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Thai K.T.D.,University of Amsterdam | Thai K.T.D.,Center for Infection and Immunity | Anders K.L.,Monash University
Experimental Biology and Medicine | Year: 2011

The mounting evidence for anthropogenic changes in global climate raises many pressing questions about the potential effects on biological systems, and in particular the transmission of infectious diseases. Vector-borne diseases, such as dengue, may be particularly sensitive to both periodic fluctuations and sustained changes in global and local climates, because vector biology and viral replication are temperature- and moisture-dependent. This paper reviews the current state of knowledge on the associations between climate variability, climate change and dengue transmission, and the tools being used to quantify these associations. The underlying causes of dengue's recent global expansion are multifactorial and poorly understood, but climatic factors should be considered within the context of the sociodemographic, economic and immunological determinants that have contributed to dengue's spread. These factors may mediate the direct effects of climate on dengue and many may operate at a very local level. Translating theoretical models of dengue transmission based on historical data into predictive models that can inform public health interventions is a critical next step and efforts should be focused on developing and refining models at smaller spatial scales to characterize the relationships between both climatic and non-climatic factors and dengue risk. © 2011 by the Society for Experimental Biology and Medicine. Source

News Article
Site: http://phys.org/biology-news/

"Tilapia is one of the most important fish industries worldwide," says Eran Bacharach, a molecular virologist at Tel Aviv University in Israel and one of the lead researchers on the study. "Moreover, because they eat algae, they are ecological gatekeepers for freshwater and they are an inexpensive, important source of protein in poorer countries." The tilapia industry is valued at US $7.5 billion each year. Various countries in Asia and South America are the largest tilapia producers and the United States is the largest importer, consuming 225,000 tons of these fish each year. In 2009, both wild tilapia species in Kinneret Lake, also known as the Sea of Galilee, and fish in commercial ponds in Israel began suffering from an unknown disease with high rates of mortality of up to 70%. A couple of years later, fish in commercial ponds in Ecuador also suffered a mass die-off. On first glance, the two diseases seemed unrelated because the fish in Israel showed brain and nervous system symptoms while the fish in Ecuador suffered from liver symptoms. In late 2012, researchers working on both outbreaks sent diseased fish samples to the lab of W. Ian Lipkin, an expert in hunting down new viruses. "This was an atypical viral discovery project," says Lipkin, John Snow professor of epidemiology and director of the Center for Infection and Immunity at Columbia University in New York City. His team's usual approach to tracking down which virus is causing a particular disease is to pursue a genetic sequence analysis of blood, feces or tissues from a diseased animal, remove all the known genetic sequences found in normal animals, and then compare what is left to known sequences in databases. "But, in this instance, what my colleague, Nischay Mishra found didn't look like any previously entered sequences," says Lipkin. In this case, the team found 10 short RNA gene sequences. "The more we studied them, the more convinced we became that what we had represented an entirely new virus," says Lipkin. While nine of the gene segments shared no similarities with any other known viral proteins, one segment looked weakly similar to a influenza C virus protein. The 10 segments also had similar starting and ending sequences, a feature of segmented viruses. And the team showed that the virus replicates itself in the nucleus of fish cells. These characteristics led the team to classify TiLV as an orthomyxo-like virus, related to the same family of viruses as influenza. The team also showed that the virus expresses 10 proteins that correspond to the 10 gene segments. They also sequenced the virus from tilapia from Ecuador and Israel and showed that it was the same virus causing the fatalities in two locations halfway around the globe. Because the viruses from the two sites shared almost identical gene sequences, Bacharach believes they came from the same source. But how the virus traveled between Israel and Ecuador, and in which direction, is still a mystery. "Our research provides the first means of detection - knowing the genetic sequence of the virus is the first step to designing diagnostic and screening assays,"says Bacharach. Such tests will allow fish farmers to detect when the virus is present in a commercial pond and limit its spread. The finding brings other practical applications with it, too, says Lipkin: "Building a vaccine would save billions of dollars and preserve an industry that ensures employment in the developing world and food security." Explore further: New virus may pose risk to wild salmon

Blackwood B.,Center for Infection and Immunity | Clarke M.,Queens University of Belfast | McAuley D.F.,Center for Infection and Immunity | McAuley D.F.,Regional Intensive Care Unit | And 4 more authors.
American Journal of Respiratory and Critical Care Medicine | Year: 2014

Systematic reviews have considerable potential to provide evidencebased data to aid clinical decision-making. However, there is growing recognition that trials involving mechanical ventilation lack consistency in the definition and measurement of ventilation outcomes, creating difficulties in combining data for meta-analyses. To address the inconsistency in outcome definitions, international standards for trial registration and clinical trial protocols published recommendations, effectively setting the "gold standard" for reporting trial outcomes. In this Critical Care Perspective, we review the problems resulting from inconsistent outcome definitions and inconsistent reporting of outcomes (outcome sets). We present data highlighting the variability of the most commonly reported ventilation outcome definitions. Ventilation outcomes reported in trials over the last 6 years typically fall into four domains: measures of ventilator dependence; adverse outcomes;mortality; and resource use. We highlight the need, first, for agreement on outcome definitions and, second, for a minimum core outcome set for trials involving mechanical ventilation. A minimum core outcome set would not restrict trialists from measuring additional outcomes, but would overcome problems of variability in outcome selection, measurement, and reporting, thereby enhancing comparisons across trials. Copyright © 2014 by the American Thoracic Society. Source

Jelocnik M.,Queensland University of Technology | Jelocnik M.,University of The Sunshine Coast | Walker E.,Central West Local Land Services | Walker E.,University of The Sunshine Coast | And 6 more authors.
Veterinary Microbiology | Year: 2014

Chlamydia pecorum is globally associated with several ovine diseases including keratoconjunctivitis and polyarthritis. The exact relationship between the variety of C. pecorum strains reported and the diseases described in sheep remains unclear, challenging efforts to accurately diagnose and manage infected flocks. In the present study, we applied C. pecorum multi-locus sequence typing (MLST) to C. pecorum positive samples collected from sympatric flocks of Australian sheep presenting with conjunctivitis, conjunctivitis with polyarthritis, or polyarthritis only and with no clinical disease (NCD) in order to elucidate the exact relationships between the infecting strains and the range of diseases. Using Bayesian phylogenetic and cluster analyses on 62 C. pecorum positive ocular, vaginal and rectal swab samples from sheep presenting with a range of diseases and in a comparison to C. pecorum sequence types (STs) from other hosts, one ST (ST 23) was recognised as a globally distributed strain associated with ovine and bovine diseases such as polyarthritis and encephalomyelitis. A second ST (ST 69) presently only described in Australian animals, was detected in association with ovine as well as koala chlamydial infections. The majority of vaginal and rectal C. pecorum STs from animals with NCD and/or anatomical sites with no clinical signs of disease in diseased animals, clustered together in a separate group, by both analyses. Furthermore, 8/13 detected STs were novel. This study provides a platform for strain selection for further research into the pathogenic potential of C. pecorum in animals and highlights targets for potential strain-specific diagnostic test development. © 2014 Elsevier B.V. Source

Stewart L.,University of Strathclyde | Ford A.,University of Strathclyde | Ford A.,Center for Infection and Immunity | Sangal V.,University of Strathclyde | And 8 more authors.
Pathogens and Disease | Year: 2014

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen particularly associated with the inherited disease cystic fibrosis (CF). Pseudomonas aeruginosa is well known to have a large and adaptable genome that enables it to colonise a wide range of ecological niches. Here, we have used a comparative genomics approach to identify changes that occur during infection of the CF lung. We used the mucoid phenotype as an obvious marker of host adaptation and compared these genomes to analyse SNPs, indels and islands within near-isogenic pairs. To commence the correction of the natural bias towards clinical isolates in genomics studies and to widen our understanding of the genomic diversity of P. aeruginosa, we included four environmental isolates in our analysis. Our data suggest that genome plasticity plays an important role in chronic infection and that the strains sequenced in this study are representative of the two major phylogenetic groups as determined by core genome SNP analysis.© 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved. Source

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