63 research outputs found
Laboratory-based evaluation of legionellosis epidemiology in Ontario, Canada, 1978 to 2006
BACKGROUND: Legionellosis is a common cause of severe community acquired pneumonia and
respiratory disease outbreaks. The Ontario Public Health Laboratory (OPHL) has conducted most
testing for Legionella species in the Canadian province of Ontario since 1978, and represents a
multi-decade repository of population-based data on legionellosis epidemiology. We sought to
provide a laboratory-based review of the epidemiology of legionellosis in Ontario over the past 3
decades, with a focus on changing rates of disease and species associated with legionellosis during
that time period.
METHODS: We analyzed cases that were submitted and tested positive for legionellosis from 1978
to 2006 using Poisson regression models incorporating temporal, spatial, and demographic
covariates. Predictors of infection with culture-confirmed L. pneumophila serogroup 1 (LP1) were
evaluated with logistic regression models.
Results: 1,401 cases of legionellosis tested positive from 1978 to 2006. As in other studies, we
found a late summer to early autumn seasonality in disease occurrence with disease risk increasing
with age and in males. In contrast to other studies, we found a decreasing trend in cases in the
recent decade (IRR 0.93, 95% CI 0.91 to 0.95, P-value = 0.001); only 66% of culture-confirmed
isolates were found to be LP1.
CONCLUSION: Despite similarities with disease epidemiology in other regions, legionellosis appears
to have declined in the past decade in Ontario, in contrast to trends observed in the United States
and parts of Europe. Furthermore, a different range of Legionella species is responsible for illness,
suggesting a distinctive legionellosis epidemiology in this North American region
Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity
Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria
Exploring the Ecological History of a Tropical Agroforestry Landscape Using Fossil Pollen and Charcoal Analysis from Four Sites in Western Ghats, India
Contrary to expectations, some human-modified landscapes are considered to sustain both human activities and biodiversity over the long-term. Agroforestry systems are among these landscapes where crops are planted under native shade trees. In this context, ancient agroforestry systems can provide insight into how farmers managed the landscape over time. Such insight can help to quantify the extent to which tropical forests (especially habitat-specialist trees) are responding to local and landscape-level management. Here, we extracted fossil pollen (indicator of past vegetation changes) and macroscopic charcoal (indicator of biomass burning) from four forest hollows’ sedimentary sequences in an ancient agroforestry system in Western Ghats, India. We used a mixed-modelling approach and a principal components analysis (PCA) to determine past trajectories of forest change and species composition dynamics for the last 900 years. In addition, we reconstructed the long-term forest canopy dynamics and examined the persistence of habitat-specialist trees over time. Our results show that the four sites diverged to a surprising degree in both taxa composition and dynamics. However, despite these differences, forest has persisted over 900 years under agricultural activities within agroforestry systems. This long-term analysis highlights the importance of different land-use legacies as a framework to increase the effectiveness of management across tropical agricultural lands
Inborn and acquired metabolic defects in cancer
The observation that altered metabolism is the fundamental cause of cancer was made by Otto Warburg nearly a century ago. However, the subsequent identification of oncogenes and tumor suppressor genes has displaced Warburg's theory pointing towards genetic aberrations as the underlining cause of cancer. Nevertheless, in the last decade, cancer-associated mutations have been identified in genes coding for tricarboxylic acid cycle (TCA cycle, also known as Krebs cycle) and closely related enzymes that have essential roles in cellular metabolism. These observations have revived interest in Warburg's hypothesis and prompted a flurry of functional studies in the hope of gaining mechanistic insight into the links between mitochondrial dysfunction, metabolic alterations, and cancer. In this review, we discuss the potential pro-oncogenic signaling role of some TCA cycle metabolites and their derivatives (oncometabolites). In particular, we focus on their effects on dioxygenases, a family of oxygen and α-ketoglutarate-dependent enzymes that control, among other things, the levels and activity of the hypoxia-inducible transcription factors and the activity of DNA and histone demethylases
Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases
Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article
What is the probability of successive cases of Legionnaires' disease occurring in European hotels?
BACKGROUND: Public health officials will normally take action at accommodation sites following an association with a cluster of cases of Legionnaires' disease. This paper seeks to determine the likelihood of such a cluster occurring at a site once it has been associated with a single case of the disease, and therefore whether more should be done at sites following individual cases. METHODS: Information for UK residents reported to the EWGLINET system between 1993 and 2000 was included in a dataset. The size and country of hotel visited by the cases were divided into six country groups (France, Italy, Spain, Turkey, other Europe and other World), and eight size groups (30%; the probability of a subsequent case occurring within 2 years of the first reached over 50% in some instances. CONCLUSIONS: There may be support for early intervention at some accommodation sites following a first case of Legionnaires' disease, in specific country and size groups
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