Nosocomial Outbreak of Coronavirus Disease 2019 by Possible Airborne Transmission Leading to a Superspreading Event.

BACKGROUND: Nosocomial outbreaks with superspreading of coronavirus disease 2019 due to a possible airborne transmission have not been reported. METHODS: Epidemiological analysis, environmental samplings, and whole-genome sequencing (WGS) were performed for a hospital outbreak. RESULTS: A superspreading event that involved 12 patients and 9 healthcare workers (HCWs) occurred within 9 days in 3 of 6 cubicles at an old-fashioned general ward with no air exhaust built within the cubicles. The environmental contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was significantly higher in air grilles (>2 m from patients' heads and not within reach) than on high-touch clinical surfaces (36.4%, 8 of 22 vs 3.4%, 1 of 29, P = .003). Six (66.7%) of 9 contaminated air exhaust grilles were located outside patient cubicles. The clinical attack rate of patients was significantly higher than of HCWs (15.4%, 12 of 78 exposed patients vs 4.6%, 9 of 195 exposed HCWs, P = .005). Moreover, the clinical attack rate of ward-based HCWs was significantly higher than of nonward-based HCWs (8.1%, 7 of 68 vs 1.8%, 2 of 109, P = .045). The episodes (mean ±â€…standard deviation) of patient-care duty assignment in the cubicles was significantly higher among infected ward-based HCWs than among noninfected ward-based HCWs (6.0 ±â€…2.4 vs 3.0 ±â€…2.9, P = .012) during the outbreak period. The outbreak strains belong to SARS-CoV-2 lineage B.1.36.27 (GISAID clade GH) with the unique S-T470N mutation on WGS. CONCLUSIONS: This nosocomial point source superspreading event due to possible airborne transmission demonstrates the need for stringent SARS-CoV-2 screening at admission to healthcare facilities and better architectural design of ventilation systems to prevent such outbreaks. Portable high-efficiency particulate filters were installed in each cubicle to improve ventilation before resumption of clinical service.

An outbreak of Burkholderia cepacia complex exit site infection among peritoneal dialysis patients caused by contaminated spray dressing.

Background: Wound dressing is intended to provide a physical barrier from microorganisms. Spray dressing is convenient and can be applied to wounds of various contours. In July 2020, a cluster of four Burkholderia cepacia complex (BCC) exit site infections was identified among peritoneal dialysis patients in a regional hospital in Hong Kong. In response, our hospital infection control team conducted an epidemiologic investigation. Methods: We conducted a retrospective cohort study of peritoneal dialysis patients with culture-confirmed BCC exit site infections from January 2011 to July 2020. Outbreak investigations, including case finding, molecular typing and post-outbreak surveillance, were performed. Discussion: A substantial increase in BCC exit site infections has been observed since 2013, rising from 0.23 in 2012 to 1.09 episodes per 100 patient-year in 2015, with the number of cases in the first half of 2020 already surpassing the total from 2019. The potential source had been traced to a spray dressing introduced to exit site care in December 2012. Burkholderia cepacia complex was isolated from both the unopened and in-use sprays from the same lot. Multilocus sequence typing analysis confirmed their genetic relatedness. The spray dressing was subsequently removed from exit site care. Post-outbreak surveillance over two years showed a marked and sustained decrease in BCC exit site infection. Conclusion: Water-based spray dressing can be a source of BCC causing wound infections. The use of contaminated spray dressing, especially in chronic wounds with proximity to indwelling catheters, may pose an inherent risk to patients.

Bacterial co-infections and antibiotic prescribing practice in adults with COVID-19: experience from a single hospital cluster.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected millions of individuals since December 2019, resulting in significant morbidity and mortality globally. During the 1918 Influenza Pandemic, it was observed that influenza was associated with bacterial co-infections. However, empirical or prophylactic antibiotic use during viral pandemics should be balanced against the associated adverse drug events. METHODS: In this retrospective cohort study, we investigated bacterial co-infections in adults with COVID-19 in Hong Kong. Notably, at the time of writing this report, patients with varying disease severities were isolated in hospitals until confirmatory evidence of virological clearance or immunity was available. The study included adults with laboratory-confirmed COVID-19 admitted to a single hospital cluster between 8 January 2020 and 1 May 2020. We obtained data regarding patient demographics, clinical presentations, blood test results, treatment, and outcomes. Bacteriological profiles and risk factors for co-infections were investigated. Antibiotic prescription practices were also reviewed. RESULTS: Of the 147 patients recruited, clinical disease was suspected in 42% (n = 62) of patients who underwent testing for other respiratory infections. Notably, 35% (n = 52) of the patients were prescribed empirical antibiotics, predominantly penicillins or cephalosporins. Of these, 35% (n = 18) received more than one class of antibiotics and 37% (n = 19) received empirical antibiotics for over 1 week. Overall, 8.2% (n = 12) of patients developed bacterial co-infections since the detection of COVID-19 until discharge. Methicillin-susceptible Staphylococcus aureus was the most common causative pathogen identified. Although 8.2% (n = 12) of patients developed hypoxia and required oxygen therapy, no mortality was observed. Multivariate analysis showed that pneumonic changes on chest radiography at the time of admission predicted bacterial co-infections. CONCLUSION: These findings emphasise the importance of judicious administration of antibiotics throughout the disease course of COVID-19 and highlight the role of antimicrobial stewardship during a pandemic.