Simon Y.C. So

Proactive infection control measures to prevent nosocomial transmission of vancomycin-resistant enterococci in Hong Kong

BACKGROUND/PURPOSE The study describes a proactive infection control approach to prevent nosocomial transmission of vancomycin-resistant enterococci (VRE) and tests if this approach is effective for controlling multiple-drug resistant organisms in a nonendemic setting. METHODS In response to the increasing prevalence of VRE in Hong Kong since 2011, we adopted a multifaceted assertive approach in our health care network. This included active surveillance culture, extensive contact tracing, directly observed hand hygiene in conscious patients before they received meals and medications, stringent hand hygiene and environmental cleanliness, and an immediate feedback antimicrobial stewardship program. We report the occurrence of VRE outbreaks in our hospital after institution of these measures and compared with the concurrent occurrence in other public hospitals in Hong Kong. RESULTS Between July 1, 2011 and November 13, 2013, VRE was identified in 0.32% (50/15,851) of admission episodes by active surveillance culture. The risk of VRE carriage was three times higher in patients with a history of hospitalization outside our hospital networks in the past 3 months (0.56% vs. 0.17%; p = 0.001) compared with those who were not. Extensive contact tracing involving 3277 patient episodes was performed in the investigation for the 25 VRE index patients upon whom implementation of contact precautions was delayed (more than 48 hours of hospitalization). One episode of VRE outbreak was identified in our hospital network, compared with the 77 VRE outbreaks reported in the other hospital networks (controls) without these proactive infection control measures. CONCLUSION Our multifaceted assertive proactive infection control approach can minimize the nosocomial transmission and outbreak of VRE in a nonendemic area.

Minimal Intervention for Controlling Nosocomial Transmission of Methicillin-Resistant Staphylococcus aureus in Resource Limited Setting with High Endemicity

Objective To control nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) in resource-limited healthcare setting with high endemicity. Methods Three phases of infection control interventions were implemented in a University-affiliated hospital between 1-January-2004 and 31-December-2012. The first phase of baseline period, defined as the first 48-months of the study period, when all MRSA patients were managed with standard precautions, followed by a second phase of 24-months, when a hospital-wide hand hygiene campaign was launched. In the third phase of 36-months, contact precautions in open cubicle, use of dedicated medical items, and 2% chlorhexidine gluconate daily bathing for MRSA-positive patients were implemented while hand hygiene campaign was continued. The changes in the incidence rates of hospital-acquired MRSA-per-1000-patient admissions, per-1000-patient-days, and per-1000-MRSA-positive-days were analyzed using segmented Poisson regression (an interrupted time series model). Usage density of broad-spectrum antibiotics was monitored. Results During the study period, 4256 MRSA-positive patients were newly diagnosed, of which 1589 (37.3%) were hospital-acquired. The reduction of hospital-acquired MRSA per 1000-patient admissions, per 1000-patient-days, and per 1000-MRSA-positive-days from phase 1 to 2 was 36.3% (p<0.001), 30.4% (p<0.001), and 19.6% (p = 0.040), while the reduction of hospital-acquired MRSA per 1000-patient admissions, per 1000-patient-days, and per 1000-MRSA-positive-days from phase 2 to 3 was 27.4% (p<0.001), 24.1% (p<0.001), and 21.9% (p = 0.041) respectively. This reduction is sustained despite that the usage density of broad-spectrum antibiotics has increased from 132.02 (phase 1) to 168.99 per 1000 patient-days (phase 3). Conclusions Nosocomial transmission of MRSA can be reduced with hand hygiene campaign, contact precautions in open cubicle, and 2% chlorhexidine gluconate daily bathing for MRSA-positive despite an increasing consumption of broad-spectrum antibiotics.

A 10-year study reveals clinical and laboratory evidence for the 'semi-invasive' properties of chronic pulmonary aspergillosis.

In recent years, infections caused by Aspergillus sp. have become an emerging focus of clinical microbiology and infectious disease, as the number of patients infected with Aspergillus sp. has increased markedly. Although chronic pulmonary aspergillosis (CPA) is considered a ‘semi-invasive’ or ‘intermediate’ disease, little data are available for the direct comparison of CPA with invasive pulmonary aspergillosis (IPA) and pulmonary aspergilloma (PA) to quantify invasiveness. In this study, we compared the characteristics of CPA with those of IPA and PA among hospitalized patients over a 10-year period. A total of 29, 51 and 31 cases of CPA, IPA and PA, respectively, were included. An increasing trend in galactomannan antigen seropositivity rate from PA (24.1%) to CPA (35.7%) to IPA (54.9%) and an opposite trend for anti-Aspergillus antibody (PA (71.0%) to CPA (45.8%) to IPA (7.1%)) were observed. Eight percent of CPA patients were infected with more than one Aspergillus sp. The survival rate of the CPA group also fell between the survival rate of PA and IPA, confirming the intermediate severity of CPA. The survival rate of the CPA group became significantly higher than that of the IPA group from day 180 onwards until 2 years after admission (P<0.05). The survival rate of the CPA group remained lower than that of the PA group from day 30 onwards until 2 years after admission. Poor prognostic factors for CPA included older age (P=0.019), higher total leukocyte count (P=0.011) and higher neutrophil count (P=0.012) on admission. This study provided clinical and laboratory evidence for the semi-invasive properties of CPA.

Successful control of emerging vancomycin-resistant enterococci by territory-wide implementation of directly observed hand hygiene in patients in Hong Kong

With the emergence of vancomycin-resistant enterococci (VRE) in our public hospitals, territory-wide implementation of directly observed hand hygiene before meals and medications for all conscious hospitalized patients reverted the rising VRE incidence of 16.5% per month (P < .001) to a reduction of -9.8% per month (P < .001). The outbreak rate reverted from an increasing trend of 10.5% per month (P < .001) to a decreasing trend of -13.3% per month (P < .001) between January 2011 and October 2015.

The importance of matrix-assisted laser desorption ionization–time of flight mass spectrometry for correct identification of Clostridium difficile isolated from chromID C. difficile chromogenic agar

The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS) for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.

Seasonal Outbreak of Bacillus Bacteremia Associated With Contaminated Linen in Hong Kong

Background A high seasonal incidence of Bacillus bacteremia was associated with the use of contaminated hospital linens. Methods An outbreak investigation was conducted to study the incidence and source of Bacillus bacteremia during the baseline, outbreak, and postoutbreak period from 1 January 2012 through 31 July 2016 at a university-affiliated teaching hospital in Hong Kong. Replicate organism detection and counting plates were used for microbial screening of linen samples. The Bacillus species isolated from patient and linen samples were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were phylogenetically analyzed. Results During the study period, a total of 113 207 blood cultures were collected from 43 271 patients, of which 978 (0.86%) specimens from 744 (1.72%) patients were identified as Bacillus species. The incidence of Bacillus bacteremia per 10 000 patient admissions and per 10 000 patient-days was significantly higher during the summer outbreak as compared with baseline and 1 year postoutbreak after cessation of the linen supply from the designated laundry and change of laundry protocol (39.97 vs 18.21 vs 2.27; 13.36 vs 5.61 vs 0.73; P < .001). The mean total aerobic bacterial count per 100 cm2 was significantly higher among the 99 linen samples screened during the outbreak period compared to the 100 screened in the postoutbreak period (916.0 ± 641.6 vs 0.6 ± 1.6; P < .001). Blood culture isolates of Bacillus cereus group in 14 of 87 (16.1%) patients were phylogenetically associated with 9 linen sample isolates. Conclusions Suboptimal conditions of hospital laundry contributed to the seasonal outbreak of Bacillus bacteremia.

The challenge of patient empowerment in hand hygiene promotion in health care facilities in Hong Kong

HighlightsPatient empowerment program in hand hygiene was attempted in 2 hospitals.Only 3% patients asked health care workers (HCWs) to clean their hands prior to this program.HCWs expressed fear of conflicts with patients.Patients preferred visual aids over verbal prompts in this program.Increased consumption of alcohol‐based handrub was noted during the program. &NA; Patient empowerment programs in hand hygiene were implemented in 2 extended‐care hospitals. Of the 223 patients approached by the infection control nurses, 167 patients (74.9%) participated in the program. A positive response from the health care workers was reported in 70 (93.3%) of 75 patients who reminded health care workers to clean hands as part of the empowerment program. A significant increase in volume of alcohol‐based handrub consumption was observed during the intervention period compared with baseline.

Emergence of Carbapenem-Resistant Acinetobacter baumannii in Nursing Homes With High Background Rates of MRSA Colonization

Carbapenem-resistant Acinetobacter baumannii (CRAB) with diverse multilocus sequence typing emerged among our nursing home residents (6.5%) with a high background rate of MRSA (32.2%). Rectal swabs yielded a higher rate of CRAB detection than axillary or nasal swabs. Bed-bound status, use of adult diapers, and nasogastric tube were risk factors for CRAB colonization. Infect Control Hosp Epidemiol 2016;37:983-986.