Streptococcus pneumoniae as a frequent cause of severe community-acquired pneumonia among children in Beijing

Persistent Pulmonary Interstitial Emphysema With Respiratory Infection: A Clinicopathological Analysis of Six Cases and Detection of Infectious Pathogens by Metagenomic Next-Generation Sequencing (mNGS)

BACKGROUND

Persistent pulmonary interstitial emphysema (PPIE) is known to be related to mechanical ventilation and preterm. However, PPIE is also reported rarely in non-ventilated and full-term infants. Its relationship with respiratory infection is rarely reported in the literature. PPIE is difficult to diagnose and always mimics other congenital thoracic malformations (CTMs), such as congenital cystic adenomatoid malformation (CCAM).

OBJECTIVE

The objective of this study was to evaluate clinicopathological and radiographic features of PPIE with respiratory infection and to detect the possible infectious pathogens.

METHODS

From January 2011 to December 2019, six cases were confirmed pathologically with PPIE from a large cohort of 477 resected CTMs in West China Hospital of Sichuan University. Clinical and radiographic features were obtained from patients' medical records and follow-up. The present study aimed to analyze clinicopathological and radiographic features and to detect the infectious pathogens by metagenomic next-generation sequencing (mNGS).

RESULTS

The six PPIE cases included four girls and two boys, ranging from 2 months to 5 years; 100% (5/5) of the available cases were full-term and without mechanical ventilation. CCAM were suspected in 66.7% (4/6) patients; 66.7% (4/6) cases affected a single lobe, and 33.3% (2/6) cases affected both lung lobes. Clinically, all six PPIEs were presented with symptoms of respiratory infection and diagnosed with pneumonia. All six patients were treated by surgery after anti-infective treatment. The pathologic characteristics showed lung cysts with variable size along the bronchovascular bundles, the cysts had a discontinuous fibrotic wall with a smooth inner surface lined with uninucleated and/or multinucleated macrophages. Streptococcus pneumoniae was detected in patient No. 1. Human beta-herpesvirus 5 was detected in patient No. 2. Neisseria mucosa, Neisseria sicca, Prevotella melaninogenica, Prevotella histicola, and Fusobacterium nucleatum were detected in patient No. 5, and no infectious pathogen was detected in 50% (3/6, No. 3, No. 4, and No. 6) of cases.

CONCLUSION

Six rare cases of PPIE with respiratory infection were treated by surgery after anti-infective treatment. All five available cases were full-term infants without mechanical ventilation. The histological characteristics of PPIE were the wall of cysts composed of a thin layer of discontinuous fibrous tissue and lined with uninucleated or/and multinucleated macrophages.

Inhibition of the PI3K/AKT Signaling Pathway or Overexpression of Beclin1 Blocks Reinfection of Streptococcus pneumoniae After Infection of Influenza A Virus in Severe Community-Acquired Pneumonia

Streptococcus pneumoniae (S. pneumoniae) and viruses are considered as primary risks of community-acquired pneumonia (CAP), and the effects of co-infection bacterial and virus in the prognosis of patients with severe CAP (SCAP) are poorly described. Therefore, this study is conducted to investigate the regulation of Beclin1-PI3K/AKT axis in reinfection of S. pneumoniae after influenza A virus in mice model of bronchoalveolar lavage fluid (BALF). Samples of sputum and BALF were collected from patients with SCAP for etiological detection. The expression of each gene was determined by RT-qPCR and western blot analysis. Influenza A/PR/8/34 and S. pneumoniae were used to establish the mice model of reinfection pneumonia. The virus quantity, expression levels of inflammatory factors, bacterial load, and myeloperoxidase (MPO) activity were tested. HE staining was applied to observe histopathology of lung tissue. The expression of Beclin1 was downregulated and the PI3K/AKT pathway was activated in viral pneumonia. In vivo experiment, the reinfection of S. pneumoniae following influenza A virus infection increased the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice. In contrast, inhibition of the PI3K/AKT pathway or overexpression of Beclin1 reduced the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice reinfected with S. pneumoniae after influenza A virus infection. Collectively, our study demonstrates that inhibition of the PI3K/AKT signaling pathway or overexpressed Beclin1 alleviates reinfection of S. pneumoniae after influenza A virus infection in SCAP.

Modeling the impact of the 7-valent pneumococcal conjugate vaccine in Chinese infants: an economic analysis of a compulsory vaccination

Background

The purpose of this study was to compare, from a Chinese societal perspective, the projected health benefits, costs, and cost-effectiveness of adding pneumococcal conjugate heptavalent vaccine (PCV-7) to the routine compulsory child immunization schedule.

Methods

A decision-tree model, with data and assumptions adapted for relevance to China, was developed to project the health outcomes of PCV-7 vaccination (compared with no vaccination) over a 5-year period as well as a lifetime. The vaccinated birth cohort included 16,000,000 children in China. A 2 + 1 dose schedule at US$136.51 per vaccine dose was used in the base-case analysis. One-way sensitivity analysis was used to test the robustness of the model. The impact of a net indirect effect (herd immunity) was evaluated. Outcomes are presented in terms of the saved disease burden, costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio.

Results

In a Chinese birth cohort, a PCV-7 vaccination program would reduce the number of pneumococcus-related infections by at least 32% and would prevent 2,682 deaths in the first 5 years of life, saving $1,190 million in total costs and gaining an additional 9,895 QALYs (discounted by 3%). The incremental cost per QALY was estimated to be $530,354. When herd immunity was taken into account, the cost per QALY was estimated to be $95,319. The robustness of the model was influenced mainly by the PCV-7 cost per dose, effectiveness herd immunity and incidence of pneumococcal diseases. With and without herd immunity, the break-even costs in China were $29.05 and $25.87, respectively.

Conclusions

Compulsory routine infant vaccination with PCV-7 is projected to substantially reduce pneumococcal disease morbidity, mortality, and related costs in China. However, a universal vaccination program with PCV-7 is not cost-effective at the willingness-to-pay threshold that is currently recommended for China by the World Health Organization.

Burden of pneumonia and meningitis caused by Streptococcus pneumoniae in China among children under 5 years of age: a systematic literature review

BACKGROUND AND METHODS

To understand the burden and epidemiology of Streptococcus pneumoniae disease among children between 1 and 59 months of age in China, we conducted a review of literature published between 1980 and 2008 applying standardized algorithms. Because of the absence of population-based surveillance for pneumococcal disease (PD), we identified all-cause pneumonia, bacteremia and meningitis burden, syndromes most commonly associated with S. pneumoniae, and applied the proportion of disease attributable to S. pneumoniae from studies that determined the etiology of these three syndromes to calculate PD burden. Because of the microbiologic difficulties in identifying S. pneumoniae-attributable pneumonia which likely underestimates the pneumonia burden, we also used the proportion obtained from vaccine efficacy trials.

RESULTS

Between 1980 and 2008, there were 12,815 cases/100,000/year of all-cause pneumonia among children between 1 month and 59 months, with 526 deaths/100,000 annually. There were 14 meningitis cases/100,000/year. We estimate that as of 2000, there were 260,768 (113,000 to 582,382) and 902 (114-4,463) cases of pneumococcal pneumonia and meningitis, respectively with 10,703 (4,638-23,904) and 75 (9-370) pneumococcal pneumonia and meningitis deaths, respectively. Pneumococcal pneumonia cases and deaths were more than two-fold higher, 695,382 (173,845-1,216,918) and 28,542 (7,136-49,949), respectively, when parameters from efficacy trials were used. Serotypes 19F, 19A and 14 were the most common serotypes obtained from pneumonia/meningitis patients. Currently available vaccines are expected to cover 79.5% to 88.4% of the prevalent serotypes. With high antibiotic resistance, introducing pneumococcal vaccines to the routine immunization program should be considered in China. Population-based studies are warranted.

Vaccine preventable community-acquired pneumonia in hospitalized children in Northwest China

BACKGROUND

Community-acquired pneumonia (CAP) is a major cause of morbidity in industrialized countries and morbidity/mortality in developing countries. In China, comprehensive studies of the etiology of CAP in children aged between 2 months and 14 years who are serious enough to require hospitalization are lacking. Previous studies have been limited in child age range, focused on fatal cases, and/or limited in etiologies sought. An understanding of the etiologies is needed for development of best prevention and management practices.

OBJECTIVE

The aim of this study was to prospectively determine during a 12-month period the etiology of CAP in hospitalized children in a center in Northwest China.

DESIGN/METHODS

A prospective 12-month study (2004-2005) of CAP cases in children who were 2 months to 14 years of age admitted to the Second Hospital of Lanzhou University, China. Testing included admission and 1-month postdischarge serum for viral and bacterial serologic analyses (respiratory syncytial virus, influenza A and B, paraflu 1-3, adenovirus; Streptococcus pneumoniae, Haemophilus influenza B, Mycoplasma, and Moraxella. catarrhalis), blood culture, a nasopharyngeal aspirate for viral antigen testing, and a chest radiograph on admission and 1 month postdischarge. The study was funded by Lanzhou University. The study was performed in compliance with the guidelines of the institutional review board of the Second Hospital of Lanzhou University.

RESULTS

CAP was the admitting diagnosis for 29% of all admissions during the 12-month study. Of the 884 CAP cases, 821 (93%) were enrolled and completed the study. The age range was 2 months to 14 years; mean age was 2.3 years; 40% were <1 year. The average length of stay was 9.2 days (range, 6-20) but varied by age and etiology. Fourteen percent had received antibiotics before admission and 14% had underlying illnesses; 12% required intensive care unit treatment and 5 died. A microbial etiology for CAP was identified in 547 (67%); viral 535 (43%), bacterial 228 (27%), mixed viral bacterial 107 (13%), mixed viral in 1%, and mixed bacterial in 1%. The etiology varied by age; respiratory syncytial virus was most common in <1 year, S. pneumoniae and Hib 1-3 years, and Mycoplasma 5 years. Three potentially vaccine preventable etiologies accounted for 35% of the cases: influenza 9%, Hib 12%, and S. pneumonia 14%.

CONCLUSIONS

CAP is a major cause of childhood admission in China. Given the etiologic findings in this study, potentially 25% to 35% of cases could be prevented if seasonal influenza vaccine and conjugated H. influenza b and conjugated pneumococcal vaccines were introduced into routine practice.

Pneumonia incidence and mortality in Mainland China: systematic review of Chinese and English literature, 1985-2008

Background

Pneumonia is a leading infectious disease killer worldwide, yet the burden in China is not well understood as much of the data is published in the non-English literature.

Methodology/Principal Findings

We systematically reviewed the Chinese- and English-language literature for studies with primary data on pneumonia incidence and mortality in mainland China. Between 1985 and 2008, 37 studies met the inclusion criteria. The quality of the studies was highly variable. For children <5 years, incidence ranged from 0.06–0.27 episodes per person-year and mortality ranged from 184–1,223 deaths per 100,000 population. Overall incidence and mortality were stable or decreased over the study period and were higher in rural compared to urban areas.

Conclusions/Significance

Pneumonia continues to be a major public health challenge in young children in China, and estimates of pneumonia incidence and mortality vary widely. Reliable surveillance data and new prevention efforts may be needed to achieve and document additional declines, especially in areas with higher incidence and mortality such as rural settings.