area;Richards;Bulletin of the World Health Organization,1976
4. Host-Parasite Interrelationships Between the Freshwater Pulmonate Biomphalaria Pfeifferi and the Trematode Schistosoma Mansoni
5. Differences in susceptibility of Brazilian strains of Australorbis glabratus to Schistosoma mansoni
Cited by
51 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献