Outbreak of invasive Group A streptococcus disease in a nursing home in Ireland in February 2023 caused by emm type 18.

An out-of-season increase in cases of invasive Group A streptococcus (iGAS) was observed in Ireland between October 2022 and August 2023. We describe the management of an iGAS outbreak involving three nursing home residents in Ireland in early 2023. A regional Department of Public Health was notified of an iGAS case in a nursing home resident in January 2023. When two further cases among residents were notified 7 days later, an outbreak was declared. Surveillance for GAS/iGAS infection in residents and staff was undertaken. The site was visited to provide infection prevention and control (IPC) support. Isolates were emm typed. A total of 38 residents and 29 staff in contact with resident cases were provided with antibiotic chemoprophylaxis. Seven additional staff with no direct resident contact also received chemoprophylaxis after finding one probable localised GAS infection among them. No more iGAS cases subsequently occurred.Site visit recommendations included advice on terminal cleaning and cleaning of shared equipment, as well as strengthening staff education on hand hygiene and masking. All isolates were of emm subtype 18.12, a subtype not previously detected in Ireland. Key outbreak control measures were rapid delivery of IPC support and chemoprophylaxis. Emm18 is infrequently associated with GAS infections.

Predicting community acquired bloodstream infection in infants using full blood count parameters and C-reactive protein; a machine learning study.

Early recognition of bloodstream infection (BSI) in infants can be difficult, as symptoms may be non-specific, and culture can take up to 48 h. As a result, many infants receive unneeded antibiotic treatment while awaiting the culture results. In this study, we aimed to develop a model that can reliably identify infants who do not have positive blood cultures (and, by extension, BSI) based on the full blood count (FBC) and C-reactive protein (CRP) values. Several models (i.e. multivariable logistic regression, linear discriminant analysis, K nearest neighbors, support vector machine, random forest model and decision tree) were trained using FBC and CRP values of 2693 infants aged 7 to 60 days with suspected BSI between 2005 and 2022 in a tertiary paediatric hospital in Dublin, Ireland. All models tested showed similar sensitivities (range 47% - 62%) and specificities (range 85%-95%). A trained decision tree and random forest model were applied to the full dataset and to a dataset containing infants with suspected BSI in 2023 and showed good segregation of a low-risk and high-risk group. Negative predictive values for these two models were high for the full dataset (> 99%) and for the 2023 dataset (> 97%), while positive predictive values were low in both dataset (4%-20%).   Conclusion: We identified several models that can predict positive blood cultures in infants with suspected BSI aged 7 to 60 days. Application of these models could prevent administration of antimicrobial treatment and burdensome diagnostics in infants who do not need them. What is Known: • Bloodstream infection (BSI) in infants cause non-specific symptoms and may be difficult to diagnose. • Results of blood cultures can take up to 48 hours. What is New: • Machine learning models can contribute to clinical decision making on BSI in infants while blood culture results are not yet known.

Where to start? The Irish Emergency Department Antimicrobial Discharge (EDAD) study: a multicentre, prospective cohort analysis.

Objectives: To determine the percentage of patients across Ireland who are discharged from the Emergency Department (ED) with an antimicrobial prescription, the indication, classification of infections, and guideline compliance. To identify potential areas for antimicrobial stewardship (AMS) interventions in the ED. Patients and methods: A multicentre, prospective cohort analysis study in EDs across eight hospitals in Ireland. At each site, patients aged 1 month and older who presented to the ED and were discharged directly from the ED were included. A random selection of records of patients discharged from the ED were reviewed until a minimum of 30 records with an infection diagnosis resulting in an antibiotic prescription were obtained per hospital. The number of patient discharges with no antibiotic prescriptions were included to calculate the denominator. The indication, infection classification and guideline compliance data were collected on the 30 prescriptions in the participating hospitals. Results: A total of 2619 patient records were reviewed. Of these, 249 (9.5%) patients were discharged with antimicrobial prescriptions from the ED. Most (158; 63%) were classified as probable bacterial infection, 21 (8%) as probable viral, and 18 (7%) had no documented evidence of infection. Three indications accounted for 73% of antimicrobial prescriptions: skin/soft tissue infection; ear, nose and throat infection; and urinary tract infection. Overall guideline compliance was 64%. Conclusions: Several areas for AMS interventions to optimize antimicrobial prescribing in the ED were identified, including targeted local and national guideline reviews, delayed prescribing, improved point-of-care testing and prescriber and patient education.

Increased rates of invasive bacterial disease in late 2022.

Invasive bacterial disease is associated with significant morbidity and mortality. In winter 2022, there was an apparent increased rate of invasive bacterial disease compared to preceding years. Cross-site retrospective analysis of the three Children's Health Ireland (CHI) hospitals looking at children admitted between 1st October 2022-31st December 2022 (Q4) with community-acquired invasive bacterial disease, defined as an abscess in a normally sterile site in the head, neck and chest or isolation or PCR detection of Streptococcus pneumoniae, Neisseria meningitidis, Streptococcus pyogenes (Group A streptococcus) or Haemophilus influenzae from a normally sterile site. Case numbers were compared to Q4 in each of 2018-2021. Eighty-two children met the case definition in Q4 2022 vs 97 (Q4 2018-2021). In 2022, 42/82 (51%) were female, median age 3.75 years (1.5-8.25 years). Only 2 (2%) were immunosuppressed and 2 others (2%) had underlying neurodisability. Fifty (61%) were admitted on second or subsequent presentation to a healthcare setting. Fifty-six (68%) had an abscess in a sterile site. Bloodstream infection (positive blood culture or PCR: 24 (29%)) was the most common site of infection, followed by neck 22 (27%) and intracranial 12 (15%). Group A streptococcus (GAS) 27 (33%) was the most common organism isolated. Seven cases (9%) died in 2022 compared to 2 patients (2%) from 2018 to 2021 (p < 0.05). More children had Paediatric Overall Performance Category (POPC) scores > 1 in 2022 than 2018-2021 (p = 0.003).  Conclusion: Invasive bacterial diseases increased in Q4 2022 with higher morbidity and mortality than in the preceding 4 years. Group A streptococcal infection was the most significant organism in 2022. What is known: • Invasive bacterial disease is the leading cause of childhood mortality globally. • There was an increase in cases of invasive Group A streptococcus infections reported in many countries (including Ireland) during the winter of 2022/23. What is new: • Head, neck and chest abscesses increased in Q4 of 2022 compared to the previous 4 years combined. • Invasive bacterial infections in Q4 of 2022 were associated with higher rates of mortality (9%), paediatric intensive care unit (PICU) admission (24%) and requirement for surgical drainage or intervention (67%) than in the preceding years.

Trends in invasive bacterial diseases during the first 2 years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries and territories in the IRIS Consortium.

BACKGROUND: The Invasive Respiratory Infection Surveillance (IRIS) Consortium was established to assess the impact of the COVID-19 pandemic on invasive diseases caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus agalactiae. We aimed to analyse the incidence and distribution of these diseases during the first 2 years of the COVID-19 pandemic compared to the 2 years preceding the pandemic. METHODS: For this prospective analysis, laboratories in 30 countries and territories representing five continents submitted surveillance data from Jan 1, 2018, to Jan 2, 2022, to private projects within databases in PubMLST. The impact of COVID-19 containment measures on the overall number of cases was analysed, and changes in disease distributions by patient age and serotype or group were examined. Interrupted time-series analyses were done to quantify the impact of pandemic response measures and their relaxation on disease rates, and autoregressive integrated moving average models were used to estimate effect sizes and forecast counterfactual trends by hemisphere. FINDINGS: Overall, 116 841 cases were analysed: 76 481 in 2018-19, before the pandemic, and 40 360 in 2020-21, during the pandemic. During the pandemic there was a significant reduction in the risk of disease caused by S pneumoniae (risk ratio 0·47; 95% CI 0·40-0·55), H influenzae (0·51; 0·40-0·66) and N meningitidis (0·26; 0·21-0·31), while no significant changes were observed for S agalactiae (1·02; 0·75-1·40), which is not transmitted via the respiratory route. No major changes in the distribution of cases were observed when stratified by patient age or serotype or group. An estimated 36 289 (95% prediction interval 17 145-55 434) cases of invasive bacterial disease were averted during the first 2 years of the pandemic among IRIS-participating countries and territories. INTERPRETATION: COVID-19 containment measures were associated with a sustained decrease in the incidence of invasive disease caused by S pneumoniae, H influenzae, and N meningitidis during the first 2 years of the pandemic, but cases began to increase in some countries towards the end of 2021 as pandemic restrictions were lifted. These IRIS data provide a better understanding of microbial transmission, will inform vaccine development and implementation, and can contribute to health-care service planning and provision of policies. FUNDING: Wellcome Trust, NIHR Oxford Biomedical Research Centre, Spanish Ministry of Science and Innovation, Korea Disease Control and Prevention Agency, Torsten Söderberg Foundation, Stockholm County Council, Swedish Research Council, German Federal Ministry of Health, Robert Koch Institute, Pfizer, Merck, and the Greek National Public Health Organization.

A scoping review and behavioural analysis of factors underlying overuse of antimicrobials.

Background: Overuse of antimicrobials is a challenging global issue that contributes to antimicrobial resistance. Despite widespread awareness of the problem among members of the medical community and various attempts to improve prescription practices, existing antimicrobial stewardship programmes are not always effective. In our view, this may reflect limited understanding of factors that influence prescription of antimicrobials as empirical therapy, implying a need to address the psychological mechanisms behind some of the specific behaviours involved. Objectives: To identify factors that influence the antimicrobials prescription as empirical therapy, and to relate these factors to findings from behavioural science. Methods: We conducted a scoping review of the literature on the factors underlying antimicrobial prescription decisions, following the protocol designed using PRISMA guidelines. Results and conclusions: From a final sample of 90 sources, we identified ten factors important in antimicrobial prescription decisions. In the second stage of our analysis, we grouped them into five final categories: (1) nature of the decision, (2) social influences, (3) individual differences, (4) characteristics of the patient, (5) context. We analyse these categories using a behavioural science perspective.

Invasive pneumococcal surveillance to assess the potential benefits of extended spectrum conjugate vaccines (PCV15/PCV20) in older adults.

The introduction of pneumococcal conjugate vaccines (PCV) into the childhood vaccination programme has reduced invasive pneumococcal disease (IPD). Although anticipated from data elsewhere, surveillance in Ireland has confirmed reductions in IPD amongst those ⩾65 years of age due to a decline of PCV serotypes in this age group. Currently, direct protection against IPD in the elderly is focused on immunisation with the 23-valent pneumococcal polysaccharide vaccine (PPV23). However, immunity may not be as effective as with PCV and, furthermore, PPV23 uptake is poor in Ireland. Hence, consideration should be given to providing a PCV to this age group.

The use of complexity theory to inform antimicrobial stewardship: a scoping review.

BACKGROUND: Complexity theory has previously been used as a conceptual lens in human healthcare research. Antimicrobial stewardship (AMS) is an inherently complex healthcare intervention; however, the extent to which complexity has been operationalized in AMS is currently unclear. AIM: To investigate if, and how, complexity theory has been used to inform AMS in human healthcare. METHODS: Scoping review methodology. Empirical research or policy specifically referencing complexity in relation to AMS were considered in any human healthcare setting and geographical location. Databases searched were: Cinahl, Cochrane Library, Embase, Medline, National Institute for Health and Care Excellence, PsycInfo, Scopus and Web of Science from inception to June 2020. Grey literature and other databases searched: EVIPNet, Google, Mednar, Proquest Theses, and the World Health Organization library of national antimicrobial resistance action plans. Non-English language articles were excluded. RESULTS: Of 612 records retrieved, 8 articles were included. Heterogeneity in study design and geographical location were noted. Three interventional studies evaluated AMS in hospital (n = 2) and long-term care (n = 1) settings. Remaining studies were non-interventional and proposed AMS strategies conceptualized through complexity theory. The importance of close engagement between researchers or policy administrators and the target population was emphasized in all studies, as a means of ensuring AMS relevance and success. CONCLUSIONS: There is a paucity of AMS research informed by complexity theory, and no policy documents could be located using complexity as a guiding theory. Mixed methods, informed by complexity theory, is a potentially suitable strategy to develop, implement and evaluate AMS as a complex intervention.

Neurological involvement in children with hemolytic uremic syndrome.

Our objective was to establish the rate of neurological involvement in Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome (STEC-HUS) and describe the clinical presentation, management and outcome. A retrospective chart review of children aged ≤ 16 years with STEC-HUS in Children's Health Ireland from 2005 to 2018 was conducted. Laboratory confirmation of STEC infection was required for inclusion. Neurological involvement was defined as encephalopathy, focal neurological deficit, and/or seizure activity. Data on clinical presentation, management, and outcome were collected. We identified 240 children with HUS; 202 had confirmed STEC infection. Neurological involvement occurred in 22 (11%). The most common presentation was seizures (73%). In the neurological group, 19 (86%) were treated with plasma exchange and/or eculizumab. Of the 21 surviving children with neurological involvement, 19 (91%) achieved a complete neurological recovery. A higher proportion of children in the neurological group had renal sequelae (27% vs. 12%, P = .031). One patient died from multi-organ failure.Conclusion: We have identified the rate of neurological involvement in a large cohort of children with STEC-HUS as 11%. Neurological involvement in STEC-HUS is associated with good long-term outcome (complete neurological recovery in 91%) and a low case-fatality rate (4.5%) in our cohort. What is Known: • HUS is associated with neurological involvement in up to 30% of cases. • Neurological involvement has been reported as predictor of poor outcome, with associated increased morbidity and mortality. What is New: • The incidence of neurological involvement in STEC-HUS is 11%. • Neurological involvement is associated with predominantly good long-term outcome (90%) and a reduced case-fatality rate (4.5%) compared to older reports.

Infant Escherichia coli urinary tract infection: is it associated with meningitis?

OBJECTIVES: Determine the prevalence of coexisting bacterial meningitis (BM) and sterile cerebrospinal fluid (CSF) with raised white cell count relative to age ('pleocytosis') in the presence of Escherichia coli urinary tract infection (UTI), with the addition of CSF E. coli PCR analysis. DESIGN: Single-centre, retrospective cohort study. SETTING: Tertiary paediatric hospital. PARTICIPANTS: Children aged 8 days to 2 years, with a pure growth of E. coli from urine and a CSF sample taken within 48 hours of a positive urine culture between 1 January 2014 and 30 April 2019. MAIN OUTCOME MEASURE: Prevalence of coexisting E. coli BM with UTI, defined as a pure growth E. coli from urine and a CSF culture with pure growth E. coli and/or positive E. coli PCR. RESULTS: 1903 patients had an E. coli UTI, of which 314 (16%) had a CSF sample taken within 48 hours. No cases of coexisting E. coli BM were identified. There were 71 (23%) cases of pleocytosis, 57 (80%) of these had PCR analysis, all of which were E. coli PCR not detected. Patients aged 1-6 months accounted for 72% of all lumbar punctures (LPs). CONCLUSION: The risk of E. coli UTI and coexisting E. coli BM is low. There is potential to reduce the number of routine LPs in infants with a diagnosis of E. coli UTI with the greatest impact in children up to 6 months of age. CSF E. coli PCR can help further reduce post-test probability of BM in the setting of pleocytosis.

Paediatric Common Infections Pathways: improving antimicrobial stewardship and promoting ambulation for children presenting with common infections to hospitals in the UK and Ireland.

Paediatric common infection pathways have been developed in collaboration between the BSAC and national paediatric groups, addressing the management of cellulitis, lymphadenitis/lymph node abscess, pneumonia/pleural empyema, pyelonephritis, tonsillitis/peritonsillar abscess, otitis media/mastoiditis, pre-septal/post-septal (orbital) cellulitis, and meningitis. Guidance for the management of a child presenting with a petechial/purpuric rash and the infant under 3 months of age with fever is also provided. The aim of these pathways is to support the delivery of high-quality infection management in children presenting to a hospital. The pathways focus on diagnostic approaches, including the recognition of red flags suggesting complex or severe infection requiring urgent intervention, approaches to antimicrobial stewardship (AMS) principles and guidance on safe and timely ambulation aligned with good practice of outpatient parenteral antimicrobial therapy (OPAT).

Risk factors for carriage of meningococcus in third-level students in Ireland: an unsupervised machine learning approach.

The aim of this study was to examine the risk factors for pharyngeal carriage of meningococci in third-level students using an unsupervised machine learning approach. Data were gathered as part of meningococcal prevalence studies conducted by the Irish Meningitis and Sepsis Reference Laboratory (IMSRL). Pharyngeal swab cultures for meningococcal carriage were taken from each student once they had completed a single-page anonymous questionnaire addressing basic demographics, social behaviors, living arrangements, vaccination, and antibiotic history. Data were analyzed using multiple correspondence analysis through a machine learning approach.In total, 16,285 students who had a pharyngeal throat swab taken returned a fully completed questionnaire. Overall, meningococcal carriage rate was 20.6%, and the carriage of MenW was 1.9% (n = 323). Young Irish adults aged under 20 years and immunized with the meningococcal C vaccine had a higher MenW colonization rate (n = 171/1260, 13.5%) compared with non-Irish adults aged 20 years or older without the MenC vaccine (n = 5/81, 6%, chi-square = 3.6, p = .05). Unsupervised machine learning provides a useful technique to explore meningococcal carriage risk factors. The issue is very complex, and asked risk factors only explain a small proportion of the carriage. This technique could be used on other conditions to explore reasons for carriage.

Invasive Group B Streptococcus Disease With Recurrence and in Multiples: Towards a Better Understanding of GBS Late-Onset Sepsis.

Group B Streptococcus (GBS) is a common intestinal colonizer during the neonatal period, but also may cause late-onset sepsis or meningitis in up to 0.5% of otherwise healthy colonized infants after day 3 of life. Transmission routes and risk factors of this late-onset form of invasive GBS disease (iGBS) are not fully understood. Cases of iGBS with recurrence (n=25) and those occurring in parallel in twins/triplets (n=32) from the UK and Ireland (national surveillance study 2014/15) and from Germany and Switzerland (retrospective case collection) were analyzed to unravel shared (in affected multiples) or fixed (in recurrent disease) risk factors for GBS disease. The risk of iGBS among infants from multiple births was high (17%), if one infant had already developed GBS disease. The interval of onset of iGBS between siblings was 4.5 days and in recurrent cases 12.5 days. Disturbances of the individual microbiome, including persistence of infectious foci are suggested e.g. by high usage of perinatal antibiotics in mothers of affected multiples, and by the association of an increased risk of recurrence with a short term of antibiotics [aOR 4.2 (1.3-14.2), P=0.02]. Identical GBS serotypes in both recurrent infections and concurrently infected multiples might indicate a failed microbiome integration of GBS strains that are generally regarded as commensals in healthy infants. The dynamics of recurrent GBS infections or concurrent infections in multiples suggest individual patterns of exposure and fluctuations in host immunity, causing failure of natural niche occupation.

Changes in the incidence of invasive disease due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis during the COVID-19 pandemic in 26 countries and territories in the Invasive Respiratory Infection Surveillance Initiative: a prospective analysis of surveillance data.

BACKGROUND: Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, which are typically transmitted via respiratory droplets, are leading causes of invasive diseases, including bacteraemic pneumonia and meningitis, and of secondary infections subsequent to post-viral respiratory disease. The aim of this study was to investigate the incidence of invasive disease due to these pathogens during the early months of the COVID-19 pandemic. METHODS: In this prospective analysis of surveillance data, laboratories in 26 countries and territories across six continents submitted data on cases of invasive disease due to S pneumoniae, H influenzae, and N meningitidis from Jan 1, 2018, to May, 31, 2020, as part of the Invasive Respiratory Infection Surveillance (IRIS) Initiative. Numbers of weekly cases in 2020 were compared with corresponding data for 2018 and 2019. Data for invasive disease due to Streptococcus agalactiae, a non-respiratory pathogen, were collected from nine laboratories for comparison. The stringency of COVID-19 containment measures was quantified using the Oxford COVID-19 Government Response Tracker. Changes in population movements were assessed using Google COVID-19 Community Mobility Reports. Interrupted time-series modelling quantified changes in the incidence of invasive disease due to S pneumoniae, H influenzae, and N meningitidis in 2020 relative to when containment measures were imposed. FINDINGS: 27 laboratories from 26 countries and territories submitted data to the IRIS Initiative for S pneumoniae (62 837 total cases), 24 laboratories from 24 countries submitted data for H influenzae (7796 total cases), and 21 laboratories from 21 countries submitted data for N meningitidis (5877 total cases). All countries and territories had experienced a significant and sustained reduction in invasive diseases due to S pneumoniae, H influenzae, and N meningitidis in early 2020 (Jan 1 to May 31, 2020), coinciding with the introduction of COVID-19 containment measures in each country. By contrast, no significant changes in the incidence of invasive S agalactiae infections were observed. Similar trends were observed across most countries and territories despite differing stringency in COVID-19 control policies. The incidence of reported S pneumoniae infections decreased by 68% at 4 weeks (incidence rate ratio 0·32 [95% CI 0·27-0·37]) and 82% at 8 weeks (0·18 [0·14-0·23]) following the week in which significant changes in population movements were recorded. INTERPRETATION: The introduction of COVID-19 containment policies and public information campaigns likely reduced transmission of S pneumoniae, H influenzae, and N meningitidis, leading to a significant reduction in life-threatening invasive diseases in many countries worldwide. FUNDING: Wellcome Trust (UK), Robert Koch Institute (Germany), Federal Ministry of Health (Germany), Pfizer, Merck, Health Protection Surveillance Centre (Ireland), SpID-Net project (Ireland), European Centre for Disease Prevention and Control (European Union), Horizon 2020 (European Commission), Ministry of Health (Poland), National Programme of Antibiotic Protection (Poland), Ministry of Science and Higher Education (Poland), Agencia de Salut Pública de Catalunya (Spain), Sant Joan de Deu Foundation (Spain), Knut and Alice Wallenberg Foundation (Sweden), Swedish Research Council (Sweden), Region Stockholm (Sweden), Federal Office of Public Health of Switzerland (Switzerland), and French Public Health Agency (France).

Genomic epidemiology of group B streptococci spanning 10 years in an Irish maternity hospital, 2008-2017.

OBJECTIVES: The genomic epidemiology of group b streptococcal (GBS) isolates from the Rotunda maternity hospital, Dublin, 2008-2017, was investigated. METHODS: Whole genome sequences of isolates (invasive, n = 114; non-invasive, n = 76) from infants and women were analysed using the PubMLST database (https://pubmlst.org/sagalactiae/). RESULTS: Serotypes III (36%), Ia (18%), V (17%), II (11%) and Ib, (9%) and sequence types (ST) 17 (23%), ST-23 (14%), ST-1 (12%) and ST-19 (7%) were most common. Core genome MLST (cgMLST) differentiated isolates of the same ST, grouped STs into five lineages congruent with known clonal complexes and identified known mother-baby pairs and suspected linked infant cases. Clonal complex (CC) 17 accounted for 40% and 22% of infant and maternal invasive cases, respectively and 21% of non-invasive isolates. CC23 and CC19 were associated with maternal disease (30%) and carriage (24%), respectively. Erythromycin (26%) and clindamycin (18%) resistance increased over the study period and was associated with presence of the erm(B) gene (55%), CC1 (33%) and CC19 (24%). A multi-resistant integrative conjugative element incorporated in the PI-1 locus was detected in CC17, an ST-12 and ST-23 isolate confirming the global dissemination of this element. All isolates possessed one or more pilus islands. Genes encoding other potential protective proteins including Sip, C5a peptidase and Srr1 were present in 100%, 99.5% and 65.8% of isolates, respectively. The srr2 gene was unique to CC17. CONCLUSIONS: The PubMLST.org website provides a valuable framework for genomic GBS surveillance to inform on local and global GBS epidemiology, preventive and control measures.

Uncovering Infant Group B Streptococcal (GBS) Disease Clusters in the United Kingdom and Ireland Through Genomic Analysis: A Population-based Epidemiological Study.

BACKGROUND: The true frequency of hospital outbreaks of invasive group B streptococcal (iGBS; Streptococcus agalactiae) disease in infants is unknown. We used whole genome sequencing (WGS) of iGBS isolates collected during a period of enhanced surveillance of infant iGBS disease in the UK and Ireland to determine the number of clustered cases. METHODS: Potentially linked iGBS cases from infants with early (<7 days of life) or late-onset (7-89 days) disease were identified from WGS data (HiSeq 2500 platform, Illumina) from clinical sterile site isolates collected between 04/2014 and 04/2015. We assessed time and place of cases to determine a single-nucleotide polymorphism (SNP) difference threshold for clustered cases. Case details were augmented through linkage to national hospital admission data and hospital record review by local microbiologists. RESULTS: Analysis of sequences indicated a cutoff of ≤5 SNP differences to define iGBS clusters. Among 410 infant iGBS isolates, we identified 7 clusters (4 genetically identical pairs with 0 SNP differences, 1 pair with 3 SNP differences, 1 cluster of 4 cases with ≤1 SNP differences) of which 4 clusters were uncovered for the first time. The clusters comprised 16 cases, of which 15 were late-onset (of 192 late-onset cases with sequenced isolates) and 1 an early-onset index case. Serial intervals between cases ranged from 0 to 59 (median 12) days. CONCLUSIONS: Approximately 1 in 12 late-onset infant iGBS cases were part of a hospital cluster. Over half of the clusters were previously undetected, emphasizing the importance of routine submission of iGBS isolates to reference laboratories for cluster identification and genomic confirmation.

Epidemiology of Haemophilus influenzae in the Republic of Ireland, 2010-2018.

The purpose of this study was to investigate H. influenzae epidemiology in the Republic of Ireland. We performed serotyping, multi-locus sequence typing (MLST) and susceptibility testing on H. influenzae isolates received by the Irish Meningitis and Sepsis Reference Laboratory from 2010 to 2018. Three hundred sixty-seven invasive and 41 non-invasive infection (NII) isolates were received. Invasive isolates were mostly recovered from paediatric (21%) and elderly (42%) populations. Invasive disease was more prevalent in females of childbearing age (72%) compared with males the same age (28%). Non-typeable H. influenzae (NTHi) predominated among invasive (83%) and NII (95%). Invasive Hib disease isolates were infrequent (4%, n = 15). Among invasive disease, Hif was the commonest encapsulated serotype (10%, n = 37), and the only encapsulated serotype detected in NII (5%, 2/41). The first PCR-confirmed serotypes d and a in Ireland were characterised among invasive disease in 2017 and 2018, respectively. MLST revealed a diverse NTHi population, while encapsulated serotypes were clonal. Sequence type (ST) 103 (n = 14) occurred exclusively in invasive NTHi disease. Ampicillin resistance (AmpR) was 18% among invasive isolates and 22% in NII. ß-Lactamase production was the main source of ampicillin resistance in invasive and NII isolates. We detected ß-lactamase negative ampicillin resistance (BLNAR) among invasive isolates. We report an NTHi fluoroquinolone-resistant clone: ST1524 among invasive (n = 2) and NII isolates (n = 2). The Hib vaccine has positively impacted on Hib disease in Ireland, given the low frequency of Hib. The dominance of NTHi, emergence of serotypes a and d and BLNAR suggest a changing H. influenzae epidemiology in Ireland.

Diversity of meningococci associated with invasive meningococcal disease in the Republic of Ireland over a 19 year period, 1996-2015.

This study examined the capsular phenotype and genotype of invasive meningococcal disease (IMD)-associated Neisseria meningitidis recovered in the Republic of Ireland (RoI) between 1996 and 2015. This time period encompasses both pre- (when IMD was hyperendemic in the RoI) and post- meningococcal serogroup C conjugate (MCC) vaccine introduction. In total, 1327 isolates representing over one-third of all laboratory-confirmed cases of IMD diagnosed each epidemiological year (EY), were characterised. Serogroups B (menB) and C (menC) predominated throughout, although their relative abundance changed; with an initial increase in the proportion of menC in the late 1990s followed by their dramatic reduction post-MCC vaccine implementation and a concomitant dominance of menB, despite an overall decline in IMD incidence. While the increase in menC was associated with expansion of specific clonal-complexes (cc), cc11 and cc8; the dominance of menB was not. There was considerable variation in menB-associated cc with declines in cc41/44 and cc32, and increases in cc269 and cc461, contributing to a significant increase in the clonal diversity of menB isolates over the study. This increase in diversity was also displayed among the serosubtyping data, with significant declines in proportions of menB isolates expressing p1.4 and p1.15 antigens. These data highlight the changing diversity of IMD-associated meningococci since 1996 in the RoI and emphasise the need for on-going surveillance particularly in view of the recent introduction of a menB vaccine.

Diagnosis and Management of Pediatric Influenza in the Era of Rapid Diagnostics.

Influenza is a significant cause of childhood morbidity and death; it contributes to up to 16% of hospitalizations for respiratory illnesses worldwide. Novel rapid viral diagnostic tests, including molecular diagnostic tests, have the potential to significantly affect both time to diagnosis and selection of optimal anti-infective therapy. However, little is known about current treatment algorithms used in US hospitals. In this study, for hospitalized children in the United States, we aimed to define the current approaches to influenza diagnosis and treatment and to explore reasons for their potential variation. In this study, we aimed to define the current approaches to pediatric influenza diagnosis and treatment in US hospitals, and to explore reasons for their potential variation. Our results suggest a rise in the availability and use of rapid molecular diagnostic testing in addition to continued variability in anti-infective management, particularly with regard to antiviral use.

Invasive Streptococcus pneumoniae Infections and Vaccine Failures in Children in Ireland From the Postvaccine Era From 2007 to 2018.

BACKGROUND: Invasive pneumococcal disease (IPD) causes life-threatening illnesses including meningitis and bloodstream infection. Here, we report the impact of 7- and 13-valent pneumococcal conjugate vaccines (PCV7/PCV13) after introduction into the Irish pediatric immunization schedule in 2008 and 2010, respectively, and the clinical details surrounding suspected PCV vaccine failures. METHODS: Serotyping and antimicrobial susceptibility testing of all culture-confirmed cases referred from children <16 years of age from July 2007 to June 2018 were assessed. Surveillance data were assessed to identify any potential vaccine failures. RESULTS: The number of IPD cases has decreased by >50% since the introduction of PCVs. The most significant decline PCV serotypes in children <2 years of age, with a 97% decline in PCV7 serotypes, incidence rate ratio (IRR) 0.03, 95% confidence interval (CI): 0.00-0.21; and a 78% decline PCV13-only (PCV13-7) serotypes, IRR 0.22, 95% CI: 0.05-1.04, respectively. However, there has been an increase in non-PCV13 serotypes in children <2 years during the same period (IRR: 2.82, 95% CI: 1.02-7.84; P = 0.0463), with similar serotype trends observed for those 2-4 and 5-15 years of age. There were no clear vaccine replacement serotypes, instead a number of different serotypes emerged. Sixteen vaccine failures were identified, 10 of which were postbooster vaccine failures. Most failures were serotype 19A and resistant to antimicrobials. CONCLUSIONS: Further reducing the incidence of IPD is more challenging as the number of non-PCV13 serotypes has expanded and is now less susceptible to antimicrobials. Consequently, higher valency or broader target vaccines are now required to further prevent IPD in children.