22 research outputs found
Setting a baseline for global urban virome surveillance in sewage
The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective
Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage
Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining representative data on AMR for healthy human populations is difficult. Here, we use meta-genomic analysis of untreated sewage to characterize the bacterial resistome from 79 sites in 60 countries. We find systematic differences in abundance and diversity of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America. Antimicrobial use data and bacterial taxonomy only explains a minor part of the AMR variation that we observe. We find no evidence for cross-selection between antimicrobial classes, or for effect of air travel between sites. However, AMR gene abundance strongly correlates with socio-economic, health and environmental factors, which we use to predict AMR gene abundances in all countries in the world. Our findings suggest that global AMR gene diversity and abundance vary by region, and that improving sanitation and health could potentially limit the global burden of AMR. We propose metagenomic analysis of sewage as an ethically acceptable and economically feasible approach for continuous global surveillance and prediction of AMR.Peer reviewe
Seasonal infection patterns in Willow Grouse Lagopus lagopus L. do not support the presence of parasite-induced winter losses
We examined the hypothesis that endoparasites of Willow Grouse (Lagopus lagopus L.) affect host winter losses, by examining two samples of Willow Grouse collected in early autumn and late winter. Body condition of juvenile birds improved from September to February, but parasite-induced host mortalities among hosts in poor condition were probably not the cause. If heavily infected hosts were removed disproportionately from the host population, the number of parasite species per host together with their prevalence and intensities should be lower in winter than in autumn. While overall parasite burden was lower in winter than in autumn, most parasite species showed no seasonal decrease in prevalence or intensities. Only one species, Trichostrongylus tenuis, showed a seasonal decrease in both prevalence and intensity. Mean intensities of Eimeria spp. decreased significantly between seasons, while prevalence did not. If mortality rates were higher among heavily infected hosts, parasite aggregation should be lower in winter than in autumn, but no such pattern was found, except for Eimeria spp. Thus, the results presented in this study yield no clear evidence for parasite-induced mortality in Willow Grouse between autumn and late winter
Parasite tags in ecological studies of terrestrial hosts: a study on ptarmigan (Lagopus spp.) dispersal
The spatial distributions of parasites may provide valuable information in studies on host ecology. This study was conducted in Troms County, Northern Norway, and focussed on the spatial and temporal variation in abundance of two nematode parasites, Ascaridia compar and Trichostrongylus tenuis, infecting the gastrointestinal tract of Willow Ptarmi-gan (Lagopus lagopus) and Rock Ptarmigan (Lagopus mutus). In an inland area preva-lence of A. compar varied between 52.2â78.1% in September during 6 years of sampling, and in a coastal area that was sampled for 10 years, the prevalence of T. tenuis ranged be-tween 25.0â75.4%. Both nematodes attained significantly higher prevalences in willow ptarmigan than in Rock Ptarmigan. The nematodes showed marked differences in geo-graphical distributions in September, where A. compar was common at inland localities while T. tenuis only was found in hosts at coastal islands. Practical use of these parasites as biological tags suggested a coast to inland winter dispersal in Rock Ptarmigan, especially among juvenile hens, but no dispersal was recorded in Willow Ptarmigan. The use of bio-logical tags in general and the use of nematodes as indicators of ptarmigan dispersal are discussed