Nasopharyngeal carriage of Streptococcus pneumoniae in healthy children aged less than five years

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.

Nasopharyngeal carriage of Streptococcus pneumoniae among children aged 30 days to <60 months in Beijing and Shenzhen, China (2018-2021) during pneumococcal conjugate vaccine introduction and the coronavirus disease (COVID-19) pandemic

Objectives

To describe the carriage rate, serotype distribution, and antimicrobial susceptibility patterns of Streptococcus pneumoniae (S. pneumoniae) nasopharyngeal (NP) isolates among healthy children aged 30 days to <60 months in the cities of Beijing and Shenzhen during 2018-2021.

Methods

A NP swab sample was collected among four annual cohorts of healthy children at routine well-child visits. S. pneumoniae was identified by culture, optochin sensitivity and bile solubility, serotypes determined by latex agglutination and Quellung, and antimicrobial susceptibility testing performed using E-test strips.

Results

S. pneumoniae NP carriage was 13.1% (645/4,911), with the highest S. pneumoniae carriage prevalence (15.3%) observed in 25 to <60 months. The carriage prevalence was 15.1% in children 13-24 months, 13.2% in children 7-12 months, and 8.2% in children 30 days to 6 months (P < 0.01). Living with siblings [20.0% vs. 9.4%: OR: 2.42 (95% CI: 2.05-2.87)] or attending day-care [31.8% vs. 11.3%: OR: 3.67 (95% CI: 2.94-4.57)] increased the risk (P < 0.01). During the period (January 2020-April 2021) of strict non-pharmaceutical interventions to prevent and control the COVID-19 pandemic, the proportion of children with S. pneumoniae colonization declined from 16.0% (94/587) to 5.8% (108/1,848) in Beijing while increasing from 14.5% (64/443) to 18.6% (379/2,033) in Shenzhen. Among S. pneumoniae isolates, 36.7% (237/645) belonged to 13-valent pneumococcal conjugate vaccine (PCV13) serotypes, 64.3% (408/645) were non-PCV13 serotypes, including 20.8% (134/645) non-serotypeable S. pneumoniae (NST). A total of 158/644 isolates (24.5%) were MDR. For the PCV13 isolates, MDR was detected in 36.3% (86/237) of isolates; in comparison, 17.6% (72/407) of non-PCV13 serotypes, including NST, were MDR (P < 0.01). S. pneumoniae NP carriage was detected in 10.7% of children with previous pneumococcal vaccination (PCV7 or PCV13 only) compared with 14.9% in children without previous pneumococcal vaccination.

Conclusions

The highest S. pneumoniae carriage prevalence were found in the oldest age group (25 to <60 months) and in children living with siblings or attending day-care. Vaccination with PCV7 or PCV13 was associated with lower PCV13-serotype colonization. In Beijing, S. pneumoniae carriage significantly declined during the COVID-19 pandemic.

Pneumococcal nasopharyngeal carriage in children under 5 years of age at an outpatient healthcare facility in Novi Sad, Serbia during the COVID-19 pandemic

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The prevalence of nasopharyngeal pneumococcal carriage in children aged 24–60 months was 31.7%.

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The prevalence was high and increased during the coronavirus disease 2019 (COVID-19) pandemic.

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This ruled out a major role of COVID-19 in suppressing carriage and, probably, transmission.

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The dominant serotypes were 15B, 6B, 19F, 11A, 6C, 6A, 3, 23F and 19A.

Objectives

To assess whether pneumococcal nasopharyngeal carriage among children aged 24–60 months reduced during the coronavirus disease 2019 (COVID-19) pandemic in Novi Sad, Serbia, and to investigate the overall prevalence of carriage, serotype distribution and dominant serotypes 2–3 years after the introduction of pneumococcal conjugate vaccine 10.

Design and methods

This prospective, observational study was conducted in February–March 2020, September–November 2020 and April–June 2021, enabling the comparison of results in the pre-pandemic/early pandemic period with two periods during the COVID-19 pandemic. Pneumococci were identified by standard microbiological methods. Serotype identification was performed using conventional multiplex polymerase chain reaction assays.

Results

Among 1623 children tested, 515 (31.7%, 95% confidence interval 29.4–34.0%) carried pneumococci. A significant increase in prevalence was found between February–March 2020 and September–November 2020 (P=0.0085), with no difference found between September–November 2020 and April–June 2021 (P=0.0524). Pneumococcal colonization was significantly higher in children who were fully vaccinated and among children who attended day care centres. The dominant serotypes were 15B, 6B, 19F, 11A, 6C, 6A, 3, 23F and 19A, representing 66.4% of all isolates.

Conclusions

This study found that pneumococcal nasopharyngeal carriage in children aged 24–60 months was high before the COVID-19 pandemic, and then increased during the pandemic. This rules out a major role of COVID-19 in the suppression of carriage and, probably, transmission.

Impact of Pneumococcal Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae and Microbiota Profiles in Preschool Children in South East Poland

In 2017, Poland introduced the 10-valent pneumococcal conjugate vaccine (PCV) into its national immunization schedule. This prospective study was conducted between March and June 2020 to determine the impact of vaccination on prevalence of the nasopharyngeal carriage of S. pneumoniae in 176 healthy children and to determine how conjugate vaccines indirectly affect colonization of nasopharyngeal microbiota. Pneumococcal isolates were analyzed by serotyping and antimicrobial resistance tests. Nasopharyngeal microbiota were detected and identified using the culture method and real-time PCR amplification primers and hydrolysis-probe detection with the 16S rRNA gene as the target. In the vaccinated group of children, colonization was in 24.2% of children, compared to 21.4% in the unvaccinated group. Serotypes 23A and 23B constituted 41.5% of the isolates. Serotypes belonging to PCV10 and PCV13 constituted 4.9% and 17.1% of the isolates, respectively. S. pneumoniae isolates were resistant to penicillin (34.1%), erythromycin (31.7%), and co-trimoxazole (26.8%). Microbial DNA qPCR array correlated to increased amounts of Streptococcus mitis and S. sanguinis in vaccinated children, with reduced amounts of C. pseudodiphtericum, S. aureus, and M. catarrhalis. Introduction of PCV for routine infant immunization was associated with significant reductions in nasopharyngeal carriage of PCV serotypes and resistant strains amongst vaccine serotypes, yet carriage of non-PCV serotypes increased modestly, particularly serotype 23B.

The application value of metagenomic next-generation sequencing in children with invasive pneumococcal disease

BACKGROUND

A retrospective analysis was conducted to explore the sensitivity and specificity of metagenomic next-generation sequencing (mNGS) in blood, cerebrospinal fluid, and pleural effusion samples in children with invasive pneumococcal disease (IPD), and the impact of detection timing on prognosis and cost.

METHODS

Children with IPD admitted to Hebei Children's Hospital from 1 January 2017 to 1 March 2021 were allocated to 1 of 3 groups according to the clinical symptoms and lesions (Group 1: bacteremia; Group 2: meningitis; Group 3: pleurisy). Taking Alere BinaxNow^® Streptococcus pneumoniae (S. pneumoniae) antigen detection and blood culture as the gold standard, receiver operating characteristic (ROC) was used to establish the diagnostic value of mNGS.

RESULTS

A total of 96 cases were enrolled in the study, comprising Group 1 (n=65), Group 2 (n=17), and Group 3 (n=14). The positive rate of mNGS test was 62.5% (n=60), and the total coincidence rate was 75.0%. Delayed mNGS was found to have no significant effect on the 30-day survival rate; however, the species-specific read number (SSRN) of S. pneumoniae detected by mNGS in the early stage of the disease was higher, and it could significantly reduce the hospitalization days and costs (P<0.05).

CONCLUSIONS

The sensitivity and specificity of mNGS are high in the identification of S. pneumoniae in blood, cerebrospinal fluid, and pleural effusion samples, and the SSRN of S. pneumoniae is related to the interval from onset to sample collection. Early mNGS detection has no significant effect on the 30-day survival rate among children with IPD, but it can reduce hospitalization costs and duration.

Respiratory Tract Pathogens in the COVID-19 Era: Data from a Pediatric Emergency Department

Objective The frequency of coinfections in pediatric Coronavirus disease 2019 (COVID-19) cases and their impact on the clinical course are not fully understood. We aimed to investigate the viral and bacterial respiratory pathogens in children admitted to the pediatric emergency department (PED), their clinical course, and the presence of coinfections during the early months of the COVID-19 pandemic.

Methods Clinical, laboratory and radiological findings, viral and bacterial pathogens detected by multiplex polymerase chain reaction (PCR) tests in nasopharyngeal swabs, clinical course, and treatments of all children who were tested for severe acute respiratory coronavirus 2 (SARS-CoV-2) at the PED between March 16 and May 15, 2020, were recorded. SARS-CoV-2 PCR-positive and negative groups were compared.

Results Out of 570 patients tested for SARS-CoV-2 during the study period, 43 were found positive (7.5%). Non-SARS-CoV-2 viral pathogens were more common in the SARS-CoV-2 PCR-negative group than the SARS-CoV-2 PCR-positive group (13.2%, n = 68 versus 4.7%, n = 2), but this result was not statistically significant. Leukocyte, neutrophil, lymphocyte, and platelet counts were lower in SARS-CoV-2 PCR-positive group. Bacterial panel positivity was significantly higher in the SARS-CoV-2 PCR-positive group compared with the SARS-CoV-2 PCR-negative group (52%, n = 12 versus 28%, n = 91; p < 0.05). The presence of coinfection did not alter the course of therapy in SARS-CoV-2 PCR-positive cases.

Conclusion While viral coinfections were rare, bacterial panel positivity was common in children with COVID-19, but this had not influenced management decisions. The limitations of the tests should be kept in mind while interpreting the results.