The molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in the major countries of East Asia

Methicillin-resistant Staphylococcus aureus (MRSA) is a successful pathogen which was historically found in hospital settings but now is a common cause of infection in communities. The rapid emergence of community-acquired MRSA (CA-MRSA) at the turn of the 21st century has established this bacterium’s presence throughout the globe and MRSA continues to be endemic in certain countries. Asia is the most populous continent in the world and also holds a high burden of MRSA infection. This presents a concern for both public health and the acquisition of antibiotic resistance in this region. This literature review describes how MRSA became a successful pathogen. It provides a systematic review of the recent literature on MRSA in East Asia to identify major MRSA clones by country as determined by their molecular characteristics. Also to identify notable genetic and epidemiological factors associated with these MRSA clones. The results of this survey provided evidence of the importance of using molecular categorization techniques to accurately distinguish MRSA strains that require specific antibiotic treatment methods. It also provided evidence of CA-MRSA clones invading hospital settings and traditional hospital-acquired MRSA (HA-MRSA) clones continuing to develop multi-drug resistance throughout East Asian countries. The results also detected novel MRSA strains across hospitals and reported the spread of major MRSA clones within and between countries. Strengthening existing surveillance systems and collaborative efforts between countries within Asia should be a priority to monitor the evolution and movement MRSA especially in the age of globalization and accessible travel

The role of regional surveillance networks in enhancing global outbreak reporting

BACKGROUND: The Program for Monitoring Emerging Diseases (ProMED) is a moderated electronic reporting system dedicated to the rapid, global dissemination of outbreak reports. Its moderators are globally diverse, carefully selected, highly trained specialists. To improve cross-border communication and rapidly identify regional health threats, ProMED created regional networks where locally-based moderators use their access to local and regional medical and public health networks and media sources to obtain information not readily available outside of their region. In this analysis, we assess the impact of the establishment of ProMED's Middle East/North Africa (MENA) and South Asia (SoAs) regional networks in April 2014 on ProMED's outbreak reports for these regions. METHODS & MATERIALS: Outbreak reports in countries within the two regions were extracted from ProMED's database, and included country, disease name, species type, spatial coordinates, and report issue date. Data analysis included visualizing spatial information, identifying unique reports, and reporting trends per country and region. Data processing and analysis were conducted using R 3.4.0 statistical software. Rates of outbreak events per total number of ProMED reports per year were calculated to adjust for temporal trends in the total number of reports posted on ProMED. Rate comparison used a two-sided t-test; P < 0.05 was considered statistically significant. RESULTS: The mean monthly incidence of ProMED reports concerning outbreaks in the MENA region increased from 28 reports (May 2012 - April 2014) to 83 reports after the establishment of the networks (May 2014 - April 2016), and from 29 reports to 101 reports concerning outbreaks in the SoAs region over the same time period. The number of reports per total number of ProMED reports increased by 259% for MENA, and 289% for SoAs (P < 0.01). MENA reports most often addressed MERS (32.3%), foot-and-mouth disease (7.0%), avian influenza (6.7%), and measles (3.8%); whereas SoAs most often addressed dengue (14.9%), anthrax (7.3%), Japanese encephalitis (7.0%), CCHF (4.9%), and rabies (4.8%). CONCLUSION: The establishment of MENA and SoAs regional networks with locally-based, expert moderators resulted in a significant increase in ProMED's outbreak reports from these regions and an increased flow of disease information across regional borders and to the global public health community

American ginseng suppresses Western diet-promoted tumorigenesis in model of inflammation-associated colon cancer: role of EGFR

<p>Abstract</p> <p>Background</p> <p>Western diets increase colon cancer risk. Epidemiological evidence and experimental studies suggest that ginseng can inhibit colon cancer development. In this study we asked if ginseng could inhibit Western diet (20% fat) promoted colonic tumorigenesis and if compound K, a microbial metabolite of ginseng could suppress colon cancer xenograft growth.</p> <p>Methods</p> <p>Mice were initiated with azoxymethane (AOM) and, two weeks later fed a Western diet (WD, 20% fat) alone, or WD supplemented with 250-ppm ginseng. After 1 wk, mice received 2.5% dextran sulfate sodium (DSS) for 5 days and were sacrificed 12 wks after AOM. Tumors were harvested and cell proliferation measured by Ki67 staining and apoptosis by TUNEL assay. Levels of EGF-related signaling molecules and apoptosis regulators were determined by Western blotting. Anti-tumor effects of intraperitoneal compound K were examined using a tumor xenograft model and compound K absorption measured following oral ginseng gavage by UPLC-mass spectrometry. Effects of dietary ginseng on microbial diversity were measured by analysis of bacterial 16S rRNA.</p> <p>Results</p> <p>Ginseng significantly inhibited colonic inflammation and tumorigenesis and concomitantly reduced proliferation and increased apoptosis. The EGFR cascade was up-regulated in colonic tumors and ginseng significantly reduced EGFR and ErbB2 activation and Cox-2 expression. Dietary ginseng altered colonic microbial diversity, and bacterial suppression with metronidazole reduced serum compound K following ginseng gavage. Furthermore, compound K significantly inhibited tumor xenograft growth.</p> <p>Conclusions</p> <p>Ginseng inhibited colonic inflammation and tumorigenesis promoted by Western diet. We speculate that the ginseng metabolite compound K contributes to the chemopreventive effects of this agent in colonic tumorigenesis.</p

Comparison of measles IgG enzyme immunoassays (EIA) versus plaque reduction neutralization test (PRNT) for measuring measles serostatus: a systematic review of head-to-head analyses of measles IgG EIA and PRNT

Abstract Background As countries move towards or achieve measles elimination status, serosurveillance is an important public health tool. However, a major challenge of serosurveillance is finding a feasible, accurate, cost-effective, and high throughput assay to measure measles antibody concentrations and estimate susceptibility in a population. We conducted a systematic review to assess, characterize, and – to the extent possible – quantify the performance of measles IgG enzyme-linked assays (EIAs) compared to the gold standard, plaque reduction neutralization tests (PRNT). Methods We followed the PRISMA statement for a systematic literature search and methods for conducting and reporting systematic reviews and meta-analyses recommended by the Cochrane Screening and Diagnostic Tests Methods Group. We identified studies through PubMed and Embase electronic databases and included serologic studies detecting measles virus IgG antibodies among participants of any age from the same source population that reported an index (any EIA or multiple bead-based assays, MBA) and reference test (PRNT) using sera, whole blood, or plasma. Measures of diagnostic accuracy with 95% confidence intervals (CI) were abstracted for each study result, where reported. Results We identified 550 unique publications and identified 36 eligible studies for analysis. We classified studies as high, medium, or low quality; results from high quality studies are reported. Because most high quality studies used the Siemens Enzygnost EIA kit, we generate individual and pooled diagnostic accuracy estimates for this assay separately. Median sensitivity of the Enzygnost EIA was 92.1% [IQR = 82.3, 95.7]; median specificity was 96.9 [93.0, 100.0]. Pooled sensitivity and specificity from studies using the Enzygnost kit were 91.6 (95%CI: 80.7,96.6) and 96.0 (95%CI: 90.9,98.3), respectively. The sensitivity of all other EIA kits across high quality studies ranged from 0% to 98.9% with median (IQR) = 90.6 [86.6, 95.2]; specificity ranged from 58.8% to 100.0% with median (IQR) = 100.0 [88.7, 100.0]. Conclusions Evidence on the diagnostic accuracy of currently available measles IgG EIAs is variable, insufficient, and may not be fit for purpose for serosurveillance goals. Additional studies evaluating the diagnostic accuracy of measles EIAs, including MBAs, should be conducted among diverse populations and settings (e.g., vaccination status, elimination/endemic status, age groups)

Assessment of population infection with SARS-CoV-2 in Ontario, Canada, March to June 2020

BackgroundSerosurveys for SARS-CoV-2 aim to estimate the proportion of the population that has been infected.AimThis observational study assesses the seroprevalence of SARS-CoV-2 antibodies in Ontario, Canada during the first pandemic wave.MethodsUsing an orthogonal approach, we tested 8,902 residual specimens from the Public Health Ontario laboratory over three time periods during March-June 2020 and stratified results by age group, sex and region. We adjusted for antibody test sensitivity/specificity and compared with reported PCR-confirmed COVID-19 cases.ResultsAdjusted seroprevalence was 0.5% (95% confidence interval (CI): 0.1-1.5) from 27 March-30 April, 1.5% (95% CI: 0.7-2.2) from 26-31 May, and 1.1% (95% CI: 0.8-1.3) from 5-30 June 2020. Adjusted estimates were highest in individuals aged ≥ 60 years in March-April (1.3%; 95% CI: 0.2-4.6), in those aged 20-59 years in May (2.1%; 95% CI: 0.8-3.4) and in those aged ≥ 60 years in June (1.6%; 95% CI: 1.1-2.1). Regional seroprevalence varied, and was highest for Toronto in March-April (0.9%; 95% CI: 0.1-3.1), for Toronto in May (3.2%; 95% CI: 1.0-5.3) and for Toronto (1.5%; 95% CI: 0.9-2.1) and Central East in June (1.5%; 95% CI: 1.0-2.0). We estimate that COVID-19 cases detected by PCR in Ontario underestimated SARS-CoV-2 infections by a factor of 4.9.ConclusionsOur results indicate low population seroprevalence in Ontario, suggesting that public health measures were effective at limiting the spread of SARS-CoV-2 during the first pandemic wave