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.
We describe a nosocomial outbreak of community-associated methicillin-resistant
Staphylococcus aureus
(CA-MRSA) ST59-SCC
mec
type V in a neonatal intensive care unit (NICU) in Hong Kong. In-depth ...epidemiological analysis was performed by whole-genome sequencing (WGS) of the CA-MRSA isolates collected from patients and environment during weekly surveillance and healthcare workers from the later phase of the outbreak. Case–control analysis was performed to analyze potential risk factors for the outbreak. The outbreak occurred from September 2017 to February 2018 involving 15 neonates and one healthcare worker. WGS analysis revealed complicated transmission dynamics between patients, healthcare worker, and environment, from an unrecognized source introduced into the NICU within 6 months before the outbreak. In addition to enforcement of directly observed hand hygiene, environmental disinfection, cohort nursing of colonized and infected patients, together with contact tracing for secondary patients, medical, nursing, and supporting staff were segregated where one team would care for CA-MRSA-confirmed/CA-MRSA-exposed patients and the other for newly admitted patients in the NICU only. Case–control analysis revealed use of cephalosporins odds ratio 49.84 (3.10–801.46),
p
= 0.006 and length of hospitalization odds ratio 1.02 (1.00–1.04),
p
= 0.013 as significant risk factors for nosocomial acquisition of CA-MRSA in NICU using multivariate analysis. WGS facilitates the understanding of transmission dynamics of an outbreak, providing insights for outbreak prevention.
The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown.
Concurrent MRSA screening and spa ...type analysis was performed in LTCFs and their network hospitals to estimate the rate of MRSA acquisition among residents during their stay in LTCFs and hospitals, by colonization pressure and MRSA transmission calculations.
In 40 LTCFs, 436 (21.6%) of 2020 residents were identified as 'MRSA-positive'. The incidence of MRSA transmission per 1000-colonization-days among the residents during their stay in LTCFs and hospitals were 309 and 113 respectively, while the colonization pressure in LTCFs and hospitals were 210 and 185 per 1000-patient-days respectively. MRSA spa type t1081 was the most commonly isolated linage in both LTCF residents (76/121, 62.8%) and hospitalized patients (51/87, 58.6%), while type t4677 was significantly associated with LTCF residents (24/121, 19.8%) compared with hospitalized patients (3/87, 3.4%) (p<0.001). This suggested continuous transmission of MRSA t4677 among LTCF residents. Also, an inverse linear relationship between MRSA prevalence in LTCFs and the average living area per LTCF resident was observed (Pearson correlation -0.443, p=0.004), with the odds of patients acquiring MRSA reduced by a factor of 0.90 for each 10 square feet increase in living area.
Our data suggest that MRSA transmission was more serious in LTCFs than in hospitals. Infection control should be focused on LTCFs in order to reduce the burden of MRSA carriers in healthcare settings.
Microscopic detection and morphological identification of parasites from clinical specimens are the gold standards for the laboratory diagnosis of parasitic infections. The limitations of such ...diagnostic assays include insufficient sensitivity and operator dependence. Immunoassays for parasitic antigens are not available for most parasitic infections and have not significantly improved the sensitivity of laboratory detection. Advances in molecular detection by nucleic acid amplification may improve the detection in asymptomatic infections with low parasitic burden. Rapidly accumulating genomic data on parasites allow the design of polymerase chain reaction (PCR) primers directed towards multi-copy gene targets, such as the ribosomal and mitochondrial genes, which further improve the sensitivity. Parasitic cell or its free circulating parasitic DNA can be shed from parasites into blood and excreta which may allow its detection without the whole parasite being present within the portion of clinical sample used for DNA extraction. Multiplex nucleic acid amplification technology allows the simultaneous detection of many parasitic species within a single clinical specimen. In addition to improved sensitivity, nucleic acid amplification with sequencing can help to differentiate different parasitic species at different stages with similar morphology, detect and speciate parasites from fixed histopathological sections and identify anti-parasitic drug resistance. The use of consensus primer and PCR sequencing may even help to identify novel parasitic species. The key limitation of molecular detection is the technological expertise and expense which are usually lacking in the field setting at highly endemic areas. However, such tests can be useful for screening important parasitic infections in asymptomatic patients, donors or recipients coming from endemic areas in the settings of transfusion service or tertiary institutions with transplantation service. Such tests can also be used for monitoring these recipients or highly immunosuppressed patients, so that early preemptive treatment can be given for reactivated parasitic infections while the parasitic burden is still low.
Highlights • Patient 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.
Highlights • Vancomycin-resistant enterococci are emerging in Hong Kong. • Directly observed hand hygiene–based infection control measures are implemented. • The burden of vancomycin-resistant ...enterococci was reduced by 83% and 97% at 12 and 24 months, respectively. • It is a simple and sustainable maneuver to reduce nosocomial transmission of vancomycin-resistant enterococci.
•Environmental reservoir is an important source of multidrug-resistant Acinetobacter baumannii (MRAB) outbreaks.•Presence of MRAB in communal areas preceded MRAB newly diagnosed in patients.•Positive ...environmental culture may alert the presence of MRAB carrier in ward.•Regular environmental culture could facilitate timely infection control measures.
Environmental reservoir is an important source of multidrug-resistant Acinetobacter baumannii (MRAB) outbreaks. The role of postoutbreak environmental surveillance for guiding sustained infection control effort has not been examined.
Enhanced environmental disinfection and regular environmental surveillance of ward communal areas after an outbreak were performed in a university-affiliated hospital. To assess the usefulness of environmental culture in predicting patients with MRAB, weekly surveillance of communal areas was continued for 3 months after the outbreak in intervention wards. The incidence of MRAB in intervention and nonintervention wards (control) was compared, whereas the other infection control measures remained identical.
Postoutbreak weekly surveillance of communal areas showed that identification of newly diagnosed MRAB patients was significantly correlated with preceding environmental contamination with MRAB (P = .001). The incidence of nosocomial MRAB infection was significantly lower in the intervention compared with nonintervention wards (0.55 vs 2.28 per 1,000 patient days, respectively; P = .04). All MRAB isolated from the environmental and patients' samples belonged to multilocus sequence typing ST457 and were blaOXA23-like positive.
Environmental surveillance may serve as a surrogate marker for the presence of MRAB carriers. Implementation of timely infection control measures should be guided by environmental culture for MRAB to minimize the risk of MRAB outbreak.
Background Hospital outbreaks of epidemiologically important pathogens are usually caused by lapses in infection control measures and result in increased morbidity, mortality, and cost. However, ...there is no benchmark to compare the occurrence of hospital outbreaks across hospitals. Methods We implemented proactive infection control measures with an emphasis on timely education of health care workers and hospitalized patients at Queen Mary Hospital, a teaching hospital. Our benchmarked performance (outbreak episodes per 1 million patient discharges and 1 million patient-days) was compared with those of other regional public hospitals without these additional proactive measures in place between 2010 and 2014. Results During the study period, Queen Mary Hospital had 1 hospital outbreak resulting in 1.48 and 0.45 outbreak episodes per 1 million patient discharges and patient-days, respectively, values significantly lower than the corresponding overall rates in the 7 acute regional hospitals (24.26 and 6.70 outbreak episodes per 1 million patient discharges and patient-days, respectively; P < .001) and that of all 42 public hospitals in Hong Kong (41.62 and 8.65 outbreak episodes per 1 million patient discharges and patient-days, respectively; P < .001). Conclusions The results of this large study on benchmarked rate of hospital outbreaks per patient discharges or patient-days suggests that proactive infection control interventions may minimize the risk of hospital outbreaks.
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