1. Parasite Population Genetic Contributions to the Schistosomiasis Consortium for Operational Research and Evaluation within Sub-Saharan Africa
- Author
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Bonnie L. Webster, Fiona Allan, Joanne P. Webster, David Rollinson, Anouk N. Gouvras, Martin Walker, Maria Inês Neves, Tom Pennance, Muriel Rabone, and Bill & Melinda Gates Foundation
- Subjects
Operations research ,law.invention ,Gene flow ,0302 clinical medicine ,law ,Prevalence ,EPIDEMIOLOGY ,Schistosomiasis ,11 Medical and Health Sciences ,Public, Environmental & Occupational Health ,Anthelmintics ,Schistosoma haematobium ,education.field_of_study ,biology ,Articles ,Fecundity ,HAEMATOBIUM ,Infectious Diseases ,Transmission (mechanics) ,Genetic structure ,Mass Drug Administration ,Schistosoma ,DENSITY-DEPENDENT FECUNDITY ,Life Sciences & Biomedicine ,ONE HEALTH ,030231 tropical medicine ,Population ,MANSONI INFECTIONS ,WORM BURDEN ,Life history theory ,03 medical and health sciences ,Tropical Medicine ,Virology ,parasitic diseases ,Animals ,Humans ,POLYMORPHIC MICROSATELLITE MARKERS ,education ,Africa South of the Sahara ,Life Cycle Stages ,Science & Technology ,PRAZIQUANTEL TREATMENT ,biology.organism_classification ,Genetics, Population ,Hybridization, Genetic ,Parasitology ,EGG COUNTS ,MULTIHOST - Abstract
Analyses of the population genetic structure of schistosomes under the “Schistosomiasis Consortium for Operational Research and Evaluation” (SCORE) contrasting treatment pressure scenarios in Tanzania, Niger, and Zanzibar were performed to provide supplementary critical information with which to evaluate the impact of these large-scale control activities and guide how activities could be adjusted. We predicted that population genetic analyses would reveal information on a range of important parameters including, but not exclusive to, recruitment and transmission of genotypes, occurrence of hybridization events, differences in reproductive mode, and degrees of inbreeding, and hence, the evolutionary potential, and responses of parasite populations under contrasting treatment pressures. Key findings revealed that naturally high levels of gene flow and mixing of the parasite populations between neighboring sites were likely to dilute any effects imposed by the SCORE treatment arms. Furthermore, significant inherent differences in parasite fecundity were observed, independent of current treatment arm, but potentially of major impact in terms of maintaining high levels of ongoing transmission in persistent “biological hotspot” sites. Within Niger, naturally occurring Schistosoma haematobium/Schistosoma bovis viable hybrids were found to be abundant, often occurring in significantly higher proportions than that of single-species S. haematobium infections. By examining parasite population genetic structures across hosts, treatment regimens, and the spatial landscape, our results to date illustrate key transmission processes over and above that which could be achieved through standard parasitological monitoring of prevalence and intensity alone, as well as adding to our understanding of Schistosoma spp. life history strategies in general.
- Published
- 2020