H. Janaka de Silva

The Global Burden of Snakebite: A Literature Analysis and Modelling Based on Regional Estimates of Envenoming and Deaths

Background Envenoming resulting from snakebites is an important public health problem in many tropical and subtropical countries. Few attempts have been made to quantify the burden, and recent estimates all suffer from the lack of an objective and reproducible methodology. In an attempt to provide an accurate, up-to-date estimate of the scale of the global problem, we developed a new method to estimate the disease burden due to snakebites. Methods and Findings The global estimates were based on regional estimates that were, in turn, derived from data available for countries within a defined region. Three main strategies were used to obtain primary data: electronic searching for publications on snakebite, extraction of relevant country-specific mortality data from databases maintained by United Nations organizations, and identification of grey literature by discussion with key informants. Countries were grouped into 21 distinct geographic regions that are as epidemiologically homogenous as possible, in line with the Global Burden of Disease 2005 study (Global Burden Project of the World Bank). Incidence rates for envenoming were extracted from publications and used to estimate the number of envenomings for individual countries; if no data were available for a particular country, the lowest incidence rate within a neighbouring country was used. Where death registration data were reliable, reported deaths from snakebite were used; in other countries, deaths were estimated on the basis of observed mortality rates and the at-risk population. We estimate that, globally, at least 421,000 envenomings and 20,000 deaths occur each year due to snakebite. These figures may be as high as 1,841,000 envenomings and 94,000 deaths. Based on the fact that envenoming occurs in about one in every four snakebites, between 1.2 million and 5.5 million snakebites could occur annually. Conclusions Snakebites cause considerable morbidity and mortality worldwide. The highest burden exists in South Asia, Southeast Asia, and sub-Saharan Africa.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific Association for the study of the liver (APASL)

The Asian Pacific Association for the Study of the Liver (APASL) set up a working party on acute-on-chronic liver failure (ACLF) in 2004, with a mandate to develop consensus guidelines on various aspects of ACLF relevant to disease patterns and clinical practice in the Asia-Pacific region. Experts predominantly from the Asia–Pacific region constituted this working party and were requested to identify different issues of ACLF and develop the consensus guidelines. A 2-day meeting of the working party was held on January 22–23, 2008, at New Delhi, India, to discuss and finalize the consensus statements. Only those statements that were unanimously approved by the experts were accepted. These statements were circulated to all the experts and subsequently presented at the Annual Conference of the APASL at Seoul, Korea, in March 2008. The consensus statements along with relevant background information are presented in this review.

Evaluation of Six Commercial Point-of-Care Tests for Diagnosis of Acute Dengue Infections: the Need for Combining NS1 Antigen and IgM/IgG Antibody Detection To Achieve Acceptable Levels of Accuracy

ABSTRACT Six assays were evaluated in this study to determine their suitability for the diagnosis of acute dengue infection using samples from 259 Sri Lankan patients with acute fevers (99 confirmed dengue cases and 160 patients with other confirmed acute febrile illnesses): (i) the Merlin dengue fever IgG & IgM combo device (Merlin), (ii) the Standard Diagnostics Dengue Duo nonstructural 1 (NS1) antigen and IgG/IgM combo device (Standard Diagnostics, South Korea), (iii) the Biosynex Immunoquick dengue fever IgG and IgM (Biosynex, France) assay, (iv) the Bio-Rad NS1 antigen strip (Bio-Rad, France), (v) the Panbio Dengue Duo IgG/IgM Cassette (Inverness, Australia), and (vi) the Panbio dengue NS1 antigen strip (Inverness, Australia). The median number of days of fever prior to admission sample collection was 5 days (interquartile range, 3 to 7 days). Sensitivity and specificity of the NS1 antigen tests ranged from 49 to 59% and from 93 to 99%, respectively, and sensitivity and sensitivity of the IgM antibody test ranged from 71 to 80% and from 46 to 90%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics Dengue Duo test gave the best compromise of sensitivity and specificity (93% and 89%, respectively) and provided the best sensitivity in patients presenting at different times after fever onset. The Merlin IgM/IgG antibody tests correctly classified 64% and 86% of the primary and secondary dengue infection cases, respectively, and the Standard Diagnostics IgM/IgG antibody tests correctly classified 71% and 83% of the primary and secondary dengue infection cases, respectively. This study provides strong evidence of the value of combining dengue antigen- and antibody-based test results in the rapid diagnostic test (RDT) format for the acute diagnosis of dengue.

Low-Dose Adrenaline, Promethazine, and Hydrocortisone in the Prevention of Acute Adverse Reactions to Antivenom following Snakebite: A Randomised, Double-Blind, Placebo-Controlled Trial

In a factorial randomized trial conducted in Sri Lanka, de Silva and colleagues evaluate the safety and efficacy of pretreatments intended to reduce the risk of serious reactions to antivenom following snakebite.

The Asia-Pacific consensus on ulcerative colitis

Inflammatory bowel disease (IBD) is increasing in many parts of the Asia‐Pacific region. There is a need to improve the awareness of IBD and develop diagnostic and management recommendations relevant to the region. This evidence‐based consensus focuses on the definition, epidemiology and management of ulcerative colitis (UC) in Asia.

Prevalence and risk factors for non-alcoholic fatty liver disease among adults in an urban Sri Lankan population

Background and Aims:  Non‐alcoholic fatty liver disease (NAFLD) is an emerging problem in the Asia–Pacific region. However, its prevalence and risk factors in Asian (especially South Asian) communities is poorly studied. In this study, the aim was to determine the community prevalence and risk factors for NAFLD among adults in an urban Sri Lankan population.

Comparison of Seven Commercial Antigen and Antibody Enzyme-Linked Immunosorbent Assays for Detection of Acute Dengue Infection

ABSTRACT Seven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection.

How should we manage patients with non-alcoholic fatty liver disease in 2007?

Evidence‐based management guidelines for non‐alcoholic fatty liver disease (NAFLD) are lacking in the Asia–Pacific region or elsewhere. This review reports the results of a systematic literature search and expert opinions. The Asia–Pacific Working Party on NAFLD (APWP‐NAFLD) has generated practical recommendations on management of NAFLD in this region. NAFLD should be suspected when there are metabolic risk factors and/or characteristic changes on hepatic ultrasonography. Diagnosis by ultrasonography, assessment of liver function and complications, exclusion of other liver diseases and screening for metabolic syndrome comprise initial assessment. Liver biopsy should be considered when there is diagnostic uncertainty, for patients at risk of advanced fibrosis, for those enrolled in clinical trials and at laparoscopy for another purpose. Lifestyle measures such as dietary restrictions and increased physical activity (aerobic exercise) should be encouraged, although the best management strategy to achieve this has yet to be defined. Complications of metabolic syndrome should be screened for regularly. Use of statins to treat hypercholesterolemia is safe and recommended; frequent alanine aminotransferase (ALT) monitoring is not required. Obese patients who do not respond to lifestyle measures should be referred to centers specializing in obesity management; consideration should be given to bariatric surgery or gastric ballooning. The role of pharmacotherapy remains investigational and is not recommended for routine clinical practice. Non‐alcoholic fatty liver disease should be recognized as part of the metabolic syndrome and managed in a multidisciplinary approach that addresses liver disease in the context of risk factors for diabetes and premature cardiovascular disease. Lifestyle changes are the first line and mainstay of management.

Iron overload in the Asian community

Hereditary hemochromatosis is an iron overload disorder that can lead to the impairment of multiple organs and is caused by mutations in one or more different genes. Type 1 hemochromatosis is the most common form of the disease and results from mutations in the HFE gene. Juvenile hemochromatosis (JH) is the most severe form, usually caused by mutations in hemojuvelin (HJV) or hepcidin (HAMP). The autosomal dominant form of the disease, type 4, is due to mutations in the SLC40A1 gene, which encodes for ferroportin (FPN). Hereditary hemochromatosis is commonly found in populations of European origin. By contrast, hemochromatosis in Asia is rare and less well understood and can be masked by the presence of iron deficiency and secondary iron overload from thalassemia. Here, we provide a comprehensive report of hemochromatosis in a group of patients of Asian origin. We have identified novel mutations in HJV, HAMP, and SLC40A1 in countries not normally associated with hereditary hemochromatosis (Pakistan, Bangladesh, Sri Lanka, and Thailand). Our family studies show a high degree of consanguinity, highlighting the increased risk of iron overload in many countries of the developing world and in countries in which there are large immigrant populations from these regions.

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.