9,452 research outputs found

    Georgia’s Rapid Expansion of Mosquito Surveillance in Response to Zika Virus

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    Objective: To describe the Georgia Department of Public Health’s (DPH) mosquito surveillance capacity before and after Zika virus was declared a public health emergency, review and compare mosquito surveillance results from 2015 to 2016, and evaluate the risk of autochthonous vector transmission of Zika virus based on 2016 surveillance data of Aedes aegypti and Aedes albopictus mosquitoes. Introduction: Zika virus was declared an international public health emergency by the World Health Organization on February 1, 2016. With Georgia hosting the world’s busiest international airport and a sub-tropical climate that can support the primary Zika virus vector, Aedes aegypti, and secondary vector, Aedes albopictus, the CDC designated Georgia as a high risk state for vector transmission. Faced with a lack of mosquito surveillance data to evaluate risk of autochthonous transmission and a few counties statewide that provide comprehensive mosquito control, the DPH rapidly scaled up a response. DPH updated existing mosquito surveillance and response plans targeted for West Nile Virus (WNV) and expanded capacity to areas that lacked previous surveillance targeting the Zika virus vector. Methods: Mosquito surveillance data provided by DPH was analyzed for years 2015 and 2016 to date. The geographical distribution of counties conducting surveillance, total number and percentage by mosquito species collected in 2015 were compared to 2016 data. The distribution of counties conducting surveillance was mapped using ArcMap 10.4.1 for pre and post Zika response. Autochthonous vector transmission risk was evaluated based on the overall numbers and percentages of Aedes aegypti and Aedes albopictus mosquitoes collected for 2016. Results: In 2015, Georgia had 14 counties conducting mosquito surveillance, with a DPH entomologist providing direct surveillance in 4 of these counties. In 2016, DPH expanded surveillance capacity to 34 counties, a 142% increase, geographically dispersed across the State in urban and rural areas. A total of 76,052 mosquitoes were trapped and identified in 2015 compared to 91,261 mosquitoes trapped to date in 2016, representing a 20% increase. A total of 37 mosquito species were identified in both years with Culex quinquefasciatus, Georgia’s primary WNV vector, representing the highest percentage (2015-79.45% and 2016-70.41%) of mosquitoes trapped overall. In addition, Aedes aegypti represented only 0.108% and 0.007% of the total mosquitoes trapped respectively each year and was found in one county. Aedes albopictus represented only 1.50% and 1.82% of the total mosquitoes trapped respectively each year and was found in a majority of the counties conducting surveillance. Conclusions: DPH was able to rapidly expand its surveillance capacity statewide by maximizing existing grant funds to hire new surveillance staff while also collaborating with academic institutions, military bases, Georgia Mosquito Control Association, and local health departments to provide training and funding for surveillance and data sharing. This expanded surveillance network provided a clearer picture of the types of mosquitoes potentially exposing the public to mosquito-borne disease risks. Historical data for the primary vector of Zika virus, Aedes aegypti has been isolated to just two counties in Georgia. Expanded surveillance in 2016 confirmed a low abundance of Aedes aegypti, suggesting the primary vector for Zika has been displaced by Aedes albopictus. This may suggest a reduced risk of autochthonous transmission of Zika virus in Georgia due to Aedes albopictus’ affinity for feeding on both humans and animals. This should be interpreted with caution due to limitations in the data related to unstandardized reporting techniques for each county. DPH is working with all counties to improve the quality of data collected and reported and continues to educate the public on ways they can reduce their individual risk of mosquito bites, which in turn reduces the risk of other mosquito-borne diseases such as WNV. In conclusion, DPH’s response to Zika virus allowed it to rapidly increase its surveillance footprint and with new data, make sound public health decisions regarding mosquito-borne disease risks

    The Trypanosoma cruzi enzyme TcGPXI is a glycosomal peroxidase and can be linked to trypanothione reduction by glutathione or tryparedoxin.

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    Trypanosoma cruzi glutathione-dependent peroxidase I (TcGPXI) can reduce fatty acid, phospholipid, and short chain organic hydroperoxides utilizing a novel redox cycle in which enzyme activity is linked to the reduction of trypanothione, a parasite-specific thiol, by glutathione. Here we show that TcGPXI activity can also be linked to trypanothione reduction by an alternative pathway involving the thioredoxin-like protein tryparedoxin. The presence of this new pathway was first detected using dialyzed soluble fractions of parasite extract. Tryparedoxin was identified as the intermediate molecule following purification, sequence analysis, antibody studies, and reconstitution of the redox cycle in vitro. The system can be readily saturated by trypanothione, the rate-limiting step being the interaction of trypanothione with the tryparedoxin. Both tryparedoxin and TcGPXI operate by a ping-pong mechanism. Overexpression of TcGPXI in transfected parasites confers increased resistance to exogenous hydroperoxides. TcGPXI contains a carboxyl-terminal tripeptide (ARI) that could act as a targeting signal for the glycosome, a kinetoplastid-specific organelle. Using immunofluorescence, tagged fluorescent proteins, and biochemical fractionation, we have demonstrated that TcGPXI is localized to both the glycosome and the cytosol. The ability of TcGPXI to use alternative electron donors may reflect their availability at the corresponding subcellular sites

    Phylogenetics of advanced snakes (Caenophidia) based on four mitochondrial genes

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    Phylogenetic relationships among advanced snakes ( Acrochordus + Colubroidea = Caenophidia) and the position of the genus Acrochordus relative to colubroid taxa are contentious. These concerns were investigated by phylogenetic analysis of fragments from four mitochondrial genes representing 62 caenophidian genera and 5 noncaenophidian taxa. Four methods of phylogeny reconstruction were applied: matrix representation with parsimony (MRP) supertree consensus, maximum parsimony, maximum likelihood, and Bayesian analysis. Because of incomplete sampling, extensive missing data were inherent in this study. Analyses of individual genes retrieved roughly the same clades, but branching order varied greatly between gene trees, and nodal support was poor. Trees generated from combined data sets using maximum parsimony, maximum likelihood, and Bayesian analysis had medium to low nodal support but were largely congruent with each other and with MRP supertrees. Conclusions about caenophidian relationships were based on these combined analyses. The Xenoderminae, Viperidae, Pareatinae, Psammophiinae, Pseudoxyrophiinae, Homalopsinae, Natricinae, Xenodontinae, and Colubrinae (redefined) emerged as monophyletic, whereas Lamprophiinae, Atractaspididae, and Elapidae were not in one or more topologies. A clade comprising Acrochordus and Xenoderminae branched closest to the root, and when Acrochordus was assessed in relation to a colubroid subsample and all five noncaenophidians, it remained associated with the Colubroidea. Thus, Acrochordus + Xenoderminae appears to be the sister group to the Colubroidea, and Xenoderminae should be excluded from Colubroidea. Within Colubroidea, Viperidae was the most basal clade. Other relationships appearing in all final topologies were (1) a clade comprising Psammophiinae, Lamprophiinae, Atractaspididae, Pseudoxyrophiinae, and Elapidae, within which the latter four taxa formed a subclade, and (2) a clade comprising Colubrinae, Natricinae, and Xenodontinae, within which the latter two taxa formed a subclade. Pareatinae and Homalopsinae were the most unstable clades

    The snake family Psammophiidae (Reptilia: Serpentes): phylogenetics and species delimitation in the African sand snakes (Psammophis Boie, 1825) and allied genera

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    This study constitutes the first evolutionary investigation of the snake family Psammophiidae—the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's familylevel snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris

    Caudate lobe resections: a single-center experience and evaluation of factors predictive of outcomes

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    BACKGROUND: Despite the increasing frequency of liver resection for multiple types of disease, caudate lobe resection remains a rare surgical event. The goal of this study is to review our experience and evaluate possible predictors of adverse outcomes in patients undergoing caudate lobectomy. METHODS: We reviewed a 1,900-patient prospective hepato-pancreatico-biliary database from January 2000 to December 2011, identifying 36 hepatectomy patients undergoing caudate lobe resection. Clinicopathologic characteristic and outcome data were compared using chi-square, T-test, ANOVA, Kaplan-Meier, and Cox regression analysis. Primary endpoints were the incidence and severity of complications, and secondary endpoints were blood loss, hospital stay, and transfusion requirements. Patients were also divided in two groups with group A being patients operated on before December 2007 and group B after 2007. We compared the demographics, risk factors, complication rates, and operative details between the two groups. RESULTS: Thirty-six patients underwent caudate lobe resection for cholangiocarcinoma (47.2%), metastatic colorectal cancer (36.1%), hepatocellular carcinoma (8.3%), or benign disease (8.3%). Nine patients (29%) had additional liver resection. Median overall survival (OS) was 21 months. Complications occurred in 52.7% (19/36) of patients with a median grade of 2. Tobacco abuse was associated with an increased risk of operative complications (73.3% vs. 38.9%, p = 0.03). Prior history of cardiac disease was associated with a higher complication rate (87% vs. 42%, p = 0.03). Neoadjuvant chemotherapy, biliary procedures, hepatitis, and prior major abdominal surgery were not predictive of complications. Major complication was also predicted by the volume of RBC transfusion (2.7 vs. 4.1 units, p = 0.003). In our subgroup analysis of the patients undergoing surgery before and after 2007, the two groups were well matched based on age, comorbidities, and risk factors. The complication rates and rates of high-grade complications were similar, but blood loss (600 ml vs. 400 ml, p = 0.03), inflow occlusion time (Pringle time 12.6 vs. 6, p = 0.00), and hospital stay (9.5 vs. 7 days, p = 0.01) were significantly lower in group B. CONCLUSIONS: With appropriate patient selection, caudate lobe resection is an effective component of surgery for hepatic disease. Tobacco use and prior cardiac history increase the risk of complications
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