Characteristics of pediatric invasive pneumococcal diseases and the pneumococcal isolates in Suzhou, China before introduction of PCV13

Prevalence of Streptococcus pneumoniae serotypes causing pneumococcal diseases in the Chinese Mainland: A systematic review and meta-analysis

Pneumococcal disease (PD) caused by Streptococcus pneumoniae (Sp) continues to be a global public health concern. Monitoring the prevalence and shift of Sp serotypes causing PD is critical for vaccination and local policies for PD management. A systematic review of published work on pneumococcal serotype distribution in the Chinese Mainland from January 1997 to July 2023 was conducted. The literature was searched in Medline, Embase, the Cochrane Library, Web of Science, CNKI, and Wanfang. Distribution of the Sp serogroups/serotypes was presented as count and proportion. Pooled distributions were calculated using a double arcsine transformation. Subgroup analyses were performed according to isolate location, strain source, patient age, period, and clinical manifestation. In total 36,477 Sp isolates in 159 studies were included. In the Chinese Mainland, the highest proportion of Sp in PD was serotype 19F, followed by 19A, 23F, 14 and 6B. Serotype 19F was the most predominant circulating serotype through all time periods. PD cases caused by non-vaccine serotypes showed a significant increase after 2019. In summary, from 1997 to 2023, the top 10 prevalent Sp serotypes causing PD in the Chinese Mainland were 19F, 19A, 6, 23F, 14, 6B, 6A, 3, 15B, and 9 V. Although the distribution of serotypes varied according to the subgroups, the increase in non-vaccine serotypes (e.g. 15A), and diversity distribution of serotypes 6A and 3 in different age groups should not be ignored.

The Epidemiologic and Clinical Features of Radiographic-Confirmed Community-acquired Pneumonia Among Chinese Children: A Retrospective Hospital-based Study

BACKGROUND

To help understand the disease burden of vaccine-preventable bacterial disease, we delineated the epidemiologic and clinical characteristics of radiographic-confirmed community-acquired pneumonia (CXR-CAP) among Chinese children.

METHODS

We retrospectively screened the electronic database of the hospital information system to identify all pediatric CAP cases admitted to the Children's Hospital of Soochow University between 2010 and 2014. Radiographic findings and clinical data were extracted from the medical charts through individual chart reviews. CXR-CAP cases were defined as the presence of consolidation or pleural effusion noted on chest radiograph reports. We employed a multivariate logistic regression model to identify the potential risk factors associated with CXR-CAP.

RESULTS

Among the 27,485 hospitalized CAP cases with radiologic data, 6322 (23.00%) were identified as CXR-CAP cases, while 21,163 (77.00%) were categorized as non-CXR-CAP cases. Children with CXR-CAP were notably older than those without CXR-CAP (non-CXR-CAP; χ 2 = 1313.22; P < 0.01). CXR-CAP cases exhibited a higher rate of intensive care unit admission (3.55% vs. 1.94%; P < 0.01), extended hospital stays (73.87% vs. 63.79%; P < 0.01) and increased mortality rates (0.19% vs. 0.04%; P < 0.01). The factors associated with CXR-CAP included age (>12 months), season (summer and autumn), fever, abnormal breath sounds, C-reactive protein (>8 mg/L) and alanine transaminase (>40 U/L).

CONCLUSIONS

CXR-CAP cases consisted of a substantial proportion of hospitalized patients with CAP and had more severe clinical manifestations than in-patients without CXR-CAP among Chinese children.

Antimicrobial susceptibility profiles of invasive bacterial infections among children from low- and middle-income countries in the Western Pacific Region (WPRO) - a systematic review and meta-analysis

Background

Antimicrobial resistance increasingly impacts paediatric mortality, particularly in resource-constrained settings. We aimed to evaluate the susceptibility profiles of bacteria causing infections in children from the Western Pacific region.

Methods

We conducted a systematic review and meta-analysis of bacteria responsible for common infections in children. We included studies published from January 2011 to December 2023 (PROSPERO CRD42021248722). Pooled susceptibilities were evaluated against empiric antibiotics recommended to treat common clinical syndromes.

Findings

Fifty-one papers met inclusion criteria, incorporating 18,330 bacterial isolates. Of available published data, only six countries from the region were represented. Escherichia coli revealed a pooled susceptibility to ampicillin of 17% (95% CI 12-23%, n = 3292), gentamicin 63% (95% CI 59-67%, n = 3956), and third-generation cephalosporins 59% (95% CI 49-69%, n = 3585). Susceptibility of Klebsiella spp. to gentamicin was 71% (95% CI 61-80%, n = 2323), third-generation cephalosporins 35% (95% CI 22-49%, n = 2076), and carbapenems 89% (95% CI 78-97%, n = 2080). Pooled susceptibility of Staphylococcus aureus to flucloxacillin was 72% (95% CI 58-83%, n = 1666), and susceptibility of Streptococcus pneumoniae meningitis isolates to ampicillin was 26% (95% CI 11-44%, n = 375), and 63% (95% CI 40-84%, n = 246) to third-generation cephalosporins.

Interpretation

The burden of antimicrobial resistance among bacteria responsible for common infections in children across the Western Pacific region is significant, and the currently recommended World Health Organization antibiotics to treat these infections may be inefficacious. Strategies to improve the availability of high-quality data to understand the burden of antimicrobial resistance in the region are necessary.

Funding

The study was supported by an Australian GovernmentNational Health and Medical Research Council Investigator Grant. This research was funded in part by the Wellcome Trust [220211/Z/20/Z]. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.

[Dose-response relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children]

OBJECTIVES

To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines.

METHODS

The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage.

RESULTS

The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates.

CONCLUSIONS

There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.

Clinical characteristics, antimicrobial resistance, and risk factors for mortality in paediatric invasive pneumococcal disease in Beijing, 2012-2017

Background

To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing.

Methods

Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed.

Results

Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/μL were independent risk factors for mortality.

Conclusion

Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.

Effectiveness of 13-valent pneumococcal conjugate vaccine against community acquired pneumonia among children in China, an observational cohort study

BACKGROUND

In China, 13-valent pneumococcal conjugate vaccine (PCV13) has been available since 2017, but only via the private market with low uptake rate. We assessed the direct effectiveness of PCV13 against community acquired pneumonia (CAP) associated with PCV13 serotype carriage (VT-CAP).

METHODS

We conducted an observational cohort study of children born during 12-Dec-2016 to 30-Nov-2018 identified in the Suzhou Centers for Disease Control vaccine registry database, and who had at least one inpatient or outpatient record at the Suzhou University Affiliated Children's hospital (SCH) health-information-system (HIS) database. The vaccine registry cohort was followed through the HIS database through 30-Jun-2019 to identify hospitalized VT-CAP. Pneumococci were isolated from deep upper respiratory aspirates and serotyped with Quellung reactions.

RESULTS

We included 139,127 children of whom 9024 (6.5%) received 1 + PCV13 doses (95.8% received 2 + doses). Within the total cohort, we identified 548 children hospitalized at SCH for VT-CAP, of whom 10 had received 2 + PCV13 doses. Adjusted for demographics, receipt of other childhood vaccines, and underlying medical conditions, the first visit vaccine effectiveness among children who had received 2 + PCV13 doses was 60.9% (95% CI: 25.8% to 79.4%) for VT-CAP and 17.9% (95% CI: 5.5% to 28.6%) for clinical CAP. Incidence rate reductions per 100,000 child-years of observation for all visits were 208 (95% CI: 118 to 298) for VT-CAP and 720 (95% CI: 304 to 1135) for clinical CAP.

CONCLUSIONS

PCV13 was protective against hospitalized VT-CAP and clinical CAP with large associated incidence rate reductions among children living in Suzhou, China.

Hospitalization for Invasive Pneumococcal Diseases in Young Children before Use of 13-Valent Pneumococcal Conjugate Vaccine, Suzhou, China

A 13-valent pneumococcal conjugate vaccine against invasive pneumococcal disease (IPD) was introduced in China in April 2017. We describe 105 children <5 years of age who were hospitalized for IPD at Soochow University Affiliated Children’s Hospital in Suzhou, China, during January 2010–December 2017. We calculated the incidence of hospitalization for IPD as 14.55/100,000 children in Suzhou. We identified 8 different capsular serotypes: 6B (28.4% of cases), 14 (18.9% of cases), 19A (18.9% of cases), 19F (12.2% of cases), 23F (10.8% of cases), 20 (4.1% of cases), 9V (4.1% of cases), and 15B/C (2.7% of cases). These results provide baseline data of IPD before the introduction of this vaccine in China, enabling researchers to better understand its effects on IPD incidence.

Non-linear relationships between children age and pneumococcal vaccine coverage: Important implications for vaccine prevention strategies

BACKGROUND

Streptococcus pneumoniae (S. pneumoniae) is an important pathogen causing both invasive and non-invasive infections in children, with significant morbidity and mortality worldwide. This study aimed to determine the potential relationships between age and vaccine coverage and between multiple phenotype-genotype characteristics of S. pneumoniae isolated from children.

METHODS

All S. pneumoniae isolates were tested for antimicrobial susceptibility, virulence genes, serotypes, and sequence types. The restricted cubic spline models were used to reveal potential relationships between children age and pneumococcal vaccine coverage.

RESULTS

For capsular-based vaccines, we observed a high coverage rate of 13-valent pneumococcal conjugate vaccine (PCV13, 85.8%) and a significantly non-linear relationship between children age and vaccine coverage (including PCV7, PCV10, and PCV13), with marked fluctuations in children aged < 2 years. For protein-based and pilus-based vaccine candidates, we demonstrated dynamic non-linear relationships between age and vaccine coverage, maintaining a stable and high coverage rate of ply and lytA for all age groups. Moreover, there were significantly high-dimensional corresponding relationships among multiple phenotype-genotype characteristics of S. pneumoniae isolates (such as ST271 associated with serotype 19F, PI-2, and extensively drug-resistance).

CONCLUSIONS

Our findings suggest that the age for high PCV coverage being children aged ≥ 2 years and also provide important evidence for supporting ply and lytA as priority candidate targets for the development of new-generation protein vaccines.

Antimicrobial Susceptibility Test for the Determination of Resistant and Susceptible S. aureus and Enterococcus spp. Using a Multi-Channel Surface Plasmon Resonance Device

The objective of this study was to investigate the development of a surface plasmon resonance (SPR) sensor platform equipped with multiple channels for the simultaneous determination of methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA) and vancomycin-resistant Enterococcus (VRE), and vancomycin-susceptible Enterococcus (VSE). Drug resistance of S. aureus strains against cefoxitin and Enterococcus strains against vancomycin were investigated both using the minimum inhibitory concentration method (MIC) assay and the SPR system equipped with single and multiple channels. The MIC values of MRSA and MSSA ranged from 32 µg/mL to >128 µg/mL and from 1 µg/mL to 4 µg/mL, respectively. The MIC values of VRE and VSE were between 64 to >128 µg/mL and 2-4 µg/mL, respectively. With the multiple-channel system, the angle shifts of MRSA, MSSA, VRE and VSE were found to be -0.030° and -0.260°, -0.010° and -0.090° respectively. The antibiotic-resistant and susceptible strains were distinguished within 3 h for S. aureus strains and within 6 h for Enterococcus strains.

Regional variations in serotype distribution and vaccination status in children under six years of age with invasive pneumococcal disease in Germany

Overview

The protective effect of infant pneumococcal conjugate vaccine (PCV) recommendation can be seen in Germany as a whole and in smaller regional groups. Comparisons between population-normalized geographic regions of Germany show different serotype distributions after program implementation, particularly in non-vaccine serotypes. The prior distinct differences in serotype distribution in children between the former East and former West German federal states have vanished. Children under six remain a vulnerable group, but the occurrence of vaccine-type (VT) invasive pneumococcal disease (IPD) in children correctly vaccinated (using a three-dose primary series plus one booster dose) with PCV13 was low (9 out of 374 cases, 2.4%). However, only 18.4% of children in Germany with IPD were correctly vaccinated with PCV13 according to the recommended schedule. Continued surveillance and better schedule adherence are essential to definitively establish the most effective PCV administration schedule.

Vaccination effects

For all PCV products used in Germany (PCV7, PCV10, and PCV13), vaccination status was the most common statistically significant predictor of infection with a particular serotype: Unvaccinated children old enough to have received at least one dose of vaccine in the PCV7 group had significantly higher odds (OR: 6.84, 95%CI: 2.66–22.06, adjusted for per capita income and residence in the northeastern federal states) of contracting VT IPD. In the PCV10 group, VT IPD had an OR of 4.52 (95% CI: 1.60–15.62, adjusted for year of infection, median household size, and residence in the southern federal states) in unvaccinated children, and in the PCV13 group, unvaccinated children continued to have higher odds (OR: 6.21, 95%CI: 3.45–11.36, adjusted for year of infection, age of child, per capita income, residence in the southern federal states, and percentage of children using public daycare) of getting vaccine-type IPD. Being unvaccinated was the most frequent significant indicator for infection with vaccine-type serotypes for each analysis group, while geographic groupings showed more limited potential to predict serotype of infection in early childhood IPD in Germany.

Serotype distribution, antibiotic resistance pattern, and multilocus sequence types of invasive Streptococcus pneumoniae isolates in two tertiary pediatric hospitals in Beijing prior to PCV13 availability

BACKGROUND

Invasive pneumococcal disease (IPD) is a serious threat to children worldwide. This study reported the serotype distribution, antibiotic resistance pattern, and multilocus sequence types of 111 IPD strains isolated from children less than 14 years old in two tertiary pediatric centers in Beijing during the years 2012-2017.

METHODS

Serotypes were determined using Quellung reaction. Antibiotic resistance was tested using the E-test or disc diffusion method. Sequence types (STs) were assigned via multilocus sequence typing.

RESULTS

The most common serotypes of the IPD isolates were 19F, 19A, 14, 23F, and 6B, and the PCV13 coverage rate was 90.1%. For the meningitis isolates, the resistance rate to penicillin was 95.7%, and the non-susceptibility rate to ceftriaxone was 65.2%. All of the non-meningitis isolates were susceptible to penicillin, and the susceptibility rate to ceftriaxone was 89.8%. All but one of the isolates were highly resistant to erythromycin. The multidrug resistance rate of all isolates was 89.2%. The most common STs were ST320, ST271, ST876, and ST81, which belonged to serotype 19A, 19F, 14, and 23F, respectively.

CONCLUSION

Given the high coverage rate of PCV13 and the worrisome non-susceptibility rate of IPD isolates to antibiotics, PCV13 use would be beneficial for Chinese children.

Clinical characteristics and antimicrobial resistance of pneumococcal isolates of pediatric invasive pneumococcal disease in China

Purpose

Streptococcus pneumoniae causes serious infections globally, including invasive pneumococcal disease (IPD). We analyze clinical features of pediatric IPD cases identified in China and antibiotic susceptibility of isolated pneumococcal strains.

Methods

Confirmed pediatric IPD patients were prospectively recruited to the study. Symptoms at the time of hospitalization, laboratory tests, antimicrobial susceptibility of pneumococcal isolates, treatments, hospital stay, and residual findings at discharge were analyzed systematically.

Results

From January 2008 to December 2017, a total of 123 hospitalized children diagnosed with IPD were enrolled: 68 from pediatric departments of Xinhua Hospital, and 55 from Lanzhou University Second Hospital. Of these pediatric IPD patients, 81 (65.86%) were male, and 98 (79.67%) <5 years old. Most cases (96, 78.05%) were diagnosed during the cold season between September and February. Sepsis was observed in 82 (66.67%) patients, 48 (39.02%) children were diagnosed with meningitis, 41 (33.33%) with pneumonia, 30 (24.39%) with pleurisy, and 4 (3.25%) with osteomyelitis. Underlying diseases were noted in 35 (28.45%) patients and concurrent infections in 45 (36.58%). The overall mortality rate was 2.44%. IPD children who developed sepsis and necrotizing pneumonia showed higher proportions of intensive care-unit admission, intravenous γ-globulin, glucocorticoid use, hemofiltration and ventilator, and longer duration of fever, hospital stay, and antibiotic use than nonsepsis and pneumonia subjects. Antimicrobial resistance of S. pneumoniae showed a highly unsusceptible rate for erythromycin (96.75%), trimethoprim-sulfamethoxazole (79.67%), and tetracycline (77.23%). All isolates were sensitive to vancomycin, linezolid, and levofloxacin.

Conclusion

Clinical symptoms were severe in the majority of pediatric IPD patients. More intensive treatments were demanded for IPD children with sepsis and necrotizing pneumonia. High resistance rates for erythromycin, trimethoprim–sulfamethoxazole, and tetracycline were found.

Phenotypic and molecular characterization of Streptococcus pneumoniae in pre-conjugate vaccine era: A Chinese hospital-based retrospective study

BACKGROUND

Streptococcus pneumoniae (S. pneumoniae) is an important pathogen in causing global morbidity and mortality among children. This study aimed to determine phenotypic and molecular characteristics of S. pneumoniae causing infections in children under five years in China.

METHODS

A hospital-based retrospective study was conducted. All 537 S. pneumoniae isolates were tested for antimicrobial susceptibility by E-test method, molecular characteristics including resistance genes, virulence genes and serotypes by multiplex polymerase chain reaction (PCR) method, and sequence types (STs) by sequencing seven housekeeping genes. Minimum spanning tree and correspondence analysis were used to reveal the potential relationship between serotypes and STs.

RESULTS

Most of S. pneumoniae isolates were resistant to erythromycin (93.9%) and tetracycline (86.4%), with the predominant resistance genes being erm(B) (92.6%) and tet(M) (95.5%). The prevalent serotypes were 19F, 6B, 19A, 23F and 14, the coverage rate of PCV13 was high in 85.8%, and the predominant STs were ST271, ST320, ST3173, ST81 and ST876. A significant correlation existed between STs and serotypes, with ST271/19F and ST320/19A as the most prevalent clones. Notably, ST271/19F and ST320/19A isolates were associated with resistance to specific antibiotics and carrying of mef(A/E), rlrA and sipA genes.

CONCLUSIONS

Our findings suggest the introduction of PCV13 vaccine to Chinese children, and underscore the value of monitoring multiple characteristics to detect new epidemiologic trends and provide implications for the formulation of multivalent pneumococcal vaccines.