Prevalence of Nasopharyngeal Carriage, Serotype Distribution, and Antimicrobial Resistance of Streptococcus pneumoniae among Children with Chronic Diseases

Pneumococcal carriage and serotype distribution in children with nephrotic syndrome

BACKGROUND

Patients with nephrotic syndrome (NS) are at a higher risk of developing invasive pneumococcal disease (IPD). Pneumococcal carriage studies are helpful tools for detecting potentially infectious serotypes and guiding immunization efforts. Pneumococcal nasopharyngeal colonization is common, and IPD can easily occur in an immunosuppressed state. Limited information is available regarding the frequency of pneumococcal carriage in individuals with NS. The aim of this study was to evaluate pneumococcal carriage and serotype distribution in children with NS.

METHODS

Pneumococcal carriage was detected by real-time PCR assays from nasopharyngeal swab samples from 98 children with NS, and 100 healthy controls. Isolates were serotyped by real-time PCR.

RESULTS

The pneumococcal carriage rate was 44.9% in children with NS. Regarding the recommendation about pneumococcal immunization in children with NS, the vaccination rate was low. Also, non-PCV13 serotypes have been detected in at least 25% of PCV13-vaccinated children. There is no statistically significant difference in total pneumococcal carriage rate, PCV13 serotype carriage rate, or non-PCV13 serotype carriage rate between children with NS and healthy controls (p > 0.05 for all).

CONCLUSIONS

The pneumococcal carriage rate was similar between children with NS and healthy controls. However, because children with NS have an increased risk for IPD, the serotype distribution of children with NS can demonstrate the improved protection offered by new pneumococcal vaccines. Regular monitoring for IPD is crucial for assessing the evolving sero-epidemiology of pneumococcal infections and evaluating the effectiveness of vaccines for children with NS.

Pneumococcal Colonization in Children With Persistent Asthma: A Retrospective Cohort

BACKGROUND

Asthma is the most common chronic medical condition among children ≥5 years of age with invasive pneumococcal disease. How asthma or its management affects pneumococcal colonization is not fully understood. Our objective was to compare pneumococcal colonization rates between children with persistent asthma and children without asthma, and to characterize the pneumococcal serotype distribution.

METHODS

We used nasal mid-turbinate samples obtained per routine care from 5- to 18-year-old children with upper respiratory symptoms from November to April (respiratory seasons) of 2017 to 2018 and 2018 to 2019 in Kansas City, United States. Pneumococcal immunization status, prior antibiotic use and other clinical data were collected. Samples were tested for pneumococcal colonization by real-time polymerase chain reaction targeting lytA gene. Positive samples underwent multiplex serotype-specific polymerase chain reaction assays to determine the serotype.

RESULTS

Of 363 children (120 with persistent asthma and 243 without asthma), 87.6% were 5 to 10 years old, 50.1% were female and 74.1% received ≥3 doses of a pneumococcal conjugate vaccine. The pneumococcal colonization rate was lower in children with persistent asthma than in children without asthma (10% versus 18.9%, P = 0.03). The odds of colonization were lower in children with persistent asthma [OR 0.4 (95% confidence interval: 0.2-0.9)] after adjusting for demographic and clinical data. Pneumococcal serotype was confirmed in 77.6% of positive samples; 35.6% of those samples corresponded to PCV13 serotypes and 64.4% to non-PCV13 serotypes. The most common serotypes were 19F (15%), 3 (13%) and 6C/6D (11%).

CONCLUSIONS

Children with persistent asthma had lower rates of pneumococcal colonization than children without asthma when seeking care for respiratory symptoms.

Identification of Clinically Relevant Streptococcus and Enterococcus Species Based on Biochemical Methods and 16S rRNA, sodA, tuf, rpoB, and recA Gene Sequencing

Streptococci and enterococci are significant opportunistic pathogens in epidemiology and infectious medicine. High genetic and taxonomic similarities and several reclassifications within genera are the most challenging in species identification. The aim of this study was to identify Streptococcus and Enterococcus species using genetic and phenotypic methods and to determine the most discriminatory identification method. Thirty strains recovered from clinical samples representing 15 streptococcal species, five enterococcal species, and four nonstreptococcal species were subjected to bacterial identification by the Vitek^® 2 system and Sanger-based sequencing methods targeting the 16S rRNA, sodA, tuf, rpoB, and recA genes. Phenotypic methods allowed the identification of 10 streptococcal strains, five enterococcal strains, and four nonstreptococcal strains (Leuconostoc, Granulicatella, and Globicatella genera). The combination of sequencing methods allowed the identification of 21 streptococcal strains, five enterococcal strains, and four nonstreptococcal strains. The 16S rRNA and rpoB genes had the highest identification potential. Only a combination of several molecular methods was sufficient for unambiguous confirmation of species identity. This study will be useful for comparison of several identification methods, both those used as a first choice in routine microbiology and those used for final confirmation.

Nomogram for pneumonia prediction among children and young people with cerebral palsy: A population-based cohort study

BACKGROUND

Pneumonia is the leading cause of death among children and young people (CYP) with severe cerebral palsy (CP). Only a few studies used nomogram for assessing risk factors and the probability of pneumonia. Therefore, we aimed to identify risk factors and devise a nomogram for identifying the probability of severe pneumonia in CYP with severe CP.

METHODS

This retrospective nationwide population-based cohort study examined CYP with newly diagnosed severe CP before 18 years old between January 1st, 1997 and December 31st, 2013 and followed them up through December 31st, 2013. The primary endpoint was defined as the occurrence of severe pneumonia with ≥ 5 days of hospitalization. Logistic regression analysis was used for determining demographic factors and comorbidities associated with severe pneumonia. These factors were assigned integer points to create a scoring system to identify children at high risk for severe pneumonia.

RESULTS

Among 6,356 CYP with newly diagnosed severe CP, 2,135 (33.59%) had severe pneumonia. Multivariable logistic regression analysis revealed that seven independent predictive factors, namely age <3 years, male sex, and comorbidities of pressure ulcer, gastroesophageal reflux, asthma, seizures, and perinatal complications. A nomogram was devised by employing these seven significant predictive factors. The prediction model presented favorable discrimination performance.

CONCLUSIONS

The nomogram revealed that age, male sex, history of pressure ulcer, gastroesophageal reflux, asthma, seizures, and perinatal complications were potential risk factors for severe pneumonia among CYP with severe CP.

Infections in children with diabetes

OBJECTIVE

The association between diabetes mellitus and infections is very common. These infections, even when mild, interfere with blood glucose control. The aim of this review is to describe infections that occur in children and adolescents with DM, as well as to provide recommendations on glycemia management during these episodes.

SOURCE OF DATA

A non-systematic review was carried out in the PubMed database, using the terms "diabetes mellitus," "infection," "children," and "adolescents." The most relevant publications were selected.

SYNTHESIS OF DATA

In addition to the usual community diseases, some infections may occur predominantly in diabetic patients, especially when there is inadequate glycemic control, and common infections can be more severe in these patients. Alterations caused by the disease itself and the immune response are responsible for the risk of higher frequency and severity of infections. During infections, an increase in blood glucose occurs and usually an increase in insulin dose is required.

CONCLUSIONS

Pediatric patients with diabetes have some immune system disorders that, when associated with high glycemia, increase the risk of infections and their severity, and should be promptly identified and treated. The presence of an infectious condition, in turn, raises blood glucose and increases the risk of decompensation, and pediatricians should be cautioned to intensify monitoring and insulin therapy, and to avoid the risk of DKA. It should also be noted that many infections are preventable and can be avoided with adequate vaccine coverage.

Why are people with asthma susceptible to pneumonia? A review of factors related to upper airway bacteria

Asthma and pneumonia are common respiratory conditions globally, affecting individuals of all ages. Streptococcus pneumoniae is the predominant bacterial cause of pneumonia, with nasopharyngeal carriage an important step towards invasive and pulmonary disease. Vaccines provide individual protection, and also prevent nasopharyngeal carriage, providing herd immunity. Asthma is associated with an increased risk of pneumonia, but there is limited information on the underlying mechanism of this predisposition. Both asthma and its treatment may conceivably alter propensity to, and density of, carriage through an altered epithelial microenvironment driven by disease-related inflammation or treatment-related immunomodulation, for example with inhaled corticosteroids. The relative importance of these factors could impact the efficacy of vaccines in this vulnerable patient population. In this review, we summarize the evidence for an increased risk of pneumonia in asthma, and discuss factors affecting nasopharyngeal carriage in the context of current guidelines for pneumococcal vaccination.