scholarly journals Using the Systematic Review Methodology To Evaluate Factors That Influence the Persistence of Influenza Virus in Environmental Matrices

2010 ◽  
Vol 77 (3) ◽  
pp. 1049-1060 ◽  
Author(s):  
C. K. Irwin ◽  
K. J. Yoon ◽  
C. Wang ◽  
S. J. Hoff ◽  
J. J. Zimmerman ◽  
...  

ABSTRACTUnderstanding factors that influence persistence of influenza virus in an environment without host animals is critical to appropriate decision-making for issues such as quarantine downtimes, setback distances, and eradication programs in livestock production systems. This systematic review identifies literature describing persistence of influenza virus in environmental samples, i.e., air, water, soil, feces, and fomites. An electronic search of PubMed, CAB, AGRICOLA, Biosis, and Compendex was performed, and citation relevance was determined according to the aim of the review. Quality assessment of relevant studies was performed using criteria from experts in virology, disease ecology, and environmental science. A total of 9,760 abstracts were evaluated, and 40 appeared to report the persistence of influenza virus in environmental samples. Evaluation of full texts revealed that 19 of the 40 studies were suitable for review, as they described virus concentration measured at multiple sampling times, with viruses detectable at least twice. Seven studies reported persistence in air (six published before 1970), seven in water (five published after 1990), two in feces, and three on surfaces. All three fomite and five air studies addressed human influenza virus, and all water and feces studies pertained to avian influenza virus. Outcome measurements were transformed to half-lives, and resultant multivariate mixed linear regression models identified influenza virus surviving longer in water than in air. Temperature was a significant predictor of persistence over all matrices. Salinity and pH were significant predictors of persistence in water conditions. An assessment of the methodological quality review of the included studies revealed significant gaps in reporting critical aspects of study design.

2018 ◽  
Vol 115 ◽  
pp. 168-174 ◽  
Author(s):  
Sayed-Hamidreza Mozhgani ◽  
Mohadeseh Zarei Ghobadi ◽  
Sina Moeini ◽  
Reza Pakzad ◽  
Pegah Kananizadeh ◽  
...  

2018 ◽  
Vol 43 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Carina Van Rooyen ◽  
Ruth Stewart ◽  
Thea De Wet

Big international development donors such as the UK’s Department for International Development and USAID have recently started using systematic review as a methodology to assess the effectiveness of various development interventions to help them decide what is the ‘best’ intervention to spend money on. Such an approach to evidence-based decision-making has long been practiced in the health sector in the US, UK, and elsewhere but it is relatively new in the development field. In this article we use the case of a systematic review of the impact of microfinance on the poor in sub-Saharan African to indicate how systematic review as a methodology can be used to assess the impact of specific development interventions.


Author(s):  
Garrett S. Bullock ◽  
Tom Hughes ◽  
Jamie C. Sergeant ◽  
Michael J. Callaghan ◽  
Gary S. Collins ◽  
...  

BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e042653
Author(s):  
Isobel Marion Harris ◽  
Heather McNeilly ◽  
Hani Benamer ◽  
Derek J Ward ◽  
Alice J Sitch ◽  
...  

ObjectiveThis systematic review aimed to explore consultant attitudes towards teaching undergraduate medical students in the UK.DesignSystematic review.MethodologyStandard systematic review methodology was followed. MEDLINE, EMBASE and OpenGrey were searched from inception to August 2019 to identify studies exploring senior doctors’ attitudes towards teaching undergraduate medical students. Two reviewers independently carried out key methodological steps including study screening/selection, quality assessment and data extraction. A narrative synthesis was undertaken.ResultsFive studies were included in the review dating 2003–2015. Two studies used questionnaires, and three used focus groups/semistructured interviews. Key findings identified across all studies were consultants generally found teaching undergraduate medical students enjoyable, and consultants identified time constraints as a barrier to teaching. Other findings were consultants feeling there was a lack of recognition for time spent teaching, and a lack of training/guidance regarding teaching students.ConclusionsThis is the first systematic review to explore senior hospital doctors’ attitudes towards teaching undergraduate medical students. Despite these five studies spanning 12 years, the same attitudes and issues regarding teaching are identified by all, suggesting lack of time particularly is a persistent problem regarding consultant-based teaching. An anecdotal impression is that consultants are no longer as enthusiastic about teaching as they once were, but it is evident over the 12 years of these studies that enjoyment levels, and presumably enthusiasm, have not changed significantly.


2014 ◽  
Vol 56 (6) ◽  
pp. 487-492 ◽  
Author(s):  
Lucas Gaíva E Silva ◽  
Alice Mamede Costa Marques Borges ◽  
Eliana Monteforte Cassaro Villalobos ◽  
Maria do Carmo Custodio Souza Hunold Lara ◽  
Elenice Maria Siquetin Cunha ◽  
...  

The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.


1970 ◽  
Vol 32 (2-3) ◽  
pp. 286-290 ◽  
Author(s):  
K. F. Shortridge ◽  
G. Belyavin ◽  
D. E. Bidwell

2015 ◽  
Vol 89 (22) ◽  
pp. 11275-11283 ◽  
Author(s):  
Heather M. Machkovech ◽  
Trevor Bedford ◽  
Marc A. Suchard ◽  
Jesse D. Bloom

ABSTRACTNumerous experimental studies have demonstrated that CD8+T cells contribute to immunity against influenza by limiting viral replication. It is therefore surprising that rigorous statistical tests have failed to find evidence of positive selection in the epitopes targeted by CD8+T cells. Here we use a novel computational approach to test for selection in CD8+T-cell epitopes. We define all epitopes in the nucleoprotein (NP) and matrix protein (M1) with experimentally identified human CD8+T-cell responses and then compare the evolution of these epitopes in parallel lineages of human and swine influenza viruses that have been diverging since roughly 1918. We find a significant enrichment of substitutions that alter human CD8+T-cell epitopes in NP of human versus swine influenza virus, consistent with the idea that these epitopes are under positive selection. Furthermore, we show that epitope-altering substitutions in human influenza virus NP are enriched on the trunk versus the branches of the phylogenetic tree, indicating that viruses that acquire these mutations have a selective advantage. However, even in human influenza virus NP, sites in T-cell epitopes evolve more slowly than do nonepitope sites, presumably because these epitopes are under stronger inherent functional constraint. Overall, our work demonstrates that there is clear selection from CD8+T cells in human influenza virus NP and illustrates how comparative analyses of viral lineages from different hosts can identify positive selection that is otherwise obscured by strong functional constraint.IMPORTANCEThere is a strong interest in correlates of anti-influenza immunity that are protective against diverse virus strains. CD8+T cells provide such broad immunity, since they target conserved viral proteins. An important question is whether T-cell immunity is sufficiently strong to drive influenza virus evolution. Although many studies have shown that T cells limit viral replication in animal models and are associated with decreased symptoms in humans, no studies have proven with statistical significance that influenza virus evolves under positive selection to escape T cells. Here we use comparisons of human and swine influenza viruses to rigorously demonstrate that human influenza virus evolves under pressure to fix mutations in the nucleoprotein that promote escape from T cells. We further show that viruses with these mutations have a selective advantage since they are preferentially located on the “trunk” of the phylogenetic tree. Overall, our results show that CD8+T cells targeting nucleoprotein play an important role in shaping influenza virus evolution.


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