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

The epidemic characteristics of Mycoplasma pneumoniae infection among children in Anhui, China, 2015-2023

The number of pediatric respiratory tract infection cases in China has significantly increased this year, and Mycoplasma pneumoniae is one of the main pathogens. This study aimed to investigate the epidemiological characteristics of M. pneumoniae in children in the Anhui region and to provide evidence for the prevention and control strategies of M. pneumoniae in children in this region. A total of 66,488 pediatric patients with respiratory tract infection were enrolled from January 2015 to November 2023 in this study. The results of this study exhibited that M. pneumoniae infection in the Anhui region was characterized by a high positive rate during 2021-2023, especially this year is considered a year of pandemic for M. pneumoniae infection. Moreover, the positive rate of M. pneumoniae in female children is significantly higher than in male children, and the infection rate of M. pneumoniae in children increases significantly with age, particularly in school-aged children.

IMPORTANCE

The number of pediatric respiratory tract infection cases in China has significantly increased this year, and Mycoplasma pneumoniae is one of the main pathogens. This study aimed to investigate the epidemiological characteristics of M. pneumoniae in children in the Anhui region and provide evidence for the prevention and control strategies of M. pneumoniae in children in this region.

An exceptionally large wave of M. pneumoniae infections among children in Tianjin post COVID-19 pandemic

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused a persistent lowering of Mycoplasma pneumoniae (M. pneumoniae), which is commonly found in children with respiratory tract infections (RTIs). However, in 2023, we observed an unusually high number of M. pneumoniae infections among children from Tianjin, the second largest city in northern China. This study sought to analyze the epidemiological characteristics of children with RTIs caused by M. pneumoniae in northern China post COVID-19, in order to provide a theoretical basis for clinical diagnosis and treatment.

Methods

Between January 2019 and December 2023, a total of 78,886 children with respiratory infections from General Hospital of Tianjin Medical University were included in this study. A rapid immunochromatographic assay kit was used to test for M. pneumoniae specific immunoglobulin M (IgM) in these patients. The relevant clinical data of M. pneumoniae-positive cases were also collected, and analyzed by SPSS software.

Results

Out of the 78,886 samples collected, a total of 11,268 tested positive for M. pneumoniae specific-IgM antibody. The average positive rate was 14.3% in the past 5 years. In the year 2023 alone, there were 5,870 M. Pneumoniae positive cases, surpassing the combined count from the previous 4 years. The incidence of M. pneumoniae had significantly surged since September 2023, peaking at 1,717 cases in November 2023, with a notable surge during the fourth quarter. The prevalence of M. pneumoniae infection was primarily observed among children aged 4-6 years and 7-9 years both before and during the COVID-19 pandemic; however, a noticeable increase was observed among children aged 10-14 years after the pandemic ended. Boys exhibited a lower positive rate (13.19%) compared to girls (15.56%). In addition, the proportion of pneumonia cases in 2023 was significantly higher than that in previous years (P<0.001).

Conclusions

Our study revealed that following a prolonged global lowering of M. pneumoniae since the COVID-19 pandemic, a significant outbreak had emerged in northern China since September 2023. The proportion of M. pneumoniae positive children in the older age group increased in 2023 compared to that observed in 2019. Additionally, there was an increase in the proportion of pneumonia among M. pneumoniae positive cases in 2023 compared to the pre-COVID-19 pandemic period.

Routine blood parameters as auxiliary diagnostic tools for Mycoplasma pneumoniae infection in children

Introduction. Recently, the incidence of Mycoplasma pneumoniae (M. pneumoniae) infection in children has been increasing annually. Early differential diagnosis of M. pneumoniae infection can not only avoid the abuse of antibiotics, but also is essential for early treatment and reduction of transmission.Gap statement. The change of routine blood parameters may have important clinical significance for the diagnosis of M. pneumoniae infection, but it has not been reported so far.Aim. This study aims to establish a predictive model for M. pneumoniae infection and explore the changes and clinical value of routine blood parameters in children with M. pneumoniae infection, serving as auxiliary indicators for the diagnosis and differentiation of clinical M. pneumoniae infection.Methodology. A total of 770 paediatric patients with respiratory tract infections were enrolled in this study, including 360 in the M. pneumoniae group, 40 in the SARS-CoV-2 group, 200 in the influenza A virus group, and 170 in the control group. The differences of routine blood parameters among all groups were compared, and risk factors were analysed using multivariate logistics analysis, and the diagnostic efficacy of differential indicators using ROC curves.Results. This study revealed that Mono% (OR: 3.411; 95% CI: 1.638-7.102; P=0.001) was independent risk factor associated with M. pneumoniae infection, and Mono% (AUC=0.786, the optimal cutoff at 7.8%) had a good discriminative ability between patients with M. pneumoniae infection and healthy individuals. Additionally, Mono% (OR: 0.424; 95% CI: 0.231-0.781; P=0.006) and Lymp% (OR: 0.430; 95% CI: 0.246-0.753; P=0.003) were independent risk factors for distinguishing M. pneumoniae infection from influenza A virus infection, and the Lymp% (AUC=0.786, the optimal cutoff at 22.1%) and Net% (AUC=0.761, the optimal cutoff at 65.2%) had good discriminative abilities between M. pneumoniae infection and influenza A infection. Furthermore, platelet distribution width (OR: 0.680; 95% CI: 0.538-0.858; P=0.001) was independent risk factor for distinguishing M. pneumoniae infection from SARS-CoV-2 infection. Meanwhile, the ROC curve demonstrated that PDW (AUC=0.786, the optimal cutoff at 15%) has a good ability to differentiate between M. pneumoniae infection and SARS-CoV-2 infection.Conclusion. This study demonstrates that routine blood parameters can be used as auxiliary diagnostic indicators for M. pneumoniae infection and provide reference for the diagnosis and differentiation of clinical M. pneumoniae infection.

Exploring the pathogenetic mechanisms of Mycoplasmapneumoniae (Review)

Mycoplasmas, the smallest self-replicating prokaryotes without a cell wall, are the most prevalent and extensively studied species in humans. They significantly contribute to chronic respiratory tract illnesses and pneumonia, with children and adolescents being particularly vulnerable. Mycoplasma pneumoniae (M. pneumoniae) infections typically tend to be self-limiting and mild but can progress to severe or even life-threatening conditions in certain individuals. Extrapulmonary effects often occur without pneumonia, and both intrapulmonary and extrapulmonary complications operate through separate pathological mechanisms. The indirect immune-mediated damage of the immune system, vascular blockages brought on by vasculitis or thrombosis and direct harm from invasion or locally induced inflammatory cytokines are potential causes of extrapulmonary manifestations due to M. pneumoniae. Proteins associated with adhesion serve as the primary factor crucial for the pathogenicity of M. pneumoniae, relying on a specialized polarized terminal attachment organelle. The type and density of these host receptors significantly impact the adhesion and movement of M. pneumoniae, subsequently influencing the pathogenic mechanism and infection outcomes. Adjacent proteins are crucial for the proper assembly of the attachment organelle, with variations in the genetic domains of P1, P40 and P90 surfaces contributing to the variability of clinical symptoms and offering new avenues for developing vaccines against M. pneumoniae infections. M. pneumoniae causes oxidative stress within respiratory tract epithelial cells by adhering to host cells and releasing hydrogen peroxide and superoxide radicals. This oxidative stress enhances the vulnerability of host cells to harm induced by oxygen molecules. The lack of superoxide dismutase and catalase of bacteria allows it to hinder the catalase activity of the host cell, leading to the reduced breakdown of peroxides. Lung macrophages play a significant role in managing M. pneumoniae infection, identifying it via Toll-like receptor 2 and initiating the myeloid differentiation primary response gene 88-nuclear factor κΒ signaling cascade. However, the precise mechanisms enabling M. pneumoniae to evade intracellular host defenses remain unknown, necessitating further exploration of the pathways involved in intracellular survival. The present comprehensive review delves into the pathogenesis of M. pneumoniae infection within the pulmonary system and into extrapulmonary areas, outlining its impact.

Comparison of Mycoplasma pneumoniae infection in children admitted with community acquired pneumonia before and during the COVID-19 pandemic: a retrospective study at a tertiary hospital of southwest China

PURPOSE

The COVID-19 pandemic has notably altered the infection dynamics of various pathogens. This study aimed to evaluate the pandemic's impact on the infection spectrum of Mycoplasma pneumoniae (M. pneumoniae) among children with community acquired pneumonia (CAP).

METHODS

We enrolled pediatric CAP patients admitted to a tertiary hospital in southwest China to compare the prevalence and characteristics of M. pneumoniae infections before (2018-2019) and during (2020-2022) the COVID-19 pandemic. Detection of M. pneumoniae IgM antibodies in serum were conducted using either indirect immunofluorescence or passive agglutination methods.

RESULTS

The study included 1505 M. pneumoniae-positive and 3160 M. pneumoniae-negative CAP patients. Notable findings were the higher age and frequency of pneumonia-associated symptoms in M. pneumoniae-positive patients, alongside a lower male proportion and fewer respiratory co-infections. The year 2019 saw a notable increase in M. pneumoniae infections compared to 2018, followed by a decline from 2020 to 2022. The COVID-19 pandemic period witnessed significant alterations in age distribution, male proportion, and co-infections with specific pathogens in both M. pneumoniae-positive and negative patients. The M. pneumoniae infections were predominantly seasonal, peaking in autumn and winter during 2018 and 2019. Although there was a sharp drop in February 2020, the infection still peaked in cold months of 2020 and 2021. However, the typical seasonal pattern was nearly absent in 2022.

CONCLUSIONS

The COVID-19 pandemic has markedly changed the infection landscape of M. pneumoniae in pediatric CAP patients, with shifts observed in infection rates, demographic profiles, co-infections, and seasonal patterns.

Contribution of Particulates to Airborne Disease Transmission and Severity: A Review

The emergence of coronavirus disease 2019 (COVID-19) has catalyzed great interest in the spread of airborne pathogens. Airborne infectious diseases are classified into viral, bacterial, and fungal infections. Environmental factors can elevate their transmission and lethality. Air pollution has been reported as the leading environmental cause of disease and premature death worldwide. Notably, ambient particulates of various components and sizes are harmful pollutants. There are two prominent health effects of particles in the atmosphere: (1) particulate matter (PM) penetrates the respiratory tract and adversely affects health, such as heart and respiratory diseases; and (2) bioaerosols of particles act as a medium for the spread of pathogens in the air. Particulates contribute to the occurrence of infectious diseases by increasing vulnerability to infection through inhalation and spreading disease through interactions with airborne pathogens. Here, we focus on the synergistic effects of airborne particulates on infectious disease. We outline the concepts and characteristics of bioaerosols, from their generation to transformation and circulation on Earth. Considering that microorganisms coexist with other particulates as bioaerosols, we investigate studies examining respiratory infections associated with airborne PM. Furthermore, we discuss four factors (meteorological, biological, physical, and chemical) that may impact the influence of PM on the survival of contagious pathogens in the atmosphere. Our review highlights the significant role of particulates in supporting the transmission of infectious aerosols and emphasizes the need for further research in this area.

Epidemiology of asthma exacerbation in children before and after the COVID-19 pandemic: a retrospective study in Chengdu, China

PURPOSE

To examine the numbers and characteristics of children affected by asthma exacerbation in Chengdu, China, before and after the COVID-19 pandemic to inform efforts to manage childhood asthma in the post epidemic era.

METHODS

Data were retrospectively collected from children admitted for asthma exacerbation to Chengdu Women and Children's Central Hospital between January 2017 and December 2022. Rates of hospitalization, ages of the affected children, comorbidities and infections, and relationships between hospitalization and seasonal or environmental factors were examined before and after the epidemic.

RESULTS

Fewer children were hospitalized for asthma exacerbation, yet more hospitalized children had severe exacerbation after the epidemic than before. Rates of hospitalization varied considerably with time of year, and the timing of peak hospitalizations differed before and after the epidemic. Only before the epidemic, rates of hospitalization for asthma exacerbation were positively correlated with humidity. Infants made up a smaller proportion of hospitalized children after the epidemic than before, with preschool children accounting for most hospitalizations after the epidemic. The proportion of children hospitalized for asthma exacerbation who also had pneumonia was significantly smaller after the epidemic than before. Conversely, the proportion of children hospitalized for asthma exacerbation who also had allergic diseases was significantly greater after the epidemic than before.

CONCLUSION

The epidemiology of asthma exacerbation in children changed after the epidemic. Future efforts to manage the condition in the paediatric population should focus on severe asthma exacerbation, prevention and management of allergic diseases, and the influence of meteorological and environmental factors.

Influence of COVID-19 pandemic on the epidemiology of Mycoplasma pneumoniae infections among hospitalized children in Henan, China

Background

Increasing reports have indicated that non-pharmaceutical interventions to control the COVID-19 pandemic may also have an effect on the prevalence of other pathogens. Mycoplasma pneumoniae is an important atypical pathogen prevalent in children with high rates of macrolide resistance. The aim of this study was to investigate the epidemiological characteristics of M. pneumoniae infection in children before and during the COVID-19 pandemic.

Methods

In this study, M. pneumoniae detection results were extracted from Henan Children's Hospital from 2018 to 2021. The epidemiological characteristics of pediatric M. pneumoniae infection were analyzed.

Results

We found that the highest positive rate of M. pneumoniae infection was 11.00 % in 2018, 14.01 % in 2019, followed by 11.24 % in 2021 and 8.75 % in 2020 (p < 0.001). Most tested children had respiratory system manifestations, and pneumoniae was the most common diagnosis (53.23 %). An increase in the number of positive cases was observed with an increase in age, with a higher number of cases among children over 6 years old. No positive cases were identified among children aged 1-28 days. The decrease in the positive rate among children aged between1-6 years old in 2020 and 2021 was found to be statistically significant (p < 0.001). The pre-pandemic period demonstrated a higher incidence rate in the fall, whereas the summers and winters exhibited a significantly higher positive rate during the pandemic period (p < 0.001). Different regions in Henan also showed different epidemic patterns.

Conclusions

In summary, strict pandemic measures influenced the spread of M. pneumoniae to some extent and changed demographic characteristics, including age, season and regional distribution. Continuous monitoring is required for the control and prevention of related diseases.

Immunological evidence of an early seroconversion to oncogenic Merkel cell polyomavirus in healthy children and young adults

Oncogenic Merkel cell polyomavirus (MCPyV) provokes a widespread and asymptomatic infection in humans. Herein, sera from healthy children and young adults (HC, n = 344) aged 0-20 years old were evaluated for anti-MCPyV immunoglobulin G (IgG) and IgM antibodies employing a recently developed immunoassay. Serum MCPyV IgG data from healthy subjects (HS, n = 510) and elderlies (ES, n = 226), aged 21-65/66-100 years old, from our previous studies, were included. The anti-MCPyV IgG and IgM rates in HC sera were 40.7% and 29.7%, respectively. A lower prevalence of anti-MCPyV IgGs was found in HC aged 0-5 years old (13%) compared to 6-10 (52.3%), 11-15 (60.5%) and 16-20 years old (61.6%) cohorts. Age-stratified HCs exhibited similar anti-MCPyV IgM rates (27.9%-32.9%). Serological profiles indicated that anti-MCPyV IgGs and IgMs had low optical densities (ODs) during the first years of life, while IgM ODs appeared to decrease throughout young adulthood. A lower anti-MCPyV IgGs rate was found in HC (40.7%) than HS (61.8%) and ES (63.7%). Upon the 5-years range age-stratification, a lower anti-MCPyV IgGs rate was found in the younger HC cohort aged 0-5 years old compared to the remaining older HC/HS/ES cohorts (52.3%-72%). The younger HC cohort exhibited the lowest anti-MCPyV IgG ODs than the older cohorts. Low anti-MCPyV IgMs rates and ODs were found in the 21-25 (17.5%) and 26-30 (7.7%) years old cohorts. Our data indicate that, upon an early-in-life seroconversion, the seropositivity for oncogenic MCPyV peaks in late childhood/young adulthood and remains at high prevalence and relatively stable throughout life.

Deconstruction of Clinical Treatment of Pneumonia and Respiratory Tract Infection Based on MRI Molecular Imaging

Pneumonia is a major research core topic in the medical field, and clinical trials of pneumonia and respiratory tract infection have been ongoing. The purpose of this study was to investigate the clinical efficacy and safety of Shuanghuanghua granules in the treatment of pneumonia and respiratory tract infection based on NMR molecular imaging, and to lay a foundation for the development of new drugs. In this paper, 126 patients were randomly divided into the control group, the treatment group 1, the and treatment group 2, and were given Fengreganmao granules, Shuanghuanghua granules (ultrafine preparation), and Shuanghuanghua granules (extract preparation), respectively. The main symptom scores, sign scores, antipyretic time, and virus content before and after treatment were recorded. Statistical analysis was carried out on this basis. The experiment showed that the body temperature of the subjects in the three groups before treatment was: control group (37.59 ± 0.78), treatment group 1 (37.8 ± 0.81), and treatment group 2 (37.6 ± 0.76). After treatment, the body temperature of subjects in the three groups was: control group (36.67 ± 0.71), treatment group 1 (36.49 ± 0.43), and treatment group 2 (36.19 ± 0.25). Experiments show that Shuanghuanghua granules can significantly reduce the nasal virus, adenovirus, parainfluenza virus, etc. in the patient's body. And it can shorten the antipyretic time of patients and has good clinical application. In addition, this study gave full play to the role of MRI molecular imaging and provided ideas and references for the clinical treatment of pneumonia and respiratory tract infection.

Prediction of Bronchopneumonia Inpatients' Total Hospitalization Expenses Based on BP Neural Network and Support Vector Machine Models

Objective

BP neural network (BPNN) model and support vector machine (SVM) model were used to predict the total hospitalization expenses of patients with bronchopneumonia.

Methods

A total of 355 patients with bronchopneumonia from January 2018 to December 2020 were collected and sorted out. The data set was randomly divided into a training set (n = 249) and a test set (n = 106) according to 7 : 3. The BPNN model and SVM model were constructed to analyze the predictors of total hospitalization expenses. The effectiveness was compared between these two prediction models.

Results

The top three influencing factors and their importance for predicting total hospitalization cost by the BPNN model were hospitalization days (0.477), age (0.154), and discharge department (0.083). The top 3 factors predicted by the SVM model were hospitalization days (0.215), age (0.196), and marital status (0.172). The area under the curve of these two models is 0.838 (95% CI: 0.755~0.921) and 0.889 (95% CI: 0.819~0.959), respectively.

Conclusion

Both the BPNN model and SVM model can predict the total hospitalization expenses of patients with bronchopneumonia, but the prediction effect of the SVM model is better than the BPNN model.

The Prevalence of Mycoplasma Pneumoniae Among Children in Beijing Before and During the COVID-19 Pandemic

Objective

Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of community acquired pneumonia. With the outbreak of coronavirus disease 2019 (COVID-19), the prevalence of some infectious respiratory diseases has varied. Epidemiological features of M. pneumoniae in children from Beijing (China) before and during the COVID-19 pandemic were investigated.

Methods

Between June 2016 and May 2021, a total of 569,887 children with respiratory infections from Children’s Hospital Affiliated to Capital Institute of Pediatrics (Beijing, China) were included in this study. M. pneumoniae specific-IgM antibody in serum specimens of these patients was tested by a rapid immunochromatographic assay kit. The relevant clinical data of M. pneumoniae-positive cases were also collected, and analyzed by RStudio software.

Results

The results showed that 13.08% of collected samples were positive for M. pneumoniae specific-IgM antibody. The highest annual positive rate was 17.59% in 2019, followed by 12.48% in 2018, 12.31% in 2017, and 11.73% in 2016, while the rate dropped to 8.9% in 2020 and 4.95% in 2021, with significant difference. Among the six years, the positive rates in summer and winter seasons were significantly higher than those in spring and autumn seasons (p < 0.001). The positive rate was the highest in school-age children (22.20%), and lowest in the infant group (8.76%, p < 0.001). The positive rate in boys (11.69%) was lower than that in girls (14.80%, p < 0.001). There were no significant differences in different seasons, age groups, or genders before and during the COVID-19 pandemic (p > 0.05).

Conclusions

Our study demonstrated that an M. pneumoniae outbreak started from the summer of 2019 in Beijing. After the COVID-19 pandemic outbreak in the end of 2019, the M. pneumoniae positive rates dropped dramatically. This may be due to the restrictive measures of the COVID-19 pandemic, which effectively controlled the transmission of M. pneumoniae. The relationships between M. pneumoniae positive rates and season, age, and gender were not statistically significant before and during the COVID-19 pandemic.

Mycoplasma pneumoniae among Chinese Outpatient Children with Mild Respiratory Tract Infections during the Coronavirus Disease 2019 Pandemic

Mycoplasma pneumoniae is a common pathogen causing respiratory disease in children. We sought to investigate the epidemiology of M. pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the coronavirus disease 2019 (COVID-19) pandemic. Eligible patients were prospectively enrolled from January 2020 to June 2021. Throat swabs were tested for M. pneumoniae RNA. M. pneumoniae IgM was tested by a colloidal gold assay. Macrolide resistance and the effect of the COVID-19 countermeasures on M. pneumoniae prevalence were assessed. Symptom scores, treatments, and outcomes were evaluated. Eight hundred sixty-two eligible children at 15 centers in China were enrolled. M. pneumoniae was detected in 78 (9.0%) patients. Seasonally, M. pneumoniae peaked in the first spring and dropped dramatically to extremely low levels over time until the next summer. Decreases in COVID-19 prevalence were significantly associated with decreases in M. pneumoniae prevalence (r = 0.76, P = 0.001). The macrolide resistance rate was 7.7%. The overall sensitivity and specificity of the colloidal gold assay used in determining M. pneumoniae infection were 32.1% and 77.9%, respectively. No more benefits for improving the severity of symptoms and outcomes were observed in M. pneumoniae-infected patients treated with a macrolide than in those not treated with a macrolide during follow-up. The prevalences of M. pneumoniae and macrolide resistance in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs. IMPORTANCE This is the first and largest prospective, multicenter, active, population-based surveillance study of the epidemiology of Mycoplasma pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the COVID-19 pandemic. Nationwide measures like strict face mask wearing and restrictions on population movement implemented to prevent the spread of COVID-19 might also effectively prevent the spread of M. pneumoniae. The prevalence of M. pneumoniae and the proportion of drug-resistant M. pneumoniae isolates in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for screening and diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs.