Hospital-acquired influenza in an Australian tertiary Centre 2017: a surveillance based study.

BACKGROUND: In 2017, Australia experienced its highest levels of influenza virus activity since the 2009 pandemic. This allowed detailed comparison of the characteristics of patients with community and hospital-acquired influenza, and infection control factors that contributed to influenza spread. METHODS: A surveillance based study was conducted on hospitalised patients with laboratory-confirmed influenza at the Canberra Hospital during April-October 2017. Differences between the hospital-acquired and community-acquired patient characteristics and outcomes were assessed by univariate analysis. Epidemiologic curves were developed and cluster distribution within the hospital was determined. RESULTS: Two hundred and ninety-two patients were included in the study. Twenty-eight (9.6%) acquired influenza in hospital, representing a higher proportion than any of the previous 5 years (range 0.9-5.8%). These patients were more likely to have influenza A (p = 0.021), had higher rates of diabetes (p = 0.015), malignancy (p = 0.046) and chronic liver disease (p = 0.043). Patients acquiring influenza in hospital met clinical criteria for influenza like illness in 25% of cases, compared with 64.4% for community-acquired cases (p < 0.001). Hospital-acquired influenza cases occurred in two distinct clusters. Patients were moved an average of 5 times after diagnosis. Mean length of stay following diagnosis was 13 days compared to 5 days for community-acquired cases (p < 0.001). Of the patients with hospital-acquired influenza, 22 were in shared rooms during their incubation period and 9 were not isolated in single rooms following diagnosis. Treatment was initiated within the recommended 48 h period following symptom onset for 62.5% of hospital-acquired cases compared with 39.8% of community-acquired cases (p = 0.033). CONCLUSIONS: Our results show that clinical presentation differed between patients with hospital-acquired influenza compared with those who acquired influenza in the community. Cases occurred in two clusters suggesting intra-hospital transmission rather than random importation from the community, highlighting the importance of infection control measures to limit influenza spread. Patients with hospital-acquired influenza may present without classical features of an influenza-like illness and this should promote earlier diagnostic testing and isolation to limit spread. Movement of patients after diagnosis is likely to facilitate spread within the hospital.

Vancomycin-resistant Enterococcus (VRE) outbreak in a neonatal intensive care unit and special care nursery at a tertiary-care hospital in Australia-A retrospective case-control study.

OBJECTIVE: We investigated the risk factors and origins of the first known occurrence of VRE colonization in the neonatal intensive care unit (NICU) at the Canberra Hospital. DESIGN: A retrospective case-control study. SETTING: A 21-bed neonatal intensive care unit (NICU) and a 15-bed special care nursey (SCN) in a tertiary-care adult and pediatric hospital in Australia. PATIENTS: All patients admitted to the NICU and SCN over the outbreak period: January-May 2017. Of these, 14 were colonized with vancomycin-resistant Enterococcus (VRE) and 77 were noncolonized. METHODS: Demographic and clinical variables of cases and controls were compared to evaluate potential risk factors for VRE colonization. Whole-genome sequencing of the VRE isolates was used to determine the origin of the outbreak strain. RESULTS: Swift implementation of wide-ranging infection control measures brought the outbreak under control. Multivariate logistic regression revealed a strong association between early gestational age and VRE colonization (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.94-7.00). Whole-genome sequencing showed the isolates to be highly clonal Enterococcus faecium ST1421 harboring a vanA gene and to be closely related to other ST1421 previously sequenced from the Canberra Hospital and the Australian Capital Territory. CONCLUSION: The colonization of NICU patients was with a highly successful clone endemic to the Canberra Hospital likely introduced into the NICU environment from other wards, with subsequent cross-contamination spreading among the neonate patients. Use of routine surveillance screening may have identified colonization at an earlier stage and have now been implemented on a 6-monthly schedule.

Chlorhexidine washing in intensive care does not reduce bloodstream infections, blood culture contamination and drug-resistant microorganism acquisition: an interrupted time series analysis.

BACKGROUND: Health care-associated infections are a major cause of morbidity and mortality in intensive care patients. The effect of daily washing with chlorhexidine on these infections is controversial. METHODS: Single-centre, retrospective, open-label, sequential period, interrupted time series (ITS) analysis in a 31-bed tertiary referral mixed intensive care unit (ICU), comparing daily washing with water and soap (from January 2011 to August 2013) with chlorhexidine washing (from November 2013 to December 2015), after the introduction of a unit-level policy of chlorhexidine washing. All patients in the ICU were included in the study, except: if they were under 18 years of age, if their ICU stay was less than 24 hours (to ensure that all studied patients had at least one exposure to the daily wash intervention), or if patients had a known allergy to chlorhexidine. Outcome measures included: clinically significant positive blood cultures attributable to the ICU stay; contaminated blood cultures; newly acquired multidrug-resistant microorganisms (MDRO) such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE) or multidrug-resistant gram-negative (MRGN) isolates attributable to ICU from clinical and screening cultures; and newly acquired Clostridium difficile infections (CDIs). Incidence rates of these outcomes were calculated per 1000 patient days. MDRO acquisition rates were corrected for background hospital period prevalence rates of MDRO. RESULTS: A total of 6634 patients were included in the study. ITS analysis showed no significant level or slope changes in any of the outcome measures after implementation of chlorhexidine washing. The incidence rate of clinically significant positive blood cultures during the chlorhexidine period compared with the water and soap period was 3.6 v 4.7 (P =0.37); blood culture contamination rates were 11.8 v 9.5 (P =0.56); incidence rates of new ICU-associated MDRO acquisitions were 3.22 v 3.69 (P =0.27); incidence rates of new CDI were 2.01 v 0.79 (P =0.16). Outcomes after adjustment for known and potential confounders were similar. CONCLUSIONS: In this real-world, long term ICU study, implementation of a unit-level policy of daily washing with chlorhexidine impregnated cloths was not associated with a reduction in the rates of ICU-associated clinically significant positive blood cultures, blood culture contamination, newly acquired MDRO isolates, and CDIs.

A point prevalence cross-sectional study of healthcare-associated urinary tract infections in six Australian hospitals.

OBJECTIVES: Urinary tract infections (UTIs) account for over 30% of healthcare-associated infections. The aim of this study was to determine healthcare-associated UTI (HAUTI) and catheter-associated UTI (CAUTI) point prevalence in six Australian hospitals to inform a national point prevalence process and compare two internationally accepted HAUTI definitions. We also described the level and comprehensiveness of clinical record documentation, microbiology laboratory and coding data at identifying HAUTIs and CAUTIs. SETTING: Data were collected from three public and three private Australian hospitals over the first 6 months of 2013. PARTICIPANTS: A total of 1109 patients were surveyed. Records of patients of all ages, hospitalised on the day of the point prevalence at the study sites, were eligible for inclusion. Outpatients, patients in adult mental health units, patients categorised as maintenance care type (ie, patients waiting to be transferred to a long-term care facility) and those in the emergency department during the duration of the survey were excluded. OUTCOME MEASURES: The primary outcome measures were the HAUTI and CAUTI point prevalence. RESULTS: Overall HAUTI and CAUTI prevalence was 1.4% (15/1109) and 0.9% (10/1109), respectively. Staphylococcus aureus and Candida species were the most common pathogens. One-quarter (26.3%) of patients had a urinary catheter and fewer than half had appropriate documentation. Eight of the 15 patients ascertained to have a HAUTI based on clinical records (6 being CAUTI) were coded by the medical records department with an International Classification of Diseases (ICD)-10 code for UTI diagnosis. The Health Protection Agency Surveillance definition had a positive predictive value of 91.67% (CI 64.61 to 98.51) compared against the Centers for Disease Control and Prevention definition. CONCLUSIONS: These study results provide a foundation for a national Australian point prevalence study and inform the development and implementation of targeted healthcare-associated infection surveillance more broadly.

Increasing incidence of Clostridium difficile infection, Australia, 2011-2012.

OBJECTIVES: To report the quarterly incidence of hospital-identified Clostridium difficile infection (HI-CDI) in Australia, and to estimate the burden ascribed to hospital-associated (HA) and community-associated (CA) infections. DESIGN, SETTING AND PATIENTS: Prospective surveillance of all cases of CDI diagnosed in hospital patients from 1 January 2011 to 31 December 2012 in 450 public hospitals in all Australian states and the Australian Capital Territory. All patients admitted to inpatient wards or units in acute public hospitals, including psychiatry, rehabilitation and aged care, were included, as well as those attending emergency departments and outpatient clinics. MAIN OUTCOME MEASURES: Incidence of HI-CDI (primary outcome); proportion and incidence of HA-CDI and CA-CDI (secondary outcomes). RESULTS: The annual incidence of HI-CDI increased from 3.25/10 000 patient-days (PD) in 2011 to 4.03/10 000 PD in 2012. Poisson regression modelling demonstrated a 29% increase (95% CI, 25% to 34%) per quarter between April and December 2011, with a peak of 4.49/10 000 PD in the October-December quarter. The incidence plateaued in January-March 2012 and then declined by 8% (95% CI, - 11% to - 5%) per quarter to 3.76/10 000 PD in July-September 2012, after which the rate rose again by 11% (95% CI, 4% to 19%) per quarter to 4.09/10 000 PD in October-December 2012. Trends were similar for HA-CDI and CA-CDI. A subgroup analysis determined that 26% of cases were CA-CDI. CONCLUSIONS: A significant increase in both HA-CDI and CA-CDI identified through hospital surveillance occurred in Australia during 2011-2012. Studies are required to further characterise the epidemiology of CDI in Australia.

Intravascular catheter bloodstream infections: an effective and sustained hospital-wide prevention program over 8 years.

OBJECTIVE: To evaluate a hospital-wide surveillance and intervention program introduced to reduce the incidence of bloodstream infections (BSIs) caused by intravascular (IV) catheters. DESIGN, SETTING AND PARTICIPANTS: Prospective surveillance of all inpatients and outpatient attendees with positive blood cultures (both hospital-onset and community-onset) at a 500-bed tertiary referral hospital from 1998 to 2005. INTERVENTIONS: Prompt review of all positive blood cultures with identification of BSIs due to IV catheters and associated preventable factors; weekly team meetings and regular reports to clinical areas, with assistance to implement targeted interventions. MAIN OUTCOME MEASURE: Number of BSI episodes due to IV catheters per year. RESULTS: There were 491 BSI episodes due to IV catheters, mainly central venous catheters. Episodes per year fell from 110 in 1998 to 48 in 2005 (from 32% of all BSI episodes to 14%; a > 50% reduction). From 1998 to 2005, the rate per 1000 discharges fell from 2.3 to 0.9 (P for trend < 0.0005) and the rate per 1000 patient-days fell from 0.6 to 0.3 (P for trend < 0.0005). CONCLUSIONS: Our program was associated with a profound drop in the number of IV catheter-related BSIs per year. Active surveillance and intervention programs can lead to substantial and sustained reductions in these common life-threatening infections.