Background: Improved diagnostic tests are needed for the early identification of Mycobacterium tuberculosis-infected young children exposed to an active TB (aTB) index case. We aimed to compare the diagnostic accuracy of new blood-based tests to that of the tuberculin skin test (TST) for the identification of all infected children and for a potential differentiation between aTB and latent TB infection (LTBI). Methods: 144 children exposed to a patient with aTB were included, and those who met all inclusion criteria (130/144) were classified in three groups based on results from classical investigations: non-infected (NI: n = 69, 53%, median age 10 months), LTBI (n = 28, 22%, median age 96 months), aTB disease (n = 33, 25%, median age 24 months). The first whole blood assay consisted of a 7-days in vitro stimulation of blood with four different mycobacterial antigens (40 μl/condition), followed by flow cytometric measurement of the proportions of blast cells appearing among lymphocytes as a result of their specific activation. Thresholds of positivity were determined by Receiver Operating Characteristic (ROC) curve analysis (results of NI children vs. children with LTBI/aTB) in order to identify infected children in a first stage. Other cut-offs were determined to discriminate subgroups of infected children in a second step (results from children with aTB/LTBI). Analysis of blood monocytes and dendritic cell subsets was performed on 100 μl of blood for 25 of these children as a second test in a pilot study. Results: Combining the results of the blast-induced CD3+ T lymphocytes by Heparin-Binding Haemagglutinin and by Culture Filtrate Protein-10 identified all but one infected children (sensitivity 98.2% and specificity 86.9%, compared to 93.4 and 100% for the TST). Further identification among infected children of those with aTB was best achieved by the results of blast-induced CD8+ T lymphocytes by purified protein derivative (sensitivity for localized aTB: 61.9%, specificity 96.3%), whereas high proportions of blood type 2 myeloid dendritic cells (mDC) were a hallmark of LTBI. Conclusions: New blood-based tests requiring a very small volume allow the accurate identification of M. tuberculosis-infected young children among exposed children and are promising to guide the clinical classification of children with aTB or LTBI.

Tuberculosis (TB) in young children differs from adult TB in that the risk of rapid progression to active TB (aTB) is higher in children than in adults. The reasons for this increased risk are not fully understood. Early differentiation remains difficult between children at risk to develop aTB from those who will remain healthy and develop a latent TB infection (LTBI). Biomarkers to differentiate aTB from LTBI in children, especially in very young children, are urgently needed. To identify M. tuberculosis-specific functional T cell subsets related to clinical manifestations in children, we enrolled 87 children exposed to M. tuberculosis. After standard clinical assessment, the children were classified as aTB, LTBI, or uninfected. Their CD4+ T cell cytokine profiles (IFN-γ, TNF-α, IL-2, IL-17) were analyzed at the single-cell level by flow cytometry after stimulation with three mycobacterial antigens, purified protein derivative (PPD), early-secreted-antigenic target-6 (ESAT-6), or heparin-binding hemagglutinin (HBHA). This approach identified age-related discriminative markers between aTB and LTBI. Whereas among the 3- to 15-year-old children, an excellent discrimination between aTB and LTBI was provided by comparing the ratio between the proportions of ESAT-6-induced IFN-γsingle+ and ESAT-6-induced TNF-αsingle+CD4+ T lymphocytes, this was not the case for children younger than 3 years. By contrast, in this group (<3years), the analysis of HBHA-induced IL-17single+CD4+ T lymphocytes allowed us to identify children with LTBI by the high proportion of this cellular lymphocyte subset, whereas this was not the case for children with aTB. The analysis at the single-cell level of T cell immune responses induced by mycobacterial antigens are, thus, different in infected children younger or older than 3 years of age. HBHA-induced IL-17 production by CD4+ T lymphocytes was associated with protection only in children under 3 years who are at high risk for rapid progression to aTB. This suggests that the HBHA-induced IL-17 production by CD4+ T lymphocytes is a potential new correlate of protection against M. tuberculosis in humans, and that the distinction between children with LTBI and those with aTB is possible based on age-related diagnostic markers.

BACKGROUND:Gastro-oesophageal reflux (GOR) is common in patients with cystic fibrosis (CF). The aim of this study was to investigate the relationship between gastric emptying (GE) and GOR in children with CF.METHODS:Multichannel intraluminal impedance-pH monitoring (MII-pH) to measure GOR and GE breath test (GEBT) to measure GE were performed in 28 children with symptoms suggestive for GOR disease (GORD) (group 1). GEBT was performed in another 28 children with/without GOR symptoms who agreed to undergo GEBT but not MII-pH (group 2).RESULTS:In group 1, we found increased acid GOR (AGOR) in 46.4% and delayed GE (DGE) in 21.4% but no relationship between increased AGOR and DGE. There was no DGE in group 2. We found DGE in 10.7% and rapid GE in 12.5% of the whole group.CONCLUSIONS:Almost half of the children with CF and symptoms suggestive for GORD have increased AGOR and almost a quarter has DGE. However, there was no relation between GOR and GE.

Community-acquired pneumonia (CAP) is a major cause of morbidity in children. This study estimated the proportion of children with pneumococcal CAP among children hospitalised with CAP in Belgium and describes the causative serotype distribution after implementation of the 7-valent pneumococcal conjugate vaccine. Children 0-14 years hospitalised with X-ray-confirmed CAP were prospectively enrolled in a multicentre observational study. Acute and convalescent blood samples were collected. Pneumococcal aetiology was assessed by conventional methods (blood or pleural fluid cultures with Quellung reaction capsular typing or polymerase chain reaction [PCR] in pleural fluid), and recently developed methods (real-time PCR in blood and World Health Organization-validated serotype-specific serology). A total of 561 children were enrolled. Pneumococcal aetiology was assessed by conventional methods in 539, serology in 171, and real-time PCR in blood in 154. Pneumococcal aetiology was identified in 12.2% (66/539) of the children by conventional methods alone but in 73.9% by the combination of conventional and recently developed methods. The pneumococcal detection rate adjusted for the whole study population was 61.7%. Serotypes 1 (42.3%), 5 (16.0%), and 7F(7A) (12.8%) were predominant. In conclusion, Streptococcus pneumoniae remains the predominant bacteria in children hospitalised for CAP in Belgium after implementation of 7-valent pneumococcal conjugate vaccine, with non-vaccine-serotypes accounting for the majority of cases. The use of recently developed methods improves diagnosis of pneumococcal aetiology.

Background & Aims: Among children hospitalized for pneumonia, those with parapneumonic effusion (PPE) are at particular risk for nutritional deterioration. This study aimed to 1) investigate the evolution of the nutritional status during hospitalization and at outpatient follow-up; 2) determine clinical risk factors for weight loss during hospitalization; 3) describe the nutritional interventions for these children.Methods: Retrospective chart review (January `07 - September `12) of 56 children with pneumonia, complicated by PPE in two Belgian hospitals for data on body weight and height at admission (t(0)) and discharge (t(1)), and two weeks (t(2)) and one month (t(3)) after discharge. Length of hospitalization (LoS), length of stay in paediatric intensive care (LoS(PICU)) and maximal in-hospital weight loss (t(max)) were calculated and nutritional interventions were recorded.Results: The median (range) age was 3.5 (1.0-14.8) years. Weight or height was lacking in five (8.9%) children at t(0) and in 28 (50%) at t(1); 21.4% was weighed only once during hospitalization. At t(max), respectively 17/44 and 5/44 children lost >= 5% and >= 10% of their weight. Median (range) LoS and LoS(PICU) were 18.0 (10-41) and 4.0 (0-23) days. One-fourth received a nutritional intervention. Weight for height at admission (WFH(t(0))) significantly predicted maximal weight loss (beta (95% CI) = -0.34 (-2.0--0.1); p = 0.03). At t(2) and t(3), 13/32 and 5/22 of the children with available follow-up data did not reach WFH(t(0)), whilst in 4/35 and 5/26 body weight remained >= 5% under the weight(t(0)).Conclusions: One-third of children with pneumonia complicated by PPE and monitored for weight and height, lost >= 5% of their body weight during hospitalization. One-fourth did not reach initial WFH one month after discharge. Those with a higher WFH at admission were at higher risk of weight loss. More attention for monitoring of weight loss and the nutritional policy during and after hospitalization is warranted.

OBJECTIVES:Clinical data are lacking on optimal levels of specific antipneumococcal antibodies (PnPsAbs) in patients with primary immunodeficiency (PID) receiving intravenous immunoglobulin (IVIG) replacement. Objectives were to conduct a prospective multicenter study providing data on total immunoglobulin G (IgG) and peak/trough levels of PnPsAbs specifically targeting the 16 most prevalent pneumococcal serotypes in IVIG-treated children with PID; to compare trough PnPsAb levels with those measured in healthy adults and the IVIG product; and to evaluate PnPsAb protection correlates with thresholds based on World Health Organization.METHODS:Patients received 7 consecutive IVIG infusions. Total IgG and PnPsAb levels were determined on plasma samples obtained before and after infusion.RESULTS:Twenty-two children with PID were treated with IVIG (mean weekly dose: 0.10 g/kg). The mean trough and peak levels of total IgG were 7.77 and 13.93 g/L, respectively. Trough and peak geometric mean concentrations and distribution curves differed between serotypes and showed wide dispersion (0.17–7.96 µg/mL). In patients (89%–100%), antibodies against most serotypes reached trough levels ≥0.2 µg/mL, a threshold considered protective against invasive pneumococcal infection. For several serotypes, trough levels reached ≥1.0 to 1.3 µg/mL, the level found in adults. Trough geometric mean concentrations correlated well with the PnPsAb contents of the IVIG product.CONCLUSIONS:In IVIG-treated children with PID, protective PnPsAb levels for most pathogenic serotypes were obtained. A correlation was observed between PnPsAb levels in patients and in the IVIG product. This offers the potential to improve infection prevention by adapting the IVIG product and dose according to epidemiology.

Background: The etiologic diagnosis of community-acquired pneumonia (CAP) remains challenging in children because blood cultures have low sensitivity. Novel approaches are needed to confirm the role of Streptococcus pneumoniae. Methods: In this study, pneumococcal etiology was determined by serology using a subset of blood samples collected during a prospective multicentre observational study of children <15 years of age hospitalized in Belgium with radiogram-confirmed CAP. Blood samples were collected at admission and 3–4 weeks later. Pneumococcal (P)-CAP was defined in the presence of a positive blood or pleural fluid culture. Serotyping of S. pneumoniae isolates was done with the Quellung reaction. Serological diagnosis was assessed for 9 serotypes using World Health Organization–validated IgG and IgA serotype-specific enzyme-linked immunosorbent assays (ELISAs). Results: Paired admission/convalescent sera from 163 children were evaluated by ELISA (35 with proven P-CAP and 128 with nonproven P-CAP). ELISA detected pneumococci in 82.8% of patients with proven P-CAP. The serotypes identified were the same as with the Quellung reaction in 82% and 59% of cases by IgG ELISA and IgA ELISA, respectively. Overall, ELISA identified a pneumococcal etiology in 55% of patients with nonproven P-CAP. Serotypes 1 (51.6%), 7F (19%) and 5 (15.7%) were the most frequent according to IgG ELISA. Conclusions: In conclusion, the serological assay allows recognition of pneumococcal origin in 55% of CAP patients with negative culture. This assay should improve the diagnosis of P-CAP in children and could be a useful tool for future epidemiological studies on childhood CAP etiology.

ABSTRACT We confirmed that chlorhexidine decontamination yielded more nontuberculous mycobacteria than did the N -acetyl- l -cysteine-NaOH-oxalic acid procedure from respiratory samples of cystic fibrosis patients on solid cultures. However, this improved recovery is mostly balanced if the latter is combined with liquid culture. Furthermore, none of the 145 cough swabs, used to sample young children, cultured positive, suggesting that swabs are low-quality samples.

To better understand vaccine-induced protection and its potential failure in light of recent whooping cough resurgence, we evaluated quantity as well as quality of memory T cell responses in B. pertussis-vaccinated preadolescent children. Using a technique based on flow cytometry to detect proliferation, cytokine production and phenotype of antigen-specific cells, we evaluated residual T cell memory in a cohort of preadolescents who received a whole-cell pertussis (wP; n = 11) or an acellular pertussis vaccine (aP; n = 13) during infancy, and with a median of 4 years elapsed from the last pertussis booster vaccine, which was aP for all children. We demonstrated that B. pertussis-specific memory T cells are detectable in the majority of preadolescent children several years after vaccination. CD4(+) and CD8(+) T cell proliferation in response to pertussis toxin and/or filamentous hemagglutinin was detected in 79% and 60% of the children respectively, and interferon-gamma or tumor necrosis factor-alpha producing CD4(+) T cells were detected in 65% and 53% of the children respectively. Phenotyping of the responding cells showed that the majority of antigen-specific cells, whether defined by proliferation or cytokine production, were CD45RA(-)CCR7(-) effector memory T cells. Although the time since the last booster vaccine was significantly longer for wP-compared to aP-vaccinated children, their proliferation capacity in response to antigenic stimulation was comparable, and more children had a detectable cytokine response after wP-compared to aP-vaccination. This study supports at the immunological level recent epidemiological studies indicating that infant vaccination with wP induces longer lasting immunity than vaccination with aP-vaccines. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Introduction: Pediatric parapneumonic effusion (PPE) incidence increases. Aims: To compare different treatment options in children with PPE. Methods: Retrospective analysis of children with PPE, admitted from 01/01/2007-30/11/2011. PPE definition: ≥1cm fluid on US or CT, and/or an opacity on chest X-ray of ≥50% of the hemithorax. Exclusion criteria: age <6m., trauma, thoracotomy. PDI and VATS were performed on clinical indication. VATS was reserved for patients (pts) with insufficient clinical improvement. Pts were treated as follows: Group A: no PDI/VATS. Group B: PDI. Group C: VATS. Group D: PDI followed by VATS. Results: 49 pts were included, F/M=23/26, median age 3.3y (range 0.8-14.8y); 15, 12, 11, and 11, in group A, B, C, and D, resp. Age, sex ratio and inflammatory parameters were similar in all groups. Total length of stay (LOS) was similar for groups B, C and D, but shorter for group A (22 vs 18d, p=.023) Oxygen need was also shorter in group A compared to the others (4 vs 12d, p<.001). PDI was performed earlier than VATS (4 vs 9d, p=.011). Oxygen need and fever resolved earlier after intervention in group C than in group B (3 vs 8d, p=.009 and 1 vs 6d, p=.04, resp). Time to drain removal, LOS and duration of antibiotic treatment after intervention (3 vs 6d, p=.001; 11 vs 18d, p=.004; and 10 vs 18d, p=.001) were shorter in group C than in group B. ICU stay after intervention was similar in the 3 groups. Conclusions: VATS is a good treatment option for PDI in children with PPE. Clinical improvement was faster with VATS than with PDI, indicating that early performed VATS might shorten LOS and duration of antibiotic treatment.

BACKGROUND:The burden of invasive pneumococcal disease in young children decreased dramatically following introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). The epidemiology of S. pneumoniae now reflects infections caused by serotypes not included in PCV7. Recently introduced higher valency pneumococcal vaccines target the residual burden of invasive and non-invasive infections, including those caused by serotypes not included in PCV7. This review is based on presentations made at the European Society of Pediatric Infectious Diseases in June 2011.DISCUSSION:Surveillance data show increased circulation of the non-PCV7 vaccine serotypes 1, 3, 6A, 6C, 7 F and 19A in countries with routine vaccination. Preliminary evidence suggests that broadened serotype coverage offered by higher valency vaccines may be having an effect on invasive disease caused by some of those serotypes, including 19A, 7 F and 6C. Aetiology of community acquired pneumonia remains a difficult clinical diagnosis. However, recent reports indicate that pneumococcal vaccination has reduced hospitalisations of children for vaccine serotype pneumonia. Variations in serotype circulation and occurrence of complicated and non-complicated pneumonia caused by non-PCV7 serotypes highlight the potential of higher valency vaccines to decrease the remaining burden. PCVs reduce nasopharyngeal carriage and acute otitis media (AOM) caused by vaccine serotypes. Recent investigations of the interaction between S. pneumoniae and non-typeable H. influenzae suggest that considerable reduction in severe, complicated AOM infections may be achieved by prevention of early pneumococcal carriage and AOM infections. Extension of the vaccine serotype spectrum beyond PCV7 may provide additional benefit in preventing the evolution of AOM. The direct and indirect costs associated with pneumococcal disease are high, thus herd protection and infections caused by non-vaccine serotypes both have strong effects on the cost effectiveness of pneumococcal vaccination. Recent evaluations highlight the public health significance of indirect benefits, prevention of pneumonia and AOM and coverage of non-PCV7 serotypes by higher valency vaccines.SUMMARY:Routine vaccination has greatly reduced the burden of pneumococcal diseases in children. The pneumococcal serotypes present in the 7-valent vaccine have greatly diminished among disease isolates. The prevalence of some non-vaccine serotypes (e.g. 1, 7 F and 19A) has increased. Pneumococcal vaccines with broadened serotype coverage are likely to continue decreasing the burden of invasive disease, and community acquired pneumonia in children. Further reductions in pneumococcal carriage and increased prevention of early AOM infections may prevent the evolution of severe, complicated AOM. Evaluation of the public health benefits of pneumococcal conjugate vaccines should include consideration of non-invasive pneumococcal infections, indirect effects of vaccination and broadened serotype coverage.

printing supported by . Visit Chiesi at Stand B2.10 TUESDAY, SEPTEMBER 4TH 2012 Age of hospitalization did not influence any scores. Conclusion: QoL nine months after hospitalization for acute bronchiolitis was negatively associated with atopic eczema, parental asthma and female gender. P4111 Respiratory complication in children with dengue Lucia Azevedo, Daniel Leal, Ana Menezes, Selma Sias, Miguel Aide, Gesmar Herdy. Department of Pediatrics, Federal Fluminense University,