Sustainability of a Virtual Community: Integrating Individual and Structural Dynamics

This study investigates how virtual communities retain active members and maintain sustainability as they grow in size. By integrating the individual and structural dynamics of a virtual community, this study develops a multi-level research model that explores how structural factors (i.e., membership and clique sizes) at the community level interact with individual factors (i.e., the extent of use of collaborative tools, the strength of emotional ties, and shared information resources) to predict an active member’s intention to stay. We tested the proposed cross-level hypotheses using survey data collected from 164 participants and 15 virtual communities. The results of this study emphasize the need to consider individual and structural dynamics simultaneously to understand virtual communities’ sustainability. Results indicate that membership size does not directly influence an active member’s intention to stay but that it exerts an indirect effect by strengthening the positive relationship between the extent of use of collaborative tools and shared information resources. This study supports the notion that, because members form cliques, the strength of emotional ties among individuals in a virtual community does not decrease despite an increase in membership size. Notably, the results suggest that, in a virtual community, a large clique size may weaken the relationship between the strength of emotional ties and the intention to stay

Gut microbiome of helminth-infected indigenous Malaysians is context dependent

Background: While microbiomes in industrialized societies are well characterized, indigenous populations with traditional lifestyles have microbiomes that are more akin to those of ancient humans. However, metagenomic data in these populations remains scarce, and the association with soil-transmitted helminth infection status is unclear. Here, we sequenced 650 metagenomes of indigenous Malaysians from fve villages with diferent prevalence of helminth infections. Results: Individuals from villages with higher prevalences of helminth infections have more unmapped reads and greater microbial diversity. Microbial community diversity and composition were most strongly associated with different villages and the efects of helminth infection status on the microbiome varies by village. Longitudinal changes in the microbiome in response to albendazole anthelmintic treatment were observed in both helminth infected and uninfected individuals. Inference of bacterial population replication rates from origin of replication analysis identifed specifc replicating taxa associated with helminth infection. Conclusions: Our results indicate that helminth efects on the microbiota were highly dependent on context, and efects of albendazole on the microbiota can be confounding for the interpretation of deworming studies. Furthermore, a substantial quantity of the microbiome remains unannotated, and this large dataset from an indigenous population associated with helminth infections is a valuable resource for future studie

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Anti-angiogenic therapy for cancer: Current progress, unresolved questions and future directions

Tumours require a vascular supply to grow and can achieve this via the expression of pro-angiogenic growth factors, including members of the vascular endothelial growth factor (VEGF) family of ligands. Since one or more of the VEGF ligand family is overexpressed in most solid cancers, there was great optimism that inhibition of the VEGF pathway would represent an effective anti-angiogenic therapy for most tumour types. Encouragingly, VEGF pathway targeted drugs such as bevacizumab, sunitinib and aflibercept have shown activity in certain settings. However, inhibition of VEGF signalling is not effective in all cancers, prompting the need to further understand how the vasculature can be effectively targeted in tumours. Here we present a succinct review of the progress with VEGF-targeted therapy and the unresolved questions that exist in the field: including its use in different disease stages (metastatic, adjuvant, neoadjuvant), interactions with chemotherapy, duration and scheduling of therapy, potential predictive biomarkers and proposed mechanisms of resistance, including paradoxical effects such as enhanced tumour aggressiveness. In terms of future directions, we discuss the need to delineate further the complexities of tumour vascularisation if we are to develop more effective and personalised anti-angiogenic therapies. © 2014 The Author(s)

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Validation of a semi-quantitative FFQ for 18-month-old toddlers : the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) study

Objective: Dietary intake of toddlers has been of growing interest due to its long-term consequences on health. However, previous works have focused largely on Caucasian populations and less is known about Asian toddlers. We aimed to validate a semi-quantitative FFQ designed to assess dietary intakes of 18-month-old toddlers in a multi-ethnic Asian cohort. Design: An FFQ of ninety-four food items, identified based on food records of 12-month-old GUSTO children, the Southampton Women’s Survey 12 Month Infancy Questionnaire and inputs from paediatric dietitians, was filled out two weeks before the 18th-month clinic visit. As the reference method, two non-consecutive 24 h recalls (24HR) were administered during and two weeks after the clinic visit. FFQ nutrient intakes were validated against averaged 24HR nutrient intakes, using the Wilcoxon signed-rank test, Spearman’s rank-order correlation, cross-classification and the Bland–Altman method. Setting: Data from the Singapore Growing Up in Singapore Towards Healthy Outcomes (GUSTO) mother–offspring birth cohort. Participants: Toddlers (n 188) aged 18 months. Results: Absolute nutrient intakes from the FFQ were significantly higher than from the 24HR, except for vitamin A. After energy adjustments, r range was 0·56–0·78 (macronutrients) and 0·40–0·54 (micronutrients). De-attenuation increased r to 0·58–0·96 and 0·45–0·65 for macro- and micronutrients, respectively. Of participants, ≥82·4 % (macronutrients) and ≥77·7 % (micronutrients) were classified in the same and adjacent quartiles. No clear systematic increase in intake differences with increasing mean intake was observed in Bland–Altman plots. Conclusions: This FFQ can provide a satisfactory assessment of toddlers’ energy-adjusted nutrient intakes, as well as accurately rank them in a group.Agency for Science, Technology and Research (A*STAR)Ministry of Health (MOH)National Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThis research is supported by the Singapore National Research Foundation under its Translational and Clinical Research (TCR) Flagship Programme and administered by the Singapore Ministry of Health’s National Medical Research Council (NMRC), Singapore (grant numbers NMRC/TCR/004-NUS/2008 and NMRC/TCR/012-NUHS/2014). K.M.G. is supported by the UK Medical Research Council (grant number MC_UU_12011/4); the National Institute for Health Research (as an NIHR Senior Investigator (grant number NF-SI-0515-10042) and through the NIHR Southampton Biomedical Research Centre); and the European Union’s Erasmus+ Capacity-Building ENeASEA Project and Seventh Framework Programme (FP7/2007-2013), projects EarlyNutrition and ODIN (grant agreement numbers 289346 and 613977). Additional funding is provided by the Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore

Validation of a semi-quantitative FFQ for 18-month-old toddlers: the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) study

ObjectiveDietary intake of toddlers has been of growing interest due to its long-term consequences on health. However, previous works have focused largely on Caucasian populations and less is known about Asian toddlers. We aimed to validate a semi-quantitative FFQ designed to assess dietary intakes of 18-month-old toddlers in a multi-ethnic Asian cohort.DesignAn FFQ of ninety-four food items, identified based on food records of 12-month-old GUSTO children, the Southampton Women’s Survey 12 Month Infancy Questionnaire and inputs from paediatric dietitians, was filled out two weeks before the 18th-month clinic visit. As the reference method, two non-consecutive 24 h recalls (24HR) were administered during and two weeks after the clinic visit. FFQ nutrient intakes were validated against averaged 24HR nutrient intakes, using the Wilcoxon signed-rank test, Spearman’s rank-order correlation, cross-classification and the Bland–Altman method.SettingData from the Singapore Growing Up in Singapore Towards Healthy Outcomes (GUSTO) mother–offspring birth cohort.ParticipantsToddlers (n 188) aged 18 months.ResultsAbsolute nutrient intakes from the FFQ were significantly higher than from the 24HR, except for vitamin A. After energy adjustments, r range was 0·56–0·78 (macronutrients) and 0·40–0·54 (micronutrients). De-attenuation increased r to 0·58–0·96 and 0·45–0·65 for macro- and micronutrients, respectively. Of participants, ≥82·4 % (macronutrients) and ≥77·7 % (micronutrients) were classified in the same and adjacent quartiles. No clear systematic increase in intake differences with increasing mean intake was observed in Bland–Altman plots.ConclusionsThis FFQ can provide a satisfactory assessment of toddlers’ energy-adjusted nutrient intakes, as well as accurately rank them in a group