Respiratory Syncytial Virus Reinfections in Children in Western Australia.

Respiratory syncytial virus (RSV) reinfection in children is poorly understood. We examined the incidence, characteristics, and outcomes of hospital-attended RSV reinfections in children <16 years in Western Australia between 2012 and 2022. Individuals with repeat RSV detections ≥56 days apart were identified using laboratory data. The incidence of reinfection in the first five years of life was estimated using the total birth population from 2012 to 2017. Clinical data on a subset of reinfection episodes were obtained from two metropolitan pediatric centers. A total of 466 children with hospital-attended reinfections were identified. The median interval between RSV detections was 460 days (interquartile range: 324, 812), with a reinfection rate of 95 per 100,000 individuals (95% confidence interval: 82, 109). Reinfection was most common in children who experienced their first RSV detection <6 months of age. Predisposing factors were identified in 56% of children; children with predisposing factors were older at first and second detections, were more likely to be admitted, and had a longer length of stay. This study highlights the significant burden of hospital-attended RSV reinfections in children with and without predisposing factors. Expanded surveillance with in-depth clinical data is required to further characterize the impact of RSV reinfection.

FeBRILe3: Safety Evaluation of Febrile Infant Guidelines Through Prospective Bayesian Monitoring.

OBJECTIVES: Despite evidence supporting earlier discharge of well-appearing febrile infants at low risk of serious bacterial infection (SBI), admissions for ≥48 hours remain common. Prospective safety monitoring may support broader guideline implementation. METHODS: A sequential Bayesian safety monitoring framework was used to evaluate a new hospital guideline recommending early discharge of low-risk infants. Hospital readmissions within 7 days of discharge were regularly assessed against safety thresholds, derived from historic rates and expert opinion, and specified a priori (8 per 100 infants). Infants aged under 3 months admitted to 2 Western Australian metropolitan hospitals for management of fever without source were enrolled (August 2019-December 2021), to a prespecified maximum 500 enrolments. RESULTS: Readmission rates remained below the prespecified threshold at all scheduled analyses. Median corrected age was 34 days, and 14% met low-risk criteria (n = 71). SBI was diagnosed in 159 infants (32%), including urinary tract infection (n = 140) and bacteraemia (n = 18). Discharge occurred before 48 hours for 192 infants (38%), including 52% deemed low-risk. At study completion, 1 of 37 low-risk infants discharged before 48 hours had been readmitted (3%), for issues unrelated to SBI diagnosis. In total, 20 readmissions were identified (4 per 100 infants; 95% credible interval 3, 6), with >0.99 posterior probability of being below the prespecified noninferiority threshold, indicating acceptable safety. CONCLUSIONS: A Bayesian monitoring approach supported safe early discharge for many infants, without increased risk of readmission. This framework may be used to embed safety evaluations within future guideline implementation programs to further reduce low-value care.

A surge in human metapneumovirus paediatric respiratory admissions in Western Australia following the reduction of SARS-CoV-2 non-pharmaceutical interventions.

AIM: Western Australian laboratory data demonstrated a decrease in human metapneumovirus (hMPV) detections through 2020 associated with SARS-CoV-2-related non-pharmaceutical interventions (NPIs), followed by a subsequent surge in metropolitan region in mid-2021. We aimed to assess the impact of the surge in hMPV on paediatric hospital admissions and the contribution of changes in testing. METHODS: All respiratory-coded admissions of children aged <16 years at a tertiary paediatric centre between 2017 and 2021 were matched with respiratory virus testing data. Patients were grouped by age at presentation and by ICD-10 AM codes into bronchiolitis, other acute lower respiratory infection (OALRI), wheeze and upper respiratory tract infection (URTI). For analysis, 2017-2019 was utilised as a baseline period. RESULTS: hMPV-positive admissions in 2021 were more than 2.8 times baseline. The largest increase in incidence was observed in the 1-4 years group (incidence rate ratio (IRR) 3.8; 95% confidence interval (CI): 2.5-5.9) and in OALRI clinical phenotype (IRR 2.8; 95% CI: 1.8-4.2). The proportion of respiratory-coded admissions tested for hMPV in 2021 doubled (32-66.2%, P < 0.001), with the greatest increase in wheeze (12-75% in 2021, P < 0.001). hMPV test percentage positivity in 2021 was higher than in the baseline period (7.6% vs. 10.1% in 2021, P = 0.004). CONCLUSION: The absence and subsequent surge underline the susceptibility of hMPV to NPIs. Increased hMPV-positive admissions in 2021 can be partially attributable to testing, but test-positivity remained high, consistent with a genuine increase. Continued comprehensive testing will help ascertain true burden of hMPV respiratory diseases.

The Impact of a Multifaceted Tertiary Pediatric Hospital's Antimicrobial Stewardship Service.

BACKGROUND: Antimicrobials are the most commonly prescribed drug class in children. Overuse through inappropriate prescribing is a key driver of antimicrobial resistance and is recognized as one of the top 10 threats to global health by the World Health Organization. METHODS: A prospective observational cohort study was performed following implementation of a multifaceted Antimicrobial Stewardship (AMS) program (January 2014 to December 2020). Data were collected on AMS and "handshake" ward rounds from patient information sources and directly from clinicians responsible for patient care. Primary outcomes include appropriateness of therapy (drug, dose, antimicrobial spectrum, duration and route), compliance with prescribing guidelines, antimicrobial expenditure, use of high-priority antimicrobials and duration of hospitalization. We compared outcomes across 3 time periods; January 2014-December 2015, January 2016-December 2017 and January 2018-December 2020. RESULTS: The appropriateness of individual antimicrobial orders improved across the study periods from 6111/7040 (79.4%) in the first 2 years following implementation of the AMS program to 17,819/19,229 (92.3%) in the latter period. Guideline compliance increased from 5426/7700 (70.5%) to 17,822/19,316 (92.3%). A reduction in overall antimicrobial expenditure (34% reduction, equivalent to $12.52 per bed day) and a decrease in antifungal expenditure (37% reduction, equivalent to $5.56 per bed day) was observed across the time periods. CONCLUSIONS: This study quantifies a comprehensive pediatric AMS program's sustained impact on reducing inappropriate antimicrobial use and expenditure and improving compliance with guidelines. The effectiveness of these interventions has been demonstrated and should be considered by institutions seeking to improve rational antimicrobial use in children.

Infectious complications and optimising infection prevention for children with cochlear implants.

AIM: To describe the clinical epidemiology of children receiving cochlear implants, as well as the management and outcomes of cochlear implant infections and adherence to infection prevention measures. METHODS: A retrospective observational study was conducted in children ≤18 years who received cochlear implants in Western Australia's tertiary paediatric hospital. Information was obtained from medical and laboratory records regarding demographics, indication for implant, implant infection and preoperative Staphylococcus aureus screening/decolonisation. Immunisation history was examined using the Australian Immunisation Register. RESULTS: Overall, 118 children received cochlear implants, with 158 devices inserted (599 cochlear implant insertion-years). An implant infection rate of 3.8% (6/158) was identified during the study period (four pneumococcal and two community-acquired methicillin resistant S. aureus infections). All required surgical management, with an overall median duration of antibiotic therapy of 37 days (interquartile range (IQR) 29-48) and median length of stay of 8 days (IQR 8-9.5). All devices were retained and there were no relapses or deaths. Half of the children who developed cochlear implant infections (50%, 3/6) were up-to-date with additional pneumococcal vaccinations and no children (0%, 0/118) received S. aureus screening/decolonisation before implant insertion. CONCLUSIONS: Favourable outcomes were achieved with cochlear implant retention; however, the treatment was burdensome for families. We demonstrate significant scope to improve adherence to existing infection prevention strategies and provide direction for optimising preventative measures in the future. These include ensuring parental education, additional pneumococcal vaccinations and S. aureus decolonisation which are delivered as an infection prevention bundle to the growing population of infants receiving cochlear implants.

P2/N95 respirators & surgical masks to prevent SARS-CoV-2 infection: Effectiveness & adverse effects.

BACKGROUND: Millions of people have acquired and died from SARS-CoV-2 infection during the COVID-19 pandemic. Healthcare workers (HCWs) are required to wear personal protective equipment (PPE), including surgical masks and P2/N95 respirators, to prevent infection while treating patients. However, the comparative effectiveness of respirators and masks in preventing SARS-CoV-2 infection and the likelihood of experiencing adverse events (AEs) with wear are unclear. METHODS: Searches were carried out in PubMed, Europe PMC and the Cochrane COVID-19 Study Register to 14 June 2021. A systematic review of comparative epidemiological studies examining SARS-CoV-2 infection or AE incidence in HCWs wearing P2/N95 (or equivalent) respirators and surgical masks was performed. Article screening, risk of bias assessment and data extraction were duplicated. Meta-analysis of extracted data was carried out in RevMan. RESULTS: Twenty-one studies were included, with most having high risk of bias. There was no statistically significant difference in respirator or surgical mask effectiveness in preventing SARS-CoV-2 infection (OR 0.85, [95%CI 0.72, 1.01]). Healthcare workers experienced significantly more headaches (OR 2.62, [95%CI 1.18, 5.81]), respiratory distress (OR 4.21, [95%CI 1.46, 12.13]), facial irritation (OR 1.80, [95%CI 1.03, 3.14]) and pressure-related injuries (OR 4.39, [95%CI 2.37, 8.15]) when wearing respirators compared to surgical masks. CONCLUSION: The existing epidemiological evidence does not enable definitive assessment of the effectiveness of respirators compared to surgical masks in preventing infection. Healthcare workers wearing respirators may be more likely to experience AEs. Effective mitigation strategies are important to ensure the uptake and correct use of respirators by HCWs.

Examining the interseasonal resurgence of respiratory syncytial virus in Western Australia.

BACKGROUND: Following a relative absence in winter 2020, a large resurgence of respiratory syncytial virus (RSV) detections occurred during the 2020/2021 summer in Western Australia. This seasonal shift was linked to SARS-CoV-2 public health measures. We examine the epidemiology and RSV testing of respiratory-coded admissions, and compare clinical phenotype of RSV-positive admissions between 2019 and 2020. METHOD: At a single tertiary paediatric centre, International Classification of Diseases, 10th edition Australian Modification-coded respiratory admissions longer than 12 hours were combined with laboratory data from 1 January 2019 to 31 December 2020. Data were grouped into bronchiolitis, other acute lower respiratory infection (OALRI) and wheeze, to assess RSV testing practices. For RSV-positive admissions, demographics and clinical features were compared between 2019 and 2020. RESULTS: RSV-positive admissions peaked in early summer 2020, following an absent winter season. Testing was higher in 2020: bronchiolitis, 94.8% vs 89.2% (p=0.01); OALRI, 88.6% vs 82.6% (p=0.02); and wheeze, 62.8% vs 25.5% (p<0.001). The 2020 peak month, December, contributed almost 75% of RSV-positive admissions, 2.5 times the 2019 peak. The median age in 2020 was twice that observed in 2019 (16.4 vs 8.1 months, p<0.001). The proportion of RSV-positive OALRI admissions was greater in 2020 (32.6% vs 24.9%, p=0.01). There were no clinically meaningful differences in length of stay or disease severity. INTERPRETATION: The 2020 RSV season was in summer, with a larger than expected peak. There was an increase in RSV-positive non-bronchiolitis admissions, consistent with infection in older RSV-naïve children. This resurgence raises concern for regions experiencing longer and more stringent SARS-CoV-2 public health measures.

Shigella species epidemiology and antimicrobial susceptibility: the implications of emerging azithromycin resistance for guiding treatment, guidelines and breakpoints.

OBJECTIVES: To examine antimicrobial susceptibility patterns and predictors of resistance among Shigella isolates in New South Wales (NSW), Australia during 2013-14 with emphasis on azithromycin. METHODS: Cross-sectional analysis of all shigellosis cases (160) notified to public health authorities in NSW, Australia was performed. RESULTS: Among 160 Shigella isolates tested, 139 (86.9%) were susceptible to azithromycin, 104 (65.0%) to ciprofloxacin and 38 (23.7%) to co-trimoxazole. Ciprofloxacin resistance was 1.9 times more common in infections acquired in Australia compared with those acquired overseas, while azithromycin resistance was 8.5 times more common in males. CONCLUSIONS: We recommend ongoing reconsideration of guidelines for the treatment of shigellosis based on emerging resistance patterns. First-line therapy may need to be reconsidered based on local resistance rates due to common resistance to co-trimoxazole and ciprofloxacin. We recommend culture and susceptibility testing for suspected and proven shigellosis. Azithromycin susceptibility breakpoints for Shigella species may need to be species specific.

Quantitative multiplexed-tandem PCR for direct detection of bacteraemia in critically ill patients.

Culture remains the gold standard for diagnosis of blood stream infections (BSI), but its clinical utility is limited by slow turnaround times. Here we describe a method for rapid quantitative detection of bacterial DNA directly extracted from whole blood using a multiplexed tandem real-time PCR (MT-PCR) assay targeting Staphylococcus, Streptococcus, Pseudomonas, Enterococcus and Enterobacteriaceae 16S rDNA genes. Results were available less than 3.5 hours after blood collection with all five bacterial targets having limits of detection between 101 and 103 CFU/mL. A small-scale clinical evaluation of the assay using blood samples collected from 15 patients admitted to the Intensive Care Unit at our institution demonstrated 93.3% (14/15) concordance between MT-PCR and blood culture when detection of persistent bacterial DNAemia by MT- PCR was considered a true result. Further evaluation with clinical samples is needed; however, this method has potential as an effective rule-in diagnostic tool for bacteraemic sepsis and septic shock.

A 15-Year Old Burmese Girl With Hemoptysis: A Case Report.

We report the case of a 15-year-old Burmese girl who presented with hemoptysis 3 years after immigrating to Australia with a background of previously treated pulmonary tuberculosis at 6 years of age. Cavitation in the right upper lobe had originally been identified on her baseline chest radiograph following arrival to Australia; extensive investigations were conducted thereafter to exclude causes of cavitary lung disease; these were negative. Paragonimus westermani was finally diagnosed on serological grounds 3 years after this child's original presentation, with subsequent identification of P. westermani ova in sputum and in stool. Clinicians should be alert to the possibility of Paragonimiasis in children who have traveled to or originate from endemic countries who present with a clinically compatible illness. Treatment is simple and effective. Failure to consider this pathogen early may result in unnecessary investigative workup and delayed diagnosis.

Nontuberculous Mycobacteria in Children: A Focus on Bloodstream Infections.

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous organisms with variable disease-causing potential. Bloodstream infections caused by NTM in children are poorly described. METHODS: We describe a retrospective case series of children with culture-confirmed mycobacterial disease managed at the Children's Hospital at Westmead between July 2005 and June 2015. RESULTS: Sixty-five patients had 149 positive NTM cultures; 55 (83.0%) episodes in 54 patients were considered clinically significant. Of the 54 children who met criteria for NTM disease, 25 (46.3%) had lymphadenitis, 13 (24.1%) lung disease, 8 (14.8%) had soft tissue infection or osteomyelitis and 8 (14.8%) had bacteremia. All children with bacteremia had a central venous catheter; those with pulmonary infection had underlying lung disease and all children with soft tissue infection or osteomyelitis had a history of recent penetrating injury. Disease caused by Mycobacterium avium-intracellulare complex was most common, accounting for 19 (76.0%) and 7 (53.8%) lymph node and lung infections, respectively. The most frequently isolated rapid growing mycobacteria were Mycobacterium fortuitum (8; 15%) and Mycobacterium abscessus (6; 11%), with M. fortuitum accounting for the majority (6; 75%) of bloodstream infections. Six (75%) patients with bacteremia had their intravenous catheter removed and all had a favorable outcome. A single disease relapse was reported in 1 of 2 patients with a retained catheter. CONCLUSION: Lymphadenitis was the most common NTM disease manifestation and not associated with comorbidity. NTM bacteremia was always associated with a central line and catheter removal with cure. We were unable to assess the added value of various antibiotic regimens.

Antibiotic duration and timing of the switch from intravenous to oral route for bacterial infections in children: systematic review and guidelines.

Few studies are available to inform duration of intravenous antibiotics for children and when it is safe and appropriate to switch to oral antibiotics. We have systematically reviewed antibiotic duration and timing of intravenous to oral switch for 36 paediatric infectious diseases and developed evidence-graded recommendations on the basis of the review, guidelines, and expert consensus. We searched databases and obtained information from references identified and relevant guidelines. All eligible studies were assessed for quality. 4090 articles were identified and 170 studies were included. Evidence relating antibiotic duration to outcomes in children for some infections was supported by meta-analyses or randomised controlled trials; in other infections data were from retrospective series only. Criteria for intravenous to oral switch commonly included defervescence and clinical improvement with or without improvement in laboratory markers. Evidence suggests that intravenous to oral switch can occur earlier than previously recommended for some infections. We have synthesised recommendations for antibiotic duration and intravenous to oral switch to support clinical decision making and prospective research.