Epidemiology of multidrug-resistant organisms before and during COVID-19 in Hong Kong.

Background: The coronavirus disease 2019 (COVID-19) has influenced antimicrobial consumption and incidence of multidrug-resistant organisms (MDROs). We aimed to study the epidemiology of MDROs before and during the COVID-19 pandemic in Hong Kong. Methods: With the maintenance of infection control measures, we described the trend of MDRO infections, including methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter species (CRA), and extended-spectrum-beta-lactamase-(ESBL)-producing Enterobacterales, in a healthcare region with 3100-bed before (1 January 2016 to 31 December 2019, period 1) and during COVID-19 (1 January 2020 to 30 September 2022, period 2), together with the antimicrobial consumption using piecewise Poisson regression. The epidemiological characteristics of newly diagnosed COVID-19 patients with or without MDRO infections were analyzed. Results: Between period 1 and 2, we observed a significant increase in the trend of CRA infections (P<0.001), while there was no significant increase in the trend of MRSA (P=0.742) and ESBL-producing Enterobacterales (P=0.061) infections. Meanwhile, a significant increase in the trend of carbapenems (P<0.001), extended-spectrum beta-lactam-beta-lactamase inhibitor combinations (BLBI) (P=0.045), and fluoroquinolones (P=0.009) consumption was observed. The observed opportunity (23,540 ± 3703 vs 26,145 ± 2838, p=0.359) and compliance (81.6% ± 0.5% vs 80.1% ± 0.8%, P=0.209) of hand hygiene per year was maintained. In a multivariable model, older age, male sex, referral from residential care home for the elderly, presence of indwelling device, presence of endotracheal tube, and use of carbapenems, use of BLBI, use of proton pump inhibitors and history of hospitalization in the past 3 months were associated with higher risks of infections by MDROs among COVID-19 patients. Conclusion: Infection control measures may control the surge of MDROs despite an increasing trend of antimicrobial consumption.

Infection of healthcare workers despite a high vaccination rate during the fifth wave of COVID-19 due to Omicron variant in Hong Kong.

Background: No nosocomial infection was recorded in our healthcare workers (HCWs) during the early phase of the coronavirus disease 2019 (COVID-19) pandemic. With the emergence of the Omicron variant of increased transmissibility, infection in HCWs occurred as expected. We aimed to study the epidemiology of infection in HCWs and to describe the infection control measures during the outbreak of the Omicron variant. Methods: With daily rapid antigen testing and molecular confirmation test for COVID-19, infected HCWs were interviewed by infection control nurses (ICNs) to investigate the potential source of infection. The epidemiology of COVID-19 in Hong Kong served as reference. Results: During the fifth wave of COVID-19 (31 December 2021 to 31 May 2022), 1,200,068 cases were reported (incidence 95 times higher than in preceding waves in Hong Kong; 162,103 vs 1,707 per million population respectively, P<0.001). The proportion of infected HCWs was significantly higher than that of the general population (24.9%, 1,607/6,452 vs 16.2%, 1,200,068/7,403,100 respectively; P<0.01). The proportion of infected non-clinical staff was significantly higher than that of clinical staff (31.8%, 536/1,687 vs 22.5%, 1,071/4,765 respectively; P<0.001). Of 82.8% (1,330/1,607) infected HCWs interviewed by ICNs, 99.5% (1,324/1,330) had been fully vaccinated; 49.5% (659/1,330) had no identifiable source; 40.7% (541/1,330) were probably infected from household members; 9.8% (130/1,330) had possible exposure to confirmed patients or HCWs, but no lapse in infection control measures or inappropriate use of personal protective equipment was recalled. Conclusion: Omicron variant is highly transmissible such that breakthrough infection occurred despite high level of vaccination.

Air dispersal of respiratory viruses other than severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and the implication on hospital infection control.

BACKGROUND: Air dispersal of respiratory viruses other than SARS-CoV-2 has not been systematically reported. The incidence and factors associated with air dispersal of respiratory viruses are largely unknown. METHODS: We performed air sampling by collecting 72,000 L of air over 6 hours for pediatric and adolescent patients infected with parainfluenza virus 3 (PIF3), respiratory syncytial virus (RSV), rhinovirus, and adenovirus. The patients were singly or 2-patient cohort isolated in airborne infection isolation rooms (AIIRs) from December 3, 2021, to January 26, 2022. The viral load in nasopharyngeal aspirates (NPA) and air samples were measured. Factors associated with air dispersal were investigated and analyzed. RESULTS: Of 20 singly isolated patients with median age of 30 months (range, 3 months-15 years), 7 (35%) had air dispersal of the viruses compatible with their NPA results. These included 4 (40%) of 10 PIF3-infected patients, 2 (66%) of 3 RSV-infected patients, and 1 (50%) of 2 adenovirus-infected patients. The mean viral load in their room air sample was 1.58×103 copies/mL. Compared with 13 patients (65%) without air dispersal, these 7 patients had a significantly higher mean viral load in their NPA specimens (6.15×107 copies/mL vs 1.61×105 copies/mL; P < .001). Another 14 patients were placed in cohorts as 7 pairs infected with the same virus (PIF3, 2 pairs; RSV, 3 pairs; rhinovirus, 1 pair; and adenovirus, 1 pair) in double-bed AIIRs, all of which had air dispersal. The mean room air viral load in 2-patient cohorts was significantly higher than in rooms of singly isolated patients (1.02×104 copies/mL vs 1.58×103 copies/mL; P = .020). CONCLUSION: Air dispersal of common respiratory viruses may have infection prevention and public health implications.

Air dispersal of severe acute respiratory coronavirus virus 2 (SARS-CoV-2): Implications for hospital infection control during the fifth wave of coronavirus disease 2019 (COVID-19) due to the SARS-CoV-2 omicron variant in Hong Kong.

We obtained 24 air samples in 8 general wards temporarily converted into negative-pressure wards admitting coronavirus disease 2019 (COVID-19) patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant BA.2.2 in Hong Kong. SARS-CoV-2 RNA was detected in 19 (79.2%) of 24 samples despite enhanced indoor air dilution. It is difficult to prevent airborne transmission of SARS-CoV-2 in hospitals.

Gastrointestinal Colonization of Carbapenem-Resistant Acinetobacter baumannii: What Is the Implication for Infection Control?

The epidemiology of patients with gastrointestinal colonization of carbapenem-resistant Acinetobacter baumannii (CRAB) has not been systematically analyzed. We aimed to analyze the incidence, risk factors, and clinical outcomes of patients with newly identified gastrointestinal colonization of CRAB in a healthcare region in Hong Kong, where a multi-pronged screening strategy for gastrointestinal colonization of CRAB, together with other multidrug-resistant organisms (MDROs), was conducted by collecting fecal specimens (rectal swab or stool) upon admission and during hospitalization. From 1 October 2015 to 31 December 2019, a total of 161,339 fecal specimens from 63,588 patients, 61,856 (97.3%) of whom were hospitalized patients, and 54,525 (88.1%) were screened upon admission, with 1309 positive for CRAB (2.4% prevalence). Among patients positive for CRAB in fecal specimens, 698 (53.3%) had newly detected gastrointestinal colonization of CRAB, giving an incidence of 10.03 per 10,000 patient admissions and constituting 2646 CRAB colonization days in the general wards. Excluding the 164 patients with co-colonization of other MDROs, 534 patients had gastrointestinal colonization with only CRAB, and 12.5% (67/534) developed symptomatic CRAB infections at a median of 61 days (range: 2 to 671 days), during prospective follow-up for 2 years. Compared with age- and sex-matched controls, patients being referred from residential care homes for the elderly, the presence of indwelling devices, use of beta-lactam/beta-lactamase inhibitors, carbapenems, and proton pump inhibitors in the preceding 6 months, and history of hospitalization in the past 6 months were significantly associated with gastrointestinal colonization with CRAB, as shown by multivariable analysis. Log-rank test showed that cases had significantly shorter survival duration than controls (p < 0.001). The adjusted hazard ratio of gastrointestinal colonization of CRAB was 1.8 (95% CI: 1.5−2.2; p < 0.001), as shown by Cox regression analysis. Whole-genome sequencing of eight patients with CRAB isolates in their blood cultures and rectal swabs during the same episode of hospitalization revealed ST-195 as the predominant type, as shown by multilocus sequencing type. Gastrointestinal colonization of CRAB poses a considerable challenge for infection prevention and control.

The impact of personal coaching on influenza vaccination among healthcare workers before and during COVID-19 pandemic.

BACKGROUND: Without the implementation of mandatory vaccination, it was difficult to increase the influenza vaccination rate among healthcare workers. We described the strategy of personal coaching and assess its impact in increasing the influenza vaccination rate among healthcare workers in Hong Kong. METHODS: Personal coaching of individual staff led by the infection control officer (ICO) and senior nursing officer (SNO) from infection control team could overcome barriers and promote on-site vaccination. The influenza vaccination rates among different categories of staff in 2016/2017 (year 1, baseline), 2017/2018 (year 2, promotion using social media), and 2018/2019 to 2020/2021 (year 3-5, promotion using personal coaching) were analysed in a healthcare region with 8490 ± 206 staff during the study period. RESULTS: With the implementation of personal coaching, the influenza vaccination rates increased significantly among medical (65.0% vs 57.0%, p = 0.048), nursing (30.6% vs 21.1%, p < 0.001), allied health (37.0% vs 27.4%, p < 0.001), care-related supporting staff (37.7% vs 27.3%, p < 0.001), and non-professional staff (27.3% vs 22.3%, p < 0.001) in year 3 compared with year 2, and also significantly increased among all staff in year 4 (38.0% vs 34.7%, p < 0.001) and year 5 (45.2% vs 38.0%, p < 0.001) when compared with the preceding year. The increase in vaccination rate was not apparent with social media promotion alone (26.4%, year 2 vs 25.6%, year 1, p = 0.305). CONCLUSION: Personal coaching led by ICO and SNO significantly increased the vaccination rates among healthcare workers in 3 consecutive years. This model could be promulgated to unit heads to establish a hospital culture conducive to vaccination.

The use of multi-pronged screening strategy to understand the epidemiology of carbapenemase-producing Enterobacteriaceae in Hong Kong: transition from epidemic to endemic setting.

A multi-pronged carbapenemase-producing Enterobacteriaceae (CPE) screening strategy was implemented in Hong Kong West healthcare network. Of 199,192 fecal specimens from 77,194 patients screening from 1 July 2011 to 30 June 2019, the incidence of CPE per 1000 patient admission significantly increased from 0.01 (2012) to 1.9 (2018) (p<0.01). With appropriate infection control measures, the incidence of nosocomial CPE per 1000 CPE colonization day decreased from 22.34 (2014) to 10.65 (2018) (p=0.0094). Exposure to wet market for purchasing raw pork (p=0.007), beef (p=0.017), chicken (p=0.026), and vegetable (p=0.034) for >3 times per week significantly associated with community acquisition of CPE. Strategic CPE control measures should be implemented in both the hospital and the community.

Absence of nosocomial influenza and respiratory syncytial virus infection in the coronavirus disease 2019 (COVID-19) era: Implication of universal masking in hospitals.

Universal masking for healthcare workers and patients in hospitals was adopted to combat coronavirus disease 2019 (COVID-19), with compliance rates of 100% and 75.9%, respectively. Zero rates of nosocomial influenza A, influenza B, and respiratory syncytial virus infection were achieved from February to April 2020, which was significantly lower than the corresponding months in 2017-2019.