Review on Pneumococcal Infection in Children

Health state utilities associated with invasive pneumococcal disease, pneumonia, and recurrent acute otitis media in young children

PURPOSE

Cost-utility analyses examining the value of new vaccines for pneumococcal disease will require health state utilities as inputs. Existing utilities for pneumococcal infections in young children are limited. The purpose of this study was to estimate health state utilities associated with pneumococcal infections in young children.

METHODS

Six health state vignettes depicting infections due to Streptococcus pneumoniae were drafted based on published literature and clinician interviews. To address methodological challenges in estimating utilities for temporary infections in children 0-5 years of age, several time trade-off approaches were explored in a pilot study (N = 28 participants). In the subsequent utility elicitation study conducted in the UK, health states were valued using the best performing method from the pilot (10-year time horizon, with infections repeated annually) with adult general population respondents imagining a child 2-5 years of age.

RESULTS

A total of 208 participants completed interviews (51.9% female; mean [SD] age = 41.0 [14.9] years). Mean (SD) utilities were 0.902 (0.092) for pneumonia requiring hospitalization, 0.901 (0.087) for bacteremia, 0.894 (0.103) for recurrent acute otitis media (AOM), 0.882 (0.107) for recurrent AOM treated with pressure equalization tubes, 0.878 (0.109) for bacteremic pneumonia, and 0.809 (0.145) for meningitis.

CONCLUSION

Lower health state utilities were associated with health states that had longer treatment periods, required more invasive treatment, and described more severe infections. Utilities from this study can be used in models examining cost-effectiveness of pneumococcal vaccines. These results have methodological implications for future research estimating utilities associated with temporary pediatric health conditions.

Fourier transform infrared spectroscopy for Streptococcus pneumoniae capsular serotype classification in pediatric patients with invasive infections

Invasive pneumococcal disease (IPD) is a major cause of morbidity and mortality worldwide, particularly in the pediatric population (children and infants), with high rates of hospitalization and death. This study aimed to create and validate a classifier for Streptococcus pneumoniae serotyping using Fourier-transform infrared (FT-IR) spectroscopy as a rapid alternative to the classical serotyping technique. In this study, a database comprising 76 clinical isolates, including 18 serotypes (predominantly serotypes 19A, 6C, and 3) of S. pneumoniae from pediatric patients with IPD, was tested at a tertiary pediatric hospital in southern Brazil during 2016-2023. All isolates were previously serotyped using the Quellung reaction, and 843 FT-IR spectra were obtained to create a classification model using artificial neural network (ANN) machine learning. After the creation of this classifier, internal validation was performed using 384 spectra as the training dataset and 459 as the testing dataset, resulting in a predictive accuracy of 98% for serotypes 19A, 6, 3, 14, 18C, 22F, 23A, 23B, 33F, 35B, and 9N. In this dataset, serotypes 10A/16F, 15ABC, and 7CF could not be differentiated and were, therefore, grouped as labels. FT-IR is a promising, rapid, and low-cost method for the phenotypic classification of S. pneumoniae capsular serotypes. This methodology has significant implications for clinical and epidemiological practice, improving patient management, monitoring infection trends, and developing new vaccines.

Detection of Macrolide-Resistant Streptococcus pneumoniae Genes and Its Clinical Outcomes in a Tertiary Teaching Hospital in Malaysia

Background

Streptococcus pneumoniae is one of the leading causes of mortality and morbidity worldwide. The dramatic increase in in-vitro resistance of antimicrobial agents, particularly beta-lactams and macrolides, makes pneumococcal infections difficult to treat. The aim of this study was to describe the drug resistance rate, assess the prevalence of macrolide-resistant genes and review the clinical complications of pneumococcal infections among patients presented to Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia.

Methods

This is a descriptive cross-sectional study. All S. pneumoniae isolates collected from clinical specimens within a 1-year period were subjected to selected antimicrobial susceptibility testing using E-test strips. Polymerase chain reaction (PCR) analysis was conducted to detect macrolide-resistant determinants. The patient's clinical data were obtained from clinical notes.

Results

A total of 113 patients with a positive growth of S. pneumoniae were included in the study. The most common predisposing factors among them were bronchopulmonary diseases (15.9%). The penicillin-resistant rate was 7.1%, with minimal inhibitory concentration (MIC) ranging between 0.012 μg/mL and >32 μg/mL, and the erythromycin-resistant rate was 26.5%, with a MIC range of 0.03 μg/mL-> 256 μg/mL. Most of the erythromycin-resistant isolates were found to have the mef(A) gene (50.4%) and the erm(B) gene (20%); 16.7% had a combination of genes mef(A) and erm(B), and 13.3% had none of the two genes. Community-acquired pneumonia is the predominant type of pneumococcal infection. There was no significant association between the presence of macrolide resistance determinants and mortality (P = 0.837) or complications (P > 0.999 for empyema and cardiac complication; P = 0.135 for subdural abscess).

Conclusion

The majority of erythromycin-resistant isolates were found to have the mef(A) gene, followed by the erm(B) gene and a combination of genes mef(A) and erm(B).

Chlamydophila pneumoniae-associated community-acquired pneumonia in paediatric patients of a tertiary care hospital in Mexico: molecular diagnostic and clinical insights

Chlamydophila pneumoniae is a cause of community-acquired pneumonia (CAP) and responsible for 1-2% of cases in paediatric patients. In Mexico, information on this microorganism is limited. The aim of this study was to detect C. pneumoniae using two genomic targets in a real-time PCR and IgM/IgG serology assays in paediatric patients with CAP at a tertiary care hospital in Mexico City and to describe their clinical characteristics, radiological features, and outcomes. A total of 154 hospitalized patients with diagnosis of CAP were included. Detection of C. pneumoniae was performed by real-time PCR of the pst and arg genes. Complete blood cell count, C-reactive protein measurement and IgM and IgG detection were performed. Clinical-epidemiological and radiological data from the patients were collected. C. pneumoniae was detected in 25 patients (16%), of whom 88% had underlying disease (P = 0.014). Forty-eight percent of the cases occurred in spring, 36% in girls, and 40% in children older than 6 years. All patients had cough, and 88% had fever. Interstitial pattern on chest-X-ray was the most frequent (68%), consolidation was observed in 32% (P = 0.002). IgM was positive in 7% and IgG in 28.6%. Thirty-six percent presented complications. Four percent died. A high proportion showed co-infection with Mycoplasma pneumoniae (64%). This is the first clinical report of C. pneumoniae as a cause of CAP in Mexican paediatric patients, using two genomic target strategy and serology. We found a frequency of 16.2% with predominance in children under 6 years of age. In addition; cough and fever were the most common symptoms. Early detection of this pathogen allows timely initiation of specific antimicrobial therapy to reduce development of complications. This study is one of the few to describe the presence of C. pneumoniae in patients with underlying diseases.

Vaccines and nephrotic syndrome: efficacy and safety

Vaccines represent the most important medical evolution in the last two centuries allowing prevention and formally eradication of a wide number of infectious diseases. Safety and effectiveness are main issues that still require an open discussion. A few clinical reports described a critical temporal relationship between vaccination and acute nephrotic syndrome, indirectly suggesting an association. For this review, the literature was reviewed to identify articles reporting associations of nephrotic syndrome with vaccines against a vast array of infectious diseases (including bacteria, virus and Sars-Cov-2). As specific aims, we evaluated effectiveness and safety in terms of occurrence of either "de novo" nephrotic syndrome in health subjects or "relapse" in those already affected by the disease. In total, 377 articles were found; 166 duplicates and 71 non-full text, animal studies or non-English language were removed. After excluding another 50 articles not containing relevant data on generic side effects or on relapses or new onset nephrotic syndrome, 90 articles met the search criteria. Overall, studies reported the effect of vaccines in 1015 patients, plus 4 nationwide epidemiologic investigations. Limited experience on vaccination of NS patients with measles, mumps, and rubella live attenuated vaccines does not allow any definitive conclusion on their safeness. VZV has been administered more frequently without side effects. Vaccines utilizing virus inactivated, recombinant, and toxoid can be utilized without risks in NS. Vaccines for influenza reduce the risk of infections during the pandemic and are associated with reduced risk of relapse of NS typically induced by the infection. Vaccines for SARS-CoV-2 (all kinds) offer a concrete approach to reduce the pandemic. "De novo" NS or recurrence are very rare and respond to common therapies.

Epidemiology and outcomes of pneumococcal sepsis in children with nephrotic syndrome in a developing country

BACKGROUND

Pneumococcal infections are common in children with nephrotic syndrome. Knowledge of the commonly available serotypes and antibiotic susceptibility will help in prevention and appropriate management of pneumococcal sepsis, especially in resource-limited countries.

METHODS

Demographic, clinical, and laboratory data on children with nephrotic syndrome and pneumococcal infections were extracted from the electronic medical records.

RESULTS

Sixty-three isolates of pneumococci obtained from 60 children with nephrotic syndrome, over a period of 14 years, were included in the study. This represented 18% of all pneumococcal infections occurring in children during the same period. Commonly available vaccines covered up to 58% of all the serotypes causing infection. Severe disease, with shock, intensive care admission and/or meningitis, was observed in 38% children and mortality was observed in 10%. Resistance to commonly used antibiotics was not observed, except for erythromycin.

CONCLUSIONS

Pneumococcal sepsis was observed to be common in children with nephrotic syndrome and results in significant morbidity and mortality. Commonly used antibiotics were observed to be effective in management of the infections.

Pneumococcal Immunization Strategies for High-Risk Pediatric Populations Worldwide: One Size Does Not Fit All

Despite the significant reduction in pneumococcal disease due to pneumococcal vaccines, protection of vulnerable high-risk individuals, especially pediatric populations, remains a great challenge. In an effort to maximize the protection of high-risk children against pneumococcal disease, a combined schedule that includes both conjugate and polysaccharide vaccines is recommended by several countries in the developed world. On the other hand, middle- and low-income countries do not have in place established policies for pneumococcal immunization of children at risk. Pneumococcal conjugate vaccines, despite their benefits, have several limitations, mainly associated with serotype replacement and the wide range of serotype coverage worldwide. In addition, PPV23-impaired immunogenicity and the hyporesponsiveness effect among populations at risk have been well-documented. Therefore, the added value of continuing to include PPV23 in vaccination schedules for high-risk individuals in the years to come remains to be determined by monitoring whether the replacing/remaining serotypes causing IPD are covered by PPV23 to determine whether its benefits outweigh its limitations. In this review, we aim to describe serotype distribution and vaccine efficacy data on pneumococcal disease in the pre- and post-PCV implementation era among high-risk children in both developed and developing countries, assessing the optimization of current recommendations for their vaccination against pneumococcal disease.