409 research outputs found
The coupling of South American soybean and cattle production frontiers: new challenges for conservation policy and land change science
Different drivers and places of land use change in South America have often been studied in isolation. Evidence suggests, however, that in many instances, both places and drivers are becoming increasingly interconnected. The growing diversification and internationalization of agricultural commodity chains is creating new linkages across production frontiers and sectors that have important implications for conservation. In this article, we explore the implications of the sectoral and geographical coupling of soybean and cattle production frontiers for forest conservation in South America, with particular attention to the potential for policy-induced deforestation leakage. We conclude that the existence of coupled frontiers creates a need for more actor-centered approaches to conservation policy and research.Fil: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; ArgentinaFil: Le Polain de Waroux, Yann. University Of Stanford; Estados Unido
Epidemiology and transmission dynamics of Streptococcus pneumoniae in low and lower-middle income settings: implications for vaccination strategies
Disease due to Streptococcus pneumoniae is a major cause of mortality and morbidity globally. Pneumococcal conjugate vaccines (PCVs) are being routinely introduced in immunisation programmes with support from Gavi, the Vaccine alliance, in low-income countries but uncertainty remains around the impact of different PCV introduction strategies in such settings, and in particular catch-up campaigns (CCs), which so far have not been conducted in Gavi-supported countries due to supply constraints.
This thesis explored the potential impact on nasopharyngeal carriage and disease of introducing PCV with and without CCs, in Nha Trang, Vietnam, through a dynamic transmission model. Vietnam is yet to introduce PCV vaccination, as are most South-East Asian countries. Additional studies on the vaccine efficacy against carriage (VEC) and its waning, social contact patterns relevant for pneumococcal transmission, and age-specific epidemiology of carriage and serotype distribution were also conducted, the results of which fed directly into the transmission model.
A meta-analysis provided the first ever-global estimates of VEC and its waning, by serotype and schedule. A large survey in southwest Uganda, collecting data on both social contact patterns and carriage from the same participants, shed light on which social contacts are important for pneumococcal transmission, showing that the frequency of close contacts, but not casual contacts, increased the colonisation risk, thereby informing the parameterisation of the transmission model. Results from the latter predicted elimination of vaccine type (VT) serotypes with near-complete replacement by non-VT across all age groups, within 10 years of PCV introduction with 90% coverage. The predicted benefit of CCs to expanded age groups was most pronounced in the first three years after PCV introduction, insofar that CCs result in limited introduction delays.
This thesis provided important insight into the epidemiology and transmission dynamics of pneumococci, to inform policy in countries that have not yet introduced PCV
The serotype distribution among healthy carriers before vaccination is essential for predicting the impact of pneumococcal conjugate vaccine on invasive disease.
Pneumococcal conjugate vaccines (PCVs) have substantially reduced morbidity and mortality of pneumococcal disease. The impact of the 7-valent PCV on all-serotype invasive pneumococcal disease (IPD) among children was reported to vary between high-income countries. We investigate the ability to predict this heterogeneity from pre-vaccination data. We propose a parsimonious model that predicts the impact of PCVs from the odds of vaccine serotype (VT) among carriers and IPD cases in the pre-PCV period, assuming that VT are eliminated in a mature PCV programme, that full serotype replacement occurs in carriage and that invasiveness of the NVT group is unchanged. We test model performance against the reported impact of PCV7 on childhood IPD in high-income countries from a recent meta-analysis. The odds of pre-PCV7 VT IPD, PCV schedule, PCV coverage and whether a catch up campaign was used for introduction was gathered from the same analysis. We conducted a literature review and meta-analysis to obtain the odds of pre-PCV7 VT carriage in the respective settings. The model predicted the reported impact on childhood IPD of mature PCV programmes; the ratio of predicted and observed incidence risk ratios was close to 1 in all settings. In the high income settings studied differences in schedule, coverage, and catch up campaigns were not associated with the observed heterogeneity in impact of PCV7 on childhood all-serotype IPD. The pre-PCV7 proportion of VT IPD alone also had limited predictive value. The pre-PCV7 proportion of VT carriage and IPD are the main determinants for the impact of PCV7 on childhood IPD and can be combined in a simple model to provide predictions of the vaccine preventable burden of IPD
The restructuring of South American soy and beef production and trade under changing environmental regulations
In response to the extensive loss of forests caused by soy and cattle expansion in South America, several countries have increased their legal restrictions on deforestation, and stepped up their enforcement. In addition, in the Brazilian Amazon, new private agreements were initiated in 2006 and 2009 to limit the purchase of soy and cattle linked with deforestation. One concern is that such policies, because they are spatially heterogeneous or focus on a subset of relevant actors, might generate negative spillovers in the form of leakage of agricultural activities and deforestation to less-regulated areas, and/or a redistribution of non-compliant product sales to non-participants. In this study, we use panel data on soy and beef production and trade in agricultural frontiers of South America to examine how changes in deforestation regulations in South America have altered soy and cattle expansion and exports in this region, and to understand how these changes, if they have occurred, influence the overall effectiveness of deforestation regulations. We find no evidence of a change in soy or pasture area expansion patterns due to changes in regulations, except within the Amazon biome where pasture expansion slowed in response to more stringent regulations and coincided with pasture intensification. We do find, however, a decrease in beef imports from biomes with more stringent deforestation regulations. While this decrease may indicate the existence of leakage to countries outside the study area, it is likely offset by pasture intensification, continued opportunities for deforestation, and increasing domestic consumption from these biomes. These results point to the potential role of substitution effects between local and international consumer markets, and between different actors, in diminishing the overall effectiveness of deforestation regulations
Biological inflammatory markers mediate the effect of preoperative pain-related behaviours on postoperative analgesics requirements
Peer reviewedPublisher PD
Event-based surveillance at health facility and community level in low-income and middle-income countries: a systematic review.
BACKGROUND: The International Health Regulations require member states to establish "capacity to detect, assess, notify and report events". Event-based surveillance (EBS) can contribute to rapid detection of acute public health events. This is particularly relevant in low-income and middle-income countries (LMICs) which may have poor public health infrastructure. To identify best practices, we reviewed the literature on the implementation of EBS in LMICs to describe EBS structures and to evaluate EBS systems. METHODS: We conducted a systematic literature search of six databases to identify articles that evaluated EBS in LMICs and additionally searched for grey literature. We used a framework approach to facilitate qualitative data synthesis and exploration of patterns across and within articles. RESULTS: We identified 778 records, of which we included 15 studies concerning 13 different EBS systems. The 13 EBS systems were set up as community-based surveillance, health facility-based surveillance or open surveillance (ie, notification by non-defined individuals and institutions). Four systems were set up in outbreak settings and nine outside outbreaks. All EBS systems were integrated into existing routine surveillance systems and pre-existing response structures to some extent. EBS was described as useful in detecting a large scope of events, reaching remote areas and guiding outbreak response. CONCLUSION: Health facility and community-based EBS provide valuable information that can strengthen the early warning function of national surveillance systems. Integration into existing early warning and response systems was described as key to generate data for action and to facilitate rapid verification and response. Priority in its implementation should be given to settings that would particularly benefit from EBS strengths. This includes areas most prone to outbreaks and where traditional 'routine' surveillance is suboptimal
Clinical Impact of MALDI-TOF MS Identification and Rapid Susceptibility Testing on Adequate Antimicrobial Treatment in Sepsis with Positive Blood Cultures.
Shortening the turn-around time (TAT) of positive blood culture (BC) identification (ID) and susceptibility results is essential to optimize antimicrobial treatment in patients with sepsis. We aimed to evaluate the impact on antimicrobial prescription of a modified workflow of positive BCs providing ID and partial susceptibility results for Enterobacteriaceae (EB), Pseudomonas aeruginosa and Staphylococcus aureus on the day of BC positivity detection. This study was divided into a pre-intervention period (P0) with a standard BC workflow followed by 2 intervention periods (P1, P2) with an identical modified workflow. ID was performed with MALDI-TOF MS from blood, on early or on overnight subcultures. According to ID results, rapid phenotypic assays were realized to detect third generation cephalosporin resistant EB/P. aeruginosa or methicillin resistant S. aureus. Results were transmitted to the antimicrobial stewardship team for patient's treatment revision. Times to ID, to susceptibility results and to optimal antimicrobial treatment (OAT) were compared across the three study periods. Overall, 134, 112 and 154 positive BC episodes in P0, P1 and P2 respectively were included in the analysis. Mean time to ID (28.3 hours in P0) was reduced by 65.3% in P1 (10.2 hours) and 61.8% in P2 (10.8 hours). Mean time to complete susceptibility results was reduced by 27.5% in P1 and 27% in P2, with results obtained after 32.4 and 32.6 hours compared to 44.7 hours in P0. Rapid tests allowed partial susceptibility results to be obtained after a mean time of 11.8 hours in P1 and 11.7 hours in P2. Mean time to OAT was decreased to 21.6 hours in P1 and to 17.9 hours in P2 compared to 36.1 hours in P0. Reducing TAT of positive BC with MALDI-TOF MS ID and rapid susceptibility testing accelerated prescription of targeted antimicrobial treatment thereby potentially improving the patients' clinical outcome
The Efficacy and Duration of Protection of Pneumococcal Conjugate Vaccines Against Nasopharyngeal Carriage: A Meta-Regression Model.
BACKGROUND: Pneumococcal conjugate vaccines (PCVs) reduce disease largely through their impact on nasopharyngeal (NP) carriage acquisition of Streptococcus pneumoniae, a precondition for developing any form of pneumococcal disease. We aimed to estimate the vaccine efficacy (VEC) and duration of protection of PCVs against S. pneumoniae carriage acquisition through meta-regression models. METHODS: We identified intervention studies providing NP carriage estimates among vaccinated and unvaccinated children at any time after completion of a full vaccination schedule. We calculated VEC for PCV7 serotypes, grouped as well as individually, and explored cross-protective efficacy against 6A. Efficacy estimates over time were obtained using a Bayesian meta-logistic regression approach, with time since completion of vaccination as a covariate. RESULTS: We used data from 22 carriage surveys (15 independent studies) from 5 to 64 months after the last PCV dose, including 14,298 children. The aggregate VEC for all PCV7 serotypes 6 months after completion of the vaccination schedule was 57% (95% credible interval: 50-65%), varying by serotype from 38% (19F) to 80%. Our model provides evidence of sustained protection of PCVs for several years, with an aggregate VEC of 42% (95% credible interval: 19-54%) at 5 years, although the waning differed between serotypes. We also found evidence of cross-protection against 6A, with a VEC of 39% 6 months after a complete schedule, decreasing to 0 within 5 years postvaccination. CONCLUSION: Our results suggest that PCVs confer reasonable protection against acquisition of pneumococcal carriage of the 7 studied serotypes, for several years after vaccination, albeit with differences across serotypes.<br/
Can viability assessment by DE-MRI predict survival in patients with multivessel disease and low ejection fraction? Influence of treatment strategies
Diagnosis and treatment of chlamydia and gonorrhoea in general practice in England 2000–2011: a population-based study using data from the UK Clinical Practice Research Datalink
Objectives: To determine the relative contribution of general practices (GPs) to the diagnosis of chlamydia and gonorrhoea in England and whether treatment complied with national guidelines. Design: Analysis of longitudinal electronic health records in the Clinical Practice Research Datalink (CPRD) and national sexually transmitted infection (STI) surveillance databases, England, 2000–2011. Setting: GPs, and community and specialist STI services. Participants: Patients diagnosed with chlamydia (n=1 386 169) and gonorrhoea (n=232 720) at CPRD GPs, and community and specialist STI Services from 2000–2011. Main outcome measures: Numbers and rates of chlamydia and gonorrhoea diagnoses; percentages of patients diagnosed by GPs relative to other services; percentage of GP patients treated and antimicrobials used; percentage of GP patients referred. Results: The diagnosis rate (95% CI) per 100 000 population of chlamydia in GP increased from 22.8 (22.4–23.2) in 2000 to 29.3 (28.8–29.7) in 2011 (p<0.001), while the proportion treated increased from 59.5% to 78.4% (p=0.001). Over 90% were prescribed a recommended antimicrobial. Over the same period, the diagnosis rate (95% CI) per 100 000 population of gonorrhoea in GP ranged between 3.2 (3–3.3) and 2.4 (2.2–2.5; p=0.607), and the proportion treated ranged between 32.7% and 53.6% (p=0.262). Despite being discontinued as a recommended therapy for gonorrhoea in 2005, ciprofloxacin accounted for 42% of prescriptions in 2007 and 20% in 2011. Over the study period, GPs diagnosed between 9% and 16% of chlamydia cases and between 6% and 9% of gonorrhoea cases in England. Conclusions: GP makes an important contribution to the diagnosis and treatment of bacterial STIs in England. While most patients diagnosed with chlamydia were managed appropriately, many of those treated for gonorrhoea received antimicrobials no longer recommended for use. Given the global threat of antimicrobial resistance, GPs should remain abreast of national treatment guidelines and alert to treatment failure in their patients
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