The aetiology of community associated pneumonia in children in Nanjing, China and aetiological patterns associated with age and season

Analysis of the results of 13 combined pathogen detection in 3966 hospitalised children with acute lower respiratory tract infection

Early and accurate identification of infectious pathogens can facilitate appropriate drug use and reduce both the duration and financial burden associated with hospital stays. This study aimed to provide reference for the clinical diagnosis, treatment, and control of acute lower respiratory tract infections in Xiamen, China, by investigating the distribution and characteristics of common viruses or atypical pathogens that cause acute lower respiratory tract infections in hospitalised paediatric patients. Data from 3966 paediatric patients with acute lower respiratory tract infections and 13 respiratory pathogens detected from December 2021 to November 2023 were retrospectively collected. The sex, age, and infectious pathogens were statistically analysed. The total detection rate of 13 combined pathogens in the 3966 hospitalised children with acute lower respiratory tract infections was 86.13%. The top five pathogens were Human rhinovirus, Human respiratory syncytial virus, Mycoplasma pneumoniae, Human parainfluenza virus, and Metapneumovirus. The lowest infection numbers were reported in the first 2 months after coronavirus containment measures were lifted. Significant differences were observed in the infection rates of most pathogens across different age groups. Influenza virus A, B, Metapneumovirus, and Mycoplasma pneumoniae infections showed clear periodicity. Mixed infections were common, and most pathogenic infections exhibited age-related trends.

Update of guidelines for management of Community Acquired pneumonia in adults by the French Infectious Disease Society (SPILF) and the French-Speaking Society of Respiratory Diseases (SPLF): Endorsed by the French intensive care society (SRLF), the French microbiology society (SFM), the French radiology society (SFR) and the French emergency society (SFMU)

Community-Acquired Pneumonia (CAP) of Presumed Bacterial Origin: Updated Management Guidelines Community-acquired pneumonia (CAP) of presumed bacterial origin is a common condition with varying severity, requiring either outpatient, hospital, or even critical care management. The French Infectious Diseases Society (SPILF) and the French Language Pulmonology Society (SPLF), in collaboration with the French Societies of Microbiology (SFM), Emergency Medicine (SFMU), Radiology (SFR), and Intensive Care Medicine (SRLF), along with representatives of general practice, have coordinated an update of the previous management guidelines, which dated back to 2010. From a therapeutic perspective, the updated recommendations define the choice of initial empiric antibiotic therapy, indications for combination therapy, the use of anti-Pseudomonas beta-lactams, antibiotic treatment duration, and the indications and modalities for prescribing systemic corticosteroids. On a biological level, indications for biomarkers and microbiological investigations have been refined. Regarding imaging, the role of different modalities in the diagnosis and follow-up of CAP has been reassessed, including chest X-ray, pleuropulmonary ultrasound, and thoracic CT scan.

Comparison of the epidemiological characteristics of mycoplasma pneumoniae infections among children during two epidemics in Wuhan from 2018 to 2024

BACKGROUND

Mycoplasma pneumoniae (M pneumoniae, MP) is a common pathogen causing respiratory tract infections, particularly in children. In 2023, a resurgence of MP epidemics was observed in Wuhan, Hubei Province, China. This study aims to examine the epidemiological trends and clinical characteristics of MP infections among children in Wuhan from 2018 to 2024, providing valuable scientific evidence to guide local prevention strategies.

METHODS

From January 1, 2018, to June 30, 2024, samples were collected from children under 14 years with Acute Respiratory Tract Infections (ARTI) at Renmin Hospital of Wuhan University. MP infections were diagnosed through MP-IgM antibody detection and MP-DNA detection. Results were analyzed and compared across distinct epidemic periods.

RESULTS

Of the 183 626 ARTI children, 57 393 (31.26%) tested positive for MP, with an average age of 4.87 ± 2.99 years and a male-to-female ratio of 1.12:1. The annual positive rates from 2018 to 2024 were 45.92%, 32.23%, 22.84%, 16.22%, 16.26%, and 42.93%, respectively. Across the study period, the highest positive rate was recored in autumn (35.13%, P < 0.05). Two distinct MP outbreaks were identified, in 2018-2019 and 2023. Significant differences were observed between the two outbreaks. The 2018-2019 epidemic peaked in summer, while the 2023 epidemic peaked in November and persisted into February 2024. By age, the 2018-2019 outbreaks predominantly affected pre-school children, whereas the 2023 outbreaks mainly involved school-aged children. In boths outbreaks, girls had higher positive rates. Antibody and DNA testing results followed similar trends.

CONCLUSION

This study highlights the epidemiological trends and clinical characteristics of MP infections in Wuhan from 2018 to 2024, including two distinct outbreaks with differing seasonal patterns. The MP strain in 2023 appeared to predominantly affect older children.The trends observed suggest that MP infections may persist into the winter of 2024. Enhanced surveillance of respiratory pathogens and early diagnosis and prevention of MP infections in children remain critical in this region.

Atypical pneumonia (Review)

Atypical pneumonia encompasses diverse pathogens, such as Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella species, which differ from typical bacterial pneumonia in their extrapulmonary manifestations. Clinical differentiation relies on systemic involvement rather than on standalone symptoms. Despite challenges in distinct diagnosis, syndromic approaches and weighted point systems aid in accurate presumptive diagnoses. Antibiotic treatment, often non-β-lactams due to the unique cell structures of atypical pathogens, targets intracellular processes. Macrolides, tetracyclines, quinolones and ketolides are effective due to their intracellular penetration, crucial for combating these intracellular pathogens. The prevalence of atypical pneumonia varies globally, with Europe, Asia/Africa and Latin America reporting detection rates between 20-28%. Streptococcus pneumoniae remains a primary cause of pneumonia; however, atypical pathogens contribute significantly to this disease, being more prevalent in outpatient settings and among young adults. Legionella stands out in severe hospitalized cases and is associated with higher mortality rates. Diagnosis proves challenging due to overlapping symptoms with other respiratory infections. Differentiation among pathogens, such as Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella relies on subtle clinical variations and imaging findings. Diagnostic methods include serological studies, cultures and polymerase chain reaction, each with limitations in sensitivity or specificity. Prognosis varies widely. Atypical pneumonia can progress to severe forms with fatal outcomes, causing multi-organ damage. Complications extend beyond the respiratory system, affecting the cardiovascular system, exacerbating conditions such as chronic obstructive pulmonary disease and asthma, and potentially linking to conditions such as lung cancer. Increasing antibiotic resistance poses a significant challenge, influencing treatment outcomes and prolonging illness duration.

Application of peripheral blood routine parameters in the diagnosis of influenza and Mycoplasma pneumoniae

OBJECTIVES

Influenza and Mycoplasma pneumoniae infections often present concurrent and overlapping symptoms in clinical manifestations, making it crucial to accurately differentiate between the two in clinical practice. Therefore, this study aims to explore the potential of using peripheral blood routine parameters to effectively distinguish between influenza and Mycoplasma pneumoniae infections.

METHODS

This study selected 209 influenza patients (IV group) and 214 Mycoplasma pneumoniae patients (MP group) from September 2023 to January 2024 at Nansha Division, the First Affiliated Hospital of Sun Yat-sen University. We conducted a routine blood-related index test on all research subjects to develop a diagnostic model. For normally distributed parameters, we used the T-test, and for non-normally distributed parameters, we used the Wilcoxon test.

RESULTS

Based on an area under the curve (AUC) threshold of ≥ 0.7, we selected indices such as Lym# (lymphocyte count), Eos# (eosinophil percentage), Mon% (monocyte percentage), PLT (platelet count), HFC# (high fluorescent cell count), and PLR (platelet to lymphocyte ratio) to construct the model. Based on these indicators, we constructed a diagnostic algorithm named IV@MP using the random forest method.

CONCLUSIONS

The diagnostic algorithm demonstrated excellent diagnostic performance and was validated in a new population, with an AUC of 0.845. In addition, we developed a web tool to facilitate the diagnosis of influenza and Mycoplasma pneumoniae infections. The results of this study provide an effective tool for clinical practice, enabling physicians to accurately diagnose and differentiate between influenza and Mycoplasma pneumoniae infection, thereby offering patients more precise treatment plans.

Clinical differences between Mycoplasma pneumoniae pneumonia and Streptococcus pneumoniae pneumonia: a case control study

Introduction

Mycoplasma pneumoniae pneumonia (MPP) and Streptococcus pneumoniae pneumonia (SPP) are frequent causes of respiratory tract infection, the aims of the study were to explore the differences in clinical features between children with MPP and those with SPP.

Methods

This retrospective study included admitted children who were diagnosed with MPP or SPP over 5 years from January 2015 to January 2020. Children with MPP were compared to children with SPP in terms of clinical features.

Results

506 patients with MPP were compared to 311 patients with SPP in terms of clinical differences. The MPP group with a median age of 60 [29-89] months and the SPP group with a median age of 24 [10-40] months. Patients with MPP were older and had a higher occurrence of receiving antibiotics before admission, fever, dry cough, polypnea and diarrhea than patients with SPP (all p < 0.01). Patients with SPP were more likely to have wheezing, cyanosis and irritability (all p < 0.01). Laboratory findings in our study showed that there were significant differences between MPP and SPP patients in mean leucocyte count, neutrophil % (N%), lymphocyte % (L%), ALT levels, AST levels, LDH levels and incidence of accelerated procalcitonin (PCT) (all p < 0.01). Lower age, no dry cough, no polypnea, lower LDH levels, and higher PCT might lead to the diagnosis of SPP. Our study showed that age had a higher accuracy in predicting MPP than LDH levels, with an age >48.5 months shown to be an independent predictive factor for the early evaluation and identification of MPP.

Discussion

In conclusion, patients with MPP and SPP usually present with fever, cough and some nonspecific symptoms. Our study showed that age, dry cough, polypnea, LDH levels, and PCT levels were independent predictive factors associated with MPP and SPP.

Diagnostic values of soluble triggering receptor expressed on myeloid cells (sTREM-1) and interferon-inducible protein-10 (IP-10) for severe mycoplasma pneumoniae pneumonia in children

OBJECTIVE

Early diagnosis of Severity Mycoplasma Pneumoniae Pneumonia (SMPP) has been a worldwide concern in clinical practice. Two cytokines, soluble Triggering Receptor Expressed on Myeloid cells (sTREM-1) and Interferon-Inducible Protein-10 (IP-10), were proved to be implicated in bacterial infection diseases. However, the diagnostic value of sTREM-1 and IP-10 in MPP was poorly known. This study aimed to investigate the diagnostic value of sTREM-1 and IP-10 for SMPP.

METHODS

In this prospective study, the authors enrolled 44 children with MPP, along with their clinical information. Blood samples were collected, and cytokine levels of sTREM-1 and IP-10 were detected with ELISA assay.

RESULTS

Serum levels of sTREM-1 and IP-10 were positively correlated with the severity of MPP. In addition, sTREM-1 and IP-10 have significant potential in the diagnosis of SMPP with an Area Under Curve (AUC) of 0.8564 (p-value = 0.0001, 95% CI 0.7461 to 0.9668) and 0.8086 (p-value = 0.0002, 95% CI 0.6918 to 0.9254) respectively. Notably, the combined diagnostic value of sTREM-1 and IP-10 is up to 0.911 in children with SMPP (p-value < 0.001, 95% CI 0.830 to 0.993).

CONCLUSIONS

Serum cytokine levels of sTREM-1 and IP-10 have a great potential diagnostic value in children with SMPP.

Construction and external validation of a scoring prediction model for mortality risk within 30 days of community-acquired pneumonia in children admitted to the pediatric intensive care unit: A multicenter retrospective case-control study

In this study, we constructed and validated a scoring prediction model to identify children admitted to the pediatric intensive care unit (PICU) with community-acquired pneumonia (CAP) at risk for early death. Children with CAP who were admitted to the PICU were included in the training set and divided into death and survival groups according to whether they died within 30 days of admission. For univariate and multifactorial analyses, demographic characteristics, vital signs at admission, and laboratory test results were collected separately from the 2 groups, and independent risk factors were derived to construct a scoring prediction model. The ability of the scoring model to predict CAP-related death was validated by including children with CAP hospitalized at 3 other centers during the same period in the external validation set. Overall, the training and validation sets included 296 and 170 children, respectively. Univariate and multifactorial analyses revealed that procalcitonin (PCT), lactate dehydrogenase (LDH), activated partial thromboplastin time (APTT), and fibrinogen (Fib) were independent risk factors. The constructed scoring prediction model scored 2 points each for PCT ≥ 0.375 ng/mL, LDH ≥ 490 U/L, and APTT ≥ 31.8 s and 1 point for Fib ≤ 1.78 g/L, with a total model score of 0-7 points. When the score was ≥ 5 points, the sensitivity and specificity of mortality diagnosis in children with CAP were 72.7% and 87.5%, respectively. In the external validation set, the sensitivity, specificity, and accuracy of the scoring model for predicting the risk of CAP-related death were 64.0%, 92.4%, and 88.2%, respectively. Constructing a scoring prediction model is worth promoting and can aid pediatricians in simply and rapidly evaluating the risk of death in children with CAP, particularly those with complex conditions.

Pneumonia among under - five children in Ethiopia: a retrospective analysis from an urban hospital

Background

Pneumonia is the leading cause of death in under-five children in low-income countries. However, the burden of pneumonia in hospital admission is not traced systematically. This study was conducted to determine the proportion of under-five pneumonia admissions among children admitted to a hospital in Addis Ababa, Ethiopia between 2017-2021.

Methods

A retrospective record of pediatric admissions to the Yekatit 12 referral hospital in Addis Ababa, Ethiopia was assessed for the period 2017- 2021. The date of admission and discharge, length of stay, and outcome at discharge were collected in accordance with the Ethiopian National Classification of Diseases (NCoD). Descriptive statistics were used to assess the proportion of under-five children with pneumonia. Survival analyses using Log rank test and cox regression analysis were done to assess time to recovery (recovering from illness). Multivariable logistic regression was used to assess the influence of selected factors on pneumonia associated hospital admission.

Results

Between 2017-2021, 2170 children age 1 to 59 months were admitted, 564 (25.99%; 95% confidence interval 24.18% to 27.87%) were diagnosed with pneumonia. Among the sixty children who died during their hospitalization, 15 had been diagnosed with pneumonia. The median time to recover from pneumonia and discharge was 6 days. The odds of pneumonia hospital admission were higher among younger children (4.36 times higher compared to elder children with 95% CI 2.77,6.87)and were increased between the months of September to November.

Conclusions

Pneumonia accounts for more than a quarter of hospital admissions in under-five children and for a quarter of deaths in this urban cohort. Hospital admission due to pneumonia was higher among older children (36-59 months of age) in the months following the heavy rain months (September to November) as compared to younger children. Our data strongly support increase of vaccination to prevent under 5 pneumonia.

Identification of Mycoplasma pneumoniae-associated pneumonia cases among hospitalized patients using CLART® microarray technology

Objectives

Community-acquired pneumonia (CAP) is a global health condition that affects populations from all age groups. The laboratory identification of Mycoplasma pneumoniae as a causative agent of CAP is challenging because of its atypical and fastidious nature. Therefore, this study assessed the diagnostic potential of PneumoCLART bacteria® in identifying M. pneumoniae as a causative agent of pneumonia in hospitalized adults.

Methods

This prospective study used a cross-sectional approach to assess the diagnostic potential of PneumoCLART bacteria® for detecting M. pneumoniae in sputum samples procured from 27 patients with pneumonia who required hospitalization.

Results

The PneumoCLART bacteria® results illustrated that 7 of 27 patients with pneumonia were positive for M. pneumoniae (26%). However, the quality of sputum varied among the M. pneumoniae-positive and M. pneumoniae-negative samples. Fifty percent of the specimens obtained from patients positive for M. pneumoniae were saliva-contaminated and unsuitable for analysis.

Conclusions

Because the leukocyte count was low and sputum specimens were saliva-contaminated, these findings require further validation to prove the utility of CLART® microarray technology for the identification of M. pneumoniae in pneumonia-positive patients. Conclusively, this prospective study included a small number of clinical samples, which likely affected its outcomes.

Q Fever as a Cause of Community-Acquired Pneumonia in French Guiana

In French Guiana, community-acquired pneumonia (CAP) represents over 90% of Coxiella burnetii acute infections. Between 2004 and 2007, we reported that C. burnetii was responsible for 24.4% of the 131 CAP hospitalized in Cayenne. The main objective of the present study was to determine whether the prevalence of Q fever pneumonia remained at such high levels. The secondary objectives were to identify new clinical characteristics and risk factors for C. burnetii pneumonia. A retrospective case-control study was conducted on patients admitted in Cayenne Hospital, between 2009 and 2012. All patients with CAP were included. The diagnosis of acute Q fever relied on titers of phase II IgG ≥ 200 and/or IgM ≥ 50 or seroconversion between two serum samples. Patients with Q fever were compared with patients with non-C. burnetii CAP in bivariate and multivariate analyses. During the 5-year study, 275 patients with CAP were included. The etiology of CAP was identified in 54% of the patients. C. burnetii represented 38.5% (106/275; 95% CI: 31.2-45.9%). In multivariate analysis, living in Cayenne area, being aged 30-60 years, C-reactive protein (CRP) > 185 mg/L, and leukocyte count < 10 G/L were independently associated with Q fever. The prevalence of Q fever among CAP increased to 38.5%. This is the highest prevalence ever reported in the world. This high prevalence justifies the systematic use of doxycycline in addition to antipneumococcal antibiotic regimens.

High Expression of MUC5AC, MUC5B, and Layilin Plays an Essential Role in Prediction in the Development of Plastic Bronchitis Caused by MPP

Plastic bronchitis (PB) is a rare respiratory condition which can result in severe respiratory complications such as respiratory failure and death. Mycoplasma pneumoniae infection is a main etiology cause of plastic bronchitis. However, the pathogenesis of plastic bronchitis complicated by Mycoplasma pneumoniae pneumonia (MPP) has not yet been fully elucidated. Our article aims to explore biomarkers for early prediction of MPP cases complicated with plastic bronchitis. We utilized a protein chip to screen for significantly different proteins among the groups of healthy, general Mycoplasma pneumoniae pneumonia (GMPP) and refractory Mycoplasma pneumoniae pneumonia (RMPP) patients, where layilin exhibited a potent change across biology information technology. Next, we demonstrated the high expression of MUC5AC, MUC5B, and layilin in bronchoalveolar lavage fluid (BALF) of MPP cases complicated with plastic bronchitis. Further study suggested that the level of layilin had a positive correlation with both MUC5AC and MUC5B. A receiver operating characteristic (ROC) analysis was performed to assess the diagnostic values of MUC5AC, MUC5B, and layilin in MPP cases with PB. Data show that the three indicators have similar diagnostic ability for MPP children with plastic bronchitis. Then, we used different concentrations of community-acquired respiratory distress syndrome (CARDS) toxin or lipid-associated membrane proteins (LAMPs) to simulate an in vitro experiment. The in vitro assay revealed that CARDS toxin or LAMPs induced A549 cells to secrete MUC5AC, MUC5B, layilin, and proinflammatory factors. These findings suggest that MUC5AC, MUC5B, and layilin are correlated with MPP. The high expression of MUC5AC, MUC5B, and layilin play an essential role in prediction in the development of plastic bronchitis caused by MPP. The high expression of MUC5AC, MUC5B, and layilin may be relevant to the severity of illness.

Efficacy of Jiedu Pingsou Decoction Combined with Azithromycin in the Treatment of Children with Mycoplasma Pneumonia and Its Effects on Inflammatory Factors and Immune Function

Objective

The purpose of this study is to detect the clinical efficacy of Jiedu Pingsou Decoction combined with azithromycin in the treatment of children with mycoplasma pneumonia and the effect on inflammatory factors and immune function in children.

Methods

A total of 68 children with mycoplasma pneumonia in our hospital from January 2021 to January 2022 were included in this study, and they were randomly divided into the control group and the observation group with 34 cases in each group. The children in the control group were treated with azithromycin, and the children in the observation group were treated with Jiedu Pingsou Decoction on this basis. The clinical manifestations, treatment effects, blood routine, serum inflammatory factor levels, and T cell subsets before and after treatment were compared between the two groups.

Results

The total effective rate in the observation group was 94.12%, which was higher than that in the control group, which was 82.35%, and the difference between the two groups was statistically significant (P < 0.05). After treatment, the levels of CD3+, CD4+, and CD4+/CD8+ in the two groups were higher than those before treatment, and the level of CD8+ was lower than before treatment. The difference between groups was statistically significant (P < 0.05). The levels of serum C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interferon gamma (IFN-γ), interleukin-6 (IL-6), and interleukin-10 (IL-10) in the two groups after treatment were lower than those before treatment, and the difference between the two groups was statistically significant (P < 0.05). The difference between groups was statistically significant (P < 0.05). There were 4 cases and 2 cases of adverse reactions in the control group and the observation group, respectively, and the difference between the two groups was statistically significant (P > 0.05).

Conclusion

Jiedu Pingsou Decoction combined with azithromycin can effectively improve the levels of T cell subsets, immune function, and inflammatory factors in children with mycoplasma pneumonia, improve clinical symptoms, and is safe and stable, and can be used in clinical practice.

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral infection of pediatric CAP in Chinese mainland. During November 2014 to June 2016, the prospective study was conducted in 13 hospitals. The hospitalized children under 18 years old who met the criteria for CAP were enrolled. The throat swabs or nasopharyngeal aspirates (NPAs) were collected which were then screened 18 respiratory viruses using multiplex PCR assay. Viral pathogens were present in 56.6% (1539/2721) of the enrolled cases, with the detection rate of single virus in 39.8% of the cases and multiple viruses in 16.8% of the cases. The most frequently detected virus was respiratory syncytial virus (RSV) (15.2%, 414/2721). The highest detection rate of virus was in < 6-month-age group (70.7%, 292/413). RSV, human metapneumovirus (HMPV), human parainfluenza viruses (HPIVs) and influenza B virus (Flu B) showed the similar prevalence patterns both in north and south China, but HPIVs, Flu A, human bocavirus (HBoV), human adenovirus (HAdV) and human coronaviruses (HCoVs) showed the distinct circulating patterns in north and south China. Human enterovirus/human rhinovirus (HEV/HRV) (27.6%, 27/98), HBoV (18.4%, 18/98), RSV (16.3%, 16/98) and HMPV (14.3%, 14/98) were the most commonly detected viruses in severe pneumonia cases with single virus infection. In conclusion, viral pathogens are frequently detected in pediatric CAP cases and may therefore play a vital role in the aetiology of CAP. RSV was the most important virus in hospitalized children with CAP in Chinese mainland.

Serum CXCL10/IP-10 may be a potential biomarker for severe Mycoplasma pneumoniae pneumonia in children

Background

How to early distinguish the severity of Mycoplasma pneumoniae pneumonia (MPP) is a worldwide concern in clinical practice. We therefore conducted this study to assess the relationship between levels of serum inflammatory chemokines and the severity of MPP.

Methods

In this prospective study, we enrolled 39 children with MPP, whose clinical information was collected, blood samples were assayed for cytokines and chemokines by ELISA.

Results

The levels of serum CXCL10 in children with severe MPP were significantly higher than those in children with mild MPP (2500.0 [1580.9–2500.0] vs. 675.7 [394.7–1134.9], P < 0.001). Measurement of CXCL10 levels in serum enabled the differentiation of children with severe MPP with an area under the curve (AUC) of 0.885 (95 % CI 0.779–0.991, P < 0.001), with a sensitivity of 81.0 % and a specificity of 83.3 %.

Conclusions

Serum CXCL10 level may be a potential biomarker for severe MPP in children.

Differences of TNF-α, IL-6 and Gal-3 in lobar pneumonia and bronchial pneumonia caused by mycoplasma pneumoniae

OBJECTIVE

To investigate the differences of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and galectin-3 concentrations in lobar pneumonia and bronchopneumonia induced by mycoplasma pneumoniae (MP) in children and to explore these related factors predicting the severity of MP.

METHODS

A total of 148 children with mycoplasma pneumoniae pneumonia (MPP) and 32 healthy controls were analyzed from March 2017 to August 2018 in our province. Clinical information was collected from the hospitalized MP patients. The 148 patients with MPP were divided into two groups: lobar pneumonia group and bronchial pneumonia group. The 32 healthy children were considered the control group. The concentrations of TNF-α, IL-6 and Gal-3 were examined in the serum of 148 children patients with MPP and 32 healthy children by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

The TNF-α, IL-6 and Gal-3 levels were obviously higher in both the lobar pneumonia and bronchial pneumonia groups, compared to those in the control group. Furthermore, these levels were significantly higher in the lobar pneumonia group, compared to the bronchial pneumonia group. After treatment, the levels of TNF-α, IL-6 and Gal-3 totally descended during the recovery period.

CONCLUSION

There are differences in serum TNF-α, IL-6 and Gal-3 concentrations in lobar pneumonia and bronchial pneumonia caused by MP in children. In general, the TNF-α, IL-6 and Gal-3 levels were significantly higher in the lobar pneumonia group, when compared to the bronchial pneumonia group. This was because most lobar pneumonia cases are much more serious than bronchial pneumonia. Moreover, it has been proven that TNF-α, IL-6 and Gal-3 may play an important role in the pathogenesis development of MPP. At the same time, these are important issues in diagnosing MPP.

Analysis of Pneumonia Occurrence in Relation to Climate Change in Tanga, Tanzania

In 2018, 70% of global fatalities due to pneumonia occurred in about fifteen countries, with Tanzania being among the top eight countries contributing to these deaths. Environmental and individual factors contributing to these deaths may be multifaceted, but they have not yet been explored in Tanzania. Therefore, in this study, we explore the association between climate change and the occurrence of pneumonia in the Tanga Region, Tanzania. A time series study design was employed using meteorological and health data of the Tanga Region collected from January 2016 to December 2018 from the Tanzania Meteorological Authority and Health Management Information System, respectively. The generalized negative binomial regression technique was used to explore the associations between climate indicators (i.e., precipitation, humidity, and temperature) and the occurrence of pneumonia. There were trend differences in climate indicators and the occurrence of pneumonia between the Tanga and Handeni districts. We found a positive association between humidity and increased rates of non-severe pneumonia (incidence rate ratio (IRR) = 1.01; 95% CI: 1.01–1.02; p ≤ 0.05) and severe pneumonia (IRR = 1.02; 95% CI: 1.01–1.03; p ≤ 0.05). There was also a significant association between cold temperatures and the rate of severe pneumonia in Tanga (IRR = 1.21; 95% CI: 1.11–1.33; p ≤ 0.001). Other factors that were associated with pneumonia included age and district of residence. We found a positive relationship between humidity, temperature, and incidence of pneumonia in the Tanga Region. Policies focusing on prevention and control, as well as promotion strategies relating to climate change-related health effects should be developed and implemented.

Effect of COVID-19 on childhood Mycoplasma pneumoniae infection in Chengdu, China

BACKGROUND

Following the outbreak of the COVID-19 pandemic, a change in the incidence and transmission of respiratory pathogens was observed. Here, we retrospectively analyzed the impact of COVID-19 on the epidemiologic characteristics of Mycoplasma pneumoniae infection among children in Chengdu, one of the largest cities of western China.

METHOD

M. pneumoniae infection was diagnosed in 33,345 pediatric patients with respiratory symptoms at the Chengdu Women's & Children's Central Hospital between January 2017 and December 2020, based on a serum antibody titer of ≥1:160 measured by the passive agglutination assay. Differences in infection rates were examined by sex, age, and temporal distribution.

RESULTS

Two epidemic outbreaks occurred between October-December 2017 and April-December 2019, and two infection peaks were detected in the second and fourth quarters of 2017, 2018, and 2019. Due to the public health response to COVID-19, the number of positive M. pneumoniae cases significantly decreased in the second quarter of 2020. The number of M. pneumoniae infection among children aged 3-6 years was higher than that in other age groups.

CONCLUSIONS

Preschool children are more susceptible to M. pneumoniae infection and close contact appears to be the predominant factor favoring pathogen transmission. The public health response to COVID-19 can effectively control the transmission of M. pneumoniae.

Analysis of mycoplasma pneumoniae infection among children with respiratory tract infections in hospital in Chengdu from 2014 to 2020

BACKGROUND

Respiratory tract infection (RTIs) is one of common diseases among the children. In recent years, the incidence of mycoplasma pneumoniae (M. pneumoniae) infection rate has been increasing, which cause respiratory tract infection. This study sought to analyze the epidemiological characteristics of M. pneumoniae hospitalized children with RTIs to provide a theoretical basis for clinical diagnosis and treatments in Chengdu, China.

METHODS

The data of 22,882 cases of children who had been hospitalized for RTIs were collected. M. pneumoniae immunoglobulin M (IgM) antibody was detected using the indirect immunofluorescence method and passive agglutination method. The demographic features of patients, clinical diagnoses and laboratory data were also analyzed.

RESULTS

A total of 4,213 children tested positive for M. pneumoniae. The total positive rate was 18.41% (18.30% for males and 22.72% for females). Female children had statistically significant higher positive rates than male children (χ²=198.078, P<0.01). The positive rates of M. pneumoniae differed significantly among children of different ages (F=162.7532, P<0.01). The incidence rate of M. pneumoniae in 2017 and 2019 was significantly higher than the average (F=538.95, P<0.01). There were higher M. pneumoniae positive rates from April to May, and September to October (P<0.05) in 2016, 2017, 2018, and 2019. There was no correlation between M. pneumoniae infection and temperature and humidity (P>0.05). There was negative correlation with PM_2.5 (particulate matter in the air <2.5 µm) (R=-0.293, P<0.01) and PM₁₀ (particulate matter in the air <10 µm). (R=-0.285, P<0.01). There were significant differences in the constituent ratios of cases of M. pneumoniae infection between in 2020 and other years (F=159.35, P<0.01). Bronchopneumonia accounted for the highest proportion of cases, followed by acute bronchitis and the exacerbation of asthma in 2020.

CONCLUSIONS

The epidemiological distribution of M. pneumoniae in children with RTIs in Chengdu was found to be related to gender, age, year and month; however, no relationship was found to temperature and humidity. There was a higher M. pneumoniae positive rate in children with bronchial pneumonia and asthma in cases. The prevention measures used to control Coronavirus Disease 2019 (COVID-19) also effectively controlled the M. pneumoniae infection rate.

Prevalence and clinical characteristics of hospitalized children with community-acquired Mycoplasma pneumoniae pneumonia during 2017/2018, Chengde, China

Community acquired-pneumonia (CAP) has varying causative pathogens and clinical characteristics. This study investigated the prevalence of Mycoplasma pneumoniae (M pneumoniae) and evaluated the clinical characteristics in infected hospitalized children by disease severity.From throat swabs of hospitalized children (5 months to 14 years) with CAP collected between November 2017 and May 2018, M pneumoniae and other CAP pathogens were identified using polymerase chain reaction (PCR). Differences in clinical and laboratory test data were compared between severe and mild case groups.Of 333 hospitalized children enrolled, 221/333 (66.4%) tested positive for M pneumoniae and 24/221 (10.9%) patients were (n = 9, aged <5 years vs n = 15, ≥5 years) single infection by PCR, however, only 170/333 (51.1%) patients were presented with M pneumoniae IgM-positive. M pneumoniae detection rate by PCR was higher than by immunoglobulin (IgM) serology. In 123/221 (55.7%) M pneumoniae infected patients, coinfection with bacterial pathogens (n = 61, <5 years vs n = 62, ≥5 years) occurred. Children (aged 3-8 years) had most M pneumoniae infection. Severe M pneumoniae pneumonia (MPP) in children occurred mostly in older age (7 [interquartile ranges {IQR}, 6-8] years; P < .0001), with longer cough days (14 [IQR, 10-19.5] days; P = .002) and hospitalization duration (9.5 [IQR, 7-12.3] days; P < .0001), lower lymphocyte ratio (24.1, [IQR, 20.0-31.1] %; P = .001), higher neutrophils ratio (66.0, [IQR, 60.2-70.3]%; P < .0001), and serum C-reactive protein (CRP) level (3.8, [IQR, 1.3-10.9] mg/L; P = .027).M pneumoniae is the most commonly detected pathogen in CAP. High coinfection prevalence increases diagnosis difficulty by clinically nonspecific characteristics. M pneumoniae detection by PCR with IgM may improve precise and reliable diagnosis of community-acquired MPP.

A Systematic Review and Meta-analysis of Sex Differences in Morbidity and Mortality of Acute Lower Respiratory Tract Infections Among African Children

Context

Although biological sex influences Acute Lower Respiratory Tract Infections (ALRIs) morbidity and mortality patterns in children living in sub-Saharan Africa, the exact mechanism about the effect is unknown.

Objective

We assessed the quality and strength of evidence on the association of sex with incidence, etiology, and outcomes of ALRI in African children.

Data Sources Study Selection and Data Extraction

We systematically searched electronic databases for publications from 1971-2016 in PubMed, African Journals Online, and Google scholar for ALRI literature in the African children. We used (pneumonia OR bronchiolitis OR "community-acquired pneumonia" OR CAP OR "hospital-acquired pneumonia" OR "nosocomial pneumonia" OR "ventilator-acquired pneumonia" OR "lung abscess" OR "pleural effusion" OR "empyema thoracis") AND (sex OR gender) AND (Africa OR Sub-Saharan) as search terms. We included the published peer-reviewed journal articles reporting on incidence, etiology, and case fatality. We summarized the findings using narrative and meta-analysis methods.

Results

We included 14 studies with sex-related data; the median (IQR) number of reported pneumonia cases was 148 (87-770) and 114 (56-599) for male and female patients, respectively. Only two studies reported a sex-specific incidence. The odds of sex were in favor of male sex, and the chances of identification of Respiratory Syncytia Virus (RSV) were significantly lower in males than in females (OR=0.60; 95% CI: 0.42, 0.86). Estimates from 9 studies showed that the death rate for males was significantly higher than for females (OR=1.26; 95% CI=1.20-1.33).

Conclusions

Sex-disaggregated data on incidence, etiology, and case fatality of pneumonia are scarcely reported in studies published in Africa. However, males appear to die more often than females, and females more likely to have RSV infection.

Viral and bacterial coinfection among hospitalized children with respiratory tract infections

BACKGROUND

The epidemiology of Mycoplasma pneumoniae (MP) and local dominant etiologies of pathogens that cause respiratory tract infections (RTIs) among central China children (≤14 years old) hospitalized are poorly understood.

METHODS

A total of 10,429 specimens were analyzed, and IgM antibodies against 9 respiratory pathogens including MP were detected using indirect immunofluorescence assay from serum.

RESULTS

It showed that 59.3% of the enrolled children were positive for at least 1 pathogen; highest detection rates included those between 3 and <6 years of age (70.4%), female (63.2%), and who were hospitalized in 2014 (80.9%). The most predominant pathogen was MP (45.6%), followed by Parainfluenza viruses (PIVs) (22.6%) and influenza B viruses (IFVB) (14.7%). Coinfection was observed in 2,907 specimens (27.9%); the coinfection combination containing MP and PIVs had the highest detection rate of 15%, followed by MP and IFVB as well as IFVB and PIVs.

CONCLUSIONS

MP was the most commonly detected bacteria among hospitalized children, which should be included in the differential diagnosis for hospitalized children with RTI. These findings will contribute to the effective prevention and therapeutic approaches of pathogens among local children suffering from RTI.

Antibodies against atypical pathogens and respiratory viruses detected by Pneumoslide IgM test in adults with community-acquired pneumonia in Guangzhou City

Background

To detect the serum antibodies against respiratory viruses and atypical pathogens in adults with community‐acquired pneumonia (CAP) in Guangzhou City (Guangdong province, China).

Methods

A retrospective study was carried out with samples from 685 adults who were admitted with CAP and 108 non‐CAP control patients. Atypical pathogens and respiratory viruses in serum were detected using the Pneumoslide IgM test from Vircell, Spain. All patients were divided into 6 groups according to age: 18‐24, 25‐44, 45‐59, 60‐74, 75‐89, and >90.

Results

The total positive rate of CAP was 35.4%, which was highest in the 18‐24 age group (P < .05). The highest positive rate, 17.11%, was observed for Mycoplasma pneumoniae (MP). The mean age of MP‐infected patients was higher than that of the controls (P < .05). The positive rates for influenza B (INFB), Legionella pneumophila (LP1), Coxiella burnetii (COX), influenza A (INFA), parainfluenza virus (PIV), respiratory syncytial virus (RSV), Chlamydophila pneumoniae (CP), and adenovirus (ADV) were 5.56%, 3.07%, 2.63%, 2.34%, 1.90%, 1.61, 0.88%, and 0.29%, respectively. There were 4.37% of patients with CAP having multiple infections. The main symptoms observed in the 685 CAP patients were cough and sputum production, in 78.4% and 67.4%. Fever was followed by 54% of CAP patients. Dyspnea (39.1%), anorexia (36.8%), increased thirst (26.7%), chills (18.7), headache (14.6%), and nausea (13.1%) were also frequently observed in the CAP patients.

Conclusions

MP infection was the most common in adult CAP patients in Guangzhou City with the highest positive rate in the 18‐24 age groups.

Cytokine signatures associate with disease severity in children with Mycoplasma pneumoniae pneumonia

Host immune response may be involved in the pathogenesis of children Mycoplasma pneumoniae pneumonia (MPP). In the current study, we investigated the alterations of cytokines levels among control, mild MPP and severe MPP children to determine whether cytokine signatures associate with MPP and correlate with disease severity. We measured 13 cytokines in bronchoalveolar lavage fluid (BALF) of 88 children with MPP and 26 children with foreign body aspiration (FB) using a Luminex system. Linear discriminant analyses were performed to develop predictive models of mild MPP and severe MPP on these children. We observed nearly complete separations of severe MPP group, mild MPP group and control group in linear discriminant analyses. Eleven cytokines significantly increased in children with MPP, and seven cytokines had statistically significant upward linear trends correlated with MPP severity. In addition, compared to control group, both IFNγ/IL4 ratio and IFNγ/IL13 ratio increased in mild MPP and severe MPP groups. Our results suggest that children MPP can alter BALF cytokines signatures which associate with disease severity and can be characterized by a distinct airway molecular phenotype that has elevated Th1/Th2 ratios.

Atypical and Typical Bacteria in Children with Community Acquired Pneumonia

This study seeks to determine the pathogens in respiratory specimens and blood serum obtained from children who present with community acquired pneumonia (CAP) diagnosed on the basis of clinical and radiological evidence. The study group consisted of 46 hospitalized children aged 1-11 years. The material for research consisted of pharyngeal swabs and samples of blood serum. One hundred and thirty eight pharyngeal swabs were examined for the presence of C. pneumoniae antigen, C. pneumoniae DNA, and for typical pathogens. C. pneumoniae DNA was detected in pharyngeal swabs with nested PCR. Classical microbiological culture was used for detection of typical bacteria. ELISA test were used for detection anti-C. pneumoniae and anti-M. pneumoniae antibodies in the serum. C. pneumoniae DNA was identified in 10.9% of children. Positive culture for typical pathogens was observed in 8.7% of children. Specific anti-C. pneumoniae IgM antibodies were found in 8.7% of children, and IgG and IgA antibodies in 1 child each. Specific anti-M. pneumoniae IgG antibodies were found in 13.1% of children and IgM antibodies in 1 child. We conclude that the underlying bacterial etiology of CAP is rather rarely conclusively confirmed in children. Nonetheless, determining the etiology of CAP is essential for the choice of treatment to optimize the use and effectiveness of antimicrobials and to avoid adverse effect. Due to considerable variations in the power of detection of the type of atypical bacteria causing CAP, the search for the optimum diagnostic methods continues.

Atypical pathogens in hospitalized patients with community-acquired pneumonia: a worldwide perspective

BACKGROUND

Empirical antibiotic coverage for atypical pathogens in community-acquired pneumonia (CAP) has long been debated, mainly because of a lack of epidemiological data. We aimed to assess both testing for atypical pathogens and their prevalence in hospitalized patients with CAP worldwide, especially in relation with disease severity.

METHODS

A secondary analysis of the GLIMP database, an international, multicentre, point-prevalence study of adult patients admitted for CAP in 222 hospitals across 6 continents in 2015, was performed. The study evaluated frequency of testing for atypical pathogens, including L. pneumophila, M. pneumoniae, C. pneumoniae, and their prevalence. Risk factors for testing and prevalence for atypical pathogens were assessed through univariate analysis.

RESULTS

Among 3702 CAP patients 1250 (33.8%) underwent at least one test for atypical pathogens. Testing varies greatly among countries and its frequency was higher in Europe than elsewhere (46.0% vs. 12.7%, respectively, p < 0.0001). Detection of L. pneumophila urinary antigen was the most common test performed worldwide (32.0%). Patients with severe CAP were less likely to be tested for both atypical pathogens considered together (30.5% vs. 35.0%, p = 0.009) and specifically for legionellosis (28.3% vs. 33.5%, p = 0.003) than the rest of the population. Similarly, L. pneumophila testing was lower in ICU patients. At least one atypical pathogen was isolated in 62 patients (4.7%), including M. pneumoniae (26/251 patients, 10.3%), L. pneumophila (30/1186 patients, 2.5%), and C. pneumoniae (8/228 patients, 3.5%). Patients with CAP due to atypical pathogens were significantly younger, showed less cardiovascular, renal, and metabolic comorbidities in comparison to adult patients hospitalized due to non-atypical pathogen CAP.

CONCLUSIONS

Testing for atypical pathogens in patients admitted for CAP in poorly standardized in real life and does not mirror atypical prevalence in different settings. Further evidence on the impact of atypical pathogens, expecially in the low-income countries, is needed to guidelines implementation.

A retrospective seroepidemiologic survey of Chlamydia pneumoniae infection in patients in Beijing between 2008 and 2017

Background

Chlamydia pneumoniae (C. pneumoniae) is an obligate intracellular bacterium and a human pathogen that causes respiratory infectious diseases. More than 50% of the adult population worldwide was once infected with C. pneumoniae, but investigations into this topic are insufficient in mainland China.

Methods

Anti-C. pneumoniae IgG and IgM antibodies were detected using micro-immunofluorescence test in serum samples of patients visiting Peking Union Medical College Hospital between 2008 and 2017 for routine medical purposes, and the aim of this retrospective study was to analyze the test results.

Results

Among 12,050 serum specimens tested for anti-C. pneumoniae IgG and IgM antibodies, the overall prevalence of anti-C. pneumoniae IgG antibodies was 86.6%, 87.2% for men and 86.0% for women. Adult men (>20 years) were found to have a significantly higher prevalence of anti-C. pneumoniae IgG than women (χ² = 30.32, P = 0.000). 3 to 5 years old patients were observed to have the lowest prevalence of anti-C. pneumoniae IgG, 42.8%, then increased with age, reaching the highest level of 98.6% in patients over 70 years of age. In the 10,434 specimens with C. pneumoniae IgG antibodies, the total geometric mean titer (GMT) for C. pneumoniae IgG was 45.71. Although GMTs were found to be significantly higher among all men than among all women (t = 5.916, P = 0.000), sex difference actually began in patients over 40 years of age and increased in the elderly. In the total 12,050 specimens, 1.2% had anti-C. pneumoniae IgM, 3.3% had anti-C. pneumoniae IgG with titers equal to or greater than 1:512; 0.39% had ≥4-fold increasing titers of antibodies in acute and convalescent phase paired samples, and 4.4% were finally confirmed to have acute antibodies against C. pneumoniae. 6 to 10 years old patients were found to have the highest rate of both IgM antibodies (3.9%) and acute antibodies (6.2%) against C. pneumoniae. Acute antibodies against C. pneumoniae were found to be more frequent in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD, 14.0%, χ² = 20.43, P = 0.000), patients with pneumonia (7.8%, χ² = 51.87, P = 0.000) and patients with acute respiratory tract infection (12.3%, χ² = 60.91, P = 0.000) than among all patients (4.4%). Both anti-C. pneumoniae IgG and IgM antibodies should be tested for acute antibodies against C. pneumoniae as testing for either alone will underestimate by a maximum of two-thirds the incidence of acute antibodies against C. pneumoniae.

Conclusions

More than 86% of Chinese patients on an average were once infected with C. pneumoniae. Adult men had both a higher prevalence and higher levels of antibodies than women. 6 to10 year old patients were found to have the most frequent acute infection of C. pneumoniae. C. pneumoniae is associated with AECOPD, pneumonia and acute respiratory tract infection. Anti-C. pneumoniae IgG and IgM should be tested simultaneously to avoid underestimation of acute antibodies against C. pneumoniae.

Comparison of enzyme-linked immunosorbent assay with indirect immunofluorescence assay for the diagnosis of Mycoplasma pneumoniae infection

BACKGROUND

The study aimed to compare enzyme-linked immunosorbent assay (ELISA) with indirect immunofluorescence assay (IFA) in the diagnosis of Mycoplasma pneumoniae infection.

METHODS

From March 2016 to May 2017, 180 patients suspected with M. pneumoniae infection were enrolled. The SeroMP kit using ELISA and PNEUMOSLIDE kit using IFA were performed in parallel to detect the IgM antibodies against M. pneumoniae. Cohen's kappa statistics were used to assess the agreement between the ELISA and IFA assays, multivariate logistic regression analysis was used to evaluate risk factors for the discordance between the ELISA and IFA assays.

RESULTS

The mean age of the enrolled subjects was 46.6 ± 21.1 years. For detection of M. pneumoniae infection, the positivities of the ELISA and IFA assays were 15.6% (95% CI: 11.0%, 21.6%) and 10.0% (95% CI: 6.4%, 15.3%), respectively. The total positivity was 19.4% (95% CI: 14.3%, 25.8%). The agreement between the ELISA and IFA assays was low (κ = 0.117, P < 0.001). Variables associated with discordant results between ELISA and IFA assays in multivariate analysis were as follows: male (OR: 0.366; 95% CI: 0.149, 0.899; P < 0.05), age (>33 years old; OR: 0.313; 95% CI: 0.129, 0.758; P < 0.05).

CONCLUSION

In detection of M. pneumoniae infection, low agreement was found in IgM assays between the ELISA and IFA methods, female and younger age were significant risk factors for the discordance. A combination of ELISA and IFA tests would be recommended, in order to detect more patients suspected of M. pneumoniae infection in clinical practice.

Clinical characteristics of pneumonia caused by Mycoplasma pneumoniae in children of different ages

To study clinical characteristics of Mycoplasma pneumoniae pneumonia (MPP) in children of different ages. We investigated the medical records of MPP patients admitted at Children's Hospital of Soochow University from January 2006 and December 2013. The presence of MP was confirmed by real-time PCR and ELISA. There were overall 3358 children with MPP. 412 (12.3%) were <6 months old. Six months to 1 year, 1-3 years, 3-5 years and ≥5 years old children constituted 423 (12.6%), 1033 (30.8%), 733 (21.8%) and 757 (22.5%) respectively. Fever was less frequent in <6 months old infants, with frequency increasing in older patients. The proportion of patients with wheeze was highest (57.9%) in patients aged 6 months to 1-year-old. Tachypnea, cyanosis and hypoxemia were more prevalent in <6 months old infants (P=0.00). Radiologically, bronchopneumonia was frequent among infants, while segmental/lobar pneumonia was frequent in ≥5 years old patients. White blood cell and platelet counts of infants were significantly higher than other children. Neutrophil count, c-reaction protein levels was significantly different amongst age groups. Our study revealed MPP patients of different ages presented with different clinical findings especially <6 months old and ≥5 years of age, which may indicate different pathological findings in age groups of patients with MPP.

[Clinical characteristics of refractory Mycoplasma pneumoniae pneumonia in children]

OBJECTIVE

To provide a basis for early diagnosis and treatment of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children by comparing the clinical characteristics of RMPP and general Mycoplasma pneumoniae pneumonia (MPP).

METHODS

Children with MPP hospitalized between October 2015 and December 2016 were selected as study subjects. According to the diagnostic criteria, children were divided into RMPP group (n=152) and MPP group (n=551). The differences between the two groups in the basic situation, clinical manifestations, infection parameters and myocardial enzymes were compared.

RESULTS

There were no significant differences in gender and age between the RMPP and MPP groups (P>0.05). The peak temperature in the RMPP group was significantly higher than that in the MPP group on the first day of admission (P<0.01). The percentage of children with augmentation in the RMPP group was lower than that in the MPP group (P=0.009). The percentage of neutrophils [Ne(%)] and serum procalcitonin (PCT) levels in the RMPP group were both higher than those in the MPP group (P<0.05), while the percentage of lymphocytes was significantly lower in the RMPP group (P<0.05). The serum levels of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in the RMPP group were also higher than those in the MPP group (P<0.05). Binary logistic regression analysis showed that the peak temperature and LDH were closely related to RMPP in children (P<0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the peak temperature and LDH for the diagnosis of RMPP was 0.647 and 0.637 respectively. In children ≤2 years old, when the threshold value of LDH was 400 U/L, the diagnostic sensitivity was 52.63% and the specificity was 54.84%. In children above 2 years old, when the threshold value of LDH was 335 U/L, the diagnostic sensitivity was 69.92% and the specificity was 51.55%.

CONCLUSIONS

The children with RMPP have a high fever in the early stage. Meanwhile there are abnormal laboratory test results in these children. Elevated serum LDH levels have a high clinical value of early diagnosis of RMPP, especially in children above 2 years.

[Clinical characteristics of refractory Mycoplasma pneumoniae pneumonia in children]

OBJECTIVE

To provide a basis for early diagnosis and treatment of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children by comparing the clinical characteristics of RMPP and general Mycoplasma pneumoniae pneumonia (MPP).

METHODS

Children with MPP hospitalized between October 2015 and December 2016 were selected as study subjects. According to the diagnostic criteria, children were divided into RMPP group (n=152) and MPP group (n=551). The differences between the two groups in the basic situation, clinical manifestations, infection parameters and myocardial enzymes were compared.

RESULTS

There were no significant differences in gender and age between the RMPP and MPP groups (P>0.05). The peak temperature in the RMPP group was significantly higher than that in the MPP group on the first day of admission (P<0.01). The percentage of children with augmentation in the RMPP group was lower than that in the MPP group (P=0.009). The percentage of neutrophils [Ne(%)] and serum procalcitonin (PCT) levels in the RMPP group were both higher than those in the MPP group (P<0.05), while the percentage of lymphocytes was significantly lower in the RMPP group (P<0.05). The serum levels of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in the RMPP group were also higher than those in the MPP group (P<0.05). Binary logistic regression analysis showed that the peak temperature and LDH were closely related to RMPP in children (P<0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the peak temperature and LDH for the diagnosis of RMPP was 0.647 and 0.637 respectively. In children ≤2 years old, when the threshold value of LDH was 400 U/L, the diagnostic sensitivity was 52.63% and the specificity was 54.84%. In children above 2 years old, when the threshold value of LDH was 335 U/L, the diagnostic sensitivity was 69.92% and the specificity was 51.55%.

CONCLUSIONS

The children with RMPP have a high fever in the early stage. Meanwhile there are abnormal laboratory test results in these children. Elevated serum LDH levels have a high clinical value of early diagnosis of RMPP, especially in children above 2 years.

Epidemiology of Respiratory Pathogens in Children with Lower Respiratory Tract Infections in Shanghai, China, from 2013 to 2015

This study aimed to explore the epidemiology of pathogens in children who were hospitalized with lower respiratory tract infections (LRTIs) at the Children's Hospital of Fudan University, Shanghai, China. Children aged less than 18 years who were hospitalized with LRTIs were enrolled from January 2013 to December 2015. Respiratory specimens were collected for the detection of common respiratory viruses, atypical bacteria, and other bacteria using current laboratory diagnostic tests. The epidemiological characteristics of the respiratory pathogens were analyzed. Of the 10,123 specimens obtained from the patients, 5,966 (58.7%) were positive for at least 1 pathogen. Mycoplasma pneumoniae (M.pneumoniae) was the most commonly detected pathogen (15.7%), followed by respiratory syncytial virus (RSV) (13.9%). Co-infections were found in 11.4% of patients. Of these co-infections, viral-bacterial co-infections were the most common. The detection rates for the respiratory pathogens varied considerably by age. RSV was the most common pathogen in children aged less than 24 months. Clear seasonal peaks were observed for RSV, M. pneumoniae, parainfluenza virus, human metapneumovirus, Moraxella catarrhalis, and Haemophilus influenza infections. Our findings demonstrate specific epidemiological patterns in children with LRTIs in Shanghai, China.

Molecular etiological profile of atypical bacterial pathogens, viruses and coinfections among infants and children with community acquired pneumonia admitted to a national hospital in Lima, Peru

OBJECTIVE

The main objective of this study was to detect the presence of 14 respiratory viruses and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae), via polymerase chain reaction in patients under 18 years old hospitalized due to community-acquired pneumonia (CAP) from Lima, Peru.

RESULTS

Atypical pathogens were detected in 40% (58/146); viral etiologies in 36% (52/146) and coinfections in 19% (27/146). The most common etiological agent was M. pneumoniae (n = 47), followed by C. pneumoniae (n = 11). The most frequent respiratory viruses detected were: respiratory syncytial virus A (n = 35), influenza virus C (n = 21) and parainfluenza virus (n = 10). Viral-bacterial and bacterium-bacterium coinfections were found in 27 cases. In our study population, atypical bacteria (40%) were detected as frequently as respiratory viruses (36%). The presence of M. pneumoniae and C. pneumoniae should not be underestimated as they can be commonly isolated in Peruvian children with CAP.

[Clinical features of children with acute lymphoblastic leukemia complicated by pulmonary infection after chemotherapy]

OBJECTIVE

To examine the clinical features of children with acute lymphoblastic leukemia (ALL) complicated by pulmonary infection after chemotherapy.

METHODS

The clinical data of 108 ALL children (115 case-times) with post-chemotherapy pulmonary infection were retrospectively reviewed. The risk factors for pulmonary infection and the relationship between pathogens and chest CT findings were evaluated.

RESULTS

The highest incidence (77.4% ) of pulmonary infection occurred during remission induction, peaking at 31-60 days after chemotherapy. Patients with neutropenia had the highest incidence rate of pulmonary infection (67.0%). Bacteria (36%) and fungi (41%) were the two most common pathogens in the 41 patients who were etiologically suspected of or diagnosed with pulmonary infection. There was no significant difference in chest CT findings between patients with bacterial and fungal infections.

CONCLUSIONS

The children with ALL are most susceptible to pulmonary infection during remission induction, especially when they are neutropenic. Bacteria and fungi are the main pathogens of pulmonary infections in these patients. However, the changes in chest CT images are poor indicators of the nature of pulmonary infection.

[Clinical features of children with acute lymphoblastic leukemia complicated by pulmonary infection after chemotherapy]

OBJECTIVE

To examine the clinical features of children with acute lymphoblastic leukemia (ALL) complicated by pulmonary infection after chemotherapy.

METHODS

The clinical data of 108 ALL children (115 case-times) with post-chemotherapy pulmonary infection were retrospectively reviewed. The risk factors for pulmonary infection and the relationship between pathogens and chest CT findings were evaluated.

RESULTS

The highest incidence (77.4% ) of pulmonary infection occurred during remission induction, peaking at 31-60 days after chemotherapy. Patients with neutropenia had the highest incidence rate of pulmonary infection (67.0%). Bacteria (36%) and fungi (41%) were the two most common pathogens in the 41 patients who were etiologically suspected of or diagnosed with pulmonary infection. There was no significant difference in chest CT findings between patients with bacterial and fungal infections.

CONCLUSIONS

The children with ALL are most susceptible to pulmonary infection during remission induction, especially when they are neutropenic. Bacteria and fungi are the main pathogens of pulmonary infections in these patients. However, the changes in chest CT images are poor indicators of the nature of pulmonary infection.

Community-Acquired Pneumonia in the Asia-Pacific Region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity worldwide. Aging population, dense urbanization, and poor access to health care make the Asia-Pacific region vulnerable to CAP. The high incidence of CAP poses a significant health and economic burden in this region. Common etiologic agents in other global regions including Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, Staphylococcus aureus, and respiratory viruses are also the most prevalent pathogens in the Asia-Pacific region. But the higher incidence of Klebsiella pneumoniae and the presence of Burkholderia pseudomallei are unique to the region. The high prevalence of antimicrobial resistance in S. pneumoniae and M. pneumoniae has been raising the need for more prudent use of antibiotics. Emergence and spread of community-acquired methicillin-resistant S. aureus deserve attention, while the risk has not reached significant level yet in cases of CAP. Given a clinical and socioeconomic importance of CAP, further effort to better understand the epidemiology and impact of CAP is warranted in the Asia-Pacific region.

Atypical pathogen infection in community-acquired pneumonia

Community-acquired pneumonia (CAP) is a world wide cause of morbidity and mortality. The etiology of CAP is different between countries and changes over time. With the increasing incidence, atypical pathogens are attracting more and more attention all over the world. In many countries, atypical pathogens are one of the main pathogens of CAP, and even could be the most prevalent etiology in China. Atypical pathogen infections can cause multi-system complications, which leads to a worse prognosis. Although still controversial, empirical antibiotic coverage of atypical pathogens in CAP may improve outcomes, shorten length of hospitalization, reduce mortality and lower total hospitalization costs. The macrolide resistance rate of atypical pathogens, especially Mycoplasma Pneumoniae (M. Pneumoniae) is high, so fluoroquinolones or tetracyclines should be considered as alternative therapy.

Microbial Etiology of Community-Acquired Pneumonia Among Infants and Children Admitted to the Pediatric Hospital, Ain Shams University

BACKGROUND

While recognizing the etiology of community-acquired pneumonia is necessary for formulating local antimicrobial guidelines, limited data is published about this etiology in Egyptian pediatric patients.

OBJECTIVES

To determine the frequency of bacterial and viral pathogens causing community-acquired pneumonia (CAP) among immunocompetent Egyptian infants and preschool children.

METHODS

Ninety infants and preschool-age children admitted to our hospital with CAP were prospectively included in the study. Etiological agents were identified using conventional bacteriological identification methods and IgM antibodies detection against common atypical respiratory bacteria and viruses.

RESULTS

An etiology was identified in 59 patients (65.5%). Bacterial pathogens were detected in 43 (47.8%) of the cases while viral pathogens were detected in 23 (25.5%). Coinfection with more than one etiologic agent was evident in seven patients (7.8%). The most common typical bacterial cause of pneumonia was Staphylococcus aureus (n = 12, 13.3%), followed by Streptococcus pneumoniae and Klebsiella pneumoniae (n = 7, 7.8%, each). The commonest atypical bacterium was Mycoplasma pneumoniae (n = 10, 11.1%), whereas the commonest viral etiology was influenza viruses (n = 11, 12.2%).

CONCLUSION

Although we could not determine the causative agent in some studied cases, this study provides preliminary data regarding the spectrum and frequency of microorganisms causing CAP in Egyptian infants and preschool children.

A GeXP-Based Assay for Simultaneous Detection of Multiple Viruses in Hospitalized Children with Community Acquired Pneumonia

The GeXP-based assay has recently been developed for simultaneous detection of multiple pathogens. So far, the application of the GeXP assay to test larger clinical samples has hardly been reported. Community-acquired pneumonia (CAP) is the leading cause of death in children worldwide and a substantial proportion of childhood CAP is caused by viruses. Rapid and accurate diagnosis of virus infection is important for the clinical management of CAP. In this study, we explored the GeXP assay for simultaneous detection of 20 types/subtypes of viruses in hospitalized children with CAP. A total of 1699 nasopharyngeal swabs were prospectively collected and viral nucleic acid was extracted and assayed. Using viral genomic DNA or RNA as template, we showed that at the concentration of 10⁴ copies of DNA or RNA of each virus/μl, all 20 target viruses were simultaneously identified by the GeXP assay. Fifteen control microorganisms, in contrast, failed to be amplified by the assay. About 65% of cases tested in this study had viral infection, with patients aged <3 years having a 70% positive rate, significantly higher than that in patients aged > 3 years (40%). The most frequently detected virus was RSV followed by PIV3, HRV, ADV and HBoV. Seasonal distribution analysis revealed that RSV was the most predominant in autumn and winter, while in spring and summer PIV3 and RSV were the most frequently identified with similar positive percentages. One hundred twenty randomly-chosen samples tested by the GeXP assay were re-evaluated by mono-RT-PCR, the results showed 97.5% diagnosis agreement between these 2 methods. Our findings suggest that the GeXP assay could be a valuable diagnostic tool for virus infection in pediatric patients with CAP.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

Recent Developments in Pediatric Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) is the most common acute infectious cause of death in children worldwide. Consequently, research into the epidemiology, diagnosis, treatment, and prevention of pediatric CAP spans the translational research spectrum. Herein, we aim to review the most significant findings reported by investigators focused on pediatric CAP research that has been reported in 2014 and 2015. Our review focuses on several key areas relevant to the clinical management of CAP. First, we will review recent advances in the understanding of CAP epidemiology worldwide, including the role of vaccination in the prevention of pediatric CAP. We also report on the expanding role of existing and emerging diagnostic technologies in CAP classification and management, as well as advances in optimizing antimicrobial use. Finally, we will review CAP management from the policy and future endeavors standpoint, including the influence of clinical practice guidelines on clinician management and patient outcomes, and future potential research directions that are in the early stages of investigation.

Prevalence of respiratory viruses among children hospitalized from respiratory infections in Shenzhen, China

BACKGROUND

The prevalence of local dominant viral etiologies is important for clinical management and prevention of common viral respiratory tract infections. Unfortunately, there is limited large-scale data about common viral respiratory infection in south China. To survey dominant viral etiology and seasonality of acute respiratory infections in hospitalized children, a 4-year consecutive study was conducted in Shenzhen, China.

METHODS

Nasopharyngeal swab specimens were obtained from 30,443 hospitalized children younger than 14 years with respiratory tract diseases in Shenzhen Children's Hospital from January 2012 to December 2015. Nasopharyngeal swabs were routinely examined by direct immunofluorescence assay to detect respiratory agents including seven respiratory viruses. Data were analyzed to describe the frequency and seasonality.

RESULTS

Of the 30,443 children enrolled in the study, 4428 (14.55 %) were positive for at least one viral pathogen, among whom 4110 (92.82 %) were ≤3 years of age. The predominant viruses were respiratory syncytial virus (RSV, 68.11 %), adenovirus (ADV, 16.01 %) and parainfluenza virus 3 (PIV-3, 11.0 %). The common respiratory viruses detected peaked in the spring (17.69 %), and were minimal in autumn (9.73 %), but PIVs detection peaked in November. The common virus detection rate in male subjects (15.40 %) was significantly higher than in female subjects (13.02 %). PIVs detection rates were complementary with RSV in autumn in each year.

CONCLUSIONS

This study demonstrated common respiratory viruses were the major cause of hospitalized acute respiratory infection (ARI) in children in Shenzhen, China. RSV was the most common detected infection, while ADV was the predominant pathogen in hospitalized children. These findings provide a better understanding of virus distribution among children of different ages, infection stratification by gender, and seasonality, all of which will contribute to modification of therapeutic approaches and development of effective prevention strategies for each respiratory virus infection during peak seasons.