Octenidine exposure was not associated with reduced octenidine susceptibility of meticillin-resistant Staphylococcus aureus in an extended-care facility in Singapore.

OBJECTIVES: Antiseptics such as chlorhexidine gluconate (CHG) and octenidine dihydrochloride (OCT) are frequently used in hospitals to prevent and control the transmission of meticillin-resistant Staphylococcus aureus (MRSA). Given the increasing prevalence of reduced CHG susceptibility of MRSA, there are concerns about the possibility of reduced OCT susceptibility. This study evaluated the prevalence of reduced CHG and OCT susceptibility over 3 years, and assessed the association between OCT exposure and reduced OCT susceptibility in MRSA. METHODS: MRSA isolates from inpatients who acquired MRSA in an extended-care facility between 2019 and 2021 were included in antiseptic susceptibility testing. Inpatients were exposed to universal daily CHG bathing from January to September 2019, and universal daily OCT bathing after October 2019. The minimum inhibitory concentrations (MICs) of CHG and OCT were determined using the broth microdilution method. Multi-variable logistic regression was used to assess if OCT exposure was independently associated with reduced OCT susceptibility. RESULTS: Of 186 isolates, 179 (96%) had reduced CHG susceptibility (MIC ≥4 mg/L) and 46 (25%) had reduced OCT susceptibility (MIC ≥2 mg/L). Reduced OCT susceptibility rates were 26.9%, 13.8% and 14.3% in 2019, 2020 and 2021, respectively. Reduced CHG susceptibility rates were 95.4%, 100% and 95.9% in 2019, 2020 and 2021, respectively. OCT exposure was not associated with reduced OCT susceptibility (adjusted odds ratio 0.23, 95% confidence interval 0.08-0.75; P=0.014), after adjusting for age, gender, race, year of sample collection, days at risk in facility, hospitalization in preceding year, and MRSA colonization/infection in preceding year. CONCLUSION: The prevalence of reduced OCT susceptibility has remained low, despite universal OCT bathing for extended inpatient care. However, the rate of reduced CHG susceptibility was high. OCT exposure was not associated with reduced OCT susceptibility in MRSA.

Impaired vision in children prenatally exposed to methadone: an observational cohort study.

BACKGROUND/OBJECTIVES: To examine prevalence of failed visual assessment at 8-10 years in children born to methadone-maintained opioid dependent (MMOD) mothers and relate this to known in utero substance exposure. SUBJECTS/METHODS: Follow up of observational cohort study of methadone-exposed and comparison children matched for birthweight, gestation and postcode of residence at birth. Participants were 144 children (98 exposed, 46 comparison). Prenatal drug exposure was previously established via comprehensive maternal and neonatal toxicology. Children were invited to attend for visual assessment and casenotes were reviewed. Presence of acuity poorer than 0.2 logMAR, strabismus, nystagmus and/or impaired stereovision constituted a 'fail'. Fail rates were compared between methadone-exposed and comparison children after adjusting for known confounding variables. RESULTS: 33 children attended in person: data were also derived from casenote review for all children. After controlling for maternal reported tobacco use, methadone-exposed children were more likely to have a visual 'fail' outcome, adjusted odds ratio 2.6, 95% CI 1.1-6.2; adjusted relative risk 1.8 (95% CI 1.1-3.4). Visual 'fail' outcome rates did not differ between methadone-exposed children who had (n = 47) or had not (n = 51) received pharmacological treatment for neonatal abstinence/opioid withdrawal syndrome (NAS/NOWS); fail rate 62% vs 53% (95% CI of difference-11-27%). CONCLUSIONS: Children born to MMOD mothers are almost twice as likely as unexposed peers to have significant visual abnormalities at primary school age. Prenatal methadone exposure should be considered in the differential diagnosis of nystagmus. Findings support visual assessment prior to school entry for children with any history of prenatal opioid exposure. TRIAL REGISTRATION: The study was prospectively registered on ClinicalTrials.gov (NCT03603301), https://clinicaltrials.gov/ct2/show/NCT03603301 .

Harnessing a real-time location system for contact tracing in a busy emergency department.

BACKGROUND: With the persistent threat of emerging infectious diseases (EIDs), digital contact tracing (CT) tools can augment conventional CT for the prevention of healthcare-associated infectious disease transmission. However, their performance has yet to be evaluated comprehensively in the fast-paced emergency department (ED) setting. OBJECTIVE: This study compared the CT performance of a radiofrequency identification (RFID)-based real-time location system (RTLS) with conventional electronic medical record (EMR) review against continuous direct observation of close contacts ('gold standard') in a busy ED during the coronavirus disease 2019 pandemic period. METHODS: This cross-sectional study was conducted at the ED of a large tertiary care hospital in Singapore from December 2020 to April 2021. CT performance [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and kappa] of the RTLS, EMR review and a combination of the two approaches (hybrid CT) was compared with direct observation. Finally, the mean absolute error (MAE) in the duration of each contact episode found via the RTLS and direct observation was calculated. RESULTS: In comparison with EMR review, both the RTLS and the hybrid CT approach had higher sensitivity (0.955 vs 0.455 for EMR review) and a higher NPV (0.997 vs 0.968 for EMR review). The RTLS had the highest PPV (0.777 vs 0.714 for EMR review vs 0.712 for hybrid CT). The RTLS had the strongest agreement with direct observation (kappa=0.848). The MAE between contact durations of 80 direct observations and their respective RTLS contact times was 1.81 min. CONCLUSION: The RTLS was validated to be a high-performing CT tool, with significantly higher sensitivity than conventional CT via EMR review. The RTLS can be used with confidence in time-strapped EDs for time-sensitive CT for the prevention of healthcare-associated transmission of EIDs.

Descriptive analysis of poisoning cases involving attention deficit hyperactivity disorder medications in Hong Kong.

INTRODUCTION: The number of poisoning cases involving attention deficit hyperactivity disorder (ADHD) medications has reportedly risen with their increased use. However, there is limited relevant evidence from Asia. We analysed the characteristics of poisoning events involving these medications in Hong Kong. METHODS: We retrieved data regarding ADHD medication-related poisoning cases from the Hong Kong Poison Information Centre and conducted a descriptive analysis of the demographic information and poisoning information including sources of cases, exposure reason, exposure location, and outcome. The HKPIC data were linked with the Hospital Authority Clinical Data Analysis and Reporting System (CDARS) via de-identified Accident and Emergency numbers of public hospitals to investigate clinical characteristics. We also retrieved ADHD medication prescription records from the CDARS, then compared trends between poisoning cases and ADHD medication use. RESULTS: We identified 72 poisoning cases involving ADHD medications between 2009 and 2019, of which approximately 70% occurred in the affected individual's residence; most were intentional poisoning events (65.3%). No statistically significant association was observed between ADHD medication prescription trends and poisoning events involving ADHD medications. Of the 66 cases (91.7%) successfully linked to CDARS, 40 (60.6%) occurred in individuals with ADHD (median age: 14 years); 26 (39.4%) occurred in individuals who lacked ADHD (median age: 33 years) but displayed higher rates of other mental disorders including depression and anxiety. CONCLUSION: No significant correlation was evident between ADHD medication prescriptions and poisoning events involving ADHD medications. However, medication management and caregiver education must be emphasised to prevent potential poisoning events.

First nosocomial cluster of COVID-19 due to the Delta variant in a major acute care hospital in Singapore: investigations and outbreak response.

OBJECTIVES: The first large nosocomial cluster of coronavirus disease 2019 (COVID-19) in Singapore in April 2021 led to partial closure of a major acute care hospital. This study examined factors associated with infection among patients, staff and visitors; investigated the possible role of aerosol-based transmission; evaluated the effectiveness of BNT162.b2 and mRNA1273 vaccines; and described the successful containment of the cluster. METHODS: Close contacts of patients with COVID-19 and the affected ward were identified and underwent surveillance for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Patient, staff and visitor cohorts were constructed and factors associated with infection were evaluated. Phylogenetic analysis of patient samples was performed. Ward air exhaust filters were tested for SARS-CoV-2. RESULTS: In total, there were 47 cases, comprising 29 patients, nine staff, six visitors and three household contacts. All infections were of the Delta variant. Ventilation studies showed turbulent air flow and swabs from air exhaust filters were positive for SARS-CoV-2. Vaccine breakthrough infections were seen in both patients and staff. Among patients, vaccination was associated with a 79% lower odds of infection with COVID-19 (adjusted odds ratio 0.21, 95% confidence interval 0.05-0.95). CONCLUSIONS: This cluster occurred despite enhancement of infection control measures that the hospital had undertaken at the onset of the COVID-19 pandemic. It was brought under control rapidly through case isolation, extensive contact tracing and quarantine measures, and led to enhanced use of hospital personal protective equipment, introduction of routine rostered testing of inpatients and staff, and changes in hospital infrastructure to improve ventilation within general wards.

Determinants of antibiotic over-prescribing for upper respiratory tract infections in an emergency department with good primary care access: a quantitative analysis.

BACKGROUND: Upper respiratory tract infections (URTI) account for the highest proportion of non-urgent visits to the emergency department (ED), resulting in unnecessary antibiotic use. AIM: This study sought to understand the determinants of antibiotic prescribing for URTI among 130 junior physicians in a busy adult ED in Singapore. METHODS: Forty-four Likert-scale statements were developed with reference to a prior qualitative study, followed by an anonymous cross-sectional survey among ED junior physicians. Data analysis was performed with factor reduction and multivariable logistic regression. FINDINGS: One-in-six (16.9%) physicians were high antibiotic prescribers (self-reported antibiotic prescribing rate of >30% of URTI patients). After adjusting for place of medical education and years of practice as a physician, perceived over-prescribing of antibiotics in the ED (adjusted odds ratio (OR) 2.37, 95% confidence interval (CI) (1.15, 4.86), P=0.019) and perceived compliance with the antibiotic prescribing practices in the ED (adjusted OR 2.10, 95% CI (1.02, 4.30), P=0.043) were positively associated with high antibiotic prescribing. In contrast, high antibiotic prescribers were 6.67 times (95% CI (1.67, 25.0), P=0.007) less likely to treat and manage patients with URTI symptomatically and 7.12 times (95% CI (1.28, 39.66), P=0.025) more likely to depend on diagnostic tests to prescribe antibiotics than the regular antibiotic prescribers. CONCLUSION: Organizational-related factors (organizational norms and culture) were strong determinants of antibiotic prescribing practices for uncomplicated URTI in the ED. Other contributing factors include diagnostic uncertainty and knowledge gaps. Role-modelling of institutional best practice norms and clinical decision support tools based on local epidemiology can optimize antibiotic prescribing in the ED.

Empowerment of nurses in antibiotic stewardship: a social ecological qualitative analysis.

BACKGROUND: Inappropriate antibiotics use and antimicrobial resistance (AMR) are increasingly becoming global health issues of great concern. Despite the established antibiotic stewardship programmes (ASPs) in many countries, limited efforts have been made to engage nurses and clearly define their roles in ASPs. AIM: An exploratory qualitative study was conducted to understand the facilitators and barriers that impact nurses' involvement and empowerment in antibiotic stewardship. METHODS: Focus group discussions (FGDs) were conducted with purposively sampled nurses from three major public hospitals in Singapore. FGDs were audio-recorded and transcribed verbatim. Data were analysed using Applied Thematic Analysis and interpreted using the Social Ecological Model. FINDINGS: At the intrapersonal level, nurses felt empowered in carrying out their roles in antibiotic administration. They saw themselves as gatekeepers to ensure that the prescribed antibiotics were administered appropriately. However, nurses felt they lacked the knowledge and expertise in antibiotic use and AMR prevention. At the interpersonal level, this deficit in knowledge and expertise in antibiotic use impacted how they were perceived by patients and caregivers as well as their interactions with the primary care team when voicing outpatient safety concerns and antibiotic administration suggestions. At the organizational level, nurses relied on drug administration guidelines to ensure appropriate antibiotic administration and as a safety net when physicians questioned their clinical practice. At the community level, nurses felt there was a lack of awareness and knowledge on antibiotic use among the general population. CONCLUSION: These findings provide important insights to harness the contributions of nurses, and to formally acknowledge and enlarge their roles in ASPs.

Intranasal octenidine and universal chlorhexidine bathing can reduce meticillin-resistant Staphylococcus aureus acquisition in an extended care facility in Singapore.

Meticillin-resistant Staphylococcus aureus (MRSA) is prevalent in extended care facilities. We conducted a quasi-experimental before-after study in a 100-bed rehabilitation hospital, from January 2013 to June 2019. Universal chlorhexidine bathing was implemented throughout the period, with intranasal octenidine for MRSA colonizers added from September 2017. Interrupted time-series with segmented regression analysis revealed that after adjusting for at-admission MRSA colonization and hand hygiene compliance, a constant trend was observed pre implementation of intranasal octenidine (adjusted mean coefficient: 0.012; 95% confidence interval: -0.037 to 0.06), with an immediate decrease with implementation (-2.145; -0.248 to -0.002; P = 0.033), followed by a significant reduction in MRSA acquisition post implementation (-0.125; -0.248 to -0.002; P = 0.047).

Initial experience with the convergent procedure for longstanding persistent atrial fibrillation: A 5 year dataset.

In patients with longstanding persistent atrial fibrillation (AF), outcomes from catheter ablation remain suboptimal. The convergent procedure combines minimally invasive surgical ablation with subsequent catheter ablation, and may contribute towards maintenance of sinus rhythm in this patient group. We performed the convergent procedure on 43 patients with longstanding persistent AF from 2013-2018. Patients underwent clinical review at 3, 6, and 12 months and thereafter as necessitated by their symptoms. Our dataset describes patients' baseline characteristics and rhythm control protocols, as well as outcomes including arrhythmia recurrence, the need for antiarrhythmic drugs, requirement for repeat rhythm control procedures, and complications. These data provide a real world insight into the risks and benefits of the convergent procedure in patients with longstanding persistent AF.

The convergent procedure versus catheter ablation alone in longstanding persistent atrial fibrillation: A single centre, propensity-matched cohort study.

BACKGROUND: Maintenance of sinus rhythm is challenging in patients with longstanding persistent atrial fibrillation (PeAF). Minimally invasive surgical AF ablation may improve outcomes when combined with catheter ablation (the 'convergent' procedure). This study evaluates the safety and efficacy of the convergent procedure versus catheter ablation alone in longstanding PeAF. METHODS: 43 consecutive patients with longstanding PeAF underwent subxiphoid endoscopic ablation of the posterior left atrium followed by catheter ablation from 2013 to 2018. The primary outcome was AF-free survival at 12 months; secondary outcomes included change in EHRA class, echocardiographic data, procedural complications, freedom from anti-arrhythmic drugs (AADs), and long term arrhythmia-free survival. Outcomes were compared with a matched group of 43 patients who underwent catheter ablation alone. Both groups underwent multiple catheter ablations as required. Baseline characteristics were similar between groups. RESULTS: After 12 months, the convergent procedure was associated with increased AF-free survival on AADs (60.5% versus 25.6%, p = .002) and off AADs (37.2% versus 13.9%, p = .025), versus catheter ablation. Allowing for multiple procedures, after 30.5 ±â€¯13.3 months' follow-up the convergent procedure was associated with increased arrhythmia-free survival on AADs (58.1% versus 30.2%, p = .016) and off AADs (32.5% versus 11.6%, p = .036) versus catheter ablation. There were more complications in the convergent procedure group (11.6% versus 2.3%, p = .2). Multivariate analysis identified only the convergent procedure (OR 3.06 (1.23-7.6), p = .017) as predictive of arrhythmia-free survival long term. CONCLUSIONS: In longstanding PeAF, the convergent procedure is associated with improved arrhythmia-free survival versus catheter ablation alone. Complication rates are significant but have been shown to depreciate with experience.

Risk factors and treatment outcomes of severe Clostridioides difficile infection in Singapore.

Severe Clostridioides difficile infection (CDI) is associated with poorer outcomes. We aimed to identify risk factors and treatment outcomes of severe CDI. This was a retrospective cohort study. Eligible patients from January to December 2012 were recruited. Severity definitions were in accordance with SHEA/IDSA 2010 guideline. Treatment outcomes were (1) diarrhoea persistence, (2) CDI recurrence, (3) major complications despite treatment and (4) 30-day mortality. Two hundred and seventy-two patients were included and 40% had severe CDI. High APACHE II score (aOR 1.112, 95% CI 1.014-1.219; p < 0.05), high C-reactive protein (aOR 1.011; 95% CI 1.004-1.019; p < 0.01) and carbapenem usage in past 90 days (aOR 3.259; 95% CI 1.105-9.609; p < 0.05) were independent risk factors of severe CDI. Majority received oral metronidazole as sole treatment (92.6% for mild-moderate, 83.9% for severe, 77% for severe-complicated). Diarrhoea persistence was 32% versus 50% (p < 0.01), CDI recurrence 16.6% versus 16.5% (p > 0.05), major complications 1.2% versus 11% (p < 0.001) and 30-day mortality 7.4% versus 20.2% (p < 0.01) in mild-moderate CDI and severe CDI groups respectively. Oral metronidazole for severe CDI was associated with persistent diarrhoea, major complications and mortality. Risk factors for severe CDI can guide doctors in diagnosing severe CDI earlier and instituting oral vancomycin treatment to improve outcomes from severe CDI.

Length of stay and odds of MRSA acquisition: a dose-response relationship?

The association between methicillin-resistant Staphylococcus aureus (MRSA) colonisation and/or infection with increased morbidity and mortality among hospital patients has long been recognised. We sought to build on previous studies to identify modifiable risk factors associated with the acquisition of MRSA colonisation and infection by conducting a retrospective cohort study on patients admitted through the Emergency Department of an acute tertiary-care general hospital in Singapore which implemented universal on-admission MRSA screening. Patients were assigned to the acquisition or non-acquisition group depending on whether they acquired MRSA during their admission. We used logistic regression models with a patient being in the acquisition group as the binary outcome to identify factors associated with MRSA acquisition. A total of 1302 acquisition and 37 949 non-acquisition group patients were analysed. Fifteen variables were included in the multivariate model. A dose-response relationship between length of stay and odds of MRSA acquisition was observed, with a length of stay 3 weeks or more (Adj OR 11.78-57.36, all P < 0.001) being the single biggest predictor of MRSA acquisition. Other variables significantly associated with MRSA acquisition were: male gender, age 65 or greater, previous MRSA colonisation or infection, exposure to certain antibiotics and surgery, and history of diabetes.

Determinants of antibiotic prescribing for upper respiratory tract infections in an emergency department with good primary care access: a qualitative analysis.

Upper respiratory tract infections (URTIs) account for substantial attendances at emergency departments (EDs). There is a need to elucidate determinants of antibiotic prescribing in time-strapped EDs - popular choices for primary care despite highly accessible primary care clinics. Semi-structured in-depth interviews were conducted with purposively sampled physicians (n = 9) in an adult ED in Singapore. All interviews were analysed using thematic analysis and further interpreted using the Social Ecological Model to explain prescribing determinants. Themes included: (1) reliance on clinical knowledge and judgement, (2) patient-related factors, (3) patient-physician relationship factors, (4) perceived practice norms, (5) policies and treatment guidelines and (6) patient education and awareness. The physicians relied strongly on their clinical knowledge and judgement in managing URTI cases and seldom interfered with their peers' clinical decisions. Despite departmental norms of not prescribing antibiotics for URTIs, physicians would prescribe antibiotics when faced with uncertainty in patients' diagnoses, treating immunocompromised or older patients with comorbidities, and for patients demanding antibiotics, especially under time constraints. Participants had a preference for antibiotic prescribing guidelines based on local epidemiology, but viewed hospital policies on prescribing as a hindrance to clinical judgement. Participants highlighted the need for more public education and awareness on the appropriate use of antibiotics and management of URTIs. Organisational practice norms strongly influenced antibiotic prescribing decisions by physicians, who can be swayed by time pressures and patient demands. Clinical decision support tools, hospital guidelines and patient education targeting at individual, interpersonal and community levels could reduce unnecessary antibiotic use.

Chlorhexidine and octenidine use, carriage of qac genes, and reduced antiseptic susceptibility in methicillin-resistant Staphylococcus aureus isolates from a healthcare network.

OBJECTIVES: With the widespread use of antiseptics in healthcare facilities for the prevention of methicillin-resistant Staphylococcus aureus (MRSA) transmission, there are concerns for antiseptic tolerance and resistance. We sought to understand the use of chlorhexidine and octenidine, carriage of qac genes, and reduced antiseptic susceptibilities. METHODS: A serial cross-sectional study was conducted in an acute care hospital and three extended-care facilities of a healthcare network in June-July, 2014-2016. Two of the extended-care facilities were exposed to intranasal octenidine and universal daily chlorhexidine/octenidine bathing. The minimum inhibitory concentration (MIC) levels and qac genes were determined by broth microdilution tests and whole genome sequencing respectively. Multivariable logistic regression was used to assess for the independent associations between antiseptic exposures, qac genes, and reduced antiseptic susceptibilities. RESULTS: A total of 878 MRSA isolates were obtained. There were associations between qacA/B carriage and chlorhexidine (adjusted odds ratio (aOR) 7.80; 95% confidence interval (CI) 3.25-18.71) and octenidine (aOR 11.79; 95% CI 5.14-27.04) exposures. Chlorhexidine exposure was associated with reduced chlorhexidine susceptibility (MIC ≥4 mg/L) (aOR 3.15; 95% CI 1.14-8.74). Carriage of qacA/B (aOR 10.65; 95% CI 4.14-27.40) or qacC (aOR 2.55; 95% CI 1.22-5.32) had an association with reduced chlorhexidine susceptibility; while MRSA sequence type modified the association. However, we found no direct association between (i) antiseptics use and qacC carriage, (ii) octenidine exposure and reduced susceptibility, and (iii) reduced octenidine susceptibility and qacA/B or qacC carriage. CONCLUSIONS: Antiseptic exposures were associated with carriage of qac genes. Chlorhexidine exposure was associated with reduced chlorhexidine susceptibility, requiring continued surveillance for the emergence of resistance.