Genetic drivers of heterogeneity in type 2 diabetes pathophysiology

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P < 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.

Gene-educational attainment interactions in a multi-population genome-wide meta-analysis identify novel lipid loci

Introduction: Educational attainment, widely used in epidemiologic studies as a surrogate for socioeconomic status, is a predictor of cardiovascular health outcomes. Methods: A two-stage genome-wide meta-analysis of low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) levels was performed while accounting for gene-educational attainment interactions in up to 226,315 individuals from five population groups. We considered two educational attainment variables: "Some College" (yes/no, for any education beyond high school) and "Graduated College" (yes/no, for completing a 4-year college degree). Genome-wide significant (p < 5 × 10-8) and suggestive (p < 1 × 10-6) variants were identified in Stage 1 (in up to 108,784 individuals) through genome-wide analysis, and those variants were followed up in Stage 2 studies (in up to 117,531 individuals). Results: In combined analysis of Stages 1 and 2, we identified 18 novel lipid loci (nine for LDL, seven for HDL, and two for TG) by two degree-of-freedom (2 DF) joint tests of main and interaction effects. Four loci showed significant interaction with educational attainment. Two loci were significant only in cross-population analyses. Several loci include genes with known or suggested roles in adipose (FOXP1, MBOAT4, SKP2, STIM1, STX4), brain (BRI3, FILIP1, FOXP1, LINC00290, LMTK2, MBOAT4, MYO6, SENP6, SRGAP3, STIM1, TMEM167A, TMEM30A), and liver (BRI3, FOXP1) biology, highlighting the potential importance of brain-adipose-liver communication in the regulation of lipid metabolism. An investigation of the potential druggability of genes in identified loci resulted in five gene targets shown to interact with drugs approved by the Food and Drug Administration, including genes with roles in adipose and brain tissue. Discussion: Genome-wide interaction analysis of educational attainment identified novel lipid loci not previously detected by analyses limited to main genetic effects.

Mistakes in managing hepatocellular carcinoma and how to avoid them: a narrative review

INTRODUCTION

Hepatocellular carcinoma (HCC) is the most common liver-related cancer and the third leading cause of worldwide cancer-related mortality.

AREAS COVERED

There have been many updated guidelines on the management of HCC in the past few years. Given the increasing burden of HCC in clinical practice, knowledge of evidence-based standards of care for these patients is essential for any practitioner managing patients with HCC. Early detection and judicious treatment based on the stage of the HCC can improve patient outcomes. We performed a PubMed (MEDLINE database) search for the latest guidelines related to the screening, detection, diagnosis, staging, and management of HCC. We aim to highlight some major considerations and common mistakes in managing HCC and attempt to provide evidence-based recommendations.

EXPERT OPINION

The field of HCC management is expected to evolve in the coming years. Increased emphasis on personalized treatment and precision medicine with earlier detection methods, the development of noninvasive diagnostic tools, increased focus on combination therapies and a shift toward more targeted treatments will become more critical.

Multi-ancestry genome-wide study in >2.5 million individuals reveals heterogeneity in mechanistic pathways of type 2 diabetes and complications

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes. To characterise the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study (GWAS) data from 2,535,601 individuals (39.7% non-European ancestry), including 428,452 T2D cases. We identify 1,289 independent association signals at genome-wide significance (P<5×10-8) that map to 611 loci, of which 145 loci are previously unreported. We define eight non-overlapping clusters of T2D signals characterised by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial, and enteroendocrine cells. We build cluster-specific partitioned genetic risk scores (GRS) in an additional 137,559 individuals of diverse ancestry, including 10,159 T2D cases, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned GRS are more strongly associated with coronary artery disease and end-stage diabetic nephropathy than an overall T2D GRS across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings demonstrate the value of integrating multi-ancestry GWAS with single-cell epigenomics to disentangle the aetiological heterogeneity driving the development and progression of T2D, which may offer a route to optimise global access to genetically-informed diabetes care.

Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis

BACKGROUND

Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.

RESULTS

To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N = 1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.

CONCLUSIONS

Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.

A saturated map of common genetic variants associated with human height

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40-50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes1. Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel2) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10-20% (14-24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries.

A multi-layer functional genomic analysis to understand noncoding genetic variation in lipids

A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.

A mechanistic model of snakebite as a zoonosis: Envenoming incidence is driven by snake ecology, socioeconomics and its impacts on snakes

Snakebite is the only WHO-listed, not infectious neglected tropical disease (NTD), although its eco-epidemiology is similar to that of zoonotic infections: envenoming occurs after a vertebrate host contacts a human. Accordingly, snakebite risk represents the interaction between snake and human factors, but their quantification has been limited by data availability. Models of infectious disease transmission are instrumental for the mitigation of NTDs and zoonoses. Here, we represented snake-human interactions with disease transmission models to approximate geospatial estimates of snakebite incidence in Sri Lanka, a global hotspot. Snakebites and envenomings are described by the product of snake and human abundance, mirroring directly transmitted zoonoses. We found that human-snake contact rates vary according to land cover (surrogate of occupation and socioeconomic status), the impacts of humans and climate on snake abundance, and by snake species. Our findings show that modelling snakebite as zoonosis provides a mechanistic eco-epidemiological basis to understand snakebites, and the possible implications of global environmental and demographic change for the burden of snakebite.

Multi-ancestry genetic study of type 2 diabetes highlights the power of diverse populations for discovery and translation

We assembled an ancestrally diverse collection of genome-wide association studies (GWAS) of type 2 diabetes (T2D) in 180,834 affected individuals and 1,159,055 controls (48.9% non-European descent) through the Diabetes Meta-Analysis of Trans-Ethnic association studies (DIAMANTE) Consortium. Multi-ancestry GWAS meta-analysis identified 237 loci attaining stringent genome-wide significance (P < 5 × 10-9), which were delineated to 338 distinct association signals. Fine-mapping of these signals was enhanced by the increased sample size and expanded population diversity of the multi-ancestry meta-analysis, which localized 54.4% of T2D associations to a single variant with >50% posterior probability. This improved fine-mapping enabled systematic assessment of candidate causal genes and molecular mechanisms through which T2D associations are mediated, laying the foundations for functional investigations. Multi-ancestry genetic risk scores enhanced transferability of T2D prediction across diverse populations. Our study provides a step toward more effective clinical translation of T2D GWAS to improve global health for all, irrespective of genetic background.

Identification of genetic effects underlying type 2 diabetes in South Asian and European populations

South Asians are at high risk of developing type 2 diabetes (T2D). We carried out a genome-wide association meta-analysis with South Asian T2D cases (n = 16,677) and controls (n = 33,856), followed by combined analyses with Europeans (neff = 231,420). We identify 21 novel genetic loci for significant association with T2D (P = 4.7 × 10-8 to 5.2 × 10-12), to the best of our knowledge at the point of analysis. The loci are enriched for regulatory features, including DNA methylation and gene expression in relevant tissues, and highlight CHMP4B, PDHB, LRIG1 and other genes linked to adiposity and glucose metabolism. A polygenic risk score based on South Asian-derived summary statistics shows ~4-fold higher risk for T2D between the top and bottom quartile. Our results provide further insights into the genetic mechanisms underlying T2D, and highlight the opportunities for discovery from joint analysis of data from across ancestral populations.

The use of personal protective equipment in endoscopy: what should the endoscopist wear during a pandemic?

Endoscopists are at high risk of exposure and nosocomial transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus) when performing endoscopic procedures due to the highly aerosol generating nature of these procedures. At present, there is still no consensus among endoscopists with regards to the type of protective equipment to be worn by healthcare workers, when performing endoscopy during the coronavirus 2019 (COVID-19) pandemic. This review encompasses a summary of currently published guidelines related to the use of personal protective equipment (PPE) when performing endoscopic procedures during the COVID-19 pandemic. With increasing calls to rationalize the use of PPE due to shortages in global supply chains, the review offers a concise summary on the most appropriate and adequate use of PPE when performing endoscopy during the pandemic. It is expected that these adaptations in the use of PPE during the pandemic will help to improve standards of care and safety of healthcare workers.

The power of genetic diversity in genome-wide association studies of lipids

Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.

Chronic health effects and cost of snakebite

The burden of disability among survivors and the socio-economic impact of snakebite have not been adequately researched. We reviewed original research articles, case reports and small case series relating to chronic physical, mental and psycho-social disability and economic burden of snakebite. Both physical and psychological health problems seem common in snakebite survivors and can lead to disability and loss of productivity. Chronic physical health effects, musculoskeletal disability being the commonest, can be largely attributed to limited and delayed access to optimal treatment of acute envenoming. The economic burden is considerable, and includes health system costs, out-of-pocket expenditure and opportunity costs, with regional variations. Health systems should be more responsive to needs and circumstances of bite victims, and a more holistic approach should be developed in the treatment of snakebite which incorporates the management of chronic health effects.

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Limited attention has been paid to chronic disability and the socio-economic impact of snakebite.

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Physical and psychological health problems occur in snakebite survivors leading to disability and loss of productivity.

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Chronic health effects can be largely attributed to limited and delayed access to optimal treatment of acute envenoming.

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Economic burden includes health system costs, out-of-pocket expenditure and opportunity costs.

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Health systems should be responsive to needs and circumstances of bite victims including care of chronic health effects.

Gene-educational attainment interactions in a multi-ancestry genome-wide meta-analysis identify novel blood pressure loci

Educational attainment is widely used as a surrogate for socioeconomic status (SES). Low SES is a risk factor for hypertension and high blood pressure (BP). To identify novel BP loci, we performed multi-ancestry meta-analyses accounting for gene-educational attainment interactions using two variables, "Some College" (yes/no) and "Graduated College" (yes/no). Interactions were evaluated using both a 1 degree of freedom (DF) interaction term and a 2DF joint test of genetic and interaction effects. Analyses were performed for systolic BP, diastolic BP, mean arterial pressure, and pulse pressure. We pursued genome-wide interrogation in Stage 1 studies (N = 117 438) and follow-up on promising variants in Stage 2 studies (N = 293 787) in five ancestry groups. Through combined meta-analyses of Stages 1 and 2, we identified 84 known and 18 novel BP loci at genome-wide significance level (P < 5 × 10-8). Two novel loci were identified based on the 1DF test of interaction with educational attainment, while the remaining 16 loci were identified through the 2DF joint test of genetic and interaction effects. Ten novel loci were identified in individuals of African ancestry. Several novel loci show strong biological plausibility since they involve physiologic systems implicated in BP regulation. They include genes involved in the central nervous system-adrenal signaling axis (ZDHHC17, CADPS, PIK3C2G), vascular structure and function (GNB3, CDON), and renal function (HAS2 and HAS2-AS1, SLIT3). Collectively, these findings suggest a role of educational attainment or SES in further dissection of the genetic architecture of BP.

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10-8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.

Development of in-house ELISAs as an alternative method for the serodiagnosis of leptospirosis

BACKGROUND

Leptospirosis is most often diagnosed clinically, and a laboratory test with high diagnostic accuracy is required.

METHODS

IgM and IgG ELISAs using Leptospira antigens were established and evaluated in relation to the microscopic agglutination test (MAT). Antigen preparation consisted of saprophytic Leptospira biflexa to detect genus-specific antibodies (genus-specific ELISA) and a pool of the five most prevalent Leptospira interrogans serovars in Sri Lanka to detect serovar-specific antibodies (serovar-specific ELISA). IgM and IgG immune responses were studied in severe and mild leptospirosis patients (n = 100 in each group).

RESULTS

The ELISAs showed high repeatability and reproducibility. The serovar-specific IgM-ELISA showed a sensitivity of 80.2% and specificity of 89%; the genus-specific IgM-ELISA showed a sensitivity of 83.3% and specificity of 91%. The serovar- and genus-specific IgG-ELISAs showed sensitivities of 73.3% and 81.7%, respectively, and specificities of 83.3% and 83.3%, respectively. The commercial IgM-ELISA showed a sensitivity of 79.2% and specificity of 93%. The commercial IgG-ELISA showed a sensitivity of 50% and specificity of 96.7%. IgM levels observed in mild and severe leptospirosis patients were significantly higher than in the healthy control group, with mean absorbance values of 0.770, 0.778, and 0.163, respectively. Severe leptospirosis patients had significantly higher mean anti-leptospiral IgG levels compared to both mild leptospirosis patients and healthy control group subjects (0.643, 0.358, and 0.116, respectively; ANOVA, p < 0.001). The presence of anti-leptospiral IgG above an optical density of 0.643 at 1:100 could predict a high risk of severe disease.

CONCLUSION

The serovar-specific in-house ELISA could be used for the laboratory diagnosis of leptospirosis in endemic settings. The high levels of anti-leptospiral IgG observed suggest its value as a predictor of disease severity.

Masks in COVID-19: let's unmask the evidence

INTRODUCTION

One of the main issues in the novel coronavirus 2019 (COVID-19) pandemic has been the lack of uniformity of recommendations for the usage of face masks.

AREAS COVERED

While Asian countries started using masks early during the epidemic, most Western countries were slow to do so. To avoid such situations, clear guidelines, need to be established, not only regarding the use of masks but also the type of mask to suit different situations. In this article, we will examine the types of masks and review the recommendations for their use based on the available evidence for each type of mask.

EXPERT OPINION

We explore future needs in research-related mask use in COVID-19 pandemic, improvements to be made in mask design, adopting guidelines for the use of masks and the psycho-social aspects of widespread and prolonged mask use.

Low-dose melatonin for sleep disturbances in early-stage cirrhosis: A randomized, placebo-controlled, cross-over trial

Background and aim

Melatonin is used to treat sleep disturbances (SDs). The aim of this study was to investigate the safety and efficacy of low‐dose melatonin for SDs in early‐stage cirrhosis.

Methods

In a single‐center, randomized, double‐blind, placebo‐controlled, cross‐over clinical trial, patients with early‐stage (Child‐Turcotte‐Pugh [CTP] class A or B) cirrhosis with SDs, without hepatic encephalopathy, were randomized to placebo or 3 mg of melatonin for 2 weeks. After 2 weeks, the patients were given a washout period of 1 week and crossed over to melatonin or placebo for a further 2 weeks. The Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were used to measure sleep quality and daytime sleepiness, respectively. Analysis of results was based on intention to treat, and linear mixed‐effect models were used to evaluate the effect of melatonin. Analysis was conducted using R‐programming language 3.5.1.

Results

Seventy one patients were recruited (mean age: 61.9 ± 8.7 years, males: 46 [64.8%], and CTP Class A = 52 [73.2%] and Class B = 19 [26.8%]). Sixty patients completed the study (mean age: 61.7 ± 8.8 years, males: 40 [66.6%], and CTP Class A = 45 [75.0%] and Class‐B = 15 [25.0%]). Two patients dropped out due to adverse events. Nine patients were lost to follow up. Patients given melatonin had a significantly lower PSQI and ESS compared to both pretreatment (P < 0.001) and postplacebo scores (P < 0.001). Incidence of adverse events was similar (two each of abdominal pain, one each of headache, one each of dizziness) in both groups.

Conclusion

Melatonin seems safe and effective for use in patients with SDs in early‐stage cirrhosis in the short term. However, larger and longer‐term studies to assess efficacy and safety are required before its clinical use can be recommended.

A multi-ancestry genome-wide study incorporating gene-smoking interactions identifies multiple new loci for pulse pressure and mean arterial pressure

Elevated blood pressure (BP), a leading cause of global morbidity and mortality, is influenced by both genetic and lifestyle factors. Cigarette smoking is one such lifestyle factor. Across five ancestries, we performed a genome-wide gene-smoking interaction study of mean arterial pressure (MAP) and pulse pressure (PP) in 129 913 individuals in stage 1 and follow-up analysis in 480 178 additional individuals in stage 2. We report here 136 loci significantly associated with MAP and/or PP. Of these, 61 were previously published through main-effect analysis of BP traits, 37 were recently reported by us for systolic BP and/or diastolic BP through gene-smoking interaction analysis and 38 were newly identified (P < 5 × 10-8, false discovery rate < 0.05). We also identified nine new signals near known loci. Of the 136 loci, 8 showed significant interaction with smoking status. They include CSMD1 previously reported for insulin resistance and BP in the spontaneously hypertensive rats. Many of the 38 new loci show biologic plausibility for a role in BP regulation. SLC26A7 encodes a chloride/bicarbonate exchanger expressed in the renal outer medullary collecting duct. AVPR1A is widely expressed, including in vascular smooth muscle cells, kidney, myocardium and brain. FHAD1 is a long non-coding RNA overexpressed in heart failure. TMEM51 was associated with contractile function in cardiomyocytes. CASP9 plays a central role in cardiomyocyte apoptosis. Identified only in African ancestry were 30 novel loci. Our findings highlight the value of multi-ancestry investigations, particularly in studies of interaction with lifestyle factors, where genomic and lifestyle differences may contribute to novel findings.

Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions

A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 × 10-6) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 × 10-8 using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.

Multi-ancestry genome-wide gene-smoking interaction study of 387,272 individuals identifies new loci associated with serum lipids

The concentrations of high- and low-density-lipoprotein cholesterol and triglycerides are influenced by smoking, but it is unknown whether genetic associations with lipids may be modified by smoking. We conducted a multi-ancestry genome-wide gene-smoking interaction study in 133,805 individuals with follow-up in an additional 253,467 individuals. Combined meta-analyses identified 13 new loci associated with lipids, some of which were detected only because association differed by smoking status. Additionally, we demonstrate the importance of including diverse populations, particularly in studies of interactions with lifestyle factors, where genomic and lifestyle differences by ancestry may contribute to novel findings.

Incidence and risk factors for metabolic syndrome among urban, adult Sri Lankans: a prospective, 7-year community cohort, follow-up study

BACKGROUND

The metabolic syndrome (MetS) is a clustering of abdominal obesity, diabetes and prediabetes, high cholesterol and high blood pressure, that confers an increased risk of cardiovascular disease. There is limited data on incidence of MetS from South Asia. This study investigated incidence and risk factors for new onset MetS in an urban adult Sri Lankan population.

METHODS

Subjects (selected by age-stratified random sampling from the Ragama Medical Officer of Health area) were screened initially in 2007 (35-64 years) and re-evaluated in 2014 (42-71 years). On both occasions they were assessed by structured interview, anthropometric measurements, liver ultrasound, and biochemical/serological tests. MetS was diagnosed on International Diabetes Federation (IDF-2006) criteria. Total body fat (TBF) and visceral fat percentage (VFP) were measured in 2014, using body impedance method. Incidence and factors at baseline, associated with new onset MetS, were investigated among those who presented for re-evaluation.

RESULTS

2985 (99.1%) [1636 (54.8%) women (54.8%); median age (IQR) 53 (47-59) years] from the initial cohort in 2007 had complete data. 2148 (71.9%) [1237 (57.6%) women; median age (IQR) 60 (54-66) years] attended follow-up. 949 of them [701 (73.9%) women; median age (IQR) 60 (54-65) years] had MetS (prevalence 47.2%, 95% CI 45.0-49.4%). Of 1246 who did not have MetS in 2007, 265 [178 (67.1%) women, median age (IQR) 57 (51-64) years] had developed MetS after 7 years (annual incidence 3.5% (95% CI 2.4-4.5%). Females (OR = 4.9, 95% CI 3.4-7.4), BMI > 23 kg/m² in 2007 (OR = 1.6 per unit increase, 95% CI 1.5-1.7), weight gain (by 2-5% OR = 2.0, 95% CI 1.1-3.5; by > 5% OR = 2.2, 95% CI 1.4-3.4), and increase in waist circumference (by 2-5% OR = 7.0, 95% CI 4.0-12.2; by > 5% OR = 13.4, 95% CI 8.3-22.4) from baseline and presence of non-alcoholic fatty liver disease (NAFLD) in 2007 (OR = 1.70, 95% CI 1.04-2.76) were associated new onset MetS. Those with MetS had abnormal VFP and TBF in 2014 [P < 0.001].

CONCLUSION

In this study, annual incidence of MetS was 3.5%. Female gender, BMI > 23 kg/m² and NAFLD in 2007 and increase in weight and waist circumference from baseline were significantly associated with new onset MetS. Obesity was the best predictor of future MetS.

Novel genetic associations for blood pressure identified via gene-alcohol interaction in up to 570K individuals across multiple ancestries

Heavy alcohol consumption is an established risk factor for hypertension; the mechanism by which alcohol consumption impact blood pressure (BP) regulation remains unknown. We hypothesized that a genome-wide association study accounting for gene-alcohol consumption interaction for BP might identify additional BP loci and contribute to the understanding of alcohol-related BP regulation. We conducted a large two-stage investigation incorporating joint testing of main genetic effects and single nucleotide variant (SNV)-alcohol consumption interactions. In Stage 1, genome-wide discovery meta-analyses in ≈131K individuals across several ancestry groups yielded 3,514 SNVs (245 loci) with suggestive evidence of association (P < 1.0 x 10-5). In Stage 2, these SNVs were tested for independent external replication in ≈440K individuals across multiple ancestries. We identified and replicated (at Bonferroni correction threshold) five novel BP loci (380 SNVs in 21 genes) and 49 previously reported BP loci (2,159 SNVs in 109 genes) in European ancestry, and in multi-ancestry meta-analyses (P < 5.0 x 10-8). For African ancestry samples, we detected 18 potentially novel BP loci (P < 5.0 x 10-8) in Stage 1 that warrant further replication. Additionally, correlated meta-analysis identified eight novel BP loci (11 genes). Several genes in these loci (e.g., PINX1, GATA4, BLK, FTO and GABBR2) have been previously reported to be associated with alcohol consumption. These findings provide insights into the role of alcohol consumption in the genetic architecture of hypertension.

A Large-Scale Multi-ancestry Genome-wide Study Accounting for Smoking Behavior Identifies Multiple Significant Loci for Blood Pressure

Genome-wide association analysis advanced understanding of blood pressure (BP), a major risk factor for vascular conditions such as coronary heart disease and stroke. Accounting for smoking behavior may help identify BP loci and extend our knowledge of its genetic architecture. We performed genome-wide association meta-analyses of systolic and diastolic BP incorporating gene-smoking interactions in 610,091 individuals. Stage 1 analysis examined ∼18.8 million SNPs and small insertion/deletion variants in 129,913 individuals from four ancestries (European, African, Asian, and Hispanic) with follow-up analysis of promising variants in 480,178 additional individuals from five ancestries. We identified 15 loci that were genome-wide significant (p < 5 × 10-8) in stage 1 and formally replicated in stage 2. A combined stage 1 and 2 meta-analysis identified 66 additional genome-wide significant loci (13, 35, and 18 loci in European, African, and trans-ancestry, respectively). A total of 56 known BP loci were also identified by our results (p < 5 × 10-8). Of the newly identified loci, ten showed significant interaction with smoking status, but none of them were replicated in stage 2. Several loci were identified in African ancestry, highlighting the importance of genetic studies in diverse populations. The identified loci show strong evidence for regulatory features and support shared pathophysiology with cardiometabolic and addiction traits. They also highlight a role in BP regulation for biological candidates such as modulators of vascular structure and function (CDKN1B, BCAR1-CFDP1, PXDN, EEA1), ciliopathies (SDCCAG8, RPGRIP1L), telomere maintenance (TNKS, PINX1, AKTIP), and central dopaminergic signaling (MSRA, EBF2).

Non-alcoholic fatty liver disease and its associations among adolescents in an urban, Sri Lankan community

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common problem across the world. We aimed to determine the prevalence of NAFLD and its associations in Sri Lankan adolescents living in an urban Sri Lankan community.

METHOD

The study population consisted of the birth cohort of the year 2000, residing in the Ragama Medical Officer of Health area. Socio-demographic and anthropometric data [anthropometric measurements, blood pressure and total body fat distribution] of these adolescents were collected by trained data collectors. Fasting blood sugar, serum insulin, fasting serum lipids and serum alanine aminotransferase (ALT) levels were measured and an abdominal ultrasound was performed. NAFLD was diagnosed on established ultrasound criteria for fatty liver and absent alcohol consumption.

RESULTS

The study sample consisted of 499 adolescents [263 (51.8%) girls]. Forty two (8.4%) had NAFLD. NAFLD was significantly associated with being breast fed for less than 4 months (33.3% vs. 17.1 in controls, p = 0.02), higher waist circumference (prevalence risk ratio 83.3/20.3, 4.1, p < 0.0001), higher body mass index (prevalence risk ratio 40.5/4.8, 8.4, p < 0/0001),higher HOMA-IR (3.7 vs. 1.9, p < 0.0001) and high triglycerides (prevalence risk ratio 14.3/5.8, 2.5, p = 0.033). Adolescents with NAFLD also had a higher amount of total body fat (p < 0.001) and subcutaneous fat (p < 0.001) than those without NAFLD. The number of children with metabolic derangements was higher among adolescents with NAFLD than those without (85.8 vs 26.3 in controls, p < 0.0001), but a family history of hypertension, diabetes, myocardial infarction or dyslipidaemia were not.

CONCLUSION

Prevalence of NAFLD was high in Sri Lankan adolescents, and was associated with metabolic derangements, especially obesity, insulin resistance and early cessation of breast feeding.

Characterising private and shared signatures of positive selection in 37 Asian populations

The Asian Diversity Project (ADP) assembled 37 cosmopolitan and ethnic minority populations in Asia that have been densely genotyped across over half a million markers to study patterns of genetic diversity and positive natural selection. We performed population structure analyses of the ADP populations and divided these populations into four major groups based on their genographic information. By applying a highly sensitive algorithm haploPS to locate genomic signatures of positive selection, 140 distinct genomic regions exhibiting evidence of positive selection in at least one population were identified. We examined the extent of signal sharing for regions that were selected in multiple populations and observed that populations clustered in a similar fashion to that of how the ancestry clades were phylogenetically defined. In particular, populations predominantly located in South Asia underwent considerably different adaptation as compared with populations from the other geographical regions. Signatures of positive selection present in multiple geographical regions were predicted to be older and have emerged prior to the separation of the populations in the different regions. In contrast, selection signals present in a single population group tended to be of lower frequencies and thus can be attributed to recent evolutionary events.

Clinical and laboratory associations of severity in a Sri Lankan cohort of patients with serologically confirmed leptospirosis: a prospective study

BACKGROUND

Leptospirosis results in significant morbidity and mortality. This study elucidates markers of severity in a cohort of Sri Lankan patients.

METHODS

Patients presenting to three healthcare institutions in the Western province of Sri Lanka with leptospirosis serological confirmed by the microscopic agglutination test (MAT) were included. Prospective data regarding demographic, clinical and laboratory parameters was extracted. Univariate associations and subsequent multivariate logistic regression models were constructed.

RESULTS

The study included 232 patients, with 68.5% (159) demonstrating severe disease. Significant associations of severe disease at a significance level of p<0.05 were fever >38.8°C on presentation, age >40 years, muscle tenderness, tachycardia on admission, highest white cell count >12 350/mm(3) and <7900/mm(3), highest neutrophil percentage >84%, haemoglobin >11.2 g/dL and <10.2 g/dL, packed cell volume (PCV) >33.8% and <29.8%, lowest platelet count <63 500/mm(3), highest alanine transaminase (ALT) >70 IU/L and hyponatremia with sodium <131 mEq/L. On multivariate analysis, PCV <29.8% (p=0.011; OR 3.750; CI: 1.394-10.423), ALT >70 IU/L (p=0.044; OR 2.639; CI: 1.028-6.774) and hyponatremia <131 mEq/L (p=0.019; OR 6.413; CI: 1.353-30.388) were independent associations of severe disease.

CONCLUSIONS

Severity associations were demonstrated with both clinical and laboratory parameters. There is a need for novel biomarkers for prediction of severity in leptospirosis.

Adverse reactions to snake antivenom, and their prevention and treatment

Antivenom is the mainstay of treatment of snakebite envenoming. However, adverse reactions to snake antivenom that is available are common in many parts of the world where snakebite is prevalent. Both acute (anaphylactic or pyrogenic) and delayed (serum sickness type) reactions occur. Acute reactions are usually mild but severe systemic anaphylaxis may develop, often within an hour or so of exposure to antivenom. Serum sickness after antivenom has a delayed onset between 5 and 14 days after its administration. Ultimately, the prevention reactions will depend mainly on improving the quality of antivenom. Until these overdue improvements take place, doctors will have to depend on pharmacological prophylaxis, where the search for the best prophylactic agent is still on-going, as well as careful observation of patients receiving antivenom in preparation for prompt management of acute as well as delayed reactions when they occur.

Asia-Pacific consensus statements on Crohn's disease. Part 2: Management

The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology (APAGE) with the goal of developing best management practices, coordinating research and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis (UC) with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis and management of Crohn's disease (CD). The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses and treatment availability. It does not intend to be all-comprehensive and future revisions are likely to be required in this ever-changing field.

Asia Pacific Consensus Statements on Crohn's disease. Part 1: Definition, diagnosis, and epidemiology: (Asia Pacific Crohn's Disease Consensus--Part 1)

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever-changing field.

Early Course of Inflammatory Bowel Disease in a Population-Based Inception Cohort Study From 8 Countries in Asia and Australia

BACKGROUND & AIMS

The incidence of inflammatory bowel disease (IBD) is increasing in Asia, but little is known about disease progression in this region. The Asia-Pacific Crohn's and Colitis Epidemiology Study was initiated in 2011, enrolling subjects from 8 countries in Asia (China, Hong Kong, Indonesia, Sri Lanka, Macau, Malaysia, Singapore, and Thailand) and Australia. We present data from this ongoing study.

METHODS

We collected data on 413 patients diagnosed with IBD (222 with ulcerative colitis [UC], 181 with Crohn's disease [CD], 10 with IBD unclassified; median age, 37 y) from 2011 through 2013. We analyzed the disease course and severity and mortality. Risks for medical and surgical therapies were assessed using Kaplan-Meier analysis.

RESULTS

The cumulative probability that CD would change from inflammatory to stricturing or penetrating disease was 19.6%. The cumulative probabilities for use of immunosuppressants or anti-tumor necrosis factor agents were 58.9% and 12.0% for patients with CD, and 12.7% and 0.9% for patients with UC, respectively. Perianal CD was associated with an increased risk of anti-tumor necrosis factor therapy within 1 year of its diagnosis (hazard ratio, 2.97; 95% confidence interval, 1.09-8.09). The cumulative probabilities for surgery 1 year after diagnosis were 9.1% for patients with CD and 0.9% for patients with UC. Patients with CD and penetrating disease had a 7-fold increase for risk of surgery, compared with patients with inflammatory disease (hazard ratio, 7.67; 95% confidence interval, 3.93-14.96). The overall mortality for patients with IBD was 0.7%.

CONCLUSIONS

In a prospective population-based study, we found that the early course of disease in patients with IBD in Asia was comparable with that of the West. Patients with CD frequently progress to complicated disease and have accelerated use of immunosuppressants. Few patients with early stage UC undergo surgery in Asia. Increasing our understanding of IBD progression in different populations can help optimize therapy and improve outcomes.

Gloriosa superba poisoning mimicking an acute infection- a case report

Background

Gloriosa superba (GSb) is a highly poisonous plant and its toxicity is due to anti-mitotic effects of constituents such as colchicine and gloriosine on rapidly proliferating cells. Poisoning is known to cause very rapid and severe clinical manifestations due gastro intestinal, neurological, cardiac and bone marrow toxicity.

Case presentation

A young male presented with an acute onset febrile illness associated with diarrhoea, confusion, haematuria and aggressive behavior of 4 days duration. He developed subconjunctival haemorrhages, bleeding gums, neck stiffness, bilateral papilloedema, tender hepatomegaly and features suggestive of subacute intestinal obstruction. He had progressive reduction in white cell counts, platelets and derrangements in liver functions. The illness mimicked acute severe leptospirosis or dengue. On day 9 of illness he started to loose his hair and was totally alopecic by day 14. At this stage of illness, possibility of GSb poisoning was suspected. He admitted the act of self harm after repeated questioning.

Conclusion

His presentation mimicked an acute severe tropical febrile illness such as leptospirosis or dengue until he started to loose his hair. Therefore we feel that Clinicians practicing in tropical setting where Gloriosa superba is endemic should be aware of its clinical presentations and should always consider the possibility of ingestion of Gloriosa superba when the patient has pancytopenia and develops shedding of hairs which results in total alopecia in a case of unexplained gastroenterocolitis, rather investigating.

Scrub typhus mimicking Parkinson's disease

Background

Scrub typhus is a re-emerging infection in Sri Lanka. It often poses a diagnostic challenge and tends to present as a febrile illness of uncertain origin. Undiagnosed illness may progress to serious multi-systemic complications. Here we report a case of scrub typhus presenting with features of Parkinsonism.

Case presentation

A 62-year-old previously healthy Sri Lankan native male from the Western province of Sri Lanka presented with high fever with malaise, myalgia and arthralgia for 17 days. On the 5th day of illness he developed intermittent resting tremor in his right arm and leg associated with stiffness, difficulty in carrying out normal work and difficulty in smiling. He denied similar previous episodes. There were no other associated neurological manifestations. Clinical examination revealed a high amplitude low frequency resting tremor in his right hand, a mask-like face and increased muscle tone limited to the right side with normal reflexes. The rest of the system examination was normal except for an eschar over the abdomen. His investigations revealed lymphocytic leukocytosis, high erythrocyte sedimentation rate and immunofluorescence assay-IgM and IgG against Orientia tsutsugamushi Karp antigen were positive with rising titers. With oral doxycycline and azithromycin his fever settled within 48 h and a complete recovery of Parkinson’s features was observed within 2 weeks.

Conclusion

Doctors practicing in endemic regions should be familiar with delayed clinical manifestations of scrub typhus and should carefully look for an eschar in order to avoid delay in the diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1428-x) contains supplementary material, which is available to authorized users.

A Randomized Controlled Trial of a Brief Intervention for Delayed Psychological Effects in Snakebite Victims

Background

Snakebite results in delayed psychological morbidity and negative psycho-social impact. However, psychological support is rarely provided to victims.

Aim

To assess the effectiveness of a brief intervention which can be provided by non-specialist doctors aimed at reducing psychological morbidity following snakebite envenoming.

Method

In a single blind, randomized controlled trial, snakebite victims with systemic envenoming [n = 225, 168 males, mean age 42.1 (SD 12.4) years] were randomized into three arms. One arm received no intervention (n = 68, Group A), the second received psychological first aid and psychoeducation (dispelling prevalent cultural beliefs related to snakebite which promote development of a sick role) at discharge from hospital (n = 65, Group B), while the third received psychological first aid and psychoeducation at discharge and a second intervention one month later based on cognitive behavioural principles (n = 69, Group C). All patients were assessed six months after hospital discharge for the presence of psychological symptoms and level of functioning using standardized tools.

Results

At six months, there was a decreasing trend in the proportion of patients who were positive for psychiatric symptoms of depression and anxiety from Group A through Group B to Group C (Chi square test for trend = 7.901, p = 0.005). This was mainly due to a decreasing trend for symptoms of anxiety (chi-square for trend = 11.256, p = 0.001). There was also decreasing trend in the overall prevalence of disability from Group A through Group B to Group C (chi square for trend = 7.551, p = 0.006), predominantly in relation to disability in family life (p = 0.006) and social life (p = 0.005). However, there was no difference in the proportion of patients diagnosed with depression between the three groups (chi square for trend = 0.391, p = 0.532), and the intervention also had no effect on post-traumatic stress disorder.

Conclusions

A brief psychological intervention, which included psychological first aid and psychoeducation plus cognitive behavioural therapy that can be provided by non-specialist doctors appeared to reduce psychiatric symptoms and disability after snakebite envenoming, but not depression or post-traumatic stress disorder.

Trial Registration

Sri Lanka Clinical Trials Registry: SLCTR/2011/003

Snakebite is an important health problem in many rural communities in tropical countries. However, little is known about the lasting physical and mental health effects following a bite. We recently reported that mental problems, with harmful social outcomes, can occur in many people after they are bitten by a snake. As the affected are often poor farmers or manual workers, this may affect their livelihoods. We, therefore, performed a trial which looked at the effectiveness of short psychological interventions, lasting about 15 and 20 minutes, which can be provided by even non-specialist doctors, in reducing these mental and social problems in people bitten by snakes. Our results show that such interventions may indeed be helpful to reduce some of these problems, but more research is needed to improve these interventions, especially so that they that can reduce post-traumatic stress disorder and depression after snakebite.

Population Pharmacokinetics of an Indian F(ab')2 Snake Antivenom in Patients with Russell's Viper (Daboia russelii) Bites

BACKGROUND

There is limited information on antivenom pharmacokinetics. This study aimed to investigate the pharmacokinetics of an Indian snake antivenom in humans with Russell's viper bites.

METHODS/PRINCIPAL FINDINGS

Patient data and serial blood samples were collected from patients with Russell's viper (Daboia russelii) envenoming in Sri Lanka. All patients received Indian F(ab')2 snake antivenom manufactured by VINS Bioproducts Ltd. Antivenom concentrations were measured with sandwich enzyme immunoassays. Timed antivenom concentrations were analysed using MONOLIXvs4.2. One, two and three compartment models with zero order input and first order elimination kinetics were assessed. Models were parameterized with clearance (CL), intercompartmental clearance (Q), central compartment volume (V) and peripheral compartment volume (VP). Between-subject-variability (BSV) on relative bioavailability (F) was included to account for dose variations. Covariates effects (age, sex, weight, antivenom batch, pre-antivenom concentrations) were explored by visual inspection and in model building. There were 75 patients, median age 57 years (40-70 y) and 64 (85%) were male. 411 antivenom concentration data points were analysed. A two compartment model with zero order input, linear elimination kinetics and a combined error model best described the data. Inclusion of BSV on F and weight as a covariate on V improved the model. Inclusion of pre-antivenom concentrations or different batches on BSV of F did not. Final model parameter estimates were CL,0.078 L h(-1), V,2.2L, Q,0.178 L h(-1) and VP,8.33L. The median half-life of distribution was 4.6 h (10-90%iles:2.6-7.1 h) and half-life of elimination, 140 h (10th-90th percentilesx:95-223h).

CONCLUSION

Indian F(ab')2 snake antivenom displayed biexponential disposition pharmacokinetics, with a rapid distribution half-life and more prolonged elimination half-life.

Diagnosis of Leptospirosis: Comparison between Microscopic Agglutination Test, IgM-ELISA and IgM Rapid Immunochromatography Test

Background

Leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (MAT). IgM-ELISA (Serion-Virion) and immunochromatography test (Leptocheck-WB) are two immunodiagnostic assays for leptospirosis. Their sensitivity, specificity and applicability in Sri Lanka have not been systematically evaluated.

Methods

Clinically diagnosed leptospirosis patients (n = 919) were recruited from three hospitals in the Western Province of Sri Lanka, during June 2012 to December 2013. MAT, IgM-ELISA and Leptocheck-WB were performed on all patient sera. MAT titer of ≥400 in single sample, four-fold rise or seroconversion ≥100 in paired samples were considered as positive for MAT. For diagnostic confirmation, MAT was performed during both acute and convalescent phases. Anti-leptospiral IgM ≥20 IU/ml and appearance of a band in the test window were considered as positive for IgM-ELISA and Leptocheck-WB test respectively. Patients with an alternative diagnosis (n = 31) were excluded. Data analysis was performed using two methods, i) considering MAT as reference standard and ii) using Bayesian latent class model analysis (BLCM) which considers each test as imperfect.

Results

MAT, IgM-ELISA and Leptocheck-WB positivity were 39.8%, 45.8% and 38.7% respectively during the acute phase. Acute-phase MAT had specificity and sensitivity of 95.7% and 55.3% respectively, when compared to overall MAT positivity. IgM-ELISA and Leptocheck-WB had similar diagnostic sensitivity when compared with acute-phase MAT as the gold standard, although IgM-ELISA showed higher specificity (84.5%) than Leptocheck-WB (73.3%). BLCM analysis showed that IgM-ELISA and Leptocheck-WB had similar sensitivities (86.0% and 87.4%), while acute-phase MAT had the lowest sensitivity (77.4%). However, acute-phase MAT had high specificity (97.6%), while IgM-ELISA and Leptocheck-WB showed similar but lower specificity (84.5% and 82.9%).

Conclusions

Both IgM-ELISA and Leptocheck-WB shows similar sensitivities and specificities. IgM-ELISA may be superior to MAT during the acute phase and suitable for early diagnosis of leptospirosis. Leptocheck-WB is suitable as a rapid immunodiagnostic screening test for resource limited settings.

Snake antivenom for snake venom induced consumption coagulopathy

BACKGROUND

Snake venom induced consumption coagulopathy is a major systemic effect of envenoming. Observational studies suggest that antivenom improves outcomes for venom induced consumption coagulopathy in some snakebites and not others. However, the effectiveness of snake antivenom in all cases of venom induced consumption coagulopathy is controversial.

OBJECTIVES

To assess the effect of snake antivenom as a treatment for venom induced consumption coagulopathy in people with snake bite.

SEARCH METHODS

The search was done on 30 January 2015. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (OvidSP), three other sources, clinical trials registers, and we also screened reference lists.

SELECTION CRITERIA

All completed, published or unpublished, randomised, controlled trials with a placebo or no treatment arm, where snake antivenom was administered for venom induced consumption coagulopathy in humans with snake bites.

DATA COLLECTION AND ANALYSIS

Two authors reviewed the identified trials and independently applied the selection criteria.

MAIN RESULTS

No studies met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

Randomised placebo-controlled trials are required to investigate the effectiveness of snake antivenom for clinically relevant outcomes in patients with venom induced consumption coagulopathy resulting from snake bite. Although ethically difficult, the routine administration of a treatment that has a significant risk of anaphylaxis cannot continue without strong evidence of benefit.

Rickettsial infection among military personnel deployed in Northern Sri Lanka

Background

Military personnel deployed in field actvities report on frequent tick bites. Therefore they may run the risk of exposure to rickettsial organisms.

Methods

In order to assess the risk of exposure to rickettsial organisms, two groups of military personnel who were deployed in field activities of Nothern Sri Lanka were investigated. The first group was studied in order to assess the sero-prevalence of rickettsioses and consisted of soldiers who were admitted following injuries during field activities. The second group was studied to identify the incidence of acute rickettsioses during their acute febrile presentations. They were tested with IFA-IgG against spotted fever group rickettsioses (SFG), scrub typhus (ST) and murine typhus.

Results

In the first group, 48/57 (84%) military personnel had serological evidence of exposure to rickettsioses (in all, IFA-IgG titer ≥ 1:128): 33/50 (66%) to SFG rickettsioses, 1/50 (2%) to ST and 14/50 (28%) had mixed titers for both (in all, titers were higher for SFG). While all of them were in military uniform most of the time and frequently slept on scrub land, 35/57 (61.4%) had never used insect repellents and none were on doxycycline prophylaxis. 48/57 (84%) had experienced tick bites during field activity.

In the second group, there were 49 who presented with acute febrile illness with a mean duration of 8.5 days (SD 3.2). 33/49 (67.3%) were serologically positive for acute rickettsioses (IgG ≥1:256); 26 (79%) due to ST and 7 (21%) due to SFG rickettsioses,

Conclusions

Exposure to rickettsial disease was common among soldiers who were deployed in Northern Sri Lanka. Scrub typhus was the predominent species accounting for acute febrile illness. Further studies are needed to understand the reasons for very high sero-prevalence for SFG rickettsioses with no anticedent febrile illness. Use of preventive measures was not satisfactory. The high sero-prevelence of SFG rickettsioses is likely to interfere with serological diagnosis of acute SFG rickettsioses in this population.

Neurotoxicity in snakebite--the limits of our knowledge

Snakebite is classified by the WHO as a neglected tropical disease. Envenoming is a significant public health problem in tropical and subtropical regions. Neurotoxicity is a key feature of some envenomings, and there are many unanswered questions regarding this manifestation. Acute neuromuscular weakness with respiratory involvement is the most clinically important neurotoxic effect. Data is limited on the many other acute neurotoxic manifestations, and especially delayed neurotoxicity. Symptom evolution and recovery, patterns of weakness, respiratory involvement, and response to antivenom and acetyl cholinesterase inhibitors are variable, and seem to depend on the snake species, type of neurotoxicity, and geographical variations. Recent data have challenged the traditional concepts of neurotoxicity in snake envenoming, and highlight the rich diversity of snake neurotoxins. A uniform system of classification of the pattern of neuromuscular weakness and models for predicting type of toxicity and development of respiratory weakness are still lacking, and would greatly aid clinical decision making and future research. This review attempts to update the reader on the current state of knowledge regarding this important issue.

Incidence and phenotype of inflammatory bowel disease based on results from the Asia-pacific Crohn's and colitis epidemiology study

BACKGROUND & AIMS

Inflammatory bowel diseases (IBD) are becoming more common in Asia, but epidemiologic data are lacking. The Asia-Pacific Crohn's and Colitis Epidemiology Study aimed to determine the incidence and phenotype of IBD in 8 countries across Asia and in Australia.

METHODS

We performed a prospective, population-based study of IBD incidence in predefined catchment areas, collecting data for 1 year, starting on April 1, 2011. New cases were ascertained from multiple overlapping sources and entered into a Web-based database. Cases were confirmed using standard criteria. Local endoscopy, pathology, and pharmacy records were searched to ensure completeness of case capture.

RESULTS

We identified 419 new cases of IBD (232 of ulcerative colitis [UC], 166 of Crohn's disease [CD], and 21 IBD-undetermined). The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia (95% confidence interval: 1.25-1.51; 0.76 for UC, 0.54 for CD, and 0.07 for IBD-undetermined) and 23.67 in Australia (95% confidence interval: 18.46-29.85; 7.33 for UC, 14.00 for CD, and 2.33 for IBD-undetermined). China had the highest incidence of IBD in Asia (3.44 per 100,000 individuals). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Median time from symptom onset to diagnosis was 5.5 months (interquartile range, 1.4-15 months). Complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P = .001), and a family history of IBD was less common in Asia (3% vs 17%; P < .001).

CONCLUSIONS

We performed a large-scale population-based study and found that although the incidence of IBD varies throughout Asia, it is still lower than in the West. IBD can be as severe or more severe in Asia than in the West. The emergence of IBD in Asia will result in the need for specific health care resources, and offers a unique opportunity to study etiologic factors in developing nations.

Response of the airways and autonomic nervous system to acid perfusion of the esophagus in patients with asthma: a laboratory study

BACKGROUND

Gastro-esophageal reflux disease (GERD) predisposes to airway disease through a vagally-mediated esophago-bronchial reflex. This study investigates this vagal response to esophageal acid perfusion.

METHODS

40 asthmatics with mild stable asthma participated. Each subject underwent spirometry and autonomic function testing (valsalva maneuver, heart rate response to deep breathing and to standing from supine position) four times: a) before intubation, b) after intubation, and then immediately after perfusion with, in random order, c) concentrated lime juice solution (pH 2-3) and d) 0.9% saline. Subjects were blinded to the solution perfused.

RESULTS

Asthmatics were of mean (SD) age 34.3 years (1.3), and 67.5% of them were females. pH monitoring demonstrated that 20 subjects had abnormal reflux and 20 did not. In each group 10 subjects had a positive GERD symptom score. Following perfusion with acid compared to saline, all subjects showed significant decreases in FEV1 and PEFR and significant increases in the mean valsalva ratio and heart rate difference on deep breathing from baseline values, but no changes in FVC or heart rate ratio on standing. There were no significant differences in any of the parameters between subjects with and without reflux.

CONCLUSIONS

Acid stimulation of the distal esophagus results in increased parasympathetic activity and concomitant broncho-constriction in asthmatics irrespective of their reflux state. This strengthens the hypothesis that GER triggers asthma-like symptoms through a vagally mediated esophago-bronchial reflex and encourages a possible role for anti-cholinergic drugs in the treatment of reflux-associated asthma.

Influence of non-alcoholic fatty liver disease on the development of diabetes mellitus

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is linked to metabolic syndrome, and is known to be associated with impaired fasting glycemia and diabetes mellitus. This prospective community-based study was conducted to determine the association between NAFLD and incidence of diabetes mellitus in an urban adult population in Sri Lanka.

METHODS

Participants of the Ragama Health Study cohort were assessed for NAFLD using established ultrasound criteria in 2007. Those who were free of diabetes at baseline were followed up for 3 years. Incidence rates of diabetes mellitus were compared between subjects with and without NAFLD at baseline.

RESULTS

Out of 2984 subjects, 926 had NAFLD and 676 had diabetes in 2007. Of the 2276 subjects who were free of diabetes in 2007, 1914 were re-assessed in 2010. After 3 years, 104 out of 528 subjects with NAFLD and 138 out of 1314 subjects without NAFLD had developed diabetes mellitus de novo. Incidence rates of diabetes were respectively 64.2 and 34 per 1000 person-years of follow up for those with and without NAFLD. NAFLD was an independent predictor of developing diabetes mellitus. Other independent predictors were impaired fasting glycemia and dyslipidemia.

CONCLUSIONS

Subjects with ultrasonically diagnosed NAFLD have an increased risk of developing diabetes mellitus. Intervention for NAFLD through lifestyle modification may prevent progression of the current diabetes epidemic.

Clinically helpful rickettsial disease diagnostic IgG titers in relation to duration of illness in an endemic setting in Sri Lanka

Background

Although an initial IFA-IgG titer greater or equal to 1/64 or 1/128 is considered positive in presumptive diagnosis, in clinical practice in an endemic setting for rickettsioses in Sri Lanka, some patients with IFA-IgG titer of 1/128 for either spotted fever group (SFG) or scrub typhus (ST) did not respond to treatment.

Findings

To determine a clinically helpful diagnostic algorithm, IFA-IgG results of serologically confirmed treatment responders were analyzed in relation to duration of illness at sampling. Of 146 suspected SFG, 3 responders of 25 patients had titers ≤1/128 with < 7 days of illness while all 9 with titers ≥1/256 responded (false negative with 1/256 cutoff was 12%, false positive was 0%). For illness > 7 days, the false negative and positive rates were 4.3% (3/59) and 11.3% (6/53). Of 115 suspected ST, false negative and positive rates with ≥1/256 cutoff at <7 days of illness were 14.2% (2/14) and 0% (0/8) respectively while > 7 days, false negative and positive rates were 2% (1/51) and 0% (0/42).

Conclusions

For clinical decision making, duration of illness at sampling is important in interpreting serology results in an endemic setting. If sample is obtained ≤7 day of illness, an IgG titer of ≤1/128 requires a follow up sample in the diagnosis and > 7 days of illness, a single ≥1/256 titer is diagnostic for all ST and 90% of SFG.

Esophageal motility, vagal function and gastroesophageal reflux in a cohort of adult asthmatics

BACKGROUND

Asthmatics are known to have esophageal hypomotility. Vagal hypofunction and prolonged intra-esophageal acidification cause esophageal hypomotility. The contribution of gastroesophageal reflux (GER) and vagal function to esophageal motility in asthmatics is unclear. We studied the relationship between esophageal motility, GER and vagal function in a cohort of adult asthmatics.

METHODS

Thirty mild, stable asthmatics (ATS criteria) and 30 healthy volunteers underwent 24-hour ambulatory esophageal monitoring, manometry, autonomic function testing and GER symptom assessment. 27 asthmatics underwent gastroscopy. A vagal function score calculated from 3 tests (valsalva maneuver, heart rate response to deep breathing and to standing from supine position) was correlated with esophageal function parameters.

RESULTS

Asthmatics (mean age 34.8 (SD 8.4), 60% female) had more frequent GERD symptoms than controls (mean age 30.9 (SD 7.7), 50% female). 10/27 asthmatics had esophageal mucosal damage, 22 showed hypervagal response, none had a hyperadrenergic response. 14 asthmatics had ineffective esophageal motility. Higher GERD-score asthmatics had significantly fewer peristaltic and more simultaneous contractions than controls, and higher esophageal acid contact times than those with lower scores. All reflux parameters were significantly higher and acid clearance time prolonged in asthmatics than controls (p < 0.001, Mann-Whitney U test). There was no correlation between vagal function score and esophageal function parameters.

CONCLUSIONS

A cohort of adult asthmatics was found to have peristaltic dysfunction and pathological GER, but otherwise normal esophageal motility. The peristaltic dysfunction seems to be associated with vagal hyperreactivity rather than vagal hypofunction.