Cell adhesion proteins in the cerebrospinal fluid of neonates prenatally exposed to Zika virus: A case-control study

To compare cell adhesion molecules levels in cerebrospinal fluid (CSF) between Zika virus (ZIKV)-exposed neonates with/without microcephaly (cases) and controls, 16 neonates (cases), 8 (50%) with and 8 (50%) without microcephaly, who underwent lumbar puncture (LP) during the ZIKV epidemic (2015-2016) were included. All mothers reported ZIKV clinical symptoms during gestation, all neonates presented with congenital infection findings, and other congenital infections were ruled out. Fourteen control neonates underwent LP in the same laboratory (2017-2018). Five cell adhesion proteins were measured in the CSF using mass spectrometry. Neurexin-1 (3.50 [2.00-4.00] vs. 7.5 [5.00-10.25], P = 0.001), neurexin-3 (0.00 [0.00-0.00] vs. 3.00 [1.50-4.00], P = 0.001) and neural cell adhesion molecule 2 (NCAM2) (0.00 [0.00-0.75] vs. 1.00 [1.00-2.00], P = 0.001) were significantly lower in microcephalic and non-microcephalic cases than in controls. When these two sub-groups of prenatally ZIKA-exposed children were compared to controls separately, the same results were found. When cases with and without microcephaly were compared, no difference was found. Neurexin-3 (18.8% vs. 78.6%, P = 0.001) and NCAM2 (25.0% vs. 85.7%, P = 0.001) were less frequently found among the cases. A positive correlation was found between cephalic perimeter and levels of these two proteins. Neurexin-2 and neurexin-2b presented no significant differences. Levels of three cell adhesion proteins were significantly lower in CSF of neonates exposed to ZIKV before birth than in controls, irrespective of presence of congenital microcephaly. Moreover, the smaller the cephalic perimeter, the lower CSF cell adhesion protein levels. These findings suggest that low CSF levels of neurexin-1, neurexin-3 and NCAM2 may reflect the effects of ZIKV on foetal brain development.

Impact of meningococcal C conjugate vaccine on incidence of invasive meningococcal disease in an 18-year time-series in Brazil and in distinct Brazilian regions

OBJECTIVE

To evaluate the impact of meningococcal C conjugate (MCC) vaccine in Brazil.

METHODS

Ecological study assessing all invasive meningococcal disease (IMD) and meningococcal C disease (MenC) cases reported in all age groups, from 2001 to 2019. MCC was implemented in 2010. Data were collected on the DATASUS platform. Joinpoint regression was performed to assess the Annual Percent Change (APC) of the incidence rate.

RESULTS

IMD incidence decreased in all Brazilian regions from 2001 onwards, without apparent additional reduction attributable to MCC vaccine in the North, Northeast and South. The higher and statistically significant APC reduction in all age groups, in the North and South, and in children <5 years, in the Northeast, occurred between 2001-2011 (-15.4%), 2004-2012 (-14.4%), and 2001-2013 (-10.3%), respectively, before MCC vaccine implementation. Annual incidence of MenC in under 5 years significantly fell in the North (-6.8%; 2011-2018), Southeast (-40.6%; 2010-2015) and Midwest (-48.6%; 2010-2014), which may be attributable to MCC implementation.

CONCLUSION

IMD and MenC behaved differently after MCC vaccine implementation in Brazil during this 18-year time-series analysis. This suggests that the control of IMD should be based on multiple public health care measures and considered on a regional basis.

Delafloxacin as a treatment option for community-acquired pneumonia infection

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality in adults. Bacterial pathogens are recognized to be frequent causative agents, which makes antibacterial treatment crucial for the evolution of these patients. There are several antimicrobial options available in daily practice. However, bacterial resistance is a problem. The chemical, pharmacokinetic, pharmacodynamics, and safety characteristics of delafloxacin, a fluoroquinolone, are discussed. The data from one phase 3 clinical trial evaluating the use of delafloxacin in adults with community-acquired pneumonia is also discussed, along with findings from other meaningful studies. In vitro data have shown that delafloxacin has broad spectrum activity. Results from phase 2 and phase 3 studies have demonstrated that delafloxacin use is safe. International guidelines have recommended respiratory fluoroquinolones as second option for non-severe cases and must be considered in very severe patients not improving to a betalactam/macrolide combination. Delafloxacin was compared to moxifloxacin in the phase 3 community-acquired pneumonia trial. Serious and life-long adverse events due to fluoroquinolones use have been recently reported. Delafloxacin may possibly replace currently available fluoroquinolones, particularly in the treatment of resistant pathogens, such as ciprofloxacin-resistant P. aeruginosa isolates when other drugs are inefficient.

Differences between children with severe acute lower respiratory infection with or without SARS-Cov-2 infection

Aim

to compare clinical features and outcome of children with severe acute lower respiratory infection (ALRI) with or without SARS-CoV-2 infection admitted to Paediatric Intensive Care Unit (PICU).

Methods

for this retrospective cohort study, all children aged<17 years admitted with severe ALRI at a PICU, in Salvador, Brazil were evaluated. Investigation of SARS-CoV-2 infection was performed by real-time reverse-transcription PCR. Clinical data, physical findings upon admission and outcome were registered. Patients were categorized by with or without SARS-Cov-2 infection. Outcomes were death and invasive mechanical ventilation (IMV).

Results

we enrolled 210 patients, whose median age was 2.8 years (IQR: 7.1 months–6.2 years). IMV was used in 33 (15.7%; 95%CI 11.3%-21.1%) patients. Eight (3.8%; 95%CI 1.8%-7.1%) cases died. 62 patients (29.5%) tested positive for SARS-CoV-2. Male gender (67.7% vs. 52.7%, P = 0.045) and sickle cell disease (6.5% vs. 0%, P = 0.007) were associated with SARS-CoV-2 infection. Wheezing upon admission was more common in patients without SARS-CoV-2 infection (38.5% vs. 21.0%, P = 0.01). IMV was more frequent among patients with SARS-CoV-2 infection (25.8% vs. 11.5%, P = 0.009) as well as death (8.1% vs. 2.0%, P = 0.05).

Conclusion

children with severe ALRI infection with SARS-CoV-2 need IMV more frequently than those without it.

Zika-exposed microcephalic neonates exhibit higher degree of inflammatory imbalance in cerebrospinal fluid

Not every neonate with congenital Zika virus (ZIKV) infection (CZI) is born with microcephaly. We compared inflammation mediators in CSF (cerebrospinal fluid obtained from lumbar puncture) between ZIKV-exposed neonates with/without microcephaly (cases) and controls. In Brazil, in the same laboratory, we identified 14 ZIKV-exposed neonates during the ZIKV epidemic (2015-2016), 7(50%) with and 7(50%) without microcephaly, without any other congenital infection, and 14 neonates (2017-2018) eligible to be controls and to match cases. 29 inflammation mediators were measured using Luminex immunoassay and multidimensional analyses were employed. Neonates with ZIKV-associated microcephaly presented substantially higher degree of inflammatory perturbation, associated with uncoupled inflammatory response and decreased correlations between concentrations of inflammatory biomarkers. The groups of microcephalic and non-microcephalic ZIKV-exposed neonates were distinguished from the control group (area under curve [AUC] = 1; P < 0.0001). Between controls and those non-microcephalic exposed to ZIKV, IL-1β, IL-3, IL-4, IL-7 and EOTAXIN were the top CSF markers. By comparing the microcephalic cases with controls, the top discriminant scores were for IL-1β, IL-3, EOTAXIN and IL-12p70. The degree of inflammatory imbalance may be associated with microcephaly in CZI and it may aid additional investigations in experimental pre-clinical models testing immune modulators in preventing extensive damage of the Central Nervous System.

The impact of 10-valent pneumococcal conjugate vaccine upon hospitalization rate of children with pneumonia in different Brazilian administrative regions

BACKGROUND

Streptococcus pneumoniae is the most frequent bacterial causative agent of pneumonia. Due to its significant contribution to the morbidity and mortality profile and the country's economy, the 10-valent pneumococcal vaccine (PCV10) was introduced in Brazil in 2010. Brazil is divided into five administrative regions which differ in social-economic indices among each other. Estimates of PCV10 impact on hospitalization rates due to pneumonia stratified by distinct Brazilian regions are limited. We assessed this issue.

METHODS

This is a population-based ecological investigation. Data about hospitalizations due to pneumonia, asthma or urinary tract infection (UTI) among patients aged under 20 years in the pre-exposure (2003-2009) and in the post-exposure (2011-2017) periods were retrieved from the National Health System - Hospital Information System (SIH-SUS) database. The total resident population by age group in each year was retrieved from the Brazilian Institute for Geography and Statistics database. Hospitalization rates were estimated for each Brazilian region and the rates obtained in the pre-exposure and in the post-exposure periods were compared by Prais-Winsten regression. The Human Development Index (HDI) evolved differently in the distinct regions during the study period.

RESULTS

Overall, hospitalization rates due to pneumonia declined by 34.5%. Similar trends were observed for hospitalization rates due to asthma and UTI. The same pattern was observed in each Brazilian region. However, the North region was the only one that presented an exponential incidence decline pattern, which could be explained by PCV10 implementation (declined by 10.8% in the quadratic regression, p < 0.01). Only in the North region, significant decline was observed among patients aged 0-4 years (-12.5%; p = 0.01), 5-9 years (-38.5%; p < 0.01) or 10-14 years (-10.7%; p = 0.03).

CONCLUSION

Significant variation in the downward trend of hospitalization rate was only found in the North region, which evolved from very low HDI in 2003; medium HDI in 2010 to high HDI in 2017.

Seasonality of distinct respiratory viruses in a tropical city: implications for prophylaxis

OBJECTIVE

The frequency and seasonality of viruses in tropical regions are scarcely reported. We estimated the frequency of seven respiratory viruses and assessed seasonality of respiratory syncytial virus (RSV) and influenza viruses in a tropical city.

METHODS

Children (age ≤ 18 years) with acute respiratory infection were investigated in Salvador, Brazil, between July 2014 and June 2017. Respiratory viruses were searched by direct immunofluorescence and real-time polymerase chain reaction for detection of RSV, influenza A virus, influenza B virus, adenovirus (ADV) and parainfluenza viruses (PIV) 1, 2 and 3. Seasonal distribution was evaluated by Prais-Winsten regression. Due to similar distribution, influenza A and influenza B viruses were grouped to analyse seasonality.

RESULTS

The study group comprised 387 cases whose median (IQR) age was 26.4 (10.5-50.1) months. Respiratory viruses were detected in 106 (27.4%) cases. RSV (n = 76; 19.6%), influenza A virus (n = 11; 2.8%), influenza B virus (n = 7; 1.8%), ADV (n = 5; 1.3%), PIV 1 (n = 5; 1.3%), PIV 3 (n = 3; 0.8%) and PIV 2 (n = 1; 0.3%) were identified. Monthly count of RSV cases demonstrated seasonal distribution (b3 = 0.626; P = 0.003). More than half (42/76 [55.3%]) of all RSV cases were detected from April to June. Monthly count of influenza cases also showed seasonal distribution (b3 = -0.264; P = 0.032). Influenza cases peaked from November to January with 44.4% (8/18) of all influenza cases.

CONCLUSIONS

RSV was the most frequently detected virus. RSV and influenza viruses showed seasonal distribution. These data may be useful to plan the best time to carry out prophylaxis and to increase the number of hospital beds.

Effect of pneumococcal conjugate vaccines on mortality from lower respiratory infections and pneumonia among under-fives

There is a well-known inverse association between mortality rate from infectious diseases and improvements in socioeconomic status, even though longer time-series are required to demonstrate this relationship. This general rule seems to apply to mortality from pneumonia in children in the pneumococcal conjugate vaccine (PCV) era. Two recent published secular trend studies spanning from about 30 years among Brazilians under the age of five show either no effect of PCV - not even death rate decline from pneumococcal meningitis - or a modest one (8% reduction). Time-series mortality studies from pneumonia are needed for both, developed and developing countries, those who have implemented PCV or not. Results from these studies would provide critical input and feedback to public health policy makers.

Systemic cytokines/chemokines associated to radiographic abnormalities in pneumonia in children

Community-acquired pneumonia (CAP) diagnosis remains a challenge in paediatrics. Chest radiography is considered gold standard for definition of pneumonia, however no previous study assessed the relationship between immune response and radiographic-confirmed-pneumonia. We assessed association between cytokines/chemokines levels and radiographic abnormalities in children with CAP. Children < 5-years-old hospitalized with CAP were investigated in a prospective study at the Federal University of Bahia Hospital, Brazil. On admission, clinical data and biological samples were collected to investigate 20 aetiological agents and determine serum cytokines/chemokines levels; chest radiographs were performed. Among 158 patients, radiographic diagnosis of pneumonia was confirmed in 126(79.7%) and 17(10.8%) had pleural effusion. Viral, bacterial and pneumococcal infection were detected in 80(50.6%), 78(49.4%) and 37(23.4%) cases. By comparing the median concentrations of serum cytokines/chemokines between children with or without pleural effusion, interleukin(IL)-6 was higher (26.6[18.6-103.7] vs 3.0[0.0-19.8]; p < 0.001) among those with pleural effusion; and between children with or without radiographic-confirmed-pneumonia, IL-6 was higher in the first subgroup (4.5[0.0-23.4] vs 0.0[0.0-3.6]; p = 0.02) after having excluded cases with pleural effusion. Stratified analyses according to aetiology showed IL-6 increase in the radiographic-confirmed-pneumonia subgroup inside the pneumococcal infection (28.2[5.9-64.1] vs 0.0[0.0-0.0]; p = 0.03) subgroup. By multivariable analysis, with IL-6 as dependent variable, pneumococcal infection and pleural effusion showed independent association with IL-6 elevation [respective OR: 5.071 (95%CI = 2.226-11.548; p < 0.001) and 13.604 (95%CI = 3.463-53.449; p = 0.0001)]. Considering the cases without pleural effusion, the area under the curve of IL-6 to predict pneumococcal infection was 0.76 (95%CI = 0.66-0.86; p < 0.001). IL-6 increase is a potential biomarker of pneumococcal infection among children with CAP without pleural effusion upon admission.

Recurrent wheezing, allergic rhinitis, and maternal asthma as predictors of asthma in children

Background: Early prediction of asthma is crucial for asthma prevention. Objective: We estimated the odds ratio (OR) of recurrent wheezing during the first 3 years of life, atopic rhinitis, and maternal asthma for asthma in school-age children (ages ≥ 6 years). Methods: This case-control study was conducted in Salvador, Brazil. Medical records of children diagnosed with asthma (cases) and of children screened for pulmonary illnesses and without asthma (controls) were reviewed. Information was retrieved and registered in standardized forms. Results: We included 125 subjects (cases) and 375 controls, whose median (percentile 25th-percentile 75th) age was 8.1 years (6.6-10.0 years) and 9.2 years (7.0-11.9 years), respectively. The subjects (cases) and the controls had at least three episodes of wheezing during the first 3 years of life (69.7% and 1.4%, respectively), a maternal history of asthma (36.0% and 4.0%, respectively), and atopic rhinitis (95.9% and 35.1%, respectively). The adjusted OR of three or more episodes of wheezing during the first 3 years of life was OR 132.5 (95% confidence interval [CI], 36.8-477.1), of a personal history of atopic rhinitis was OR 21.3 (95% CI, 5.3-85.0), and of maternal asthma was OR 10.2 (95% CI, 3.1-33.6) for asthma in a logistic regression (which also included age, gender, and maternal history of allergic rhinitis [OR insignificant for these factors]). Conclusion: Children with a history of three or more episodes of wheezing during the first 3 years of life were at least 37 times more likely to develop asthma than children without this history. A maternal history of asthma and a personal history of atopic rhinitis are also predictors of asthma in children.

Evolution of cytokines/chemokines in cases with community-acquired pneumonia and distinct etiologies

AIM

To compare the systemic cytokines/chemokines levels over time during the evolution of children hospitalized with community-acquired pneumonia (CAP) with and without pneumococcal infection.

METHODS

Children less than 5-years-old hospitalized with CAP were prospectively investigated in Salvador, Brazil. Clinical data and biological samples were collected to investigate 20 etiological agents and to determine serum cytokines/chemokines levels on admission and 2 to 4 weeks later. Cases with pneumococcal infection received this diagnosis irrespective of also having other etiologies.

RESULTS

A total of 277 patients were enrolled, however, serum sample was unavailable for cytokine measurement upon admission (n = 61) or upon follow-up visit (n = 36), etiology was undetected (n = 50) and one patient did not attend the follow-up visit. Therefore, this study group comprised of 129 cases with established etiology. The median (interquartile range) age and sampling interval was 18 (9-27) months and 18 (16-21) days, respectively. Established etiology was viral (52.0%), viral-bacterial (30.2%), and bacterial (17.8%). Pneumococcal infection was found in 31 (24.0%) patients. Overall, median interleukin-6 (IL-6; 10.6 [4.7-30.6] vs 21.0 [20.2-21.7]; P = .03), IL-10 (3.5 [3.1-4.5] vs 20.1 [19.8-20.4]; P < .001), and CCL2 (19.3 [12.4-23.2] vs 94.0 [67.2-117.8]; P < .001) were significantly higher in convalescent serum samples, whereas median CXCL10 (83.6 [36.4-182.9] vs 14.6 [0-116.6]; P < .001) was lower. Acute vs convalescent levels evolution of IL-10, CCL2, and CXCL10 did not differ among patients with or without pneumococcal infection. However, IL-6 decreased (27.8 [12.3-48.6] vs 20.8 [20.2-22.6]; P = .1) in patients with pneumococcal infection and increased (9.0 [4.2-22.6] vs 21.0 [20.2-21.7]; P = .001) in patients without it.

CONCLUSION

The marked increase of IL-6 serum levels during the acute phase makes it a potential biomarker of pneumococcal infection among children with CAP.

The Negative Predictive Ability of Immature Neutrophils for Bacteremia in Children With Community-Acquired Infections

Background: Bacteremia is a serious condition. We aimed to assess the role of immature neutrophils in peripheral blood smears for prediction of bacteremia in children. Methods: In this cross-sectional study conducted in Salvador, Brazil, blood cultures collected from patients aged ≤18 years were identified. White Blood Cell count (WBC) was performed upon admission. Medical charts were reviewed and cases from the community were included. Results: Out of 833 potentially eligible patients, 263 (31.6%) were excluded. Therefore, the study group comprised 570 patients being blood collected for culture upon admission from all of them and WBC performed upon admission from 566. The median age was 2 years (IQR: 9.4 mo-5 y) and 300 (52.6%) were male. Acute respiratory infection was the most frequent diagnosis (n = 388; 68.1%), being 250 (43.9%) lower (LRTI) and 138 (24.2%) upper respiratory tract infections. Blood culture was positive in 9 (1.6%; 95% CI: 0.8-2.9%) cases, out of which 7 (2.8%) had LRTI. Streptococcus pneumoniae (n = 3), Haemophilus (n = 2), Neisseria meningitidis, viridans streptococci, Streptococcus agalactiae, and Acinetobacter baumanii (n = 1 each) were isolated. The total WBC/mm3 did not differ when children with positive or negative blood culture were compared (12,100 [IQR: 6,950-15,250] vs. 11,000 [IQR: 7,900-14,900]; P = 0.9). However, presence of any immature neutrophil was significantly more frequent among patients with bacteremia in comparison with patients without bacteremia (100% [9/9] vs. 40% [223/557]; P < 0.001). The absolute number of immature neutrophils was significantly lower among children without bacteremia (0 [IQR: 0-259] vs. 325 [IQR: 275-1,106]; P < 0.001). Overall, the area under the ROC curve of the number of immature neutrophils in regard to bacteremia was 0.82 (95% CI: 0.76-0.88; P = 0.001). Among 413 patients with absolute number of immature neutrophils <242/mm³, none had bacteremia; among 153 patients with absolute number of immature neutrophils ≥242/mm³, 9 (5.9%) had bacteremia. Absolute number of immature neutrophils ≥242/mm3 showed: sensitivity 100% (95% CI: 71.7-100%), specificity 74.1% (95% CI: 70.4-77.7%), negative predictive value 100% (95% CI: 99.3-100.0%), and positive predictive value 5.9% (95% CI: 2.9-10.5%). When only children with LRTI were analyzed, the results were similar. Conclusion: The absolute number of immature neutrophils in peripheral blood smear is a potential tool to rule out bacteremia among children with community-acquired infections.

Wheezing independently predicts viral infection in children with community-acquired pneumonia

AIM

To assess whether there was a difference in the frequency of symptoms and signs among children with community-acquired pneumonia (CAP) with viral or bacterial infection.

METHODS

A prospective cross-sectional study was conducted in Salvador, Brazil. Children less than 5-years-old hospitalized with CAP were recruited. Viral or only bacterial infection was diagnosed by an investigation of 11 viruses and 8 bacteria. Bacterial infection was diagnosed by blood culture, detection of pneumococcal DNA in acute buffy coat, and serological tests. Viral infection was diagnosed by detection of respiratory virus in nasopharyngeal aspirate and serological tests. Viral infection comprised only viral or mixed viral-bacterial infection subgroups.

RESULTS

One hundred and eighty-eight patients had a probable etiology established as only viral (51.6%), mixed viral-bacterial (30.9%), and only bacterial infection (17.5%). Asthma was registered for 21.4%. Report of wheezing (47.4% vs 21.2%; P = 0.006), rhonchi (38.0% vs 15.2%; P = 0.01), and wheezing detected on physical examination (51.0% vs 9.1%; P < 0.001) were the differences found. Among children with asthma, detected wheezing was the only different finding when children with viral infection were compared with those with only bacterial infection (75.0% vs 0%; P = 0.008). By multivariable analysis, viral infection (AdjOR [95% CI]: 9.6; 95%CI: 2.7-34.0), asthma (AdjOR [95% CI]: 4.6; 95%CI: 1.9-11.0), and age (AdjOR [95% CI]: 0.95; 95%CI: 0.92-0.97) were independently associated with wheezing on physical examination. The positive predictive value of detected wheezing for viral infection was 96.3% (95% CI: 90.4-99.1%).

CONCLUSION

Wheezing detected on physical examination is an independent predictor of viral infection.

Clinical, Neuroimaging, and Neurophysiological Findings in Children with Microcephaly Related to Congenital Zika Virus Infection

Zika virus (ZIKV) infection appeared in Brazil in 2015, causing an epidemic outbreak with increased rates of microcephaly and other serious birth disorders. We reviewed 102 cases of children who were diagnosed with microcephaly at birth and who had gestational exposure to ZIKV during the outbreak. We describe the clinical, neuroimaging, and neurophysiological findings. Most mothers (81%) reported symptoms of ZIKV infection, especially cutaneous rash, during the first trimester of pregnancy. The microcephaly was severe in 54.9% of the cases. All infants presented with brain malformations. The most frequent neuroimaging findings were cerebral atrophy (92.1%), ventriculomegaly (92.1%), malformation of cortical development (85.1%), and cortical–subcortical calcifications (80.2%). Abnormalities in neurological exams were found in 97.0% of the cases, epileptogenic activity in 56.3%, and arthrogryposis in 10.8% of the infants. The sensorineural screening suggested hearing loss in 17.3% and visual impairment in 14.1% of the infants. This group of infants who presented with microcephaly and whose mothers were exposed to ZIKV early during pregnancy showed clinical and radiological criteria for congenital ZIKV infection. A high frequency of brain abnormalities and signs of early neurological disorders were found, and epileptogenic activity and signs of sensorineural alterations were common. This suggests that microcephaly can be associated with a worst spectrum of neurological manifestations.

In situ Immune Signatures and Microbial Load at the Nasopharyngeal Interface in Children With Acute Respiratory Infection

Acute respiratory infection (ARI) is the most frequent cause for hospitalization in infants and young children. Using multiplexed nCounter technology to digitally quantify 600 human mRNAs in parallel with 14 virus- and 5 bacterium-specific RNAs, we characterized viral and bacterial presence in nasopharyngeal aspirates (NPA) of 58 children with ARI and determined the corresponding in situ immune profiles. NPA contained different groups of organisms and these were classified into bacterial (n = 27), viral (n = 5), codetection [containing both viral and bacterial transcripts (n = 21), or indeterminate intermediate where microbial load is below threshold (n = 5)]. We then identified differentially expressed immune transcripts (DEITs) comparing NPAs from symptomatic children vs. healthy controls, and comparing children presenting NPAs with detectable microbial load vs. indeterminate. We observed a strong innate immune response in NPAs, due to the presence of evolutionarily conserved type I Interferon (IFN)-stimulated genes (ISG), which was correlated with total bacterial and/or viral load. In comparison with indeterminate NPAs, adaptive immunity transcripts discriminated among viral, bacterial, and codetected microbial profiles. In viral NPAs, B cell transcripts were significantly enriched among DEITs, while only type III IFN was correlated with viral load. In bacterial NPAs, myeloid cells and coinhibitory transcripts were enriched and significantly correlated with bacterial load. In conclusion, digital nCounter transcriptomics provide a microbial and immunological in situ “snapshot” of the nasopharyngeal interface in children with ARI. This enabled discrimination among viral, bacterial, codetection, and indeterminate transcripts in the samples using non-invasive sampling.

Comparison of serological assays using pneumococcal proteins or polysaccharides for detection of Streptococcus pneumoniae infection in children with community-acquired pneumonia

The aim of this study was to compare the results of serological assays using pneumococcal proteins or polysaccharides for the detection of pneumococcal infection in childhood pneumonia. Serological assays measured IgG against eight pneumococcal proteins (Ply,CbpA,PspA1,PspA2,PcpA,PhtD,StkP-C,PcsB-N), C-polysaccharide [in the whole study population, n = 183], or 19 pneumococcal capsular polysaccharides (1,2,4,5,6B,7F,8,9 V,10A,11A,12F,14,15B,17F,18C,19F,20,23F,33F) [only in a subgroup of patients, n = 53] in paired serum samples of children aged <5 years-old hospitalized with clinical and radiological diagnosis of community-acquired pneumonia. We also performed an inhibition of binding test with the anti-capsular polysaccharide assay in order to confirm the specificity of the antibody responses detected. Invasive pneumococcal pneumonia was investigated by blood culture and PCR (ply-primer). Among 183 children, the anti-protein assay detected antibody response in 77/183(42.1%) patients and the anti-C-polysaccharide assay in 28/183(15.3%) patients. In a subgroup of 53 children, the anti-protein assay detected response in 32/53(60.4%) patients, the anti-C-polysaccharide assay in 11/53(20.8%) patients, and the anti-capsular polysaccharide in 25/53(47.2%) patients. Simultaneous antibody responses against ≥2 different capsular polysaccharides were detected in 11/53(20.8%) patients and this finding could not be explained by cross-reactivity between different serotypes. Among 13 patients with invasive pneumococcal pneumonia, the sensitivity of the anti-protein assay was 92.3%(12/13), of the anti-C-polysaccharide assay 30.8%(4/13), and of the anti-capsular polysaccharide assay 46.2%(6/13). The serological assay using pneumococcal proteins is more sensitive for the detection of pneumococcal infection in children with pneumonia than the assay using pneumococcal polysaccharides. Future studies on childhood pneumonia aetiology should consider applying serological assays using pneumococcal proteins.

Respiratory viruses among children with non-severe community-acquired pneumonia: A prospective cohort study

•

Respiratory viruses were detected in almost all children with non-severe pneumonia.

•

Multiple virus detection comprised two thirds of these cases.

•

RSVA-B, FluA-B, PIV1-4 were similarly found among multiple or sole detection cases.

Background

Community-acquired pneumonia (CAP) causes a major burden to the health care system among children under-5 years worldwide. Information on respiratory viruses in non-severe CAP cases is scarce.

Objectives

To estimate the frequency of respiratory viruses among non-severe CAP cases.

Study design

Prospective study conducted in Salvador, Brazil. Out of 820 children aged 2–59 months with non-severe CAP diagnosed by pediatricians (respiratory complaints and radiographic pulmonary infiltrate/consolidation), recruited in a clinical trial (ClinicalTrials.gov Identifier NCT01200706), nasopharyngeal aspirate samples were obtained from 774 (94.4%) patients and tested for 16 respiratory viruses by PCRs.

Results

Viruses were detected in 708 (91.5%; 95%CI: 89.3–93.3) cases, out of which 491 (69.4%; 95%CI: 65.9–72.7) harbored multiple viruses. Rhinovirus (46.1%; 95%CI: 42.6–49.6), adenovirus (38.4%; 95%CI: 35.0–41.8), and enterovirus (26.5%; 95%CI: 23.5–29.7) were the most commonly found viruses. The most frequent combination comprised rhinovirus plus adenovirus. No difference was found in the frequency of RSVA (16.1% vs. 14.6%; P = 0.6), RSVB (10.9% vs. 13.2%; P = 0.4) influenza (Flu) A (6.3% vs. 5.1%; P = 0.5), FluB (4.5% vs. 1.8%; P = 0.09), parainfluenza virus (PIV) 1 (5.1% vs. 2.8%; P = 0.2), or PIV4 (7.7% vs. 4.1%; P = 0.08), when children with multiple or sole virus detection were compared. Conversely, rhinovirus, adenovirus, enterovirus, bocavirus, PIV2, PIV3, metapneumovirus, coronavirus OC43, NL63, 229E were significantly more frequent among cases with multiple virus detection.

Conclusions

Respiratory viruses were detected in over 90% of the cases, out of which 70% had multiple viruses. Several viruses are more commonly found in multiple virus detection whereas other viruses are similarly found in sole and in multiple virus detection.

Infection by Streptococcus pneumoniae in children with or without radiologically confirmed pneumonia

OBJECTIVE

Community-acquired pneumonia is an important cause of morbidity in childhood, but the detection of its causative agent remains a diagnostic challenge. The authors aimed to evaluate the role of the chest radiograph to identify cases of community-aquired pneumonia caused by typical bacteria.

METHODS

The frequency of infection by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis was compared in non-hospitalized children with clinical diagnosis of community acquired pneumonia aged 2-59 months with or without radiological confirmation (n=249 and 366, respectively). Infection by S. pneumoniae was diagnosed by the detection of a serological response against at least one of eight pneumococcal proteins (defined as an increase ≥2-fold in the IgG levels against Ply, CbpA, PspA1 and PspA2, PhtD, StkP-C, and PcsB-N, or an increase ≥1.5-fold against PcpA). Infection by H. influenzae and M. catarrhalis was defined as an increase ≥2-fold on the levels of microbe-specific IgG.

RESULTS

Children with radiologically confirmed pneumonia had higher rates of infection by S. pneumoniae. The presence of pneumococcal infection increased the odds of having radiologically confirmed pneumonia by 2.8 times (95% CI: 1.8-4.3). The negative predictive value of the normal chest radiograph for infection by S. pneumoniae was 86.3% (95% CI: 82.4-89.7%). There was no difference on the rates of infection by H. influenzae and M. catarrhalis between children with community-acquired pneumonia with and without radiological confirmation.

CONCLUSIONS

Among children with clinical diagnosis of community-acquired pneumonia submitted to chest radiograph, those with radiologically confirmed pneumonia present a higher rate of infection by S. pneumoniae when compared with those with a normal chest radiograph.

Serologically diagnosed acute human bocavirus 1 infection in childhood community-acquired pneumonia

AIM

To assess the role of human bocavirus 1 (HBoV1) as a causative agent of non-severe community-acquired pneumonia (CAP) in children.

METHODS

Patients aged 2-59 months with non-severe CAP (respiratory complaints and radiographic pulmonary infiltrate/consolidation) attending a University Hospital in Salvador, Brazil were enrolled in a prospective cohort. From 820 recruited children in a clinical trial (ClinicalTrials.gov NCT01200706), nasopharyngeal aspirate (NPA), and acute and convalescent serum samples were obtained from 759 (92.6%) patients. NPAs were tested for 16 respiratory viruses by PCR. Acute HBoV1 infection was confirmed by measuring specific IgM and IgG responses in paired serum samples.

RESULTS

Respiratory viruses were detected in 693 (91.3%; 95%CI: 89.1-93.2) CAP cases by PCR. HBoV1-DNA was detected in 159 (20.9%; 95%CI: 18.2-24.0) cases. Of these 159 PCR positive cases, acute HBoV1 infection was confirmed serologically in 38 cases (23.9%; 95%CI: 17.8-31.0). Overall, acute HBoV1 infection was confirmed in 5.0% (38/759) of non-severe CAP patients. HBoV1 was detected in 151 cases with at least one other virus making 31.7% of all multiple virus (n = 477) detections. Among all 759 cases, 216 had one respiratory virus detected, and sole HBoV1 was detected in only 8 (3.7%). Acute HBoV1 infection was serologically diagnosed in 34 (22.5%) HBoV1-DNA-positive cases with another virus, compared to 4 (50.0%) cases with sole virus detection (p = 0.09).

CONCLUSION

HBoV1 was detected by PCR in one fifth of the children with non-severe CAP and acute HBoV1 infection was serologically confirmed in one quarter of these cases.

Systemic cytokines and chemokines on admission of children hospitalized with community-acquired pneumonia

Community-acquired pneumonia (CAP) is the main cause of death in children under-5 years worldwide and Streptococcus pneumoniae is the most common bacterial agent. However, it is difficult to identify pneumococcal infection among children with CAP. We aimed to assess association between any cytokine/chemokine and pneumococcal infection in childhood CAP. Furthermore, we evaluated the diagnostic value of cytokine/chemokine for pneumococcal infection. This prospective study was conducted at an Emergency Room, in Salvador, Brazil. Children <5-years-old hospitalized with CAP in a 21-month period were evaluated. On admission, clinical and radiological data were collected along with biological samples to investigate 20 etiological agents and determine serum cytokines (interleukin (IL)-8, IL-6, IL-10, IL-1β, IL-12, TNF-α, IL-2, IL-4, IL-5, γ-interferon), and chemokines (CCL2, CCL5, CXCL9, CXCL10) concentration. From 166 patients with etiology detected, pneumococcal infection was detected in 38 (22.9%) cases among which the median IL-6(pg/ml) was 31.2 (IQR: 12.4-54.1). The other 128 cases had other causative agents detected (Haemophilus influenzae, Moraxella catarrhalis, atypical bacteria and viruses) with the median IL-6 concentration being 9.0 (IQR: 4.1-22.0; p < 0.001). The area under the ROC curve for IL-6 to predict pneumococcal CAP was 0.74 (95%CI: 0.65-0.83; p < 0.001). By multivariate analysis, with pneumococcal CAP as dependent variable, IL-6 was an independent predictor for pneumococcal infection (OR = 5.56; 95%CI: 2.42-12.75, cut-off point = 12.5 pg/ml; p = 0.0001). The negative predictive value of IL-6 under 12.5 pg/ml for pneumococcal infection was 90% (95%CI: 82-95%). Independently significant difference was not found for any other cytokines/chemokines. Serum IL-6 concentration on admission is independently associated with pneumococcal infection among children under-5 years hospitalized with CAP.

Determination of avidity of IgG against protein antigens from Streptococcus pneumoniae: assay development and preliminary application in clinical settings

The measurement of antibody levels is a common test for the diagnosis of Streptococcus pneumoniae infection in research. However, the quality of antibody response, reflected by avidity, has not been adequately evaluated. We aimed to evaluate the role of avidity of IgG against eight pneumococcal proteins in etiologic diagnosis. Eight pneumococcal proteins (Ply, CbpA, PspA1 and 2, PcpA, PhtD, StkP-C, and PcsB-N) were used to develop a multiplex bead-based avidity immunoassay. The assay was tested for effects of the chaotropic agent, multiplexing, and repeatability. The developed assay was applied to paired samples from children with or without pneumococcal disease (n = 38 for each group), determined by either serology, polymerase chain reaction (PCR), or blood culture. We found a good correlation between singleplex and multiplex assays, with r ≥ 0.94.The assay was reproducible, with mean inter-assay variation ≤ 9% and intra-assay variation < 6%. Children with pneumococcal disease had lower median avidity indexes in the acute phase of disease for PspA1 and 2 (p = 0.042), PcpA (p = 0.002), PhtD (p = 0.014), and StkP-C (p < 0.001). When the use of IgG avidity as a diagnostic tool for pneumococcal infection was evaluated, the highest discriminative power was found for StkP-C, followed by PcpA (area under the curve [95% confidence interval, CI]: 0.868 [0.759-0.977] and 0.743 [0.607-879], respectively). The developed assay was robust and had no deleterious influence from multiplexing. Children with pneumococcal disease had lower median avidity against five pneumococcal proteins in the acute phase of disease compared to children without disease.

Respiratory syncytial virus a and b display different temporal patterns in a 4-year prospective cross-sectional study among children with acute respiratory infection in a tropical city

Respiratory syncytial virus (RSV) is one of the most common etiological agents of childhood respiratory infections globally. Information on seasonality of different antigenic groups is scarce. We aimed to describe the frequency, seasonality, and age of children infected by RSV antigenic groups A (RSVA) and B (RSVB) among children with ARI in a 4-year period.Children (6-23 months old) with respiratory infection for ≤7 days were enrolled in a prospective cross-sectional study, from September, 2009 to October, 2013, in Salvador, in a tropical region of Brazil. Upon recruitment, demographic, clinical data, and nasopharyngeal aspirates (NPA) were collected. A multiplex quantitative real-time polymerase chain reaction (RT-PCR) with a group-specific primer and probeset for RSVA and RSVB was used. Seasonal distribution of infection by RSV different antigenic groups was evaluated by Prais-Wisten regression.Of 560 cases, the mean age was 11.4 ± 4.5 months and there were 287 (51.3%) girls. Overall, RSV was detected in 139 (24.8%; 95% CI: 21.4%-28.5%) cases, RSVA in 74 (13.2%; 95% CI: 10.6%-16.2%) cases, and RSVB in 67 (12.0%; 95% CI: 9.5%-14.9%) cases. Two (0.4%; 95% CI: 0.06%-1.2%) cases had coinfection. RSVA frequency was 9.6%, 18.4%, 21.6%, and 3.1% in 2010, 2011, 2012, and 2013, respectively. RSVB frequency was 19.2%, 0.7%, 1.4%, and 35.4% in the same years. RSVA was more frequently found from August to January than February to July (18.2% vs. 6.4%, P < 0.001). RSVB was more frequently found (P < 0.001) between March and June (36.0%) than July to October (1.0%) or November to February (1.6%). RSVB infection showed seasonal distribution and positive association with humidity (P = 0.02) whereas RSVA did not. RSVA was more common among children ≥1-year-old (17.8% vs. 1.8%; P = 0.02), as opposed to RSVB (11.5% vs. 12.2%; P = 0.8).One quarter of patients had RSV infection. RSVA compromised more frequently children aged ≥1 year. RSVA predominated in 2011 and 2012 whereas RSVB predominated in 2010 and 2013. In regard to months, RSVA was more frequent from August to January whereas RSVB was more often detected between March and June. Markedly different monthly as well as yearly patterns for RSVA and RSVB reveal independent RSV antigenic groups' epidemics.

Comparison of the frequency of bacterial and viral infections among children with community-acquired pneumonia hospitalized across distinct severity categories: a prospective cross-sectional study

Background

The comparison of the frequencies of bacterial and viral infections among children with community-acquired pneumonia (CAP) admitted in distinct severity categories, in an original study, is lacking in literature to-date. We aimed to achieve this goal.

Methods

Children aged 2-59-months-old hospitalized with CAP were included in this prospective study in Salvador, Brazil. Clinical data and biological samples were collected to investigate 11 viruses and 8 bacteria. Severity was assessed by using the World Health Organization criteria.

Results

One hundred eighty-one patients were classified as “non-severe” (n = 53; 29.3 %), “severe” (n = 111; 61.3 %), or “very severe” (n = 17; 9.4 %) CAP. Overall, aetiology was detected among 156 (86.2 %) cases; viral (n = 84; 46.4 %), bacterial (n = 26; 14.4 %) and viral-bacterial (n = 46; 25.4 %) infections were identified. Viral infection frequency was similar in severe/very severe and non-severe cases (46.1 % vs. 47.2 %; p = 0.9). Pneumococcal infection increased across “non-severe” (13.2 %), “severe” (23.4 %), and “very severe” (35.3 %) cases (qui-squared test for trend p = 0.04). Among patients with detected aetiology, after excluding cases with co-infection, the frequency of sole bacterial infection was different (p = 0.04) among the categories; non-severe (12.5 %), severe (29.3 %) or very severe (55.6 %). Among these patients, sole bacterial infection was independently associated with severity (OR = 4.4 [95 % CI:1.1–17.6]; p = 0.04) in a model controlled for age (OR = 0.7 [95 % CI:0.5–1.1]; p = 0.1).

Conclusions

A substantial proportion of cases in distinct severity subgroups had respiratory viral infections, which did not differ between severity categories. Bacterial infection, particularly pneumococcal infection, was more likely among severe/very severe cases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0645-3) contains supplementary material, which is available to authorized users.

An update on antimicrobial options for childhood community-acquired pneumonia: a critical appraisal of available evidence

INTRODUCTION

Community-acquired pneumonia (CAP) is a leading cause of death and a major cause of morbidity in children under the age of 5. Appropriate antimicrobial use is one crucial tool in controlling childhood CAP mortality and suffering.

AREAS COVERED

Structured search of current literature. PubMed was consulted for published trials conducted in children with CAP. We aimed to provide a comprehensive evaluation of antimicrobials used to treat childhood CAP, including a critical appraisal of the methodological aspects of these clinical trials.

EXPERT OPINION

Amoxicillin is the preferred option to treat non-severe non-complicated CAP among children aged ≥2 months. Amoxicillin may be used to treat children in this age group with severe CAP if they do not require hospital assistance. If the patient warrants hospitalization, intravenous penicillin is the chosen option. Heterogeneity was high in the included trials, in regard to clinical inclusion criteria, use of radiological inclusion criteria, placebo use and masking. Higher quality evidence was found in the studies which included amoxicillin. There is a clear dearth of randomized, placebo-controlled, well-performed clinical trials evaluating children with CAP aged under 2 months, or aged 2 months and above with very severe or complicated CAP, or in specific age groups like teenagers.

Differences upon admission and in hospital course of children hospitalized with community-acquired pneumonia with or without radiologically-confirmed pneumonia: a retrospective cohort study

Background

The use of chest radiograph (CXR) for the diagnosis of childhood community-acquired pneumonia (CAP) is controversial. We assessed if children with CAP diagnosed on clinical grounds, with or without radiologically-confirmed pneumonia on admission, evolved differently.

Methods

Children aged ≥ 2 months, hospitalized with CAP diagnosed on clinical grounds, treated with 200,000 IU/Kg/day of aqueous penicillin G for ≥ 48 h and with CXR taken upon admission, without pleural effusion, were included in this retrospective cohort. One researcher, blinded to the radiological diagnosis, collected data on demographics, clinical history and physical examination on admission, daily hospital course during the first 2 days of treatment, and outcome, all from medical charts. Radiological confirmation of pneumonia was based on presence of pulmonary infiltrate detected by a paediatric radiologist who was also blinded to clinical data. Variables were initially compared by bivariate analysis. Multi-variable logistic regression analysis assessed independent association between radiologically-confirmed pneumonia and factors which significantly differed during hospital course in the bivariate analysis. The multi-variable analysis was performed in a model adjusted for age and for the same factor present upon admission.

Results

109 (38.5 %) children had radiologically-confirmed pneumonia, 143 (50.5 %) had normal CXR and 31 (11.0 %) had atelectasis or peribronchial thickening. Children without radiologically-confirmed pneumonia were younger than those with radiologically-confirmed pneumonia (median [IQR]: 14 [7–28 months versus 21 [12–44] months; P = 0.001). None died. The subgroup with radiologically-confirmed pneumonia presented fever on D1 (33.7 vs. 19.1; P = 0.015) and on D2 (31.6 % vs. 16.2 %; P = 0.004) more frequently. The subgroup without radiologically-confirmed pneumonia had chest indrawing on D1 (22.4 % vs. 11.9 %; P = 0.027) more often detected. By multi-variable analysis, Fever on D2 (OR [95 % CI]: 2.16 [1.15-4.06]) was directly and independently associated with radiologically-confirmed pneumonia upon admission.

Conclusion

The compared subgroups evolved differently.

Pathogen transcriptional profile in nasopharyngeal aspirates of children with acute respiratory tract infection

•

nCounter enables detection of pathogen transcripts in NPA with low RNA input.

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nCounter detects, in a single reaction, the presence of multiple pathogens in NPA.

•

nCounter displayed a good agreement with Real-Time PCR for RSV.

Background

Acute respiratory tract infections (ARI) present a significant morbidity and pose a global health burden. Patients are frequently treated with antibiotics although ARI are most commonly caused by virus, strengthening the need for improved diagnostic methods.

Objectives

Detect viral and bacterial RNA in nasopharyngeal aspirates (NPA) from children aged 6–23 months with ARI using nCounter.

Study design

A custom-designed nCounter probeset containing viral and bacterial targets was tested in NPA of ARI patients.

Results

Initially, spiked control viral RNAs were detectable in ≥6.25 ng input RNA, indicating absence of inhibitors in NPA. nCounter applied to a larger NPA sample (n = 61) enabled the multiplex detection of different pathogens: RNA viruses Parainfluenza virus (PIV 1–3) and RSV A-B in 21%, Human metapneumovirus (hMPV) in 5%, Bocavirus (BoV), CoV, Influenza virus (IV) A in 3% and, Rhinovirus (RV) in 2% of samples, respectively. RSV A-B was confirmed by Real Time PCR (86.2–96.9% agreement). DNA virus (AV) was detected at RNA level, reflecting viral replication, in 10% of samples. Bacterial transcripts from Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Mycoplasma pneumoniae and Chlamydophila pneumoniae were detected in 77, 69, 26, 8, 3 and 2% of samples, respectively.

Conclusion

nCounter is robust and sensitive for the simultaneous detection of viral (both RNA and DNA) and bacterial transcripts in NPA with low RNA input (<10 ng). This medium-throughput technique will increase our understanding of ARI pathogenesis and may provide an evidence-based approach for the targeted and rational use of antibiotics in pediatric ARI.

Prevalence and risk factors for wheezing in Salvador, Brazil: a population-based study

BACKGROUND

Wheezing is one of the most frequent causes of visit to emergency rooms among children. However, data on wheezing burden are mostly provided at healthcare setting, and particularly only for infants.

AIMS

We sought to estimate the prevalence of wheezing in children under 4 years and to assess potential risk factors in the community.

DESIGN

This was a cross-sectional analysis of a population-based cohort study.

METHODS

The sample comprised children aged <4 years living in Salvador, Brazil. Data were collected via home visits when the parents/guardians were interviewed. Data were recorded on standardized forms.

RESULTS

Of 1534 children, mean age was 21 ± 14 months (minimum 3 days; maximum 47 months; 6% <2 months); 780 (51%) were males and 501 [33%; 95% confidence interval (95% CI): 30-35%] reported wheezing in the last 12 months. Among wheezers, 321 (64%) had occasional wheezing. Overall, 180 (12%; 95% CI: 10-14%) had recurrent wheezing and 157 (10%; 95% CI: 9-12%) had asthma. For children in the first, second, third and fourth year of life wheezing was reported in 23, 41, 34 and 37%, respectively. Mother atopic-related disease was independently associated with recurrent wheezing (AdjPR[95% CI]: 1.54 [1.12-2.11]) and asthma (AdjPR[95% CI]: 1.54 [1.10-2.16]). Smoker at home (AdjPR[95% CI]: 1.34 [1.07-1.67]) and low birth weight (AdjPR[95%CI]: 1.38 [1.05-1.81]) were independently associated with occasional wheezing.

CONCLUSIONS

One-third of under 4 years reported wheezing; history of mother's atopic-related disease was an independent risk factor for recurrent wheezing and asthma; smoker at home and low birth weight were independent risk factors for occasional wheezing.

A fluorescent multiplexed bead-based immunoassay (FMIA) for quantitation of IgG against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis protein antigens

Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are pathogens commonly associated with infectious diseases in childhood. This study aimed to develop a fluorescent multiplexed bead-based immunoassay (FMIA) using recombinant proteins for the quantitation of serum IgG antibodies against these bacteria. Eight pneumococcal proteins (Ply, CbpA, PspA1, PspA2, PcpA, PhtD, SP1732-3 and SP2216-1), 3 proteins of H. influenzae (NTHi Protein D, NTHi0371-1, NTHi0830), and 5 proteins of M. catarrhalis (MC Omp CD, MC_RH4_2506, MC_RH4_1701, MC_RH4_3729-1, MC_RH4_4730) were used to develop the FMIA. Optimal coupling concentrations for each protein, comparison of singleplex and multiplex assays, specificity, reproducibility, and correlation to ELISA for six pneumococcal antigens were determined for validation. FMIA was then used to analyze acute and convalescent paired serum samples of 50 children with non-severe pneumonia. The coupling concentrations varied for different antigens, ranging from 1.6 to 32μg of protein/million beads. Correlation between singleplexed and multiplexed assays was excellent, with R≥0.987. The FMIA was specific, reaching >92% homologous inhibition for all specificities; heterologous inhibition ≥20% was found only in six cases. The assay was repeatable, with averages of intra-assay variation ≤10.5%, day-to-day variation ≤9.7% and variation between technicians ≤9.1%. Comparison with ELISA for pneumococcal antigens demonstrated good correlation with R ranging from 0.854 (PspA2) to 0.976 (PcpA). The samples from children showed a wide range of antibody concentrations and increases in convalescent samples. In conclusion, the FMIA was sensitive, specific, and repeatable, using small amounts of recombinant proteins and sera to detect antibodies against S. pneumoniae, H. influenzae and M. catarrhalis. The methodology would be suitable for studies investigating etiological diagnosis and in experimental vaccine studies.

Retrospective analysis of the efficacies of two different regimens of aqueous penicillin G administered to children with pneumonia

Community-acquired pneumonia (CAP) is an important childhood health problem. Penicillin remains appropriate for treating children with CAP. Clinical data are lacking on disease evolution in children treated with different posologic schemes of aqueous penicillin G. To assess if there were differences in disease evolution between children with CAP treated with 6 or 4 daily doses of aqueous penicillin G, we reviewed the medical charts of hospitalized patients 2 months to 11.5 years of age. Pneumonia was radiologically confirmed based on the detection of pulmonary infiltrate or pleural effusion on the chest radiograph taken on admission and read by a pediatric radiologist blinded to the clinical data. The total daily dose of aqueous penicillin G was 200,000 IU/kg of body weight. Data were recorded on admission, during disease evolution up to the 7th day of treatment, and at the final outcome. The results of hospitalization and the daily frequency of physical signs suggestive of pneumonia were assessed. The subgroups comprised 120 and 144 children who received aqueous penicillin G in 6 or 4 daily doses, respectively. Children≥5 years of age were more frequent in the 4-daily-doses subgroup (16.0% versus 4.2%; respectively, P=0.02). There were no differences between the compared subgroups in terms of final outcomes, lengths of hospitalization, durations of aqueous penicillin G use, frequencies of aqueous penicillin G substitution, or daily frequencies of tachypnea, fever, chest retraction, lower chest recession, nasal flaring, and cyanosis up to the 7th day of treatment. The studied posologic regimens were similarly effective in treating children hospitalized with a radiologically confirmed CAP diagnosis. Aqueous penicillin G (200,000 IU/kg/day) may be given in 4 daily doses to children with CAP.

Respiratory viral infections among children with community-acquired pneumonia and pleural effusion

Pleural effusion (PE), a complication of community-acquired pneumonia (CAP), is usually attributed to a bacterial infection. Nonetheless, viral infections have not been investigated routinely. We searched for bacterial and viral infections among 277 children hospitalized with CAP. Among these children 206 (74%) had radiographic confirmation, of whom 25 (12%) had PE. The aetiology was established in 18 (72%) PE cases: bacterial (n = 5; 28%), viral (n = 9; 50%), and viral-bacterial (n = 4; 22%) infections were found. Infection by rhinovirus (n = 3), enterovirus, Streptococcus pneumoniae (n = 2 each), Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, influenza A virus, and respiratory syncytial virus (RSV) (n = 1 each) were detected as probable sole infections. Parainfluenza virus 1/3 + influenza A virus and RSV + influenza A virus (n = 1 each) were identified as mixed viral-viral infections. Probable viral non-bacterial infection was identified in a third of the cases with CAP and PE. It is advisable to investigate viral as well as bacterial infections among children with CAP and PE.

Wheezing in infants: frequency, clinical characteristics and treatment

OBJECTIVE

To estimate the frequency and describe the clinical characteristics and respective treatments of previous history of wheezing.

METHODS

Infants aged 6-23 months with upper respiratory tract complaints and reporting previous wheezing were followed-up retrospectively. Data were registered on a validated standardized form.

RESULTS

Out of 451 infants, 164 (36.4%; 95%CI:31.9-41.0) had a report of prior history of wheezing, 148 (32.8%; 95%CI:28.5-37.4) during the first year of life. The mean age at the first episode of wheezing was 5.3±3.9 months. Among those who had had their first episode before 12 months of age, 38.5% reported 3 to 6 episodes and 14.2% > 6 episodes. Mean age at first episode was lower for those with ≥ 3 episodes in comparison with those with ≤ 2 episodes (3.2±2.7 vs. 5.7±2.5 months, p < 0.001).

CONCLUSION

One third of the infants reported wheezing during the first year of life. The earlier the first episode occurs, the more frequently wheezing recurs.

Differences in evolution of children with non-severe acute lower respiratory tract infection with and without radiographically diagnosed pneumonia

OBJECTIVE

To identify differences in the evolution of children with non-severe acute lower respiratory tract infection between those with and without radiographically diagnosed pneumonia.

DESIGN

Prospective cohort study.

SETTING

A public university pediatric hospital in Salvador, Northeast Brazil.

PATIENTS

Children aged 2-59 months.

METHODS

By active surveillance, the pneumonia cases were prospectively identified in a 2-year period. Each case was followed-up for changes in various clinical symptoms and signs. Demographic, clinical and radiographic data were recorded in standardized forms. Exclusion was due to antibiotic use in the previous 48 hours, signs of severe disease, refusal to give informed consent, underlying chronic illness, hospitalization in the previous 7 days or amoxicillin allergy. Chest X-ray (CXR) was later read by at least 2 independent pediatric radiologists.

MAIN OUTCOME MEASURES

Radiographic diagnosed pneumonia based on agreed detection of pulmonary infiltrate or pleural effusion in 2 assessments.

RESULTS

A total of 382 patients receiving amoxicillin were studied, of whom, 372 (97.4%) had concordant radiographic diagnosis which was pneumonia (52%), normal CXR (41%) and others (7%). By multivariate analysis, age (OR=1.03; 95% CI: 1.02-1.05), disease > 5 days (OR = 1.04; 95% CI: 1.001-1.08), reduced pulmonary expansion (OR = 3.3; 95% CI: 1.4-8.0), absence of wheezing (OR = 0.5; 95% CI: 0.3-0.9), crackles on admission (OR = 2.0; 95% CI: 1.2-3.5), inability to drink on day 1 (OR = 4.2; 95% CI: 1.05-17.3), consolidation percussion sign (OR = 7.0; 95% CI: 1.5-32.3), tachypnea (OR = 2.0; 95% CI: 1.09-3.6) and fever (OR = 3.6; 95% CI: 1.4-9.4) on day 2 were independently associated with pneumonia. The highest positive predictive value was at the 2nd day of evolution for tachypnea (71.0%) and fever (81.1%).

CONCLUSION

Persistence of fever or tachypnea up to the second day of amoxicillin treatment is predictive of radiographically diagnosed pneumonia among children with non-severe lower respiratory tract diseases.

Characteristics of radiographically diagnosed pneumonia in under-5 children in Salvador, Brazil

OBJECTIVE

To assess the association of demographic and clinical aspects with radiographically diagnosed pneumonia.

DESIGN

By active surveillance, the admitted pneumonia cases by the pediatrician on duty were identified in a 2 year period. Demographic, clinical and radiographic data were registered into standardized forms.

SETTING

A public university pediatric hospital in Salvador, Northeast Brazil.

PATIENTS

Children <5 years-old.

MAIN OUTCOME MEASURES

Radiographically diagnosed pneumonia based on detection of pulmonary infiltrate/ consolidation.

RESULTS

301 cases had the chest X-ray evaluated by a pediatric radiologist blinded to clinical information, among whom pulmonary infiltrate and consolidation were described in 161 (54%) and 119 (40%), respectively. Chest X-ray was read normal for 140 cases. Overall, the median age was 17 months (mean 20±14, range 12 days-59 months). Pulmonary infiltrate was less frequently described among patients aged under 1 year (41.3% vs 59.9%, P=0.002, OR [95% CI] = 0.47 [0.29-0.76]) and hyperinflation was significantly more frequent in this age group (27.9% vs 4.1%, P<0.001, OR [95% CI] = 9.14 [4.0-20.9]). By multiple logistic regression, fever on admission was independently associated with pulmonary infiltrate (OR [95% CI] = 1.68 [1.03-2.73]) or consolidation (1.79 [1.10-2.92]), wheezing was independently associated with absence of pulmonary infiltrate (0.53 [0.33-0.86]) or of consolidation (0.53 [0.33-0.87]). The positive likelihood ratio of fever on examination for pulmonary infiltrate and consolidation was 1.49 (95% CI:1.11-1.98) and 1.49 (95% CI: 1.14-1.94), respectively.

CONCLUSION

Presence of fever enhanced 2.5 times the chance of children hospitalized with lower respiratory tract disease to have radiographically diagnosed pneumonia.

Sole infection by human metapneumovirus among children with radiographically diagnosed community-acquired pneumonia in a tropical region

Please cite this paper as: Nascimento‐Carvalho et al. (2011) Sole infection by human metapneumovirus among children with radiographically diagnosed community‐acquired pneumonia in a tropical region. Influenza and Other Respiratory Viruses 5(4), 285–287

Background  Limited information is available on the role of human metapneumovirus (HMPV) as the unique pathogen among children hospitalized for community‐acquired pneumonia (CAP) in a tropical region.

Objective  We aimed to describe HMPV infection among children with CAP investigating bacterial and viral co‐infections.

Patients and methods  A prospective study was carried out in Salvador, North‐East Brazil. Overall, 268 children aged <5 years hospitalized for CAP were enrolled. Human metapneumovirus RNA was detected in nasopharyngeal aspirates (NPA) by reverse transcription polymerase chain reaction. Sixteen other bacterial and viral pathogens were investigated by an expanded panel of laboratory methods. Chest X‐ray taken on admission was read by an independent paediatric radiologist unaware of clinical information or the established aetiology.

Results  Human metapneumovirus RNA was detected in NPAs of 11 (4.1%) children, of which 4 (36%) had sole HMPV infection. The disease was significantly shorter among patients with sole HMPV infection in comparison with patients with mixed infection (4 ± 1 versus 7 ± 2 days, P = 0.03). Three of those four patients had alveolar infiltrates.

Conclusion  Sole HMPV infection was detected in children with CAP in Salvador, North‐East Brazil. HMPV may play a role in the childhood CAP burden.

Outcome of children hospitalized with community-acquired pneumonia treated with aqueous penicillin G

OBJECTIVE

To describe the evolution and outcome of children hospitalized with community-acquired pneumonia receiving penicillin.

METHODS

A search was carried out for all hospitalized community-acquired pneumonia cases in a 37-month period. Inclusion criteria comprised age >2 months, intravenous penicillin G use at 200,000 IU/kg/day for >48 h and chest x-ray results. Confounders leading to exclusion included underlying debilitating or chronic pulmonary illnesses, nosocomial pneumonia or transference to another hospital. Pneumonia was confirmed if a pulmonary infiltrate or pleural effusion was described by an independent radiologist blind to the clinical information. Data on admission and evolution were entered on a standardized form.

RESULTS

Of 154 studied cases, 123 (80%) and 40 (26%) had pulmonary infiltrate or pleural effusion, respectively. Penicilli was substituted by other antibiotics in 28 (18%) patients, in whom the sole significant decrease was in the frequency of tachypnea from the first to the second day of treatment (86% vs. 50%, p = 0.008). Among patients treated exclusively with penicillin G, fever (46% vs. 26%, p = 0.002), tachypnea (74% vs. 59%, p = 0.003), chest indrawing (29% vs. 13%, p<0.001) and nasal flaring (10% vs. 1.6%, p = 0.001) frequencies significantly decreased from admission to the first day of treatment. Patients treated with other antimicrobial agents stayed longer in the hospital than those treated solely with penicillin G (16 ± 6 vs. 8 ± 4 days, p<0.001, mean difference (95% confidence interval) 8 (6-10)). None of the studied patients died.

CONCLUSION

Penicillin G successfully treated 82% (126/154) of the study group and improvement was marked on the first day of treatment.

Adding fever to WHO criteria for diagnosing pneumonia enhances the ability to identify pneumonia cases among wheezing children

OBJECTIVE

To examine the ability of the criteria proposed by the WHO to identify pneumonia among cases presenting with wheezing and the extent to which adding fever to the criteria alters their performance.

DESIGN

Prospective classification of 390 children aged 2-59 months with lower respiratory tract disease into five diagnostic categories, including pneumonia. WHO criteria for the identification of pneumonia and a set of such criteria modified by adding fever were compared with radiographically diagnosed pneumonia as the gold standard.

RESULTS

The sensitivity of the WHO criteria was 94% for children aged <24 months and 62% for those aged ≥24 months. The corresponding specificities were 20% and 16%. Adding fever to the WHO criteria improved specificity substantially (to 44% and 50%, respectively). The specificity of the WHO criteria was poor for children with wheezing (12%). Adding fever improved this substantially (to 42%). The addition of fever to the criteria apparently reduced their sensitivity only marginally (to 92% and 57%, respectively, in the two age groups).

CONCLUSION

The authors' results reaffirm that the current WHO criteria can detect pneumonia with high sensitivity, particularly among younger children. They present evidence that the ability of these criteria to distinguish between children with pneumonia and those with wheezing diseases might be greatly enhanced by the addition of fever.