Moist heat as a promising method to decontaminate N95 masks: A large scale clinical study comparing four decontamination modalities-moist heat, steam, ultraviolet-C irradiation, and hydrogen peroxide plasma.

BACKGROUND: Early in the COVID-19 pandemic, there was a global shortage of masks. Although mask reprocessing was practiced, no clinical study has assessed systematically the impact of repeated cycles of wear and decontamination on the integrity of N95 filtering facepiece respirators (FFRs). METHODS: We evaluated mask fit assessed by qualitative respirator fit test (QRFT) after each cycle of wear and decontamination, as well as four measures of mask integrity-bacterial filtration efficacy, particle filtration efficacy, differential pressure, and splash resistance through five cycles of wear and decontamination using one of the four modalities (moist heat, steam, ultraviolet-C irradiation, and hydrogen peroxide plasma). RESULTS: A total of 60.6% (hydrogen peroxide plasma) to 77.5% (moist heat) of the FFRs passed five cycles of wear and decontamination, as assessed by the wearers passing QRFT all five times. Moist heat-decontaminated FFRs retained all technical measures of integrity through all five cycles. CONCLUSIONS: This is the first large-scale study to assess systematically the impact (clinically and quantitatively) on N95 FFR integrity of repeated cycles of wearing followed by decontamination. Our results suggest that moist heat is a promising method for decontaminating N95 FFRs. Performing QRFT after every cycle of wear and decontamination ensures wearer safety. Although there is currently no mask shortage, reprocessing may reduce medical waste and improve sustainability.

A retrospective review of tuberculosis exposure among health care workers in a tertiary hospital.

BACKGROUND: We evaluated tuberculosis (TB) acquisition rate and risk factors among health care workers (HCWs) exposed to index TB patients. METHODS: We performed a retrospective cohort study on exposed HCWs from August 2016 to January 2018 at a tertiary hospital in Singapore. Demographic factors and TB exposure episodes per HCW were obtained. A modified Poisson regression model was used to identify factors associated with TB infection. RESULTS: A total of 32 TB exposure events occurred during the study period. A total of 881 HCWs with 1,536 exposure episodes were screened with QuantiFERON-TB Gold In-tube assay (QFT-GIT) at baseline and 8 weeks. A total of 129 (14.6%) HCWs had positive QFT-TB at baseline, whereas 22 (2.5%) HCWs had QFT-GIT conversion, with a latent TB infection (LTBI) rate of 1.14 cases per 100 exposure episodes per year. Foreign nationality, non-Chinese ethnicity, and age above 40 years were independently associated with baseline LTBI, whereas having >2 TB exposure episodes and working in internal medicine, medical subspecialties, and psychiatry wards were associated with QFT-GIT conversion. DISCUSSION: The QFT-GIT conversion rate among screened HCWs is low. Foreign HCWs with LTBI likely came from countries with higher TB transmission. Targeted prevention of repeated TB exposures can reduce QFT-GIT conversion. CONCLUSIONS: The study results will guide TB contact tracing protocols in health care institutions.

Risk factors for acquisition of carbapenem resistant Enterobacteriaceae in an acute tertiary care hospital in Singapore.

BACKGROUND: Carbapenem resistant Enterobacteriaceae (CRE) is increasingly reported worldwide. A similar increase is seen in Singapore since identification of its first case in 2008. The aim of this study was to identify local risk factors for carriage of CRE in patients from an acute tertiary care hospital in Singapore. METHOD: A matched case-control study was conducted on inpatients treated from January 1, 2011 till December 31, 2013. Two hundred and three cases of CRE infection or colonization were matched with 203 controls. CRE types were identified by PCR. Statistical analysis of data including a multivariate logistic regression analysis was done using SPSS 21.0. RESULTS: CREs were commonly seen in Klebsiella pneumoniae (42.2 %), Escherichia coli (24.3 %) and Enterobacter cloacae complex (17.2 %) in the 268 isolates. NDM-1 was the commonest CRE type seen (44.4 %), followed by KPC (39.9 %) whilst OXA-48 only constituted (7.8 %). Univariate analysis identified key risk factors associated with CRE as history of previous overseas hospitalization (OR: 33.667; 95 % CI: 4.539-259.700), admission to ICU (OR: 11.899; 95 % CI: 4.986-28.399) and HD/ICA (OR: 6.557; 95 % CI: 4.057-10.596); whilst a multivariate analysis revealed exposure to antibiotics penicillin (OR: 4.640; 95 % CI: 1.529-14.079] and glycopeptide (OR: 5.162; 95 % CI: 1.377-19.346) and presence of central line device (OR: 3.117; 95 % CI: 1.167-8.330) as significant independent predictors. CONCLUSIONS: The identification of risk factors amongst our local population helped to refine the criteria used for target active surveillance screening for CRE amongst inpatients at time of hospital admission.

Impact of a hospital-wide hand hygiene promotion strategy on healthcare-associated infections.

BACKGROUND: During the Severe Acute Respiratory Syndrome (SARS) outbreak, high compliance in healthcare workers to hand hygiene was primarily driven by fear. However, the post-SARS period confirmed that this practice was not sustainable. At the Singapore General Hospital, a 1,600-bedded acute tertiary care hospital, the hand hygiene program was revised in early 2007 following Singapore's signing of the pledge to the World Health Organization (WHO) "Clean Care is Safer Care" program. FINDINGS: A multi-prong approach was used in designing the hand hygiene program. This included system change; training and education; evaluation and feedback; reminders in the workplace; and institutional safety climate. Hand hygiene compliance rate improved from 20% (in January 2007) to 61% (2010). Improvement was also seen annually in the compliance to each of the 5 moments as well as in all staff categories. Healthcare-associated MRSA infections were reduced from 0.6 (2007) to 0.3 (2010) per 1000 patient-days. CONCLUSIONS: Leadership's support of the program evidenced through visible leadership presence, messaging and release of resources is the key factor in helping to make the program a true success. The hospital was recognised as a Global Hand Hygiene Expert Centre in January 2011. The WHO multi-prong interventions work in improving compliance and reducing healthcare associated infections.

First outbreak of colonization and infection with vancomycin-resistant Enterococcus faecium in a tertiary care hospital in Singapore.

We report the first outbreak of vancomycin-resistant Enterococcus faecium colonization and infection among inpatients in the hematology ward of an acute tertiary care public hospital in Singapore. Two cases of bacteremia and 4 cases of gastrointestinal carriage were uncovered before implementation of strict infection control measures resulted in control of the outbreak.