An Outbreak of Community Associated Methicillin Resistant Staphylococcus aureus Subtype USA300 at an International School in Singapore

Community associated methicillin-resistant Staphylococcus aureus (CA-MRSA) subtype USA300 remains relatively well confined within North American shores. Between August and November 2010, a large international school in Singapore recorded 27 skin and soft tissue infections, 8 of which were confirmed USA 300. This study reports the outbreak investigation and the interventions instituted.

Severe infection with H1N1 requiring intensive care--lessons for preparedness programmes

<p><b>INTRODUCTION</b>The influenza pandemic has generated much interest in the press and the medical world. We report our experience with 15 cases of severe novel influenza A H1N1 (2009) infections requiring intensive care. The aim of this review is to improve our preparedness for epidemics and pandemics by studying the most severely affected patients.</p><p><b>CLINICAL PICTURE</b>During the epidemic, hospitals were required to provide data on all confirmed H1N1 cases admitted to an intensive care unit (ICU) to the Ministry of Health. We abstracted information from this dataset for this report. To highlight learning points, we reviewed the case notes of, and report, the fi ve most instructive cases.</p><p><b>TREATMENT</b>There were 15 cases admitted to an ICU from July 4, 2009 to August 30, 2009. Two patients died.</p><p><b>CONCLUSIONS</b>The lessons we wish to share include the following: preparedness should include having intermediate-care facilities that also provide single room isolation and skilled nursing abilities, stringent visitor screening should be implemented and influenza may trigger an acute myocardial infarction in persons with risk factors.</p>

Healthcare workers and HIV health issues

Should healthcare workers (HCWs) be routinely tested for HIV? The authors reviewed the literature on the risk and incidence of HIV transmission from HCW to patients and offer recommendations for HIV testing in HCWs in Singapore. Management of HCWs who are tested seropositive for HIV infection is also discussed in this paper.

Independent predictors for mortality in patients with positive Stenotrophomonas maltophilia cultures

<p><b>INTRODUCTION</b>Stenotrophomonas maltophilia is an emerging pathogen in nosocomial infections that may result in high mortality. S. maltophilia often present as part of a polymicrobial culture and it is not well established when treatment is indicated. We aimed to identify predictors of mortality in patients with positive cultures of S. maltophilia.</p><p><b>MATERIALS AND METHODS</b>A retrospective cohort study in a tertiary care medical centre was performed in 150 adult patients with positive cultures of S. maltophilia. Patients' demographics, underlying diseases, severity of illness, length of hospitalisation, prior antibiotic exposure, number/types of indwelling catheters, culture sites, and appropriateness of empiric therapy were collected. Logistic regression was used to determine the independent risk factor(s) for infection-attributed mortality.</p><p><b>RESULTS</b>Ninety-nine males and 51 females were studied. The mean (SD) age and APACHE II score of the patients were 61.9 (16.0) and 14.0 (6.1), respectively. The respiratory tract was the most frequent site (55.3%) where S. maltophilia was isolated. Infection-attributed mortality was observed in 22 of the 150 patients (14.7 %). Admission to ICU [Odds ratio (OR), 3.767; 95% confidence interval (CI), 1.277-11.116, P = 0.016], and delayed effective treatment (OR, 18.684; 95% CI, 4.050-86.188; P <0.001) were identified as independent risk factors for mortality.</p><p><b>CONCLUSIONS</b>Predictors of mortality in patients with positive cultures of S. maltophilia were identified, which may guide clinicians in patient assessment and devising therapeutic decisions. Further studies are needed to validate our results.</p>

Vancomycin-resistant enterococcus: a review from a Singapore perspective

<p><b>INTRODUCTION</b>Vancomycin-resistant enterococcus (VRE) can cause serious infections in vulnerable, immunocompromised patients.</p><p><b>MATERIALS AND METHODS</b>In this article, we summarise current data on epidemiology, detection, treatment and prevention of VRE.</p><p><b>RESULTS</b>VRE was first isolated in Singapore in 1994 and until 2004 was only sporadically encountered in our public hospitals. After 2 outbreaks in 2004 and in 2005, VRE has become established in our healthcare institutions. Multiple studies have shown that VRE spreads mainly via contaminated hands, cloths and portable equipment carried by healthcare workers.</p><p><b>CONCLUSIONS</b>Only a comprehensive programme (consisting of active surveillance, isolation of colonised/infected patients, strict adherence to proper infection control practices and anti-microbial stewardship) can limit the spread of these organisms. In addition to monitoring the compliance with traditional infection control measures, new strategies that merit consideration include pre-emptive isolation of patients in high-risk units and molecular techniques for the detection of VRE.</p>

Predictors of vancomycin-resistant enterococcus (VRE) carriage in the first major VRE outbreak in Singapore

<p><b>INTRODUCTION</b>Until recently, vancomycin-resistant enterococcus (VRE) infection or colonisation was a rare occurrence in Singapore. The first major VRE outbreak involving a 1500-bed tertiary care institution in March 2005 presented major challenges in infection control and came at high costs. This study evaluates the predictors of VRE carriage based on patients' clinical and demographic profiles.</p><p><b>MATERIALS AND METHODS</b>Study patients were selected from the hospital inpatient census population during the VRE outbreak (aged 16 years or more). Clinical information from 84 cases and 377 controls were analysed.</p><p><b>RESULTS</b>Significant predictors of VRE carriage included: age>65 years Odds ratio (OR), 1.98; 95% CI (confidence interval), 1.14 to 3.43); female gender (OR, 2.15; 95% CI, 1.27 to 3.65); history of diabetes mellitus (OR, 1.94; 95% CI, 1.14 to 3.30), and staying in a crowded communal ward (OR, 2.75; 95% CI, 1.60 to 4.74). Each additional day of recent hospital stay also posed increased risk (OR, 1.03; 95% CI, 1.01 to 1.04).</p><p><b>CONCLUSION</b>Elderly diabetic females with prolonged hospitalisation in crowded communal wards formed the profile that significantly predicted VRE carriage in this major hospital-wide outbreak of VRE in Singapore. It is imperative that active VRE surveillance and appropriate infection control measures be maintained in these wards to prevent future VRE outbreaks.</p>

Community-associated methicillin-resistant Staphylococcus aureus: overview and local situation

<p><b>INTRODUCTION</b>Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged worldwide. In contrast to healthcare-associated MRSA (HA-MRSA), CA-MRSA isolates are usually susceptible to multiple non-beta-lactam antibiotics and cause a distinct spectrum of infections in epidemiologically disparate populations - in particular, cutaneous abscesses, necrotising fasciitis and necrotising pneumonia. They arise from a broader genetic background, and possess differing virulence genes. We aim to describe the distribution of different molecular subtypes of CA-MRSA among various regions and discuss briefly the implications of CA-MRSA from a local perspective.</p><p><b>METHODS</b>Literature review of articles on CA-MRSA, focusing mainly on reports where the genetic background of isolates had been analysed using multi-locus sequence typing (MLST). Singapore data were obtained from the local CA-MRSA database.</p><p><b>RESULTS</b>MLST analysis demonstrated the presence of epidemic subtypes of CA-MRSA within most geographic areas. In parts of the United States, community MRSA infections currently exceed those caused by their methicillin-susceptible counterparts. In Singapore, CA-MRSA infections are increasing, predominantly as a result of the spread of ST30 clones.</p><p><b>CONCLUSION</b>Available evidence suggests that the emergence of MRSA from the community is not going to be a transient phenomenon. Local guidelines for dealing with this phenomenon at both therapeutic and preventive levels are needed prior to the potential development of a situation mirroring that of meso-endemic HA-MRSA in local hospitals or CA-MRSA epidemics in parts of USA.</p>