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

Bacterial etiology of pneumonia in children up to 2 months of age: a systematic review

Background: Following the widespread introduction of childhood pneumococcal conjugate vaccines (PCVs), a significant impact on pneumonia mortality in children under five years of age has been reported. It is still unknown whether PCVs are expected to reduce pneumonia burden in younger children, particularly ≤2 months of age, as current evidence on the role of S. pneumoniae in pneumonia etiology in this age group is scarce. We aimed to summarize the evidence of bacterial etiology of pneumonia in children ≤2 months of age. Methods: We conducted a systematic review considering studies evaluating a variety of syndromes associated with pneumonia, and reporting on laboratory confirmed etiologies, considering any diagnostic method and a variety of clinical specimens.  We searched Medline/PubMed, Embase, WoS, Central and Index Medicus Global published in any language till April 30th, 2021. We included studies addressing the outcomes of interest in children ≤2 months of age and reporting on clinical trials, observational studies, and case series with at least 10 events. Screening of citations and data extraction were conducted in duplicate by independent reviewers, according to the study protocol registered on PROSPERO. Descriptive analyses of the various etiologic agents by syndrome are reported. Results: We identified 3,744 citations, of which 22 publications reporting on 13 studies were included. Study methods varied significantly. Nonetheless, gram positive organisms, in particular S. pneumoniae, were identified as important etiologic agents of pneumonia in children ≤2 months of age. Viral etiologies, in particular Respiratory Syncytial Virus, Rhinovirus, and Influenza were also identified. Conclusions: This review provides the most comprehensive analysis to date of the etiologies of pneumonia in children ≤2 months of age, suggesting that PCV impact is expected to occur in this age group. These results also have major implications for diagnosis and treatment of pneumonia in this age group.

Viruses and Mycoplasma pneumoniae are the main etiological agents of community-acquired pneumonia in hospitalized pediatric patients in Spain

OBJECTIVES

To describe the etiology of community-acquired pneumonia (CAP) in hospitalized children in Spain and analyze the predictors of the etiology.

HYPOTHESIS

The different etiological groups of pediatric CAP are associated with different clinical, radiographic, and analytical data.

DESIGN

Observational, multicenter, and prospective study.

PATIENT SELECTION

This study included children aged 1 month to 17 years with CAP, who were hospitalized between April 2012 and May 2019.

METHODS

An extensive microbiological workup was performed. The clinical, radiographic, and analytical parameters were analyzed for three etiological groups.

RESULTS

Among the 495 children included, at least one causative pathogen was identified in 262 (52.9%): pathogenic viruses in 155/262 (59.2%); atypical bacteria (AB), mainly Mycoplasma pneumonia, in 84/262 (32.1%); and typical bacteria (TyB) in 40/262 (15.3%). Consolidation was observed in 89/138 (64.5%) patients with viral CAP, 74/84 (88.1%) with CAP caused by AB, and 40/40 (100%) with CAP caused by TyB. Para-pneumonic pleural effusion (PPE) was observed in 112/495 (22.6%) patients, of which 61/112 (54.5%) presented a likely causative pathogen: viruses in 12/61 (19.7%); AB in 23/61 (37.7%); and TyB in 26/61 (42.6%). Viral etiology was significantly frequent in young patients and in those with low oxygen saturation, wheezing, no consolidation, and high lymphocyte counts. CAP patients with AB as the etiological agent had a significantly longer and less serious course as compared to those with other causative pathogens.

CONCLUSIONS

Viruses and M. pneumoniae are the main causes of pediatric CAP in Spain. Wheezing, young age, and no consolidation on radiographs are indicative of viral etiology. Viruses and AB can also cause PPE. Since only a few cases can be directly attributed to TyB, the indications for antibiotics must be carefully considered in each patient.

New insights and antimicrobial stewardship opportunities in viral pneumonia: five lung ultrasound cases

Background

Antimicrobial stewardship is crucial to avoid antimicrobial resistance in microbes and adverse drug effects in patients. In respiratory infections, however, viral pneumonia is difficult to distinguish from bacterial pneumonia, which explains the overuse of antibiotic therapy in this indication.

Cases

Five cases of lung consolidation are presented. Lung ultrasound, in conjunction with procalcitonin levels, were used to exclude or corroborate bacterial pneumonia.

Conclusion

Lung ultrasound is easy to learn and perform and is helpful in guiding diagnosis in unclear cases of pneumonia and may also offer new insights into the spectrum of certain virus diseases. The use of lung ultrasound can raise awareness in clinicians of the need for antimicrobial stewardship and may help to avoid the unnecessary use of antibiotics.

Supplementary Information

The online version of this article (10.1007/s00508-021-01946-4) contains supplementary material, which is available to authorized users.

Prevalence and Associated Factors with Mixed Coinfections among under 5-Year-Old Children with Severe Viral Pneumonia in Vietnam

Community-acquired pneumonia (CAP) is well-recognized as a leading cause of disease burden in children. This study aimed to identify the prevalence of coinfection and associated factors in Vietnamese children ages 1 month to 5 years with viral pneumonia. We performed a cross-sectional study of children who were diagnosed with severe viral pneumonia. Demographic, clinical, and subclinical characteristics were compared between children with viral alone and bacterial coinfection. Multivariate logistic regression was used to determine which factors were associated with risk of coinfection. Of 202 children with severe viral pneumonia, the most common causative agent was respiratory syncytial virus (respiratory syncytial virus [RSV]: 36.1%), followed by influenza virus A (24.3%) and adenovirus (19.8%). Fifty-three children (26.2%) had bacterial superinfection and/or coinfection with other viruses. Haemophilus influenza was the most common bacterium (9.4%), followed by Klebsiella pneumoniae and Pseudomonas aeruginosa (with 4.0%). In infants (toddlers), ages 12 to 24 months with severe viral pneumonia, (odds ratio [OR] = 3.37, 95% confidence interval [CI]: 1.22–9.33), the higher concentrations of procalcitonin (PCT; OR = 1.16; 95% CI: 1.00–1.34), and neutrophils (OR = 1.13; 95% CI: 1.04–1.22) were associated with a higher risk of coinfection. This study underlined the pervasiveness of coinfections among young children with severe viral pneumonia. Provision of effective antiviral treatment, especially for RSV, as well as the advancement of sensitive and rapid diagnostic tools for screening pathogens of pneumonia, is critical to reducing the burden of this disease.

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.

Mixed viral infections of the respiratory tract; an epidemiological study during consecutive winter seasons

The current study aimed to describe the molecular epidemiology of mixed respiratory viral infections during consecutive winter seasons in a tertiary care hospital. Patients with symptoms of respiratory tract infection were evaluated during the 2009‐2011 and 2013‐15 winter seasons. A clinical microarray technique was used for viral detection. Clinical and epidemiological data were correlated with mixed viral detection and the need for hospitalization. In 332 out of 604 (54.4%) evaluated patients (17.6% children) a respiratory virus was identified. Mixed viral infections were diagnosed in 68/332 (20.5%) patients with virus detection (66.2% mixed Influenza‐RSV infections). Mixed viral infections were more commonly detected in children (OR 3.7; 95%CI 1.9‐5.6, P < 0.01) and patients with comorbidities. In logistic regression analyses, mixed viral infections were associated with younger age (mean age 30.4 years vs. 41.8 years, P ≤ 0.001) and increased rates of fever (OR: 2.7; 95%CI 1.04‐7.2, P < 0.05) but no adverse outcomes or increased rates of hospitalization. High rates of mixed viral infections were noted during all winter seasons (especially Influenza and RSV) and were more common in younger patients. The clinical significance of mixed respiratory viral infection needs further elucidation.

Burden of Culture-Confirmed Pediatric Pneumococcal Pneumonia in Latin America and the Caribbean: A Systematic Review and Meta-Analysis

BACKGROUND

Pneumococcal pneumonia (PP) causes almost one in five deaths in children younger than 5 years worldwide. In Latin America and the Caribbean (LAC), pneumonia causes 14% of all deaths. Although pneumococcal disease is a vaccine-preventable disease that accounts for a significant proportion of this burden, the decision-making process to introduce pneumococcal conjugate vaccines in official schedules is still complex in LAC. Confirmed PP cases and epidemiology are the basis for broader projections.

OBJECTIVE

To gather all the information available in the LAC region to assist decision makers.

METHODS

We performed a systematic review of studies of consolidating and culture-confirmed pediatric PP in LAC (2000-2016) using a generic academic Internet search and search engines without language restrictions. Pairs of reviewers independently selected and assessed the studies' methodological quality. We analyzed meta-information on pneumococcal serotypes available from the SIREVA laboratory-based surveillance system.

RESULTS

A total of 35 out of 750 initially identified studies were included. In the age group between 0 and 59 years, the incidence of culture-confirmed PP ranged from 10.2 to 43.0/100,000 children, with a pooled incidence of 20.4/100,000 children (95% confidence interval 0.0-123.2). Mortality ranged from 0.4 to 5.7/100,000 children, and the pooled mortality was 2.9/100,000 children (95% confidence interval 0.3-8.2). The pooled serotype distribution from surveillance data showed that serotypes 14, 1, and 6B were the most frequent serotypes in LAC, all included in licensed vaccines.

CONCLUSIONS

Studies on confirmed pediatric PP were scarce in LAC in 2000 to 2016. Epidemiology indicators and health resource use are still poorly defined.

Serological diagnosis of pneumococcal infection in children with pneumonia using protein antigens: A study of cut-offs with positive and negative controls

The etiological diagnosis of infection by Streptococcus pneumoniae in children is difficult, and the use of indirect techniques is frequently warranted. We aimed to study the use of pneumococcal proteins for the serological diagnosis of pneumococcal infection in children with pneumonia. We analyzed paired serum samples from 13 Brazilian children with invasive pneumococcal pneumonia (positive control group) and 23 Finnish children with viral pharyngitis (negative control group), all aged <5years-old. Children with pharyngitis were evaluated for oropharyngeal colonization, and none of them carried S. pneumoniae. We used a multiplex bead-based assay with eight proteins: Ply, CbpA, PspA1 and 2, PcpA, PhtD, StkP and PcsB. The optimal cut-off for increase in antibody level for the diagnosis of pneumococcal infection was determined for each antigen by ROC curve analysis. The positive control group had a significantly higher rate of ≥2-fold rise in antibody levels against all pneumococcal proteins, except Ply, compared to the negative controls. The cut-off of ≥2-fold increase in antibody levels was accurate for pneumococcal infection diagnosis for all investigated antigens. However, there was a substantial increase in the accuracy of the test with a cut-off of ≥1.52-fold rise in antibody levels for PcpA. When using the investigated protein antigens for the diagnosis of pneumococcal infection, the detection of response against at least one antigen was highly sensitive (92.31%) and specific (91.30%). The use of serology with pneumococcal proteins is a promising method for the diagnosis of pneumococcal infection in children with pneumonia. The use of a ≥2-fold increase cut-off is adequate for most pneumococcal proteins.

Aetiology of paediatric pneumonia with effusion in the Dominican Republic and the potential impact of pneumococcal conjugate vaccines

Pleural effusion is a serious complication of pneumonia, and Streptococcus pneumoniae is a leading cause. We describe the aetiology of pneumonia with effusion among children in the Dominican Republic before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV) in 2013 and the performance characteristics of a rapid immunochromatographic test (ICT) for detecting S. pneumoniae in pleural fluid. From July 2009 to June 2011, we enrolled children <15 years old admitted with pneumonia and pleural effusion to Robert Reid Cabral Children’s Hospital, Dominican Republic. Pleural fluid was tested by culture, polymerase chain reaction (PCR) for bacterial (S. pyogenes, S. pneumoniae) and viral (respiratory syncytial virus and human rhinovirus) pathogens, and by ICT for S. pneumoniae. We calculated the performance of ICT and culture compared with PCR. Among 121 cases, the median age was 31 months (range 1 week to 14 years). Pleural fluid culture (n = 121) and PCR testing (n = 112) identified an aetiology in 85 (70.2%) cases, including 62 S. pneumoniae (51.2%) and 19 Staphylococcus aureus (15.7%). The viruses tested were not detected. The most prevalent pneumococcal serotypes were 14 (n = 20), 1 (n = 13), and 3 (n = 12). Serotype coverage of the 10- and 13-valent PCVs would be 70.5% and 95.1%, respectively. The sensitivity of point-of-care ICT was 100% (95% confidence interval [CI] 94.1%–100%), while specificity was 86.3% (95% CI 73.7%–94.3%). S. pneumoniae caused more than half of paediatric pneumonia with effusion cases; introduction of PCV in the Dominican Republic could reduce the burden by 36–49%. ICT is a practical, valid diagnostic tool for clinical care and surveillance in settings with limited laboratory capacity.