Search for: All records

Changes in the quality and quantity of food consumed can affect the health of hosts, their ability to control infections and potentially shape the likelihood of pathogen spillover. Dietary shifts have been proposed as one of the factors driving spillovers of zoonotic viruses from bats to humans. In this study, we examined how diet composition alters the immune response to viral shedding and the risk of spillover by developing a mechanistic model fitted to experimental data of Jamaican fruit bats infected with influenza A virus H18N11 and fed different diets. The model selected from alternative immune and metabolic relationships showed that the coupled effects of citrulline and tumour necrosis factor alpha (TNF) affected the control of viral shedding with parameters that varied with diet. Bats on the suboptimal fat diet appeared to control shedding more successfully than bats on suboptimal sugar or optimal protein diets. Yet, bats on the optimal diet could potentially cause lower hazard of spillover because of reduced food consumption, suggesting fewer and/or shorter visits at the feeding sites and thus transmission to secondary hosts. This study provides a parsimonious explanation of the barriers that affect viral shedding by reservoir hosts and the consequences for the hazard of spillover. 

Land-use change may drive viral spillover from bats into humans, partly through dietary shifts caused by decreased availability of native foods and increased availability of cultivated foods. We experimentally manipulated diets of Jamaican fruit bats to investigate whether diet influences viral shedding. To reflect dietary changes experienced by wild bats during periods of nutritional stress, Jamaican fruit bats were fed either a standard diet or a putative suboptimal diet, which was deprived of protein (suboptimal-sugar diet) and/or supplemented with fat (suboptimal-fat diet). Upon H18N11 influenza A-virus infection, bats fed on the suboptimal-sugar diet shed the most viral RNA for the longest period, but bats fed the suboptimal-fat diet shed the least viral RNA for the shortest period. Bats on both suboptimal diets ate more food than the standard diet, suggesting nutritional changes may alter foraging behaviour. This study serves as an initial step in understanding whether and how dietary shifts may influence viral dynamics in bats, which alters the risk of spillover to humans. 

Abstract Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.