Children's scabies survey indicates high prevalence and misdiagnosis in Auckland educational institutions

AIM

Here, we present results of a survey of scabies prevalence in childcare centres and primary schools in Auckland.

METHODS

Children whose parents agreed to take part in participating centres in the Auckland region were examined for scabies by general practitioners and given questionnaires of relevant symptoms. Diagnoses of clinical or suspected scabies were made according to the International Alliance for the Control of Scabies (IACS) criteria. The survey was a stratified random sample of schools and early childcare centres. A quantitative polymerase chain reaction (PCR) test was also used to complement the IACS criteria.

RESULTS

A total of 181 children were examined, with 145 children with history information, 16 of whom (11.0%) met the criteria for 'clinical' or 'suspected' scabies. Weighted analysis, accounting for the survey design, indicated that the prevalence of scabies in early childcare centres was 13.2% (95% CI: 4.3 to 22.1), with no school-aged children fulfilling these criteria. A higher proportion had clinical signs of scabies with 23 (12.7%) having typical scabies lesions and a further 43 (23.8%) had atypical lesions. A total of 64 PCR tests were taken and 15 (23%) were positive. None of these cases were receiving treatment for scabies. Five were undergoing topical skin treatment: three with topical steroid and two with calamine lotion.

CONCLUSIONS

The prevalence of children with scabies is high in early childcare centres in Auckland. Misdiagnosis is suggested by several PCR positive cases being treated by topical agents used to treat other skin conditions.

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017-2020

Background

New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice.

Methods

The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM).

Findings

Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028).

Interpretation

IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes.

Funding

This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.

Planning and executing a national point prevalence study: a blueprint for the future

Healthcare-associated infections (HAIs) are a significant risk for patients and a burden on the health system. In 2021, the Te Tāhū Hauora Health Quality & Safety Commission New Zealand Infection Prevention and Control Team undertook a national HAI point prevalence survey (PPS) across all 20 district health boards (DHBs). We describe the process that was undertaken to plan for and execute the PPS. The key stages of this project were planning, communication and engagement, piloting and then refining the process, training surveyors, delivering the full PPS, and finally, data analysis and reporting. Support for the PPS was received at a national level from clinical and non-clinical management. The sharing of this information may support other health provider groups to use similar methodology to better understand the epidemiology of both infectious and non-infectious diseases locally. It provides a useful planning strategy for those considering similar surveys.

Current Epidemiology and Clinical Features of Cryptococcus Infection in Patients Without Human Immunodeficiency Virus: A Multicenter Study in 46 Hospitals in Australia and New Zealand

BACKGROUND

Patients without human immunodeficiency virus (HIV) are increasingly recognized as being at risk for cryptococcosis. Knowledge of characteristics of cryptococcosis in these patients remains incomplete.

METHODS

We conducted a retrospective study of cryptococcosis in 46 Australian and New Zealand hospitals to compare its frequency in patients with and without HIV and describe its characteristics in patients without HIV. Patients with cryptococcosis between January 2015 and December 2019 were included.

RESULTS

Of 475 patients with cryptococcosis, 90% were without HIV (426 of 475) with marked predominance in both Cryptococcus neoformans (88.7%) and Cryptococcus gattii cases (94.3%). Most patients without HIV (60.8%) had a known immunocompromising condition: cancer (n = 91), organ transplantation (n = 81), or other immunocompromising condition (n = 97). Cryptococcosis presented as incidental imaging findings in 16.4% of patients (70 of 426). The serum cryptococcal antigen test was positive in 85.1% of tested patients (319 of 375); high titers independently predicted risk of central nervous system involvement. Lumbar puncture was performed in 167 patients to screen for asymptomatic meningitis, with a positivity rate of 13.2% where meningitis could have been predicted by a high serum cryptococcal antigen titer and/or fungemia in 95% of evaluable cases. One-year all-cause mortality was 20.9% in patients without HIV and 21.7% in patients with HIV (P = .89).

CONCLUSIONS

Ninety percent of cryptococcosis cases occurred in patients without HIV (89% and 94% for C. neoformans and C. gattii, respectively). Emerging patient risk groups were evident. A high level of awareness is warranted to diagnose cryptococcosis in patients without HIV.

Blood culture quality assurance: findings from a RCPAQAP Key Incident Monitoring and Management Systems (KIMMS) audit of blood culture performance

Blood cultures (BC) are the gold standard investigation for bloodstream infection. Standards exist for BC quality assurance, but key quality indicators are seldom measured. The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) Key Incident Monitoring and Management Systems (KIMMS) invited laboratories for the first time to participate in an audit to determine adult BC positivity rates, contamination rates, sample fill volumes and the proportion received as a single set. The overall aim of the KIMMS audit was to provide laboratories with a mechanism for peer review and benchmarking. Results from 45 laboratories were analysed. The majority of laboratories (n=28, 62%) reported a positivity rate outside the recommended range of 8-15%. Contamination rates ranged from zero (n=5) to 12.5%, with seven laboratories (15%) reporting a contamination rate greater than the recommended 3%. Fifteen laboratories (33%) reported an average fill volume of less than the recommended 8-10 mL per bottle, with 11 laboratories (24%) reporting fill volumes of 5 mL or less whilst 13 (28%) laboratories were not able to provide any fill volume data. Thirteen laboratories (29%) reported that 50% or more of BC were received as single set, and eight (17%) were not able to report this data. This audit highlights there are deficiencies in BC quality measures across laboratories. To support BC quality improvement efforts, RCPAQAP KIMMS will offer a yearly BC quality assurance audit to encourage laboratories to monitor their BC quality performance.

Species distribution and susceptibility of Nocardia isolates in New Zealand 2002-2021

The aim was to record the distribution and susceptibility of Nocardia species in New Zealand. Local and referred isolates were identified by an evolving approach over the study period including conventional phenotypic methods, susceptibility profiles, matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF) and molecular sequencing. Isolates previously identified as a Nocardia sp. or part of the N. asteroides complex were reidentified by MALDI-TOF and/or molecular methods. Antimicrobial susceptibility to eight antibiotics was performed by standard microbroth dilution. The site of isolation, susceptibility profiles and species distribution were analysed. A total of 383 isolates were tested: N. brasiliensis 23 (6%), N. cyriacigeorgica 42 (11%), N. farcinica 41 (11%), N. nova complex 226 (59%), and 51 (13%) other species/complexes. The respiratory tract was the most common site of infection (244, 64%), with skin and soft tissue the second most common site (104, 27%). All 23 N. brasiliensis isolates were from skin and soft tissue specimens. Almost all isolates (≥98%) were susceptible to amikacin, linezolid and trimethoprim-sulfamethoxazole; 35% and 77% were resistant to clarithromycin and quinolones, respectively. The expected susceptibility profiles of the four common species and complex were observed for most agent-organism parings. Multi-drug resistance was uncommon (3.4%). The spectrum of Nocardia species in New Zealand is similar to overseas reports and our most common group is the N. nova complex. While amikacin, linezolid and trimethoprim-sulfamethoxazole remain good empiric treatment choices, other agents should have their activity confirmed before use.

Mental Disorders and Oral Diseases: Future Research Directions

The poor physical health (including oral health) of people with mental disorders is a global problem. The burden of oral diseases among this group is substantial given their high prevalence and ability to increase the personal, social, and economic impacts of mental disorders. This article summarizes causes of mental disorders and oral diseases, critically reviews current evidence on interventions to reduce the burden of oral diseases in people with mental disorders, and suggests future research directions. The relationship between mental disorders and oral diseases is complex due to the shared social determinants and bidirectional interaction mechanisms that involve interconnected social, psychological, behavioral, and biological processes. Research has, to date, failed to produce effective and scalable interventions to tackle the burden of oral diseases among people with mental disorders. Transformative research and actions informed by a dynamic involvement of biological, behavioral, and social sciences are needed to understand and tackle the complex relationship between mental disorders and oral diseases, as well as inform the design of complex interventions. Examples of future research on complex public health, health service, and social care interventions are provided. The design and testing of these interventions should be carried out in real-world settings, underpinned by the principles of coproduction and systems thinking, and conducted by a transdisciplinary team. We propose this starts with setting research priorities and developing complex intervention theory, which we report to support future research to improve oral health and hence physical and mental health in this disadvantaged group.

Surgical Helmet Systems Are Associated With a Lower Rate of Prosthetic Joint Infection After Total Knee Arthroplasty: Combined Results From the New Zealand Joint Registry and Surgical Site Infection Improvement Programme

BACKGROUND

This study aimed to identify the risk factors, in particular the use of surgical helmet systems (SHSs), for prosthetic joint infection (PJI) after total knee arthroplasty (TKA). Data recorded by the New Zealand Surgical Site Infection Improvement Programme (SSIIP) and the New Zealand Joint Registry (NZJR) were combined and analyzed.

METHODS

Primary TKA procedures performed between July 2013 and June 2018 that were recorded by both the SSIIP and NZJR were analyzed. Two primary outcomes were measured: (1) PJI within 90 days as recorded by the SSIIP and (2) revision TKA for deep infection within 6 months as recorded by the NZJR. Univariate and multivariate analyses were performed to identify risk factors for both outcomes with results considered significant at P < .05.

RESULTS

A total of 19,322 primary TKAs were recorded by both databases in which 97 patients had a PJI within 90 days as recorded by the SSIIP (0.50%), and 90 patients had a revision TKA for deep infection within 6 months (0.47%) as recorded by the NZJR. An SHS was associated with a lower rate of PJI (adjusted odds ratio [OR] = 0.50, P = .008) and revision for deep infection (adjusted OR = 0.55, P = .022) than conventional gowning. Male sex (adjusted OR = 2.6, P < .001) and an American Society of Anesthesiologists score >2 were patient risk factors for infection (OR = 2.63, P < .001 for PJI and OR = 1.75, P = .017 for revision for deep infection).

CONCLUSION

Using contemporary data from the SSIIP and NZJR, the use of the SHS was associated with a lower rate of PJI after primary TKA than conventional surgical gowning. Male sex and a higher American Society of Anesthesiologists score continue to be risk factors for infection.

Risk factors differ for Gram-negative surgical site infection following hip and knee arthroplasty: an observational study from a national surveillance system

AIM

To describe risk factors for surgical site infection (SSI) caused by aerobic Gram-negative organisms after hip and knee arthroplasty.

METHOD

Publicly funded hip and knee arthroplasties (performed between 1 July 2013 and 31 December 2017) that developed SSIs were compared to those that did not. SSIs were grouped by causative organism: Gram-negative (Pseudomonas spp. or enteric Gram-negative bacilli) or staphylococcal (pure or mixed growth of Staphylococcus spp.). Independent risk factors in each group were identified.

RESULTS

24,842 (54%) hip and 20,993 (46%) knee arthroplasties were performed. There were 497 (1.1%) SSIs. Staphylococci were responsible for 233 SSIs (47%) and Gram-negatives were responsible for 73 (15%). Age, sex, body mass index ≥35kg/m2, smoking status, socioeconomic deprivation, American Society of Anesthesiologists classification, revision surgery and prophylactic antibiotic dose were all independent predictors of all-cause SSI. On subgroup analysis, socioeconomic deprivation and Pasifika ethnicity were independent risk factors for Gram-negative SSI, but not staphylococcal SSI.

DISCUSSION

In this study, socioeconomic deprivation and ethnicity were independent and novel risk factors for Gram-negative SSI following arthroplasty. Some of the SSI risk factors can be modified before arthroplasty (e.g., appropriate timing of prophylactic antibiotics, smoking cessation, weight loss). Non-modifiable risk factors can help identify high-risk procedures where additional pre- and post-operative interventions may be warranted.

A national audit of performance standards for blood cultures in Aotearoa New Zealand: opportunities for improvement

AIMS

To audit key quality indicators for blood culture (BC) practices across Aotearoa New Zealand to facilitate national BC practice peer review and promote BC quality improvement interventions.

METHOD

Microbiology laboratories providing diagnostic services to district health board (DHB) hospitals were invited to participate. Practice was compared against published BC recommendations. Laboratories were required to submit data for BC positivity and contamination rates, BC bottle fill volume and the proportion of BC received as a single set.

RESULTS

Laboratories serving 15 of the 20 DHBs participated in the audit. Nine DHBs (60%) demonstrated a positivity rate within the target range of 8% to 15%. Eight DHBs (53%) reported a contamination rate lower than the accepted 3%, but seven (47%) DHBs exceeded this target and two reported a contamination rate greater than 5%. Mean BC bottle fill volumes were generally greater than the target of 8mL, but this volume was not reached by three DHBs and a further three were unable to provide fill volume data. No DHB met the audit standard for single-set BCs representing <20%, and for six DHBs single-set BC comprised more than half of all samples. No DHB failed all audit targets.

CONCLUSION

This audit demonstrates wide variation in BC performance across New Zealand. In most instances an inadequate volume of blood is being collected, lowering the chance of culturing a pathogen. A significant opportunity for improvement exists; clinical services and laboratories are encouraged to work together to implement targeted quality improvement processes to correct deficiencies in practice.

Validation of a molecular assay to detect SARS-CoV-2 in saliva

AIM

To validate a reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) assay to detect SARS-CoV-2 in saliva in two independent Aotearoa New Zealand laboratories.

METHODS

An RT-qPCR assay developed at University of Illinois Urbana-Champaign, USA, was validated in two New Zealand laboratories. Analytical measures, such as limit of detection (LOD) and cross-reactivity, were performed. One hundred and forty-seven saliva samples, each paired with a contemporaneously collected nasal swab, mainly of nasopharyngeal origin, were received. Positive (N=33) and negative (N=114) samples were tested blindly in each laboratory. Diagnostic sensitivity and specificity were then calculated.

RESULTS

The LOD was <0.75 copy per µL and no cross-reactivity with MERS-CoV was detected. There was complete concordance between laboratories for all saliva samples with the quantification cycle values for all three genes in close agreement. Saliva had 98.7% concordance with paired nasal samples: and a sensitivity, specificity and accuracy of 97.0%, 99.1% and 99.1%, respectively.

CONCLUSION

This saliva RT-qPCR assay produces reproducible results with a low LOD. High sensitivity and specificity make it a reliable option for SARS-CoV-2 testing, including for asymptomatic people requiring regular screening.

The emergence of azole resistance in Aspergillus fumigatus complex in New Zealand

BACKGROUND

Azole resistance in Aspergillus fumigatus (A. fumigatus) is increasing globally. A pan-azole-resistant isolate prompted genetic analysis of local azole-resistant isolates to determine resistance genotypes.

METHODS

All A. fumigatus complex isolates were tested by the broth colorimetric micro-dilution method, Sensititre® YeastOne® (SYO) (TREK Diagnostic Systems, West Sussex, England). Epidemiological cutoff values derived from the Clinical & Laboratory Standards Institute method were used to determine the proportion of non-wild-type (non-WT) isolates (ie, those with an increased likelihood to harbour acquired mechanisms of resistance). Non-WT isolates were identified by ß-tubulin gene sequencing and the genotype for azole resistance was determined. The history of the patient with the first pan-resistant isolate was reviewed along with the treatment history of patients with azole-resistant strains.

RESULTS

From January 2001 to August 2020, antifungal susceptibility testing was performed on 260 A. fumigatus complex isolates: six isolates were non-WT for one or more azole agent, two A. fumigatus sensu stricto and four other members within the species complex: two A. fischeri and two A. lentulus. There were three non-WT isolates for amphotericin B, three for itraconazole, five for posaconazole and five for voriconazole. All six non-WT strains were isolated in the past nine years (P<0.01), and four in the past three years. Azole-resistance genotyping for the A. fumigatus sensu stricto isolates detected amino acid changes at hot spots in the cyp51A gene: one at G54E and one at G138C. All six isolates were WT for caspofungin. Five of the six patients with azole-resistant strains had previous azole treatment, and the patient with the pan-azole-resistant strain had been on continuous azole treatment for 42 months preceding strain isolation.

CONCLUSIONS

New Zealand can be added to the growing list of countries with azole-resistant A. fumigatus complex isolates, including pan-azole resistance in A. fumigatus sensu stricto. While uncommon and mostly found in cryptic species within the complex, azole resistance is increasing. The results provide a baseline for monitoring this emerging antifungal resistance trend in A. fumigatus in New Zealand.

Invasive infections with Purpureocillium lilacinum: clinical characteristics and outcome of 101 cases from FungiScope® and the literature

OBJECTIVES

To provide a basis for clinical management decisions in Purpureocillium lilacinum infection.

METHODS

Unpublished cases of invasive P. lilacinum infection from the FungiScope® registry and all cases reported in the literature were analysed.

RESULTS

We identified 101 cases with invasive P. lilacinum infection. Main predisposing factors were haematological and oncological diseases in 31 cases (30.7%), steroid treatment in 27 cases (26.7%), solid organ transplant in 26 cases (25.7%), and diabetes mellitus in 19 cases (18.8%). The most prevalent infection sites were skin (n = 37/101, 36.6%) and lungs (n = 26/101, 25.7%). Dissemination occurred in 22 cases (21.8%). Pain and fever were the most frequent symptoms (n = 40/101, 39.6% and n = 34/101, 33.7%, respectively). Diagnosis was established by culture in 98 cases (97.0%). P. lilacinum caused breakthrough infection in 10 patients (9.9%). Clinical isolates were frequently resistant to amphotericin B, whereas posaconazole and voriconazole showed good in vitro activity. Susceptibility to echinocandins varied considerably. Systemic antifungal treatment was administered in 90 patients (89.1%). Frequently employed antifungals were voriconazole in 51 (56.7%) and itraconazole in 26 patients (28.9%). Amphotericin B treatment was significantly associated with high mortality rates (n = 13/33, 39.4%, P = <0.001). Overall mortality was 21.8% (n = 22/101) and death was attributed to P. lilacinum infection in 45.5% (n = 10/22).

CONCLUSIONS

P. lilacinum mainly presents as soft-tissue, pulmonary or disseminated infection in immunocompromised patients. Owing to intrinsic resistance, accurate species identification and susceptibility testing are vital. Outcome is better in patients treated with triazoles compared with amphotericin B formulations.

Estimating the effect of selective border relaxation on COVID-19 in New Zealand

AIMS

We developed a model, updated daily, to estimate undetected COVID-19 infections exiting quarantine following selectively opening New Zealand's borders to travellers from low-risk countries.

METHODS

The prevalence of infectious COVID-19 cases by country was multiplied by expected monthly passenger volumes to predict the rate of arrivals. The rate of undetected infections entering the border following screening and quarantine was estimated. Level 1, Level 2 and Level 3 countries were defined as those with an active COVID-19 prevalence of up to 1/105, 10/105 and 100/105, respectively.

RESULTS

With 65,272 travellers per month, the number of undetected COVID-19 infections exiting quarantine is 1 every 45, 15 and 31 months for Level 1, Level 2 and Level 3 countries, respectively. The overall rate of undetected active COVID-19 infections exiting quarantine is expected to increase from the current 0.40 to 0.50 per month, or an increase of one extra infection every 10 months.

CONCLUSIONS

Loosening border restrictions results in a small increase in the rate of undetected COVID-19 infections exiting quarantine, which increases from the current baseline by one infection every 10 months. This information may be useful in guiding decision-making on selectively opening of borders in the COVID-19 era.

Antifungal susceptibility of clinical mould isolates in New Zealand, 2001-2019

The objective of this study was to review the antifungal susceptibility of clinical mould isolates performed by the New Zealand Mycology Reference Laboratory. Isolates were either local or referred for testing from other New Zealand laboratories. All isolates were tested by the broth colorimetric microdilution method, Sensititre YeastOne (SYO). Epidemiological cut-off values (ECVs) derived from either the Clinical and Laboratory Standards Institute (CLSI) method or SYO were used to determine the proportion of non-wild type (non-WT) isolates, i.e., those with an increased likelihood to harbour acquired mechanisms of resistance. A total of 614 isolates were tested. Most isolates (55%) were from the respiratory tract followed by musculoskeletal tissue (17%), eye (10%) and abdomen (5%). The azoles had similar activity except for voriconazole which was less active against the Mucorales. The echinocandins had good activity against Aspergillus spp., other hyaline moulds and dematiaceous isolates but were inactive against Fusarium spp., Lomentospora prolificans and the Mucorales. Amphotericin B had best activity against the Mucorales. The two least susceptible groups were Fusarium spp. and L. prolificans isolates. Three Aspergillus isolates were non-WT for amphotericin B, and four non-WT for azoles. Non-WT were not encountered for caspofungin. Non-Aspergillus isolates in New Zealand have susceptibility patterns similar to those reported elsewhere. In contrast to a growing number of other countries, azole resistance was rare in A. fumigatus sensu stricto. Non-WT isolates were uncommon. The results provide a baseline for monitoring emerging antifungal resistance in New Zealand and support current Australasian treatment guidelines for invasive fungal infections.

Long-read sequencing based clinical metagenomics for the detection and confirmation of Pneumocystis jirovecii directly from clinical specimens: A paradigm shift in mycological diagnostics

The advent of next generation sequencing technologies has enabled the characterization of the genetic content of entire communities of organisms, including those in clinical specimens, without prior culturing. The MinION from Oxford Nanopore Technologies offers real-time, direct sequencing of long DNA fragments directly from clinical samples. The aim of this study was to assess the ability of unbiased, genome-wide, long-read, shotgun sequencing using MinION to identify Pneumocystis jirovecii directly from respiratory tract specimens and to characterize the associated mycobiome. Pneumocystis pneumonia (PCP) is a life-threatening fungal disease caused by P. jirovecii. Currently, the diagnosis of PCP relies on direct microscopic or real-time quantitative polymerase chain reaction (PCR) examination of respiratory tract specimens, as P. jirovecii cannot be cultured readily in vitro. P. jirovecii DNA was detected in bronchoalveolar lavage (BAL) and induced sputum (IS) samples from three patients with confirmed PCP. Other fungi present in the associated mycobiome included known human pathogens (Aspergillus, Cryptococcus, Pichia) as well as commensal species (Candida, Malassezia, Bipolaris). We have established optimized sample preparation conditions for the generation of high-quality data, curated databases, and data analysis tools, which are key to the application of long-read MinION sequencing leading to a fundamental new approach in fungal diagnostics.

Blood culture quality assurance: what Australasian laboratories are measuring and opportunities for improvement

Blood cultures are among the most important specimen types received and processed by the microbiology laboratory. Several publications list which variables should be measured to ensure quality. We undertook a qualitative structured questionnaire of Australian and New Zealand clinical microbiology laboratories to document current blood culture practices and to determine whether expected quality standards are being met. Questions included a wide range of pre-analytical, analytical, and post-analytical aspects of blood cultures from adults. The responses from 71 laboratories were analysed. Compliance was high for use of a biological safety cabinet (90%), incubating for 5 days (86%), and commenting on likely contaminants (85%). While Gram stains were reported within 2 hours during normal hours (93%), reporting was slower after hours (59%), p<0.001. The volume of blood collected for a clinical episode was poorly monitored with only 11% (n=8) of laboratories regularly auditing the number of blood culture sets and 3% (n=2) monitoring adequacy of fill. Most laboratories received blood cultures from off-site with just 34% (n=21) meeting guidance for loading bottles onto the analyser within 4 hours. More laboratories met standards for loading bottles onto the analyser during working hours than after hours: 87% vs 56%, p<0.001. Most laboratories did not monitor the contamination rate, 56% (n=40), and only 27% (n=19) knew their rate was below the guidance threshold of less than -3%. Considerable opportunities exist to improve quality assurance of blood culture practice in Australia and New Zealand, especially for the most critical aspect affecting culture sensitivity, the volume of blood collected.

Surgical site infection rate is higher following hip and knee arthroplasty when cefazolin is underdosed

PURPOSE

While many guidelines recommend higher doses of cefazolin for patients with higher body weights, there are scant outcome data showing the benefit of higher doses. Surgical site infection (SSI) rates by dose of cefazolin used for surgical prophylaxis after hip or knee arthroplasty were analyzed.

METHODS

Analysis of patient data entered into New Zealand's national, prospective, surveillance and quality improvement SSI Improvement Programme database for the period July 2013 through December 2017 was conducted. The US Centers for Disease Control and Prevention's National Healthcare Safety Network SSI definitions were used, and patients were followed for 90 days after surgery. Underdosing was defined as use of 1 g of cefazolin in patients weighing 80 kg or more or a cefazolin dose of <3 g in those weighing 120 kg or more.

RESULTS

There were 38,288 procedures where cefazolin was used for prophylaxis; patient body weight was known for all these procedures. Of the 1,840 patients who received 1 g of cefazolin, 676 (37%) weighed 80 kg or more. Of the 2,011 patients weighing 120 kg or more, 1,464 (73%) were underdosed. After multivariable analysis, male gender, higher total surgical risk scores, performance of revision and hip arthroplasties, and cefazolin underdosing were associated with higher SSI rates. For the 2,106 underdosed patients, the odds ratio for SSI was 2.19 (95% confidence interval, 1.61-2.99; P < 0.0001). The number of higher-weight patients needed to treat to prevent 1 SSI was 83, with an estimated cost of <NZ$500 to prevent 1 infection costing an estimated NZ$40,000.

CONCLUSION

Patients undergoing hip or knee arthroplasty and with weights of ≥80 kg and those with weights of ≥120 kg should receive cefazolin doses of 2 g and ≥3 g, respectively, for SSI prophylaxis. The question of whether a dose of ≥4 g is needed in patients weighing 120 kg or more or who are above a given body mass index threshold (eg, >35 kg/m2 or >40 kg/m2) remains unanswered.

Completeness and capture rate of publicly funded arthroplasty procedures in the New Zealand Joint Registry

BACKGROUND

Registry-based studies have become more common due to the availability of a large study cohort. However, the validity of findings is dependent on the completeness of the registry. This study aimed to validate the capture rate of the New Zealand Joint Registry (NZJR) by matching procedures that have been recorded separately via clinical coding by the New Zealand Government's National Surgical Site Infection Improvement Programme (SSIIP).

METHODS

The National Health Index, a unique identification code for all patients, was combined with the arthroplasty procedure performed (primary total knee arthroplasty (TKA), primary total hip arthroplasty (THA), revision TKA or revision THA) and operation side. Publicly funded procedures recorded in the NZJR were matched with procedures recorded by the SSIIP on a record-by-record basis. This identified the total number of arthroplasty procedures performed in New Zealand, which was used as the denominator value to calculate the procedure capture rate of the NZJR.

RESULTS

Between 2013 and 2018, 24 556 primary TKA, 28 970 primary THA, 2107 revision TKA and 4263 revision THA procedures were recorded by both datasets. The NZJR recorded 95.5% of primary TKA procedures, 96.3% of primary THA procedures, 97.1% of revision TKA procedures and 95.2% of revision THA procedures.

CONCLUSION

The NZJR recorded >95% of publicly funded arthroplasty procedures. In contrast, there were inaccuracies in clinical coding by hospitals, particularly with revision procedures, demonstrating the benefits of an arthroplasty registry. However, data recorded by an infection surveillance programme may supplement arthroplasty registry data to strengthen the quality of research.

The effect of inner-sphere reorganization on charge separated state lifetimes at sensitized TiO2 interfaces

Improving the efficiency of photo-electrocatalytic cells depends on controlling the rates of interfacial electron transfer to promote the formation of long-lived charge separated states. Ultimately, for efficient catalytic assemblies to see widespread implementation, repeated electron transfer in the absence of charge recombination needs to be realized. In this study, a series of manganese-based transition metal complexes known to undergo charge transfer-induced spin crossover are employed to study how significant increases in inner-sphere reorganization energy affect the rates of interfacial electron transfer. Each complex is characterized by transient spectroscopic and electrochemical methods to calculate the rate of electron transfer to a model chromophore anchored to the surface of a TiO₂ film. Likewise, open-circuit voltage decay measurements were used to determine the voltage-dependent lifetime of injected electrons in TiO₂ in the presence of each complex. To further characterize the rates of electronic recombination, density functional theory was used to calculate the inner-sphere and outer-sphere reorganization energy for each complex. These calculations were then combined with classical Marcus theory to determine the theoretical rate of back-electron transfer from the TiO₂ conduction band. These results show that, in model complexes, a significant reduction in the recombination rate constant is achieved for complexes possessing a significant inner-sphere reorganization energy.

Deprivation and child dental attendance in England: exploring the shape and moderators

OBJECTIVE

To describe the shape of the relationship between area deprivation and dental attendance (DA) in children aged 5 years and under in England and the modifying effect of caries prevalence, ethnicity, family profile and dentist-to-population ratio.

BASIC RESEARCH DESIGN

DA rates were calculated at lower-tier local authority level (LA, n=326) using NHS data for the year to March 2017. LA deprivation was determined by Index of Multiple Deprivation 2015. Caries prevalence was retrieved from the 2016/17 National Dental Epidemiology Programme; ethnicity and family profile from Census 2011 and dentist-to-population ratio from NHS statistics. Fractional polynomial (FP) models explored the shape of the relationship. Multivariable regression models were adjusted for covariates. The effect of moderators was estimated by adjusted marginal effects.

CLINICAL SETTING

English Lower-tier LAs.

MAIN OUTCOME MEASURE

Shape of the relationship between DA and deprivation and its moderators.

RESULTS

Best-fitting second-order FP model (p=0.582) did not provide a better fit for the relationship than the linear model. Therefore, the linear model was selected for final analysis. Deprivation was associated with decreased DA rates (Coefficient=-0.39, 95%CI=-0.53,-0.24; p=⟨0.001); while White ethnicity (Coefficient=0.35, 95%CI=0.29, 0.41; p=⟨0.001), single parenthood (Coefficient = 2.21, 95%CI=0.91,3.51; p=0.001) and caries prevalence (Coefficient =0.34, 95%CI=0.25,0.44; p=⟨0.001) with increased rates. These moderated the relationship.

CONCLUSIONS

We hypothesised that the shape of the relationship between deprivation and DA could be curvilinear with higher rates in the extreme ends of deprivation. However, the analysis showed a linear association, moderated by the effect of ethnicity, single parenthood and disease level.

Diagnosis, management and prevention of Candida auris in hospitals: position statement of the Australasian Society for Infectious Diseases

Candida auris is an emerging drug-resistant yeast responsible for hospital outbreaks. This statement reviews the evidence regarding diagnosis, treatment and prevention of this organism and provides consensus recommendations for clinicians and microbiologists in Australia and New Zealand. C. auris has been isolated in over 30 countries (including Australia). Bloodstream infections are the most frequently reported infections. Infections have crude mortality of 30-60%. Acquisition is generally healthcare-associated and risks include underlying chronic disease, immunocompromise and presence of indwelling medical devices. C. auris may be misidentified by conventional phenotypic methods. Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry or sequencing of the internal transcribed spacer regions and/or the D1/D2 regions of the 28S ribosomal DNA are therefore required for definitive laboratory identification. Antifungal drug resistance, particularly to fluconazole, is common, with variable resistance to amphotericin B and echinocandins. Echinocandins are currently recommended as first-line therapy for infection in adults and children ≥2 months of age. For neonates and infants <2 months of age, amphotericin B deoxycholate is recommended. Healthcare facilities with C. auris should implement a multimodal control response. Colonised or infected patients should be isolated in single rooms with Standard and Contact Precautions. Close contacts, patients transferred from facilities with endemic C. auris or admitted following stay in overseas healthcare institutions should be pre-emptively isolated and screened for colonisation. Composite swabs of the axilla and groin should be collected. Routine screening of healthcare workers and the environment is not recommended. Detergents and sporicidal disinfectants should be used for environmental decontamination.

Healthcare-associated Staphylococcus aureus bacteraemia: time to reduce the harm caused by a largely preventable event

Staphylococcus aureus disease is associated with significant morbidity and mortality and of concern, it disproportionally affects Māori and Pacific Peoples. New Zealand has high rates of skin and soft tissue infection caused by S. aureus. Healthcare-associated S. aureus bacteraemia (HA-SAB) accounts for a significant proportion of all S. aureus bacteraemia events. Measurement of HA-SAB has been reported in New Zealand for over 20 years but it has not been linked to quality improvement interventions to reduce the rate. It has been used as an outcome measure for the Hand Hygiene New Zealand programme; however, a recent review of submitted data questioned the accuracy of it. This has been addressed. National programmes such as the Health Quality & Safety Commissions Hand Hygiene New Zealand and the Surgical Site Infection Improvement programme have led to reduced harm from healthcare-associated infections. Interventions targeted at reducing the HA-SAB rate, such as bundles of care for insertion and maintenance of vascular access devices and skin and nasal decolonisation of staphylococci prior to surgery, are urgently required.

RCPAQAP audit of antimicrobial reporting in Australian and New Zealand laboratories: opportunities for laboratory contribution to antimicrobial stewardship

Objectives

A 2017 laboratory survey conducted by the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) asked participants which antimicrobials they would report for given organisms in either blood or urine cultures in order to identify opportunities for improvement of antimicrobial reporting.

Methods

Over-reporting was defined as reporting of broad-spectrum antimicrobials on isolates susceptible to narrow-spectrum antimicrobials. Inappropriate reporting was defined as reporting antimicrobials not appropriate for the site of infection.

Results

For a fully susceptible Escherichia coli in blood culture, 65% of laboratories (55/84) over-reported at least one antimicrobial. Importantly, 15% (10/65) of laboratories that tested meropenem reported the result. A significant proportion of laboratories (12%, 10/84) reported antimicrobials generally considered inappropriate for treatment of bacteraemia on blood culture isolates. Overall, 82% (77/94) of laboratories either over-reported or inappropriately reported at least one antimicrobial.

Conclusions

This survey identifies significant opportunities for improvement and standardization of 'cascade' or 'selective' reporting of antimicrobials and highlights ways in which microbiology laboratories can contribute to antimicrobial stewardship and judicious use of antimicrobials.

Persistent Socioeconomic Inequality in Child Dental Caries in England despite Equal Attendance

INTRODUCTION

Despite a decline in the prevalence of dental caries among children in England and ongoing arrangements for the provision of free dental care up to the age of 18 y, there is limited information on the pattern and trend of socioeconomic inequalities in dental caries and dental attendance.

METHODS

We estimated the magnitude of deprivation-related inequalities for dental caries and dental attendance in young children, using publicly available data and 2 regression-based summary measures of inequalities: slope index of inequality and relative index of inequality.

RESULTS

We found no significant absolute or relative inequalities in dental attendance across English areas in the past decade, while there were persistent absolute and relative inequalities in dental caries. Socioeconomic inequalities in dental caries decreased between 2007 and 2012; thereafter, the relative inequalities increased.

CONCLUSIONS

The apparent widening inequality in child dental caries in England despite equal access to dental care is a challenge for policy makers.

KNOWLEDGE TRANSFER STATEMENT

While caries prevalence among English children has declined over the past decade, there has been an increase in socioeconomic inequalities in oral health despite there being no inequality in dental attendance. This has implications for the development of oral health strategy and planning dental services.

Inequalities in orthodontic outcomes in England: treatment utilisation, subjective and normative need

OBJECTIVE

To investigate inequalities in three aspects of access to orthodontic care: uptake of orthodontic treatment, normative need and subjective need in England.

METHODS

We used data from two surveys in England: 12 and 15-year-olds from the 2013 Child Dental Health Survey (CDHS 2013) and 12-year-olds from the 2008/2009 NHS Dental Epidemiology Programme for England (NDEP 2008/2009). Summary variables representing orthodontic status were calculated. Two regression-based summary measures of inequalities were used to investigate the relationship between deprivation level and orthodontic outcomes: Slope and Relative indices of Inequality.

RESULTS

There were significant absolute and relative inequalities in uptake of orthodontic treatment. The least deprived were 1.9 times more likely to have received orthodontic treatment compared to the most deprived in both surveys. Normative need was not associated with deprivation in either the analyses of CDHS 2013 (SII= 0.03, 95% CI: -0.04, 0.1; RII=1.06, 95% CI: 0.91, 1.24) or the NDEP 2007/2008 (SII= 0.03, 95% CI: -0.02, 0.07; RII=1.06, 95% CI: 0.96, 1.18). There was greater willingness to have teeth straightened in more deprived children from CDHS 2013 (SII=-0.09, 95% CI: -0.16, -0.03; RII=0.85, 95% CI: 0.75, 0.96) but not in NDEP 2007/2008 (SII=0.03, 95% CI: 0, 0.06; RII=1.07, 95% CI: 0.99, 1.15).

CONCLUSIONS

Being deprived was associated with lower uptake of orthodontic treatment. Normative need was not related to deprivation. The association between deprivation and subjective need was only partly established, with poorer children showing a greater desire to have their teeth straightened in one survey.

Socioeconomic Variation in the association between Malocclusion and Oral Health Related Quality of Life

OBJECTIVES

Oral health related quality of life (OHRQoL) has been linked to malocclusion. We aimed (a) to investigate the association between malocclusion and OHRQoL among children, and (b) to examine whether this association varied by socioeconomic status.

METHODS

Cross-sectional analysis of data for 4,217 children aged 12 & 15 years, who participated in the 2013 Children Dental Health Survey (CDHS); a nationally representative survey of children in England, Wales, and Northern Ireland. Malocclusion was determined using the modified Index of Orthodontic Treatment Need (IOTN). OHRQoL was measured using the Child Oral Impacts on Daily Performance (Child-OIDP). For socioeconomic status, we used the pupils' eligibility for free school meals (FSM) and Index of Multiple Deprivation (IMD). Adjusted marginal effects were estimated controlling for confounding variables. Separate analyses were carried out for the two age groups.

RESULTS

Malocclusion was associated with 6% and 15% increases in the probability of reporting negative impact of OHRQoL for 12- and 15-year olds respectively, which was significant for 15-year olds (marginal effect=0.15, 95% CI=0.08-0.22). Malocclusion was associated with the prevalence of oral impacts for 12 year olds (marginal effect=0.1, 95% CI=0.02-0.17) and 15-year olds (marginal effect=0.2, 95% CI 95%=0.13-0.28) not eligible for FSM and for 15-year olds in the most (marginal effect=0.2, 95% CI=0.1-0.29) and least (marginal effect=0.26, 95% CI=0.13-0.4) deprived IMD quintiles.

CONCLUSIONS

Malocclusion was associated with impacts on OHRQoL for 15-year olds. There was evidence of a relationship between SES, malocclusion and OHRQoL.

Low rates of dental attendance by the age of one and inequality between local government administrative areas in England

OBJECTIVE

To describe child dental attendance (DA) by 1 year of age in England and its relationship with area deprivation.

BASIC RESEARCH DESIGN

Analysis of National Health Service data for the 12 months to June 2017. Deprivation was measured by Index of Multiple Deprivation Rank of Average Score (2015) for upper-tier and unitary local authorities in England (LAs, n=151). DA rates were calculated for children under 1 year (⟨1yr) and children aged 1 year and under (⟨1yr). A Spearman's test assessed strength of association with deprivation. The Slope Index of Inequality (SII) and Relative Index of Inequality (RII) explored equity.

CLINICAL SETTING

Upper-tier and unitary LAs in England.

MAIN OUTCOME MEASURE

Attending an NHS primary care dental service.

RESULTS

DA rates ranged from 0 to 12.3% (Median:2; IQR:1.4,3.9) in children ⟨1yr and from 3.7 to 37.6% (Median:10; IQR:7.4,17) in children ≤1yr. DA rates decreased as deprivation decreased (Spearman=-0.25, p=0.0019 in children ⟨1yr; Spearman=-0.21, p=0.0104 in children ≤1yr). The SII suggested a 2 percentage point difference in DA rate across the deprivation distribution in children ⟨1yr (SII=-0.02, 95% CI=-0.01,-0.04; p=⟨0.001); and a 5 point difference in children ≤1yr (SII=-0.05, 95% CI=-0.02,-0.09; p=0.003). The DA rate in the most deprived LA was 2.1 higher than the least deprived LA (RII=2.1, 95% CI=1.4,3.2; p=⟨0.001) in children ⟨1yr and 1.5 higher (RII=1.5, 95% CI=1.2,2; p=0.004) in children ≤1yr.

CONCLUSIONS

DA rates were low for all LAs and only partially explained by deprivation. More deprived LAs were, unexpectedly, more likely to report higher DA rates.

Reduction in surgical site infections in the Southern Cross Hospitals network, 2004-2015: successful outcome of a long-term surveillance and quality improvement project

AIM

To report on the reduction in the surgical site infection (SSI) rate in the Southern Cross Hospitals network over a 12-year period, 2004-2015, following active surveillance and quality improvement actions.

METHODS

Ten hospitals in the network performed prospective SSI surveillance using standard definitions across a range of ten surgical procedure groups. Data was manually collected on a standardised form and entered into a bespoke database. Information collected included timing and dose of surgical antibiotic prophylaxis, type of surgical site skin preparation used, and patient information on smoking, diabetes and body mass index (BMI). Patients were contacted 30 days after their elective surgery to detect SSIs presenting after discharge from hospital. Surveillance results were widely reported to infection control and clinical review committees. Quality improvement activities to increase use of best practice interventions for surgical antibiotic prophylaxis and alcohol-based skin preparations were initiated during the surveillance period.

RESULTS

42,792 procedures performed in ten hospitals were analysed. There were 932 (2.2%) SSIs. The SSI rate decreased from 3.5% in 2004 to 1.2% in 2015, r-0.865, p=<0.0001, a decrease of 59%, approximately 5% a year. Rates decreased in seven of the 10 hospitals, p≤0.02 for each, and in five of the ten procedure groups, p≤0.02 for each. Diabetic patients, odds ratio (OR) 1.4 (95% confidence interval (CI) 1.1-1.9), obese patients (BMI>30), OR 2.0 (95% CI 1.6-2.4), and those with a surgical risk score of ≥1 OR 1.3 (95% CI 1.1-1.6) had higher SSI rates. These three patient risk factors increased during the 12-year period. The use of alcohol-based skin preparations increased during the period from 63% to 84% in the first two and last two years respectively, p<0.0001. Use of an alcohol-based skin preparation was associated with a reduction in SSIs OR 0.54 (95% CI 0.47-0.62). On time prophylaxis improved from 72% to 95% over the 12 years, p<0.0001, and on time prophylaxis was associated with a reduction in SSIs, OR=0.62 (95% CI 0.51-0.75). The use of 2g doses of cefazolin increased significantly after 2010, p<0.0001. The most common cause of SSI was Staphylococcus aureus which was present in 54% of cases with a positive culture.

CONCLUSIONS

This long-term surveillance and quality improvement programme has made a significant contribution to the overall reduced rate of SSIs in Southern Cross Hospitals. This reduction occurred despite patient risk factors for SSI increasing. Further reduction is possible with higher adherence to best practice and interventions aimed at reducing S. aureus SSIs.

The New Zealand Surgical Site Infection Improvement (SSII) Programme: a national quality improvement programme reducing orthopaedic surgical site infections

AIMS

The New Zealand Surgical Site Infection Improvement (SSII) Programme was established in 2013 to reduce the incidence of surgical site infections (SSI) in publicly funded hip and knee arthroplasties in New Zealand hospitals.

METHODS

The programme pursued a three-pronged strategy: 1. Surveillance of SSI with a nationwide system 2. Promotion of consistent adherence to evidence-based practices proven to reduce SSI 3. Monitoring and publicly reporting changed practice and outcome data.

RESULTS

Between quarter 3 2013 and quarter 4 2016 there has been a nationwide increase in compliance with all process measures: correct timing for antibiotic prophylaxis; use of the recommended antibiotic in the recommended dose and alcohol-based skin antisepsis. The SSI rate in hip and knee arthroplasties has shown a significant improvement. The nationwide median rate has fallen to 0.91% since June 2015, compared with 1.36% during the baseline period of April 2013 to March 2014 (p<0.01). This equates to approximately 55 fewer infections between August 2015 and June 2017, savings of NZD$2.2 million in avoided treatment and avoided disability-adjusted life years (DALYs) of NZD$5 million.

CONCLUSIONS

The introduction of a nationwide SSI reduction programme for hip and knee arthroplasties resulted in an increase in compliance across the country with best practice that was associated with a reduction in incidence of SSI since June 2015 from the baseline period of April 2013 to March 2014, sustained to June 2017.

BMI is a key risk factor for early periprosthetic joint infection following total hip and knee arthroplasty

AIM

To identify patient and surgical risk factors that are associated with periprosthetic joint infection (PJI), especially whether obesity is a risk factor following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

New Zealand Surgical Site Infection Improvement Programme data was analysed using deep infection within 90 days of the index procedure as the outcome. This was tested against surgical and patient factors for statistical associations in a multivariate model.

RESULTS

A total of 10,690 primary THAs and 9,481 primary TKAs were recorded by the NZSSIIP between 2013 and 2015. Multivariate analysis showed statistically significant associations with deep infections for BMI (BMI >40kg/m2 OR 5.62, 95% CI 2.25-14.0), male gender (OR 1.7, 95% CI 1.05-2.74) and age greater than 75 for THAs (age <55 years OR 0.35, 95% CI 0.14-0.87). For TKAs, multivariate analysis showed statistically significant associations with deep infection for BMI (BMI >40kg/m2 OR 1.94, 95% CI: 0.63-5.70) and male gender (OR 2.96, 95% CI 1.51-5.80).

CONCLUSIONS

These findings show that obesity is one of the most important modifiable patient factors in predicting PJI following THA and TKA.

PLD Protein-Protein Interactions With Signaling Molecules and Modulation by PA

We describe methods for studying phospholipase D (PLD) interactions with signaling proteins and modulation of these interactions by the PLD reaction product, phosphatidic acid (PA). PLD is fundamental to the physiological maintenance of cellular/intracellular membranes, protein trafficking, cytoskeletal dynamics, membrane remodeling, cell proliferation, meiotic division and sporulation. PA is an acidic phospholipid involved in the biosynthesis of many other lipids that affects the enzymatic activities of many different signaling proteins via protein-lipid interactions or as a substrate. The involvement of PLD as an effector of protein-protein interactions and downstream signaling via PA-mediated processes has led to the investigation of PA-binding domains in target protein partners. We present here data and protocols detailing the interaction between PLD2-Rac2 interaction and modulation of this interaction by PA. We describe biochemical techniques to measure interactions between PLD, PA, and the small GTPase Rac2, which are associated in the cell. We found two maxima concentrations of PA that contributed to association or dissociation of Rac2 with PLD2, as well as the PLD2 lipase and guanine nucleotide exchange factor (GEF) activities. Fluctuations in the Rac2-PLD2 protein-protein binding interaction facilitate shuttling of Rac2 and/or PLD2 within the cell dependent on local cellular PA concentration. Fluorescence resonance emission transfer stoichiometry for PLD2 and Rac2 binding yielded a 3:1 ratio of Rac2:PLD2. Detection of PA in mammalian cells with a new biosensor showed colocalization in and around the nucleus. We also described methods for quantitation of PA in biological materials by HPLC electrospray ionization tandem mass spectrometry.

Excess cost associated with primary hip and knee joint arthroplasty surgical site infections: a driver to support investment in quality improvement strategies to reduce infection rates

AIM

To determine the excess costs attributable to surgical site infections (SSI) following primary hip and knee joint arthroplasty at Auckland City Hospital.

METHODS

A retrospective case-control study. Cases were patients who developed a SSI following primary hip (THA) and knee arthroplasty (TKA) surgery within 90 days of the procedure. Cases were matched 1:2 with controls; patients whose primary hip and knee arthroplasty procedures were not complicated by infection. Controls were matched for age, gender, date of surgery, type of surgery, and ASA category. The length of stay (LOS) and hospital costs for the initial admission and subsequent readmission for infection were calculated from the clinical costing system at Auckland District Health Board.

RESULTS

Eleven cases were identified; 3 following TKA, 7 following THA, and 1 following hemiarthroplasty of the hip. Infections were classified as superficial, 1, joint space, 1, and deep incisional, 9. Five SSI were identified during the initial admission for joint arthroplasty and 6 patients were readmitted with an SSI. Compared to the control patients, SSIs were associated with an excess mean cost of $40,121 and an excess mean LOS of 42 days.

CONCLUSIONS

There is a significant increase in LOS and cost associated with SSI following primary THA and TKA at Auckland City Hospital. In addition to the excess cost associated with SSI, there are also opportunity costs resulting from their impact on elective surgical waiting lists. This reinforces the significant positive economic impact a successful strategy to reduce SSIs associated with primary joint arthroplasty procedures will have.

Ruthenium(ii)-polypyridyl zirconium(iv) metal-organic frameworks as a new class of sensitized solar cells

A series of Ru(ii)L2L' (L = 2,2'-bipyridyl, L' = 2,2'-bipyridine-5,5'-dicarboxylic acid), RuDCBPY, -containing zirconium(iv) coordination polymer thin films have been prepared as sensitizing materials for solar cell applications. These metal-organic framework (MOF) sensitized solar cells, MOFSCs, each are shown to generate photocurrent in response to simulated 1 sun illumination. Emission lifetime measurements indicate the excited state quenching of RuDCBPY at the MOF-TiO2 interface is extremely efficient (>90%), presumably due to electron injection into TiO2. A mechanism is proposed in which RuDCBPY-centers photo-excited within the MOF-bulk undergo isotropic energy migration up to 25 nm from the point of origin. This work represents the first example in which a MOFSC is directly compared to the constituent dye adsorbed on TiO2 (DSC). Importantly, the MOFSCs outperformed their RuDCBPY-TiO2 DSC counterpart under the conditions used here and, thus, are solidified as promising solar cell platforms.

A new surgical site infection improvement programme for New Zealand: early progress

Two to five percent of those who have an inpatient surgical procedure will experience a surgical site infection (SSI). The Health Quality & Safety Commission has instituted New Zealand's first national Surgical Site Infection Improvement Programme (the SSII Programme), delivered jointly by Auckland and Canterbury District Health Boards. Through a combined package of surveillance and improvement interventions the SSII Programme aims to reduce the incidence of SSIs in New Zealand hospitals, beginning initially with hip and knee arthroplasties. Within one year of the programme starting there has been a significant nationwide improvement in the timing of surgical antimicrobial prophylaxis (p<0.0001), and the administration of the correct dose (p<0.0001). National compliance with an alcohol-based skin preparation remains high at > 95 %. In this paper we describe the purpose, background, structure and rationale of the programme and provide results to date.

Plasmid-mediated AmpC beta-lactamase-producing Escherichia coli causing urinary tract infection in the Auckland community likely to be resistant to commonly prescribed antimicrobials

AIM

To estimate the prevalence and characterise plasmid-mediated AmpC beta-lactamase (PMACBL)- producing Escherichia coli in the Auckland community.

METHOD

All cefoxitin non-susceptible (NS) E. coli identified at the two Auckland community laboratories between 1 January and 31 August 2011 were referred to ESR for boronic acid double-disc synergy testing, to detect the production of AmpC beta-lactamase, and polymerase chain reaction (PCR) to identify the presence of PMACBL genes. PMACBL-producing isolates were typed using pulsed-field gel electrophoresis (PFGE), and PCR was used to determine their phylogenetic group and to identify multilocus sequence type (ST)131. Antimicrobial susceptibility testing and detection of extended-spectrum beta-lactamases (ESBLs) were performed according to the Clinical and Laboratory Standards Institute recommendations.

RESULTS

101 (51%) and 74 (37%) of 200 non-duplicate cefoxitin-NS E. coli were PMACBL producers or assumed hyper-producers of chromosomal AmpC beta-lactamase, respectively. The prevalence of PMACBL-producing E. coli was 0.4%. PMACBL-producing E. coli were significantly less susceptible to norfloxacin, trimethoprim and nitrofurantoin than E. coli that produced neither a PMACBL nor an ESBL. Very few (4%) PMACBL-producing E. coli co-produced an ESBL. Most (88%) of the PMACBL-producing isolates had a CMY-2-like PMACBL. The PMACBL-producing E. coli isolates were diverse based on their PFGE profiles, 44% belonged to phylogenetic group D, and only four were ST131. 100 of the 101 PMACBL-producing E. coli were cultured from urine, and were causing urinary tract infection (UTI) in the majority of patients. The median patient age was 56 years and most (94%) of the patients were women. A greater proportion of patients with community-acquired UTI caused by PMACBL-producing E. coli received a beta-lactam antimicrobial than patients with community-acquired UTI caused by other non-AmpC, non-ESBL-producing E. coli. Thirty-six (43%) patients with community-acquired UTI due to PMACBL-producing E. coli were neither hospitalised nor had any antimicrobial treatment in the previous 6 months.

CONCLUSION

The prevalence of PMACBL-producing E. coli was relatively low in the Auckland community, but has increased in recent years. Typing revealed that the majority of the PMACBL-producing E. coli in the Auckland region were genetically unrelated meaning that a point source or direct person to person transmission are not drivers of local community spread currently. The isolates were more resistant to non-beta-lactam antimicrobials than other non-AmpC, non-ESBL-producing E. coli, leaving few treatment options. The majority of the PMACBL-producing E. coli isolates seemed to be acquired in the community and were most frequently isolated from women with UTI. A large proportion of patients with community-acquired UTI had not been hospitalised nor had any antimicrobial treatment in the previous 6 months.

Infective endocarditis in New Zealand: data from the International Collaboration on Endocarditis Prospective Cohort Study

AIMS

The International Collaboration on Endocarditis Prospective Cohort Study (ICE-PCS) collected worldwide data on the presentation, management and outcome of infective endocarditis (IE). We present data from patients with endocarditis enrolled from New Zealand.

METHODS

Patients who fulfilled the Duke criteria for definite or probable endocarditis were enrolled from five district health boards: Auckland, Counties Manukau, Waitemata, Capital and Coast, and Canterbury, between June 2000 and September 2005.

RESULTS

There were 336 New Zealand patients enrolled in the ICE-PCS. Prosthetic valve endocarditis occurred in 31%. Underlying medical conditions were present in 28% of patients, but only 4% of patients had rheumatic heart disease. Forty patients (12%) had healthcare-associated endocarditis. Viridans streptococci were the most common cause of IE (32%), followed by Staphylococcus aureus (24%). Patients with S. aureus IE were more likely to present within a week of symptom onset than those with viridans streptococcus IE (OR 4.18, 95% CI 2.36-7.42). Surgery was performed in 33% of patients. In total, 20 patients (6%) died in hospital. Those with endocarditis caused by coagulase-negative staphylococci had an increased risk of death compared with those viridans streptococcus endocarditis (RR 4.7, 95% CI 1.2-17). The risk of stroke was higher in those with endocarditis caused by S. aureus and coagulase-negative staphylococci (RR 2.7, 95% CI 1.2-6.05, and 4.9, 95% CI 1.9-13, respectively).

CONCLUSION

While viridans streptococci remain the predominant causative organisms of IE in New Zealand, many 'traditional' clinical and management aspects of this disease no longer apply. This paper provides a reference for local practitioners assessing and managing IE.

A prospective single-centre evaluation of the intra-individual variability of faecal calprotectin in quiescent Crohn's disease

BACKGROUND

As a non-invasive marker of gastrointestinal inflammation, faecal calprotectin (FC) is being increasingly used to guide the management of Crohn's disease. It is therefore a concern that studies have shown variability in day to day levels.

AIM

To determine the degree of this intrapersonal variability in the context of quiescent Crohn's disease.

METHODS

A single-centre prospective study was undertaken in 143 Crohn's disease patients in clinical remission. Three faecal calprotectin levels were analysed from stool samples on consecutive days. Consistency of faecal calprotectin levels was determined by measuring the intraclass correlation (ICC). Due to higher variability at higher faecal calprotectin levels, the ICC was calculated for the log-transformed values. The reliability of detecting a 'case' of active inflammation as defined for specific concentrations of faecal calprotectin was measured by the kappa statistic.

RESULTS

Ninety-eight complete sets of results were obtained. The ICC was 0.84 (95% CI: 0.79-0.89), which represents low variability across samples. The kappa statistic for the reliability of detecting a case as defined by an FC level of >50 μg/g was substantial at 0.648 (0.511-0.769).

CONCLUSIONS

Day to day variability of faecal calprotectin is low in our cohort of quiescent Crohn's disease patients and the reliability of defining a 'case' is moderately good. These data provide reassurance to clinicians using a single calprotectin sample to inform therapeutic strategies in this cohort.