Estimated strain coverage of serogroup B meningococcal vaccines: A retrospective study for disease and carrier strains in Greece (2010-2017).

Invasive meningococcal disease (IMD) is associated with high case fatality rates and long-term sequelae among survivors. Meningococci belonging to six serogroups (A, B, C, W, X, and Y) cause nearly all IMD worldwide, with serogroup B meningococci (MenB) the predominant cause in many European countries, including Greece (~80% of all IMD). In the absence of protein-conjugate polysaccharide MenB vaccines, two protein-based vaccines are available to prevent MenB IMD in Greece: 4CMenB (Bexsero™, GlaxoSmithKline), available since 2014; and MenB-FHbp, (Trumenba™, Pfizer), since 2018. This study investigated the potential coverage of MenB vaccines in Greece using 107 MenB specimens, collected from 2010 to 2017 (66 IMD isolates and 41 clinical samples identified solely by non-culture PCR), alongside 6 MenB isolates from a carriage study conducted during 2017-2018. All isolates were characterized by multilocus sequence typing (MLST), PorA, and FetA antigen typing. Whole Genome Sequencing (WGS) was performed on 66 isolates to define the sequences of vaccine components factor H-binding protein (fHbp), Neisserial Heparin Binding Antigen (NHBA), and Neisseria adhesin A (NadA). The expression of fHbp was investigated with flow cytometric meningococcal antigen surface expression (MEASURE) assay. The fHbp gene was present in-frame in all isolates tested by WGS and in 41 MenB clinical samples. All three variant families of fHbp peptides were present, with subfamily B peptides (variant 1) occurring in 69.2% and subfamily A in 30.8% of the samples respectively. Sixty three of 66 (95.5%) MenB isolates expressed sufficient fHbp to be susceptible to bactericidal killing by MenB-fHbp induced antibodies, highlighting its potential to protect against most IMD in Greece.

A patient with respiratory toxigenic diphtheria in Greece after more than 30 years.

The introduction of treatment and systematic vaccination has significantly reduced diphtheria mortality; however, toxigenic strains continue to circulate worldwide. The emergence of an indigenous diphtheria case with fatal outcome in Greece, after 30 years, raised challenges for laboratory confirmation, clinical and public health management. Toxigenic Corynebacterium diphtheriae was isolated from an incompletely vaccinated 8-year-old boy with underlying conditions. The child passed away due to respiratory distress syndrome, before the administration of diphtheria antitoxin (DAT). All close contacts in family, school and hospital settings were investigated. Pharyngeal swabs were obtained to determine asymptomatic carriage. Chemoprophylaxis was given for 7 days to all close contacts and a booster dose to those incompletely vaccinated. Testing revealed a classmate, belonging to a subpopulation group (Roma), and incompletely vaccinated, as an asymptomatic carrier with an indistinguishable toxigenic strain (same novel multilocus sequence type, designated ST698). This case highlights the role of asymptomatic carriage, as the entry of toxigenic strains into susceptible populations can put individuals and their environment at risk. Maintenance of high-level epidemiological and microbiological surveillance, implementation of systematic vaccination in children and adults with primary and booster doses, availability of a DAT stockpile, and allowing timely administration are the cornerstone to prevent similar incidents in the future.

Establishing nationally representative central line-associated bloodstream infection surveillance data for paediatric patients in Greece.

BACKGROUND: Healthcare-associated infections (HCAIs) are associated with increased morbidity and mortality and with excess costs. Central line-associated bloodstream infections (CLABSIs) are the most common HCAIs in neonates and children. AIM: To establish national benchmark data for rates of CLABSI in neonatal and paediatric intensive care units (NICUs and PICUs) and paediatric oncology units (ONCs). METHODS: Active surveillance for CLABSI was conducted from June 2016 to February 2017. A collaborative of 14 NICUs, four PICUs, and six ONCs participated in the programme. Surveillance definitions of central line (CL), central line utilization (CLU) ratio, CLABSI event, and CLABSI rate were based on the Centers for Disease Control and Prevention's 2014 National Healthcare Safety Network criteria. Medical records were assessed daily for calculating CL-days, patient-days, and susceptibility of isolated organisms. FINDINGS: A total of 111 CLABSI episodes were recorded. The overall mean CLABSI rate was 4.41 infections per 1000 CL-days, and the CLU ratio was 0.31. CLABSI rates were 6.02 in NICUs, 6.09 in PICUs, and 2.78 per 1000 CL-days in ONCs. A total of 123 pathogens were isolated. The most common pathogens were Enterobacteriaceae (36%), followed by Gram-positive cocci (29%), non-fermenting Gram-negative bacteria (16%), and fungi (16%). Overall, 37% of Gram-negative pathogens were resistant to third-generation cephalosporins and 37% to carbapenems. CONCLUSION: Nationally representative CLABSI rates were determined for paediatric patients. These data could be used to benchmark and serve as baseline data for the design and evaluation of infection control and antimicrobial stewardship interventions.

Distinction between rhinovirus-induced acute asthma and asthma-augmented influenza infection.

BACKGROUND: Rhinovirus (RV) is an established trigger of asthma attacks, whereas such a link is less consistent for influenza virus (IFV). OBJECTIVE: In the context of precision medicine, we hypothesized that IFV infection may cause a condition essentially different from RV, and we investigated this by evaluating clinical characteristics of RV/IFV-positive and -negative children with respiratory symptoms and/or fever. METHODS: One thousand two hundred and seven children, 6 months to 13 years old, hospitalized for flu-like illness were recruited in this cross-sectional study. Collected information included demographics, medical history, symptoms/physical findings/diagnosis at presentation and treatment. Nasal secretions were PCR-tested for IFV/RV. Associations were evaluated with adjusted logistic regression models. RESULTS: Rhinovirus positivity was associated with an asthma-like presentation, including increased wheeze/effort of breathing/diagnosis of acute asthma, and decreased fever/vomiting. Conversely, IFV+ children presented with less wheeze/effort of breathing/diagnosis of acute asthma, while they were more frequently febrile. In those with previous asthma history, both viruses induced wheeze; however, IFV was uniquely associated with a more generalised and severe presentation including fever, rales, intercostal muscle retractions and lymphadenopathy. These symptoms were not seen in RV+ asthmatics, who had fewer systemic signs and more cough. CONCLUSIONS AND CLINICAL RELEVANCE: In children with respiratory symptoms and/or fever, RV but not IFV is associated with wheeze and an asthma-like presentation. In those with an asthma history, IFV causes more generalised and severe disease that may be better described as "asthma-augmented influenza" rather than an "asthma attack." Differences in the acute conditions caused by these viruses should be considered in the design of epidemiological studies.

Management of child MDR-TB contacts across countries in the WHO European Region: a survey of current practice.

The World Health Organization European Region has one of the highest rates of multidrug-resistant tuberculosis (MDR-TB) in the world, resulting in many vulnerable children being exposed each year. Evidence for preventive therapy following MDR-TB exposure is limited and current guidance is conflicting. An internet-based survey was performed to determine clinical practice in this region. Seventy-two clinicians from 25 countries participated. Practices related to screening and decision-making were highly variable. Just over half provided preventive therapy for children exposed to MDR-TB; the only characteristic associated with provision was practice within the European Union (adjusted OR 4.07, 95%CI 1.33-12.5).

Community-associated Staphylococcus aureus pneumonia among Greek children: epidemiology, molecular characteristics, treatment, and outcome.

Staphylococcus aureus is an infrequent cause of community-associated (CA-SA) pneumonia in children. The aim of this study was to evaluate the clinical, epidemiological, microbiological, and molecular characteristics of CA-SA pneumonia among children hospitalized in two large tertiary care referral centers during an 8-year period. Cases of CA-SA pneumonia admitted between 2007 and 2014 were retrospectively examined through medical record review. Molecular investigation was performed for available strains; mecA, Panton-Valentine leukocidin (PVL) (lukS-lukF-PV), and fibronectin binding protein A (fnbA) genes were detected by polymerase chain reaction (PCR). Clones were assigned by agr groups, pulsed-field gel electrophoresis (PFGE), SCCmec, and multilocus sequencing typing (MLST). In total, 41 cases were recorded (boys, 61 %), with a median age of 4.3 months (range, 1-175). Methicillin-resistant S. aureus (MRSA) accounted for 31 cases (75.6 %). Complications included empyema (25/41, 61 %), pneumatoceles (7/41, 17 %), and lung abscess (1/41, 2.5 %). Intensive care unit (ICU) admission was required in 58.5 %. Two deaths occurred (4.9 %). Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each). All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1-2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin. Among the 25 studied strains, 20 were mecA-positive (MRSA), carrying also the fnbA gene. Of these, 90 % belonged to the ST80-IV/agr3/PVL-positive clone. Methicillin-susceptible S. aureus (MSSA) strains showed polyclonality, 3/5 were PVL-positive, and 3/5 were fnbA-positive. MRSA and particularly the ST80-IV clone predominated among staphylococcal pneumonia cases in children. Treatment provided was effective in all but two patients, despite the relatively high minimum inhibitory concentration (MIC) of vancomycin and a high resistance to clindamycin.

Variation in paediatric hospital antibiotic guidelines in Europe.

OBJECTIVE: To assess the availability and source of guidelines for common infections in European paediatric hospitals and determine their content and characteristics. DESIGN: Participating hospitals completed an online questionnaire on the availability and characteristics of antibiotic prescribing guidelines and on empirical antibiotic treatment including duration of therapy for 5 common infection syndromes: respiratory tract, urinary tract, skin and soft tissue, osteoarticular and sepsis in neonates and children. RESULTS: 84 hospitals from 19 European countries participated in the survey of which 74 confirmed the existence of guidelines. Complete guidelines (existing guidelines for all requested infection syndromes) were reported by 20% of hospitals and the majority (71%) used a range of different sources. Guidelines most commonly available were those for urinary tract infection (UTI) (74%), neonatal sepsis (71%) and sepsis in children (65%). Penicillin and amoxicillin were the antibiotics most commonly recommended for respiratory tract infections (RTIs) (up to 76%), cephalosporin for UTI (up to 50%) and for skin and soft tissue infection (SSTI) and bone infection (20% and 30%, respectively). Antistaphylococcal penicillins were recommended for SSTIs and bone infections in 43% and 36%, respectively. Recommendations for neonatal sepsis included 20 different antibiotic combinations. Duration of therapy guidelines was mostly available for RTI and UTI (82%). A third of hospitals with guidelines for sepsis provided recommendations for length of therapy. CONCLUSIONS: Comprehensive antibiotic guideline recommendations are generally lacking from European paediatric hospitals. We documented multiple antibiotics and combinations for most infections. Considerable improvement in the quality of guidelines and their evidence base is required, linking empirical therapy to resistance rates.

Interferon gamma inducible protein-10 in the diagnosis of paediatric tuberculosis infection in a low TB incidence country.

OBJECTIVE: To assess interferon-gamma inducible protein 10 (IP-10) as a diagnostic marker for tuberculous infection in children, particularly in relation to its differential diagnostic performance in young children. DESIGN AND RESULTS: A case-control study was conducted among 161 children and adolescents (mean age 6.3 years ± standard deviation 1.7; males n = 79, 49%). Fifty-four (33.5%) had active TB, 53 (33%) had latent tuberculous infection (LTBI), and 54 (33.5%) were non-LTBI controls. Unstimulated IP-10 levels did not differ between groups (P > 0.05 for all comparisons). TB-specific antigen stimulated IP-10 levels were more profoundly increased in infected groups than in controls (P < 0.001 for all comparisons). None of the IP-10-based diagnostic indexes demonstrated the ability to discriminate active disease from LTBI. A value of IP-10 ⩾ 1222 pg/ml had 83.3% sensitivity, 79.6% specificity, 80.4% positive predictive value and 82.7% negative predictive value for the diagnosis of LTBI. IP-10 based indexes demonstrated a trend towards better performance in the population group aged <5 years. CONCLUSION: The IP-10 assay could be useful in improving the diagnosis of LTBI in patients aged <5 years in combination with existing interferon-gamma release assays.

Pandemic influenza A vs seasonal influenza A in hospitalized children in Athens.

BACKGROUND: Data on pandemic H1N1 influenza (pH1N1) virus infection in hospitalised children are limited. AIMS AND OBJECTIVES: To examine the epidemiological and clinical characteristics of children hospitalised with pH1N1 at a large tertiary-care centre in Athens and compare them with those of children hospitalised with seasonal influenza A in previous years. METHODS: All children (n = 146) admitted with confirmed pH1N1 between October 2009 to February 2010 and January 2011 to May 2011 were included. Data on children ≧ 6 months of age (n = 109) were compared with those of 138 children admitted with seasonal influenza A who were examined during two previous influenza seasons (2002-2003 and 2004-2005). RESULTS: The age distribution was similar between seasonal and pandemic H1N1. Bronchial asthma was significantly more common in the seasonal influenza group but the clinical presentation was similar in the two groups, except that fever was more common in patients with pH1N1. Children admitted with seasonal influenza were more likely to develop acute otitis media. There were no significant differences between the two groups for severe outcomes (admission to the ICU, mechanical ventilation or death). Only one child with seasonal influenza (0.6%) and three with pH1N1 influenza (2%) required admission to the ICU. Mean length of hospitalisation was longer in the seasonal influenza group. CONCLUSION: Clinical manifestations were similar between pH1N1 and seasonal influenza, and the pandemic virus did not appear to cause more severe disease in hospitalised children.

Oral L-arginine supplementation and faecal calprotectin levels in very low birth weight neonates.

OBJECTIVE: The objective of this study is to determine the potential effect of oral L-arginine supplementation on intestinal inflammation in very low birth weight (VLBW) neonates, as estimated by faecal calprotectin levels. STUDY DESIGN: The study enrolled 83 VLBW neonates with birth weight ≤1500 g and gestational age ≤34 weeks. In this double-blind study, 40 neonates received daily oral L-arginine supplementation of 1.5 mmol kg(-1) per day between the 3rd and 28th day of life, and 43 neonates placebo. Stool samples were collected on days 3, 14 and 28, and calprotectin was measured by enzyme-linked immunosorbent assay. RESULT: Calprotectin values significantly decreased over time in both groups (P=0.032). No difference in faecal calprotectin values was recorded between neonates receiving arginine supplementation and neonates receiving placebo at days 3, 14 and 28. CONCLUSION: Faecal calprotectin values decrease with increasing postnatal age in VLBW infants, but this is not related to arginine supplementation.

Trends in the epidemiology of childhood tuberculosis in Greece.

SETTING: A hospital referral center for childhood tuberculosis (TB). OBJECTIVE: To evaluate the epidemiological and clinical features of childhood TB in the Greater Athens area in the last decade. DESIGN: We retrospectively reviewed the medical records of patients aged <14 years treated for active TB between January 2000 and December 2009 at our pediatric TB clinic and compared the results with the patient turnover during the previous decade (1990-1999). Data concerning demographic and clinical characteristics were analyzed. RESULTS: A total of 321 children (median age 5.57 years, 157 males) with active TB were identified. About one third originated from areas where TB was previously recognized to be highly endemic. Twenty-three children (7%) had extra-pulmonary TB, and 61% of them originated from TB-endemic areas. Bacteriological confirmation was obtained in 40% of patients from whom specimens were obtained: 1 of 26 (3.8%) strains was multidrug-resistant. Most cases with drug-resistant Mycobacterium tuberculosis were noted among immigrant children. The average annual TB incidence was estimated at 5.37 per 100 000 for children aged <14 years in the Greater Athens area. Time trend analysis for the 20-year period revealed a significant reduction in the total number of TB cases (P = 0.002) and in TB among children from low-incidence countries (P < 0.0001). CONCLUSIONS: In our settings, active TB is decreasing among children of Greek origin; disease epidemiology and drug resistance is influenced by the increasing influx of immigrants from areas where the disease is highly prevalent.

Influenza A/H1N1/2009 outbreak in a neonatal intensive care unit.

BACKGROUND: Outbreaks of influenza A/H1N1/2009 in neonatal intensive care units (NICUs) have been reported only rarely. Annual vaccination of all healthcare workers (HCWs) against seasonal influenza is recommended but compliance is low and exposure to infected staff as the source of nosocomial outbreaks has been described. AIM: To report an outbreak of influenza A/H1N1/2009 in a tertiary level NICU that resulted in considerable morbidity. METHODS: When the first influenza case was identified, a prospective study was conducted and control measures were implemented to reduce the spread of infection throughout the NICU. Neonates who developed influenza were treated with oseltamivir, and exposed neonates were given prophylaxis with oseltamivir. FINDINGS: Two infected infants who were immature by gestational age and birth weight developed pneumonitis requiring respiratory support, and a third full-term neonate had a mild uncomplicated illness. No significant adverse effects were noted during antiviral treatment or prophylaxis. The investigation identified infected HCWs as the likely source of the outbreak. There was a very low influenza vaccination rate of 15% among nursing staff. CONCLUSION: Nosocomial influenza can cause considerable morbidity, especially in high risk neonates, and is readily transmissible in the NICU setting by unvaccinated staff members who contract influenza. To prevent outbreaks, in addition to infection control measures, the implementation of HCW vaccination is very important. Oseltamivir treatment was well-tolerated even among premature infants and appeared to be effective, because neonates with influenza had complete recovery and only one of those who received prophylaxis developed the infection.

Impact of the Gen-Probe Amplified MTD® Test on tuberculosis diagnosis in children.

OBJECTIVE: To evaluate the performance of the Gen-Probe Amplified MTD® Test (AMTD) for childhood tuberculosis (TB) diagnosis compared to conventional culture. DESIGN: We retrospectively studied 121 childhood cases (73 males; median age 7 years, range 1-16). Pulmonary samples (104/152, 68%) included gastric aspirates (n = 53), induced sputum samples (n = 43), bronchial aspirates and bronchoalveolar lavage (n = 8). Extra-pulmonary samples (48/152, 32%) included lymph nodes (n = 34) and other sterile fluids (n = 14). Specimens were examined using acid-fast bacilli (AFB) microscopy, AMTD and bacterial culture using BACTEC™ MGIT™ 960 and Löwenstein-Jensen (LJ) media. RESULTS: A clinical diagnosis of TB was made in 50/121 (41%) children (43/50 pulmonary disease). AFB microscopy was positive in 6%; Mycobacterium tuberculosis was recovered by culture from 16/50 (32%) and AMTD was positive in 29/50 (58%). AMTD sensitivity, specificity, positive predictive value and negative predictive value compared to culture were respectively 100%, 85%, 50% and 100%. For pulmonary vs. extra-pulmonary disease, the performance of AMTD compared to culture was respectively 100%, 77%, 46% and 100% vs. 100%, 97.5%, 75% and 100%. CONCLUSIONS: Nucleic acid amplification tests are more sensitive and very specific methods for the rapid detection of M. tuberculosis. The AMTD technique increases TB detection in children compared to conventional culture.

Latent tuberculosis infection in children: diagnostic approaches.

Tuberculosis (TB) remains an important public health problem and a leading infectious cause of death. Diagnosis and treatment of latent tuberculosis infection (LTBI) is important for TB control and elimination. Nevertheless, the diagnosis of LTBI in both adults and children remains complex, since there is no gold standard. The development of interferon gamma release assays was a major breakthrough in the diagnosis of LTBI. The evaluation of IGRAs in the diagnosis of LTBI in children is proven to be difficult since childhood TB differs from adults as immune responses vary with age. Separate studies assessing IGRAs performance in children are still limited, and only a few of them divide results by narrow age groups Nevertheless, new approaches are being exploited by the ongoing research for the development of more efficient diagnostic tools. It is likely that many changes in both the diagnosis and management of LTBI will occur in the near future. We believe that better understanding of the immunopathology of latency can ultimately lead to the development of more effective strategies in TB control. In the present review we summarize current data on diagnosis of LTBI in children, underscoring the existing challenges and limitations.

Impact of influenza infection on children's hospital admissions during two seasons in Athens, Greece.

A prospective epidemiologic surveillance of hospitalizations associated with influenza was conducted in order to calculate population-based hospitalization rates. Eligible children were 6 months to 13 years of age and were admitted to one of the two large children's hospitals in the Athens area during two influenza seasons. Nasopharyngeal aspirates were tested for influenza by a polymerase reaction assay. Influenza accounted for 9.9-11.8% of all admissions during the influenza season and the overall annual rate of hospitalizations was 13.6-16.8 cases per 10,000 children being highest for children under 5 years of age (26-31.2/10,000 children). Febrile seizures and acute otitis media were the two most common complications associated with influenza and antibiotics were administered to 61% of flu positive patients. Influenza is associated with high hospitalization rates among young children and these may be substantially reduced with the introduction of routine immunization.

Performance of rapid influenza testing in hospitalized children.

Influenza infection is associated with high hospitalization rates among young children. Rapid diagnosis of influenza infection is particularly useful in order to prevent nosocomial infection and allows for the timely initiation of antiviral treatment. We evaluated the performance of a rapid influenza test in hospitalized children during the influenza season. All children (aged 6 months to 14 years) hospitalized with fever and/or respiratory symptoms, admitted during the 2005 influenza season, participated in the study. A multiplex reverse transcriptase polymerase chain reaction (RT-PCR), able to identify IFV-A H1N1, H3N2, and IFV-B subtypes, was performed on nasopharyngeal aspirates. The nasal swab was tested with a lateral-flow immunoassay (QuickVue Influenza Test). The performance of the rapid test was compared with the results of PCR. Influenza infection was diagnosed by PCR in 41/217 (19%) patients. Infection with influenza A virus (H3N2) was diagnosed in all cases. The performance of the QuickVue Influenza Test was estimated as follows: sensitivity 67.5%, specificity 96%, positive predictive value 79%, and negative predictive value 93%. The sensitivity of the test was higher in infants aged 6-12 months, in those with short duration of symptoms, and in the peak phase of the epidemic. The QuickVue Influenza Test is useful and reasonably accurate to detect influenza infection in hospitalized children during the influenza season. Infection with influenza virus is unlikely if the test is negative. A positive result suggests that infection is probable if influenza virus circulates in the community.

Scedosporium apiospermum skeletal infection in an immunocompetent child.

Abstract This is a case of Scedosporium apiospermum skeletal infection in a 10-year-old immunocompetent girl whose chief complaint was left knee swelling and pain. The child had a history of a bicycle accident two months before with a resultant deep penetrating trauma. Systematic administration of broad-spectrum antibiotics for 10 days was used, with no clinical improvement. Magnetic Resonance Imaging and arthrotomy of the affected joint revealed findings suggestive of osteomyelitis. Empirical intravenous antimicrobial therapy was instituted for a total of two months but one month after completion of antibacterial therapy the child returned to the hospital because of persistent knee swelling and pain. Following a new arthrotomy, Scedosporium apiospermum was isolated. The patient was cured with intravenous administration of voriconazole without any side effects and has no evidence of relapse after four years of follow-up.