Effectiveness of HealthTracker for post-caesarean section surgical site infection surveillance: An intervention study.

This intervention study aimed to implement and evaluate the effectiveness of HealthTracker, a post-discharge surgical site infection surveillance system. Participants were 730 women birthing by caesarean section at a large hospital over a 6-month period. Data were downloaded from clinical data systems and HealthTracker. Receiver operating characteristics were used to assess HealthTracker. Over a 6-month period, 382 women completed HealthTracker, with 83 scoring ≥6, indicating signs and symptoms of surgical site infection. Of this 83, 58 sought advice from health professionals, 29 returned to hospital, and 45 received antibiotics. A total of 20 infections from a total population of 730 were confirmed, with 14 out of 382 respondents confirmed via HealthTracker. Receiver operating characteristics identified HealthTracker as an excellent indicator of surgical site infection. HealthTracker is a feasible mHealth option for monitoring post-discharge surgical site infection post-caesarean section. In addition, by providing alerts, advising women to monitor their symptoms and seek treatment if necessary, HealthTracker has the potential to enhance self-efficacy for surgical wound monitoring at home.

The incidence of nosocomial bloodstream infection and urinary tract infection in Australian hospitals before and during the COVID-19 pandemic: an interrupted time series study.

BACKGROUND: The COVID-19 pandemic has had a significant impact on healthcare including increased awareness of infection prevention and control (IPC). The aim of this study was to explore if the heightened awareness of IPC measures implemented in response to the pandemic influenced the rates of healthcare associated infections (HAI) using positive bloodstream and urine cultures as a proxy measure. METHODS: A 3 year retrospective review of laboratory data from 5 hospitals (4 acute public, 1 private) from two states in Australia was undertaken. Monthly positive bloodstream culture data and urinary culture data were collected from January 2017 to March 2021. Occupied bed days (OBDs) were used to generate monthly HAI incidence per 10,000 OBDs. An interrupted time series analysis was undertaken to compare incidence pre and post February 2020 (the pre COVID-19 cohort and the COVID-19 cohort respectively). A HAI was assumed if positive cultures were obtained 48 h after admission and met other criteria. RESULTS: A total of 1,988 bloodstream and 7,697 urine positive cultures were identified. The unadjusted incident rate was 25.5 /10,000 OBDs in the pre-COVID-19 cohort, and 25.1/10,000 OBDs in the COVID-19 cohort. The overall rate of HAI aggregated for all sites did not differ significantly between the two periods. The two hospitals in one state which experienced an earlier and larger outbreak demonstrated a significant downward trend in the COVID-19 cohort (p = 0.011). CONCLUSION: These mixed findings reflect the uncertainty of the effect the pandemic has had on HAI's. Factors to consider in this analysis include local epidemiology, differences between public and private sector facilities, changes in patient populations and profiles between hospitals, and timing of enhanced IPC interventions. Future studies which factor in these differences may provide further insight on the effect of COVID-19 on HAIs.

Time to positive blood culture in early onset neonatal sepsis: A retrospective clinical study and review of the literature.

AIM: Neonatal early onset sepsis (EOS) is a low-incidence, high-risk disease which has prompted significant overtreatment with antibiotics for the standard duration of 48 h. The aims of this study were to determine whether blood cultures collected from term and late preterm neonates for EOS would return a positive result for pathogenic bacteria within 24 h and to review the literature to supplement the results. METHODS: This is a retrospective observational study of time to positive blood culture in the BACTEC culture system from neonates ≥34 weeks in a single referral centre between 1999 and 2018. A literature review was conducted through PubMed, MEDLINE and Embase using search terms of 'neonatal sepsis' AND 'blood culture'. Studies were included if they reported time to positive blood culture in EOS. RESULTS: Forty positive cultures were included in this report, with 39 (98%) showing bacterial growth within 24 h. One culture, obtained after commencement of antibiotics, became positive at 3 days. Sixteen papers were included in our literature review and six presented data for an EOS cohort; a median of 96.5% of pathogenic EOS blood cultures become positive within 24 h. CONCLUSIONS: All pathogenic blood cultures collected pre-therapy from neonates ≥34 weeks suspected of EOS returned a positive result within 24 h of incubation. Similar studies have found that 92-100% of cultures are positive by 24 h. This data could contribute to re-evaluation of the current standard duration of antibiotic use in term and late preterm neonates with suspected EOS.

Vancomycin-resistant Enterococcus faecium sequence type 796 - rapid international dissemination of a new epidemic clone.

Background: Vancomycin-resistant Enterococcus faecium (VRE) is a leading cause of hospital-acquired infections. New, presumably better-adapted strains of VRE appear unpredictably; it is uncertain how they spread despite improved infection control. We aimed to investigate the relatedness of a novel sequence type (ST) of vanB E. faecium - ST796 - very near its time of origin from hospitals in three Australian states and New Zealand. Methods: Following near-simultaneous outbreaks of ST796 in multiple institutions, we gathered then tested colonization and bloodstream infection isolates' antimicrobial resistance (AMR) phenotypes, and phylogenomic relationships using whole genome sequencing (WGS). Patient meta-data was explored to trace the spread of ST796. Results: A novel clone of vanB E. faecium (ST796) was first detected at one Australian hospital in late 2011, then in two New Zealand hospitals linked by inter-hospital transfers from separate Melbourne hospitals. ST796 also appeared in hospitals in South Australia and New South Wales and was responsible for at least one major colonization outbreak in a Neonatal Intensive Care Unit without identifiable links between centers. No exceptional AMR was detected in the isolates. While WGS analysis showed very limited diversity at the core genome, consistent with recent emergence of the clone, clustering by institution was observed. Conclusions: Evolution of new E. faecium clones, followed by recognized or unrecognized movement of colonized individuals then rapid intra-institutional cross-transmission best explain the multi-center, multistate and international outbreak we observed.

Relentless spread and adaptation of non-typeable vanA vancomycin-resistant Enterococcus faecium: a genome-wide investigation.

Background: VRE are prevalent among patients in ICUs. Non-typeable vanA VRE, due to loss of one of the genes used for MLST (pstS), have increased in Australia, suggestive of a new, hospital-acquired lineage. Objectives: To understand the significance of this lineage and its transmission using WGS of strains isolated from patients in ICUs across New South Wales, Australia. Methods: A total of 240 Enterococcus faecium isolates collected between February and May 2016, and identified by conventional PCR as vanA positive, were sequenced. Isolates originated from 12 ICUs in New South Wales, grouped according to six local health districts, and represented both rectal screening swab (n = 229) and clinical (n = 11) isolates. Results: ST analysis revealed the absence of the pstS gene in 84.2% (202 of 240) of vanA isolates. Two different non-typeable STs were present based on different allelic backbone patterns. Loss of the pstS gene appeared to be the result of multiple recombination events across this region. Evidence for pstS-negative lineage spread across all six local health districts was observed suggestive of inter-hospital transmission. In addition, multiple outbreaks were detected, some of which were protracted and lasted for the duration of the study. Conclusions: These findings confirmed the evolution, emergence and dissemination of non-typeable vanA E. faecium. This study has highlighted the utility of WGS when attempting to describe accurately the hospital-based pathogen epidemiology, which in turn will continue to inform optimal infection control measures necessary to halt the spread of this important nosocomial organism.

Is gentamicin safe and effective for severe community-acquired pneumonia? An 8-year retrospective cohort study.

Gram-negative bacilli are the causative organisms in a significant proportion of patients with severe community-acquired pneumonia (CAP) admitted to the intensive care unit (ICU). Clinical guidelines recommend broad-spectrum antimicrobials for empirical treatment despite alarming global trends in antimicrobial resistance. In this study, we aimed to assess the safety and efficacy of gentamicin, an aminoglycoside with potent bactericidal activity, for empirical Gram-negative coverage of severe CAP in patients admitted to the ICU. A retrospective cohort study was performed at a university teaching hospital where the severe CAP guideline recommends penicillin, azithromycin and gentamicin as empirical cover. Ceftriaxone plus azithromycin is used as an alternative. Adults with radiologically-confirmed severe CAP were included, comparing those who received gentamicin in the first 72 h of admission with those who did not. Participants were identified using ICD-10 codes for bacterial pneumonia and data manually extracted from electronic medical records. Of 148 patients admitted with severe pneumonia, 117 were given at least one dose of gentamicin whereas the remaining 31 were not. The two groups were well matched in terms of demographics, co-morbidities and disease severity. There were no significant differences between the gentamicin and no-gentamicin groups in the incidence of acute kidney injury [60/117 (51%) vs. 16/31 (52%), respectively], hospital mortality [20/117 (17%) vs. 7/31 (23%)] and secondary outcomes including relapse and length of hospital stay. In conclusion, gentamicin is safe and has similar outcomes to alternative Gram-negative antimicrobial regimens for empirical coverage in severe CAP patients admitted to the ICU.

The increasing importance of community-acquired methicillin-resistant Staphylococcus aureus infections.

OBJECTIVES: To identify groups at risk of methicillin-resistant Staphylococcus aureus (MRSA) infection, patterns of antimicrobial resistance, and the proportion of patients with MRSA infections but no history of recent hospitalisation. DESIGN, SETTING AND PARTICIPANTS: Case series of 39 231 patients with S. aureus isolates from specimens processed by the Hunter New England Local Health District (HNELHD) public pathology provider during 2008-2014. MAIN OUTCOME MEASURES: Proportion of MRSA infections among people with S. aureus isolates; antimicrobial susceptibility of MRSA isolates; origin of MRSA infections (community- or health care-associated); demographic factors associated with community-associated MRSA infections. RESULTS: There were 71 736 S. aureus-positive specimens during the study period and MRSA was isolated from 19.3% of first positive specimens. Most patients (56.9%) from whom MRSA was isolated had not been admitted to a public hospital in the past year. Multiple regression identified that patients with community-associated MRSA were more likely to be younger (under 40), Indigenous Australians (odds ratio [OR], 2.6; 95% CI, 2.3-2.8), or a resident of an aged care facility (OR, 4.7; 95% CI, 3.8-5.8). The proportion of MRSA isolates that included the dominant multi-resistant strain (AUS-2/3-like) declined from 29.6% to 3.4% during the study period (P < 0.001), as did the rates of hospital origin MRSA in two of the major hospitals in the region. CONCLUSIONS: The prevalence of MRSA in the HNELHD region decreased during the study period, and was predominantly acquired in the community, particularly by young people, Indigenous Australians, and residents of aged care facilities. While the dominance of the multi-resistant strain decreased, new strategies for controlling infections in the community are needed to reduce the prevalence of non-multi-resistant strains.

Risk factors for relapse or persistence of bacteraemia caused by Enterobacter spp.: a case-control study.

BACKGROUND: Enterobacter spp. possess chromosomal AmpC beta-lactamases that may be expressed at high levels. Previous studies have demonstrated a risk of relapsed bacteraemia following therapy with third generation cephalosporins (3GCs). What additional factors predict microbiological failure in Enterobacter bacteraemia is unclear. We aimed to determine factors associated with microbiological failure in Enterobacter bacteraemia. METHODS: We retrospectively identified cases of bacteraemia caused by Enterobacter spp. occurring in four hospitals. Using a case-control design, we determined clinical risk factors for persistence or relapse defined as repeated positive blood cultures collected between 72 hours and up to 28 days post initial positive blood culture. RESULTS: During the study period a total of 922 bacteraemia events caused by Enterobacter spp. in adults were identified. The overall risk of relapsed or persisting bacteraemia at 28 days was low (31 of 922, 3.4%), with only 2 patients experiencing emergent resistance to 3GCs. A total of 159 patients were included in the case-control study. Using multivariate logistic regression, independent predictors for relapse were a line-associated source of infection (OR 3.87; 95% CI 1.56-9.60, p = 0.004) and the presence of immunosuppression (OR 2.70; 95% CI 1.14-6.44, p = 0.02). On univariate analysis definitive therapy with a broad-spectrum beta-lactam-beta-lactamase inhibitor (BLBLI, e.g. piperacillin-tazobactam) was not associated with relapse (OR 1.83; 95% CI 0.64-5.21, p = 0.26) although the proportion of patients receiving a BLBLI as definitive therapy was relatively small (21/159, 13.2%). CONCLUSIONS: The risk of relapsed or persistent Enterobacter bacteraemia appears to be low in Australia. A line-associated source of infection and immunocompromise were significant independent predictors for relapse. Larger, preferably randomized, studies are needed to address whether BLBLIs represent an effective carbapenem-sparing option for Enterobacter bacteraemia.

Emergence of endemic MLST non-typeable vancomycin-resistant Enterococcus faecium.

BACKGROUND: Enterococcus faecium is a major nosocomial pathogen causing significant morbidity and mortality worldwide. Assessment of E. faecium using MLST to understand the spread of this organism is an important component of hospital infection control measures. Recent studies, however, suggest that MLST might be inadequate for E. faecium surveillance. OBJECTIVES: To use WGS to characterize recently identified vancomycin-resistant E. faecium (VREfm) isolates non-typeable by MLST that appear to be causing a multi-jurisdictional outbreak in Australia. METHODS: Illumina NextSeq and Pacific Biosciences SMRT sequencing platforms were used to determine the genome sequences of 66 non-typeable E. faecium (NTEfm) isolates. Phylogenetic and bioinformatics analyses were subsequently performed using a number of in silico tools. RESULTS: Sixty-six E. faecium isolates were identified by WGS from multiple health jurisdictions in Australia that could not be typed by MLST due to a missing pstS allele. SMRT sequencing and complete genome assembly revealed a large chromosomal rearrangement in representative strain DMG1500801, which likely facilitated the deletion of the pstS region. Phylogenomic analysis of this population suggests that deletion of pstS within E. faecium has arisen independently on at least three occasions. Importantly, the majority of these isolates displayed a vancomycin-resistant genotype. CONCLUSIONS: We have identified NTEfm isolates that appear to be causing a multi-jurisdictional outbreak in Australia. Identification of these isolates has important implications for MLST-based typing activities designed to monitor the spread of VREfm and provides further evidence supporting the use of WGS for hospital surveillance of E. faecium.

Laboratory-based surveillance of Clostridium difficile circulating in Australia, September - November 2010.

Clostridium difficile rose in prominence in the early 2000s with large-scale outbreaks of a particular binary toxin-positive strain, ribotype 027, in North America and Europe. In Australia outbreaks of the same scale had not and have not been seen. A survey of C. difficile across Australia was performed for 1 month in 2010. A collection of 330 C. difficile isolates from all States and Territories except Victoria and the Northern Territory was amassed. PCR ribotyping revealed a diverse array of strains. Ribotypes 014/020 (30.0%) and 002 (11.8%) were most common, followed by 054 (4.2%), 056 (3.9%), 070 (3.6%) and 005 (3.3%). The collection also contained few binary toxin positive strains, namely 027 (0.9%), 078 (0.3%), 244 (0.3%), 251 (0.3%) and 127 (0.3%). The survey highlights the need for vigilance for emerging strains in Australia, and gives an overview of the molecular epidemiology of C. difficile in Australia prior to an increase in incidence noted from mid-2011.

Prevalence of patients with acute febrile illnesses and positive dengue NS1 tests in a tertiary hospital in Papua New Guinea.

Because the prevalence of dengue fever in urban settings in Papua New Guinea is unknown, we investigated the presence of dengue using the NS1 antigen test in an outpatient-based prospective observational study at Port Moresby General Hospital. Of 140 patients with acute febrile illnesses, dengue fever was diagnosed in 14.9% (20 of 134; 95% confidence interval [95% CI] = 9.6-22.4). Malaria (2 of 137; 1.5%; 95% CI = 0.3-5.7), chikungunya (3 of 140; 2.1%; 95% CI = 0.6-6.6), and bacterial bloodstream infections (0 of 80; 0%; 95% CI = 0-5.7) were uncommon. Dengue fever should no longer be considered rare in Papua New Guinea.

Clostridium difficile laboratory testing in Australia and New Zealand: national survey results and Australasian Society for Infectious Diseases recommendations for best practice.

AIMS: In order to improve the future reliability of surveillance for Clostridium difficile infection (CDI), an Australia/New Zealand-wide survey was conducted to examine methods of laboratory diagnosis in use, identify deficiencies in practice and burden of CDI. METHODS: An online survey of 48 Australian and New Zealand microbiology laboratories (private and public) was conducted in late 2009 and 2010 to collect information about methods of detection in use and collective testing experience from July 2008 to June 2009. RESULTS: The overall prevalence (proportion positive of all faecal specimens tested) of C. difficile in 123,574 tested samples was 5.3%. The incidence rate across jurisdictions varied between 18.0 per 100,000 population in Victoria to 35.8 per 100,000 population in Tasmania, with a mean for Australia of 25.6 per 100,000 population. The incidence rate in New Zealand was 21.5 per 100,000 population. Most laboratories (60%) screened stools with an enzyme immunoassay (EIA) or equivalent that detected both toxins A and B. CONCLUSIONS: The low overall rates reported here may reflect the lack of sensitivity of diagnostic testing procedures currently used in Australia and New Zealand to detect C. difficile. Recommendations for best practice in diagnosis of C. difficile were developed by the Australasian Society for Infectious Diseases (ASID) C. difficile working party and later endorsed by ASID.

Australasian Society for Infectious Diseases guidelines for the diagnosis and treatment of Clostridium difficile infection.

Clostridium difficile is the most common cause of health care-associated and antibiotic-associated diarrhoea. These guidelines are intended to provide advice to clinicians on the clinical assessment, diagnosis and management of C. difficile infection (CDI). Hypervirulent strains of C. difficile, including PCR ribotype 027 strains recently identified in Australia, have been associated elsewhere with epidemic spread and high rates of severe disease and death. Diagnostic tests include stool culture, polymerase chain reaction-based assays, cell-culture cytotoxicity assays and enzyme immunoassays detecting C. difficile glutamate dehydrogenase, and/or toxin A and/or B. To treat an initial episode and a first recurrence, metronidazole is the preferred antibiotic, with oral vancomycin reserved for severe disease and subsequent recurrences. Surgery should be considered for fulminant disease.

ASID (HICSIG) position statement: infection control guidelines for patients with influenza-like illnesses, including pandemic (H1N1) influenza 2009, in Australian health care facilities.

Standard and Droplet Precautions are considered adequate to control the transmission of influenza in most health care situations. Vaccination of health care staff, carers and vulnerable patients against seasonal and, eventually, pandemic influenza strains is an essential protective strategy. Management principles include: performance of hand hygiene before and after every patient contact or contact with the patient environment, in accord with the national 5 Moments for Hand Hygiene Standard; disinfection of the patient environment; early identification and isolation of patients with suspected or proven influenza; adoption of a greater minimum distance of patient separation (2 metres) than previously recommended; use of a surgical mask and eye protection for personal protection on entry to infectious areas or within 2 metres of an infectious patient; contact tracing for patient and health care staff and restriction of prophylactic antivirals mainly to those at high risk of severe disease; in high aerosol-risk settings, use of particulate mask, eye protection, impervious long-sleeved gown, and gloves donned in that sequence and removed in reverse sequence, avoiding self-contamination; exclusion of symptomatic staff from the workplace until criteria for non-infectious status are met; reserving negative-pressure ventilation rooms (if available) for intensive care patients, especially those receiving non-invasive ventilation; ensuring that infectious postpartum women wear surgical masks when caring for their newborn infants and practise strict hand hygiene; and implementation of special arrangements for potentially infected newborns who require nursery or intensive care.

Cure of multiresistant Acinetobacter baumannii central nervous system infections with intraventricular or intrathecal colistin: case series and literature review.

OBJECTIVES: CNS infections due to multiresistant Acinetobacter baumannii (MRAB) are an emerging problem in neurosurgical patients. Colistin remains one of the few remaining treatment options for MRAB but has poor CNS penetration. We describe our experience with intraventricular or intrathecal colistin for this infection. METHODS: Cases known to have received intraventricular or intrathecal colistin for CNS infections due to MRAB were retrospectively reviewed regarding colistin treatment, colistin efficacy and adverse events. RESULTS: Five patients were identified. All were admissions to the neurosurgical ICU and all were cured of their CNS infections. Three cases were complicated by drug-induced aseptic meningitis or ventriculitis. CONCLUSIONS: This largest case series to date shows that direct instillation of colistin into the CNS may cause chemical meningitis or ventriculitis but it is an effective treatment option for MRAB CNS infection. Further study of dosing regimens is needed.