Serosurvey for Japanese encephalitis virus antibodies following an outbreak in an immunologically naïve population, Victoria, 2022: a cross-sectional study.

OBJECTIVES: To investigate the distribution and prevalence of Japanese encephalitis virus (JEV) antibody (as evidence of past infection) in northern Victoria following the 2022 Japanese encephalitis outbreak, seeking to identify groups of people at particular risk of infection; to investigate the distribution and prevalence of antibodies to two related flaviviruses, Murray Valley encephalitis virus (MVEV) and West Nile virus Kunjin subtype (KUNV). STUDY DESIGN: Cross-sectional serosurvey (part of a national JEV serosurveillance program). SETTING: Three northern Victorian local public health units (Ovens Murray, Goulburn Valley, Loddon Mallee), 8 August - 1 December 2022. PARTICIPANTS: People opportunistically recruited at pathology collection centres and by targeted recruitment through community outreach and advertisements. People vaccinated against or who had been diagnosed with Japanese encephalitis were ineligible for participation, as were those born in countries where JEV is endemic. MAIN OUTCOME MEASURES: Seroprevalence of JEV IgG antibody, overall and by selected factors of interest (occupations, water body exposure, recreational activities and locations, exposure to animals, protective measures). RESULTS: 813 participants were recruited (median age, 59 years [interquartile range, 42-69 years]; 496 female [61%]); 27 were JEV IgG-seropositive (3.3%; 95% confidence interval [CI], 2.2-4.8%) (median age, 73 years [interquartile range, 63-78 years]; 13 female [48%]); none were IgM-seropositive. JEV IgG-seropositive participants were identified at all recruitment locations, including those without identified cases of Japanese encephalitis. The only risk factors associated with JEV IgG-seropositivity were age (per year: prevalence odds ratio [POR], 1.07; 95% CI, 1.03-1.10) and exposure to feral pigs (POR, 21; 95% CI, 1.7-190). The seroprevalence of antibody to MVEV was 3.0% (95% CI, 1.9-4.5%; 23 of 760 participants), and of KUNV antibody 3.3% (95% CI, 2.1-4.8%; 25 of 761). CONCLUSIONS: People living in northern Victoria are vulnerable to future JEV infection, but few risk factors are consistently associated with infection. Additional prevention strategies, including expanding vaccine eligibility, may be required to protect people in this region from Japanese encephalitis.

An integrated public health response to an outbreak of Murray Valley encephalitis virus infection during the 2022-2023 mosquito season in Victoria.

Introduction: Murray Valley encephalitis virus (MVEV) is a mosquito-borne flavivirus known to cause infrequent yet substantial human outbreaks around the Murray Valley region of south-eastern Australia, resulting in significant mortality. Methods: The public health response to MVEV in Victoria in 2022-2023 included a climate informed pre-season risk assessment, and vector surveillance with mosquito trapping and laboratory testing for MVEV. Human cases were investigated to collect enhanced surveillance data, and human clinical samples were subject to serological and molecular testing algorithms to assess for co-circulating flaviviruses. Equine surveillance was carried out via enhanced investigation of cases of encephalitic illness. Integrated mosquito management and active health promotion were implemented throughout the season and in response to surveillance signals. Findings: Mosquito surveillance included a total of 3,186 individual trapping events between 1 July 2022 and 20 June 2023. MVEV was detected in mosquitoes on 48 occasions. From 2 January 2023 to 23 April 2023, 580 samples (sera and CSF) were tested for flaviviruses. Human surveillance detected 6 confirmed cases of MVEV infection and 2 cases of "flavivirus-unspecified." From 1 September 2022 to 30 May 2023, 88 horses with clinical signs consistent with flavivirus infection were tested, finding one probable and no confirmed cases of MVE. Discussion: The expanded, climate-informed vector surveillance system in Victoria detected MVEV in mosquitoes in advance of human cases, acting as an effective early warning system. This informed a one-health oriented public health response including enhanced human, vector and animal surveillance, integrated mosquito management, and health promotion.

Laboratory evaluation of ELISA and indirect immunofluorescence assay in response to emergence of Japanese encephalitis virus genotype IV in Australia.

The unexpected recent emergence of Japanese encephalitis virus (JEV) genotype IV in multiple southern states of Australia necessitated an evaluation of JEV serological tests suitable for diagnosing acute infection and for seroprevalence studies. This study examined the analytical and clinical performance of two high-throughput JEV assays, Euroimmun immunofluorescence assay (IFA) and Euroimmun enzyme-linked immunosorbent assay (ELISA), across four cohorts; (1) surveillance of piggery workers in outbreak areas, (2) surveillance of residents in outbreak areas, (3) acute JEV infection and (4) post-JEV vaccination. ELISA and IFA IgM demonstrated minimal cross-reactivity (0-1.8%) with other endemic flaviviruses, with high sensitivity (100%) for acute JEV infection in this low endemicity setting. Differences in IgG serodynamics between the two assays suggest convalescent and paired testing with IgM are critical in diagnosing acute infection. High assay concordance was observed between ELISA and IFA when used in serosurveillance (97.4% agreement, Cohen' κ 0.74 [95% CI 0.614-0.860]) and vaccination cohorts (91.1% agreement, Cohen's κ 0.806 [95% CI 0.672-0.941]). In conclusion, this study highlights the clinical & epidemiological applications and limitations of these two commercial JEV assays.

Surveillance for severe influenza and COVID-19 in patients admitted to sentinel Australian hospitals in 2020: the Influenza Complications Alert Network (FluCAN).

Introduction: Influenza is a common cause of acute respiratory infection, and is a major cause of morbidity and mortality. Coronavirus disease 2019 (COVID-19) is an acute respiratory infection that emerged as a pandemic worldwide before the start of the 2020 Australian influenza season. This report summarises the epidemiology of hospitalisations with laboratory-confirmed influenza and COVID-19 during the 2020 influenza season in a sentinel surveillance system. Methods: The Influenza Complications Alert Network (FluCAN) is a sentinel hospital-based surveillance program that operates at sites in all jurisdictions in Australia. Influenza and COVID-19 cases were defined as patients hospitalised at sentinel hospitals and confirmed by nucleic acid detection. Results: There were 448 patients with COVID-19 admitted between 16 March and 31 December 2020, and only 20 patients with influenza admitted between 1 April and 30 November 2020, to one of 22 FluCAN hospitals. Of the COVID-19 cases, 173 (39%) were > 65 years of age, 36 (8%) were children (< 16 years), 6 (1%) were Aboriginal and Torres Strait Islander peoples, 4 (1%) were pregnant and 289 (65%) had chronic comorbidities. COVID-19 hospital admissions peaked between weeks 13 and 15 (first wave) nationally, and again between weeks 31 and 35 (Victoria), with most admissions represented by those above 40 years of age. Discussion: There was an unusually low number of hospital admissions with laboratory-confirmed influenza in this season, compared to recent seasons. This is likely to be due to effective public health interventions and international border closures as a result of a rise in COVID-19 respiratory infections and associated hospitalisations.

Influenza epidemiology in patients admitted to sentinel Australian hospitals in 2019: the Influenza Complications Alert Network (FluCAN).

Influenza is a common cause of acute respiratory infection, and is a major cause of morbidity and mortality. This report summarises the epidemiology of hospitalisations with laboratory-confirmed influenza during the 2019 influenza season. The Influenza Complications Alert Network (FluCAN) is a sentinel hospital-based surveillance program that operates at sites in all jurisdictions in Australia. Cases were defined as patients hospitalised at any of the 17 sentinel hospitals with influenza confirmed by nucleic acid detection. Data were also collected on a frequency matched control group of influenza-negative patients admitted with acute respiratory infection. During the period 1 April to 31 October 2019 (the 2019 influenza season), there were 4,154 patients admitted with confirmed influenza to one of 17 FluCAN sentinel hospitals. Of these, 44% were elderly (≥ 65 years), 21% were children (< 16 years), 7.7% were Aboriginal and Torres Strait Islander peoples, 1.7% were pregnant and 73% had chronic comorbidities. Most admissions were due to influenza A infection (85%). Estimated vaccine coverage was 75% in the elderly, 49% in non-elderly adults with medical comorbidities, and 27% in young children (< 5 years). The estimated vaccine effectiveness in the target adult population was 42% (95% confidence interval [95% CI]: 36%, 49%). There were a larger number of hospital admissions detected with confirmed influenza in this national observational surveillance system in 2019 than in 2018.

Patient satisfaction with a consumer codesigned lower limb cellulitis leaflet.

Objective This study evaluated whether a consumer codesigned leaflet about the common skin infection cellulitis would improve patient satisfaction. Methods A patient information leaflet was codesigned with consumers incorporating health literacy principles and attached to a new adult lower limb cellulitis management plan launched in three regional Victorian health services. Health service staff were educated to provide the leaflet during hospital care. Patients discharged with a diagnosis of cellulitis in an 8-month period were followed-up via telephone between 31 and 60 days after their discharge. Each patient was asked to provide feedback on the utility of the leaflet (if received) and their overall satisfaction with the information provided to them using a five-point scale (with scores of 4 or 5 considered to indicate satisfaction). Results In all, 81 of 127 (64%) patients (or carers) were contactable, consented to the study and answered the questions. Of these, 27% (n = 22) reported receiving, accepting and reading the leaflet. The proportion of patients who were satisfied with the information provided to them about cellulitis was 100% for those who received the leaflet, compared with 78% for those who did not receive the leaflet (95% confidence interval 4.8-34%; P = 0.02). Conclusion The provision of a consumer codesigned leaflet increased patient satisfaction with the information received about cellulitis. Real-world strategies to embed the delivery of such resources are required to ensure that more patients receive the benefit. What is known about the topic? There are known deficiencies in the information provided to patients about the common skin condition cellulitis. There is little published evaluation of strategies to address these knowledge deficiencies. What does this paper add? This study evaluated a simple strategy to address patient knowledge deficiencies on cellulitis. It highlights that pertinent information delivered in an accessible way can significantly increase patient satisfaction with the information provided to them. What are the implications for practitioners? These findings are a timely reminder for practitioners that even a simple intervention, such a providing a hard copy information leaflet, can improve patient satisfaction. A national repository of similar consumer codesigned materials would be valuable and could minimise existing duplication of effort in resource development across health sectors. Real-world strategies to embed the delivery of such resources is required to ensure that more patients receive the benefit.

Correlation between Buruli Ulcer Incidence and Vectorborne Diseases, Southeastern Australia, 2000-2020.

Researchers have hypothesized that mosquitoes are vectors involved in Mycobacterium ulcerans transmission. Previous findings of a correlation between incidence of M. ulcerans, which causes Buruli ulcer, and locally acquired vectorborne diseases in southeastern Australia further strengthened this argument. However, our updated data indicate that this correlation has not continued beyond 2008.

Implementation of a Cellulitis Management Plan in Three Australian Regional Health Services to Address an Evidence-Practice Gap in Antibiotic Prescribing.

Despite the availability of evidence-based guidelines, antibiotics for cellulitis remain inappropriately prescribed. This evidence-practice gap is more evident in low-resource settings, such as rural hospitals. This implementation study developed and introduced a cellulitis management plan to improve antibiotic prescribing for cellulitis in three health services in regional Australia. Appropriateness of antibiotic prescribing for cellulitis at Day 1 was the primary outcome measure. Adults with ICD-10-AM codes for lower-limb cellulitis admitted as inpatients of the three health services between May and November 2019 (baseline, n = 165) and March and October 2020 (post-implementation, n = 127) were included in the assessment. The uptake of the cellulitis management plan was 29.1% (37/127). The appropriateness of antibiotic prescribing for cellulitis at Day 1 was similar at baseline (78.7%, 144/183) and in the intention-to-treat post-implementation group (81.8%, 126/154) [95% CI -5.6% to 11.3%, p = 0.50]. Commencement of the cellulitis management plan resulted in a non-statistically significant increase in antibiotic appropriateness at Day 1 compared to when a cellulitis management plan was not commenced (88.1% vs. 79.5%; 95% CI -5.6% to 19.8%; p = 0.20) Evaluation of more real-world strategies to address evidence-practice gaps, such as the appropriateness of antibiotic prescribing for cellulitis, is required.

Antimicrobial stewardship in Australia: the role of qualitative research in programme development.

Antimicrobial stewardship (AMS) in Australia is supported by a number of factors, including enabling national policies, sectoral clinical governance frameworks and surveillance programmes, clinician-led educational initiatives and health services research. A One Health research programme undertaken by the National Centre for Antimicrobial Stewardship (NCAS) in Australia has combined antimicrobial prescribing surveillance with qualitative research focused on developing antimicrobial use-related situational analyses and scoping AMS implementation options across healthcare settings, including metropolitan hospitals, regional and rural hospitals, aged care homes, general practice clinics and companion animal and agricultural veterinary practices. Qualitative research involving clinicians across these diverse settings in Australia has contributed to improved understanding of contextual factors that influence antimicrobial prescribing, and barriers and facilitators of AMS implementation. This body of research has been underpinned by a commitment to supplementing 'big data' on antimicrobial prescribing practices, where available, with knowledge of the sociocultural, technical, environmental and other factors that shape prescribing behaviours. NCAS provided a unique opportunity for exchange and cross-pollination across the human and animal health programme domains. It has facilitated synergistic approaches to AMS research and education, and implementation of resources and stewardship activities. The NCAS programme aimed to synergistically combine quantitative and qualitative approaches to AMS research. In this article, we describe the qualitative findings of the first 5 years.

Barriers to performing onsite COVID-19 testing during the second wave in Victoria: Experiences of general practices.

BACKGROUND AND OBJECTIVES: The approach to performing COVID-19 testing in general practice has been going through an evolution and is variable. The aim of this study was to determine what underlying factors, if any, impeded onsite COVID-19 testing in general practices for patients during the second wave of the pandemic in Victoria. METHOD: This study was conducted during August 2020 and October 2020. Fourteen semi-structured interviews with general practitioners, practice nurses and practice managers were conducted. RESULTS: Barriers to performing onsite testing for COVID-19 were identified as: 1) individual, 2) practitioner perception of fear, 3) lack of personal protective equipment, 4) inappropriate clinic design/location, 5) risk of patient avoidance, 6) financial risk, 7) a lack of knowledge and 8) lack of guidelines. DISCUSSION: This study's findings relate to a unique period in Victoria, which at the time accounted for 70% of the nation's total cases and 90% of deaths. Therefore, the barriers identified in this study may help inform policymakers in regard to planning for future responses to similar situations.

Impact of time to first antimicrobial dose on length of stay and 30-day hospital readmission in patients with lower limb cellulitis.

OBJECTIVES: There have been efforts to promote timely antimicrobial administration for patients with sepsis, but the importance for other infections is uncertain. This study analysed whether time to first antimicrobial dose (TFAD) in patients with lower limb cellulitis influenced outcome measures such as acute length of stay (LOS) in hospital and 30-day hospital readmission rates for cellulitis. METHODS: Medical records of patients admitted with lower limb cellulitis or erysipelas over a 15-month period (1 May 2019 to 30 November 2019 and 1 March 2020 to 31 October 2020) were reviewed. Patients requiring intensive care unit (ICU) admission were excluded. The TFAD was the difference (in minutes) between the emergency department triage time and the time that the antimicrobial was first recorded as administered. Analysis included log-transformed linear regression (for LOS) and logistic regression (for 30-day readmission with cellulitis), controlling for confounders where possible. RESULTS: The study included 282 patients with lower limb cellulitis. The median TFAD was 177 min (interquartile range, 98-290 min). Linear regression suggested a weak association between TFAD and LOS (P = 0.05; adjusted R2 = 0.01), which was non-significant after adjusting for confounders (P = 0.18). There were too few patients readmitted within 30 days with cellulitis for meaningful analysis. CONCLUSION: After controlling for confounders, no association between increased TFAD and increased acute LOS was identified for patients with lower limb cellulitis who did not require ICU admission (i.e. without septic shock). Conclusions could not be made for 30-day readmission rates for cellulitis.

Bittersweet: infective complications of drug-induced glycosuria in patients with diabetes mellitus on SGLT2-inhibitors: two case reports.

BACKGROUND: Sodium-glucose co-transporter 2 (SGLT2) inhibitors are novel hypoglycemic agents which reduce reabsorption of glucose at the renal proximal tubule, resulting in significant glycosuria and increased risk of genital mycotic infections (GMI). These infections are typically not severe as reported in large systematic reviews and meta-analyses of the medications. These reviews have also demonstrated significant cardiovascular benefits through other mechanisms of action, making them attractive options for the management of Type 2 diabetes mellitus (T2DM). We present two cases with underlying abnormalities of the urogenital tract in which the GMI were complicated and necessitated cessation of the SGLT2 inhibitor. CASE PRESENTATIONS: Both cases are patients with T2DM on empagliflozin, an SGLT2 inhibitor. The first case is a 64 year old man with Candida albicans balanitis and candidemia who was found to have an obstructing renal calculus and prostatic abscess requiring operative management. The second case describes a 72 year old man with Candida glabrata candidemia who was found to have prostatomegaly, balanitis xerotica obliterans with significant urethral stricture and bladder diverticulae. His treatment was more complex due to fluconazole resistance and concerns about urinary tract penetration of other antifungals. Both patients recovered following prolonged courses of antifungal therapy and in both cases the SGLT2 inhibitor was ceased. CONCLUSIONS: Despite their cardiovascular benefits, SGLT2 inhibitors can be associated with complicated fungal infections including candidemia and patients with anatomical abnormalities of the urogenital tract may be more susceptible to these infections as demonstrated in these cases. Clinicians should be aware of their mechanism of action and associated risk of infection and prior to prescription, assessment of urogenital anatomical abnormalities should be performed to identify patients who may be at risk of complicated infection.

Risk Factors Associated with Antibiotic Treatment Failure of Buruli Ulcer.

Combination antibiotic therapy is highly effective in curing Buruli ulcer (BU) caused by Mycobacterium ulcerans Treatment failures have been uncommonly reported with the recommended 56 days of antibiotics, and little is known about risk factors for treatment failure. We analyzed treatment failures among BU patients treated with ≥56 days of antibiotics from a prospective observational cohort at Barwon Health, Victoria, from 1 January 1998 to 31 December 2018. Treatment failure was defined as culture-positive recurrence within 12 months of commencing antibiotics under the following conditions: (i) following failure to heal the initial lesion or (ii) a new lesion developing at the original or at a new site. A total of 430 patients received ≥56 days of antibiotic therapy, with a median duration of 56 days (interquartile range [IQR], 56 to 80). Seven (1.6%) patients experienced treatment failure. For six adult patients experiencing treatment failure, all were male, weighed >90 kg, did not have surgery, and received combination rifampin-clarithromycin (median rifampin dose, 5.6 mg per kg of body weight per day; median clarithromycin dose, 8.1 mg/kg/day). When compared to those who did not fail treatment on univariate analysis, treatment failure was significantly associated with a weight of >90 kg (P < 0.001), male gender (P = 0.02), immune suppression (P = 0.04), and a first-line regimen of rifampin-clarithromycin compared to a regimen of rifampin-fluoroquinolone (P = 0.05). There is a low rate of treatment failure in Australian BU patients treated with rifampin-based oral combination antibiotic therapy. Our study raises the possibility that treatment failure risk may be increased in males, those with a body weight of >90 kg, those with immune suppression, and those taking rifampin-clarithromycin antibiotic regimens, but future pharmacokinetic and pharmacodynamics studies are required to determine the validity of these hypotheses.

The role of nurses in antimicrobial stewardship near the end of life in aged-care homes: A qualitative study.

BACKGROUND: The excessive use of antimicrobials in aged-care homes is a widely recognised phenomenon. This is problematic because it can harm residents, and is detrimental to public health. Residents in the final month of life are increasingly likely to be prescribed an antimicrobial, commonly without having signs and symptoms of infection that support antimicrobial use. OBJECTIVES: We aimed to describe the perspectives of health professionals on antimicrobial use near the end of life in aged-care homes and investigate the potential opportunities for nurses to undertake antimicrobial stewardship activities near the end of life in aged-care homes. DESIGN: One-on-one, semi-structured, qualitative interviews. SETTINGS AND PARTICIPANTS: Twelve nurses, six general practitioners and two pharmacists providing routine care to residents of aged-care homes in Victoria, Australia were interviewed. Diversity in terms of years of experience, aged-care funding type (government, private-for-profits and not-for-profits) and location (metropolitan and regional) were sought. METHODS: Interviews were transcribed and open coded in a descriptive manner using validated frameworks for understanding behaviour change. The descriptive code was then used to build an interpretive code structure based on questions founded in grounded theory. RESULTS: Thematic saturation was reached after fourteen interviews, and an additional six interviews were conducted to ensure emergent themes were consistent and definitive. There are opportunities for aged-care home nurses to undertake antimicrobial stewardship activities near the end of life in the provision of routine care. Aged-care home nurses are influential in antimicrobial decisions near the end of life in routine care because of their leadership in advance care planning, care co-ordination and care provision in an environment with stopgap and visiting medical resources. Nurses also have social influence among residents, families and medical professionals during critical conversations near the end of life. Past negative social interactions within the aged-care home environment between nurses and families can result in 'fear-based' social influences on antimicrobial prescribing. CONCLUSIONS: The work of facilitating advance care planning, care coordination, care delivery, and communicating with families and medical professionals provide important opportunities for aged-care home nurses to lead appropriate antimicrobial stewardship activities near the end of life.

Measuring antimicrobial prescribing quality in outpatient parenteral antimicrobial therapy (OPAT) services: development and evaluation of a dedicated national antimicrobial prescribing survey.

BACKGROUND: Antimicrobial stewardship programmes are important in driving safety and quality of antimicrobial prescribing. The National Antimicrobial Prescribing Survey (NAPS) is a point-prevalence audit of inpatient antimicrobial prescribing in Australian hospitals. OBJECTIVES: To design and adapt the NAPS tool for use in the outpatient parenteral antimicrobial therapy (OPAT) and hospital-in-the-home (HITH) setting. METHODS: An inter-disciplinary working group with expertise in OPAT and HITH services was established to adapt the NAPS template for use in the OPAT setting-called HITH-NAPS. This was initially trialled in 5 HITH services, subsequently adapted following participant feedback, then offered nationally to 50 services in 2017. RESULTS: There were 1154 prescriptions for 715 patients audited via the HITH-NAPS. The most common antimicrobials prescribed were cefazolin (22%), flucloxacillin (12%), piperacillin/tazobactam (10%) and ceftriaxone (10%). The most common infections treated were cellulitis (30%) and respiratory tract infections (14%). Eighty-seven percent of prescriptions were assessed as appropriate, 11% inappropriate and 2% not assessable. Prolonged durations of antimicrobials and unnecessarily broad-spectrum antibiotics were used in 9% of prescriptions. CONCLUSIONS: The HITH-NAPS pilot project revealed that auditing of this type is feasible in HITH. It showed that antibiotic use in these HITH services was generally appropriate, but there are some areas for improvement. A national OPAT/HITH-NAPS can facilitate benchmarking between services, identify potentially inappropriate prescribing and help guide quality improvement.

Six vs Eight Weeks of Antibiotics for Small Mycobacterium ulcerans Lesions in Australian Patients.

BACKGROUND: Antibiotics are highly effective in curing Mycobacterium ulcerans lesions, but are associated with significant toxicity. In those not undergoing surgery, we compared 6 weeks with the currently recommended 8 weeks of combination antibiotic therapy for small M. ulcerans lesions. METHODS: Mycobacterium ulcerans cases from an observational cohort at Barwon Health, Victoria, treated with antibiotics alone from 1 October 2010 to 31 March 2018 were included. The 6-week antibiotic group received ≥28 days and ≤42 days and the 8-week antibiotic group received ≥56 days of antibiotic therapy, respectively. Only World Health Organization category 1 lesions were included. RESULTS: 207 patients were included; 53 (25.6%) in the 6-week group and 154 (74.4%) in the 8-week group. The median age of patients was 53 years (interquartile range [IQR], 33-69 years) and 100 (48.3%) were female. Lesions were ≤900 mm2 in size in 79.7% of patients and 93.2% were ulcerative. Fifty-three patients (100%) achieved treatment cure in the 6-week group compared with 153 (99.4%) in the 8-week group (P = .56). No patients died or were lost to follow-up during the study. Median time to heal was 70 days (IQR, 60-96 days) in the 6-week group and 128 days (IQR, 95-173 days) in the 8-week group (P < .001). Two (3.8%) patients in the 6-week group experienced a paradoxical reaction compared with 39 (25.3%) patients in the 8-week group (P = .001). CONCLUSIONS: For selected small M. ulcerans lesions, 6 weeks may be as effective as 8 weeks of combined antibiotic therapy in curing lesions without surgery.