West Nile Virus Genetic Diversity is Maintained during Transmission by Culex pipiens quinquefasciatus Mosquitoes

Due to error-prone replication, RNA viruses exist within hosts as a heterogeneous population of non-identical, but related viral variants. These populations may undergo bottlenecks during transmission that stochastically reduce variability leading to fitness declines. Such bottlenecks have been documented for several single-host RNA viruses, but their role in the population biology of obligate two-host viruses such as arthropod-borne viruses (arboviruses) in vivo is unclear, but of central importance in understanding arbovirus persistence and emergence. Therefore, we tracked the composition of West Nile virus (WNV; Flaviviridae, Flavivirus) populations during infection of the vector mosquito, Culex pipiens quinquefasciatus to determine whether WNV populations undergo bottlenecks during transmission by this host. Quantitative, qualitative and phylogenetic analyses of WNV sequences in mosquito midguts, hemolymph and saliva failed to document reductions in genetic diversity during mosquito infection. Further, migration analysis of individual viral variants revealed that while there was some evidence of compartmentalization, anatomical barriers do not impose genetic bottlenecks on WNV populations. Together, these data suggest that the complexity of WNV populations are not significantly diminished during the extrinsic incubation period of mosquitoes

Grand Challenges in global eye health: a global prioritisation process using Delphi method

Background: We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations. Methods: Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists. Findings: Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity. Interpretation: This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenges. Funding: The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, The Seva Foundation, British Council for the Prevention of Blindness, and Christian Blind Mission. Translations: For the French, Spanish, Chinese, Portuguese, Arabic and Persian translations of the abstract see Supplementary Materials section

'IHPBA-APHPBA clinical practice guidelines': international Delphi consensus recommendations for gallbladder cancer

BACKGROUND: The Delphi consensus study was carried out under the auspices of the International and Asia-Pacific Hepato-Pancreato-Biliary Associations (IHPBA-APHPBA) to develop practice guidelines for management of gallbladder cancer (GBC) globally. METHOD: GBC experts from 17 countries, spanning 6 continents, participated in a hybrid four-round Delphi consensus development process. The methodology involved email, online consultations, and in-person discussions. Sixty eight clinical questions (CQs) covering various domains related to GBC, were administered to the experts. A consensus recommendation was accepted only when endorsed by more than 75% of the participating experts. RESULTS: Out of the sixty experts invited initially to participate in the consensus process 45 (75%) responded to the invitation. The consensus was achieved in 92.6% (63/68) of the CQs. Consensus covers epidemiological aspects of GBC, early, incidental and advanced GBC management, definitions for radical GBC resections, the extent of liver resection, lymph node dissection, and definitions of borderline resectable and locally advanced GBC. CONCLUSIONS: This is the first international Delphi consensus on GBC. These recommendations provide uniform terminology and practical clinical guidelines on the current management of GBC. Unresolved contentious issues like borderline resectable/locally advanced GBC need to be addressed by future clinical studies

Global, regional, and national levels of maternal mortality, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015

Seventeen Sustainable Development Goals (SDGs) were adopted by the global community to provide benchmark targets for global development between 2015 and 2030 and to reframe the Millennium Development Goals (MDGs) to achieve sustainable global development. This report presents data on maternal mortality in 195 countries from 1990 to 2015. Maternal mortality data were categorized in 3 formats, namely, number of deaths, cause-specific mortality rate per capita, and cause fraction. The overall maternal mortality was modeled using cause-of-death ensemble modeling (CODEm). The number of deaths, maternal mortality ratios (MMRs), and 95% uncertainty intervals were reported for all estimates. The results indicate that the overall decline in global maternal deaths from 1990 to 2015 was approximately 29% (390,185 in 1990; 374,321 in 2000; and 275,288 in 2015), and the reduction in MMR was 30% (282 in 1990, 288 in 2000, and 196 in 2015). In 1990, it was found that 60 countries had an MMR of more than 200, 40 countries had an MMR of more than 400, 15 countries had an MMR of more than 600, and 1 country had an MMR of more than 1000. By 2015, 122 countries had an MMR of less than 70, and 49 countries had an MMR of less than 15. Although MMR and Sociodemographic Index improved between 1990 and 2015 in almost all regions, it was observed that MMR did not universally track with Sociodemographic Index over the whole time period in any single region. The observed minus expected (O - E) MMR ratio was consistently found to be 1.25 or more in many regions; however, MMR reductions slowed considerably, and the O - E MMR ratio was 1.41 in 2015. The risk of maternal mortality increased greatly with age, but decreased greatly in almost all age groups from 1990 to 2015. It was observed that MMR in 10- to 14-year-old girls in 2015 was 278; it then decreased and was lowest in women aged 15 to 29 years before increasing significantly to 1832 in 50- to 54-year-old women. Direct obstetric causes accounted for 86% of all maternal deaths in 2015 due to maternal hemorrhage, maternal hypertensive disorders, and other maternal disorders in comparison to 1990 when direct complications accounted for 87% of all maternal deaths. Other maternal disorders caused approximately 74,299 deaths in 1990 and decreased to 32,734 deaths in 2015. The study authors conclude that although there is global progress in reducing maternal mortality in the past 15 years, more and better data collection systems should be put in place to devise better health care policies and to educate women about reproductive care options available to them

Global, regional, and national levels of maternal mortality, 1990-2015 : a systematic analysis for the Global Burden of Disease Study 2015

Background In transitioning from the Millennium Development Goal to the Sustainable Development Goal era, it is imperative to comprehensively assess progress toward reducing maternal mortality to identify areas of success, remaining challenges, and frame policy discussions. We aimed to quantify maternal mortality throughout the world by underlying cause and age from 1990 to 2015. Methods We estimated maternal mortality at the global, regional, and national levels from 1990 to 2015 for ages 10-54 years by systematically compiling and processing all available data sources from 186 of 195 countries and territories, 11 of which were analysed at the subnational level. We quantified eight underlying causes of maternal death and four timing categories, improving estimation methods since GBD 2013 for adult all-cause mortality, HIV-related maternal mortality, and late maternal death. Secondary analyses then allowed systematic examination of drivers of trends, including the relation between maternal mortality and coverage of specific reproductive health-care services as well as assessment of observed versus expected maternal mortality as a function of Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Findings Only ten countries achieved MDG 5, but 122 of 195 countries have already met SDG 3.1. Geographical disparities widened between 1990 and 2015 and, in 2015, 24 countries still had a maternal mortality ratio greater than 400. The proportion of all maternal deaths occurring in the bottom two SDI quintiles, where haemorrhage is the dominant cause of maternal death, increased from roughly 68% in 1990 to more than 80% in 2015. The middle SDI quintile improved the most from 1990 to 2015, but also has the most complicated causal profile. Maternal mortality in the highest SDI quintile is mostly due to other direct maternal disorders, indirect maternal disorders, and abortion, ectopic pregnancy, and/or miscarriage. Historical patterns suggest achievement of SDG 3.1 will require 91% coverage of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled birth attendance. Interpretation Several challenges to improving reproductive health lie ahead in the SDG era. Countries should establish or renew systems for collection and timely dissemination of health data; expand coverage and improve quality of family planning services, including access to contraception and safe abortion to address high adolescent fertility; invest in improving health system capacity, including coverage of routine reproductive health care and of more advanced obstetric care-including EmOC; adapt health systems and data collection systems to monitor and reverse the increase in indirect, other direct, and late maternal deaths, especially in high SDI locations; and examine their own performance with respect to their SDI level, using that information to formulate strategies to improve performance and ensure optimum reproductive health of their population.Peer reviewe

The development of the Indian vision function questionnaire: field testing and psychometric evaluation.

OBJECTIVE: To develop and evaluate the acceptability, reliability, validity, and responsiveness of the Indian vision function questionnaire (IND-VFQ). METHODS: Problem statements from previous qualitative studies were reduced to a 45 item interviewer administered questionnaire representing three a priori domains (general functioning, psychosocial impact, and visual symptoms) which was evaluated in patients with cataract (n = 420), glaucoma (n = 120), diabetic retinopathy, or age related macular degeneration (n = 120) and normal controls (n = 120). Standard methods were used for item reduction and to evaluate psychometric properties. RESULTS: Psychometric item reduction produced a 33 item questionnaire. Psychometric evaluation showed that two of the three scales (psychosocial impact and visual symptoms) had good acceptability, and that all three scales showed high internal consistency (alpha >0.80; item-total correlations 0.54-0.86) and test-retest reliability (>0.89). All three scales showed moderate evidence of convergent and discriminant validity. Responsiveness, assessed in cataract patients (n = 120) before and after surgery, was good for all three scales (effect sizes >1). CONCLUSIONS: The IND-VFQ33 is a psychometrically sound measure of vision function addressing a gap in patient defined measures of vision function developed in populations living in low income countries

Tracking Dengue Virus Intra-host Genetic Diversity during Human-to-Mosquito Transmission.

Dengue virus (DENV) infection of an individual human or mosquito host produces a dynamic population of closely-related sequences. This intra-host genetic diversity is thought to offer an advantage for arboviruses to adapt as they cycle between two very different host species, but it remains poorly characterized. To track changes in viral intra-host genetic diversity during horizontal transmission, we infected Aedes aegypti mosquitoes by allowing them to feed on DENV2-infected patients. We then performed whole-genome deep-sequencing of human- and matched mosquito-derived DENV samples on the Illumina platform and used a sensitive variant-caller to detect single nucleotide variants (SNVs) within each sample. >90% of SNVs were lost upon transition from human to mosquito, as well as from mosquito abdomen to salivary glands. Levels of viral diversity were maintained, however, by the regeneration of new SNVs at each stage of transmission. We further show that SNVs maintained across transmission stages were transmitted as a unit of two at maximum, suggesting the presence of numerous variant genomes carrying only one or two SNVs each. We also present evidence for differences in selection pressures between human and mosquito hosts, particularly on the structural and NS1 genes. This analysis provides insights into how population drops during transmission shape RNA virus genetic diversity, has direct implications for virus evolution, and illustrates the value of high-coverage, whole-genome next-generation sequencing for understanding viral intra-host genetic diversity