Epidemiological Study on Mycoplasma pneumoniae and Chlamydia pneumoniae Infection of Hospitalized Children in a Single Center During the COVID-19 Pandemic

Navigating the outbreak: a comprehensive analysis of pediatric Mycoplasma pneumoniae pneumonia via targeted next-generation sequencing in Wuhan, 2022-2023

This study aims to delineate the epidemiological characteristics and impacts of the Mycoplasma pneumoniae (MP) outbreak, utilizing targeted next-generation sequencing (tNGS) to assess pathogen prevalence and co-infections in pediatric pneumonia cases. Pediatric patients admitted to Wuhan Children's Hospital with pneumonia from 1 October 2022 to 31 October 2023 were included. tNGS was used for comprehensive pathogen detection, including MP and other respiratory pathogens, with additional sequencing of the 23S rRNA gene V region to identify macrolide resistance mutations. This study enrolled 10,223 patients with pneumonia with a positivity rate of 98.4% by targeted next-generation sequencing. Fever (86.4%) and cough (79.3%) were the most common symptoms of Mycoplasma pneumoniae pneumonia (MPP). Lung consolidation (25.8%) was a common imaging feature, and corticosteroid use was noted in 22.5% of MPP patients. MP proved to be the primary pathogen, particularly evident during the MP pandemic, which began in March 2023 and peaked in October with a detection rate of 63.2%. Of the 4,397 MPP cases, 34.5% were sole infections, while 65.6% were co-infections, mostly with viruses. The main causative agents of co-infections were Haemophilus influenzae and Rhinovirus. The macrolide resistance rate was 79.03%. The A2063G mutation in the 23S rRNA V region is the dominant mutation. High-sensitivity C-reactive protein and serum amyloid A were significantly elevated in MPP, while the absolute counts of CD3+T, CD4+T, CD8+T, CD19+B, and NK cells were significantly reduced. This study demonstrates the utility of tNGS in identifying MP co-infections and macrolide resistance and highlights the role of inflammatory markers and lymphocyte subpopulations in differentiating MPP from non-Mycoplasma pneumoniae pneumonia for clinical management.IMPORTANCEOur study is of great scientific value as it provides practical solutions to clinical challenges and supports both clinical decision-making and public health policy. First, it presents new and important insights into the application of targeted next-generation sequencing (tNGS) technology, which enables rapid and accurate pathogen detection and overcomes the limitations of conventional diagnostic methods. Second, the large sample size, focusing specifically on children during a Mycoplasma pneumoniae epidemic, provides valuable epidemiologic data specifically for the Wuhan region. Finally, by integrating rapid tNGS detection with inflammatory markers and lymphocyte subsets, our study demonstrates direct clinical applications that have the potential to improve patient outcomes. This approach highlights the practical utility of our research in enhancing clinical decision-making and contributes important knowledge to the field.

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.

Combined use of respiratory multiplex PCR and procalcitonin to reduce antibiotic exposure in sickle-cell adult patients with acute chest syndrome (The ANTIBIO-STA study): a randomised, controlled, open-label trial

Background

Respiratory infection may account for 30% of acute chest syndrome (ACS) aetiologies. However, antimicrobials are routinely prescribed, and de-escalation and/or discontinuation are challenging. Multiplex Polymerase Chain Reaction (mPCR) with an enlarged respiratory panel might support antimicrobial stewardship, and procalcitonin (PCT) measurements help reduce duration of antibiotic therapy. We hypothesized that a strategy combining the use of mPCR with repeated PCT measurements would reduce antibiotic exposure during ACS.

Methods

We conducted a randomised, controlled, parallel group, open-label study in two French hospitals. Consecutive adult patients with ACS were randomly assigned to the conventional or interventional strategy, where antibiotic therapy was targeted on the results of mPCR performed on lower respiratory tract secretions (LRTS) samples, and antibiotic discontinuation based on PCT values and kinetics at Day 1 (D1), D3 and D7. The primary outcome was the number of days of antibiotic exposure at D28 after randomisation. This trial was registered on ClinicalTrial.gov (NCT03919266) and is closed to recruitment.

Findings

From June 2020 to September 2022, 72 patients were assigned to the interventional (n = 37) or conventional strategy (n = 35). Despite a higher rate of microbiological documentation with the intervention (n = 25; 67.6% versus n = 13; 37.1%; difference, 30.4%; 95% CI 6.7%-51.5%), antibiotic exposure at D28 was similar between the two strategies (6 days [4.0-8.0] versus 6 days [5.0-9.0], respectively; difference, 0.0 day; 95% CI, -2.1 to 2.1). The time to clinical stability, and ICU and hospital lengths of stay did not differ.

Interpretation

As compared with conventional tests, an enlarged respiratory panel mPCR combined with a PCT-guided algorithm did not reduce antibiotic exposure at D28 in adults with ACS.

Funding

Assistance Publique-Hôpitaux de Paris, AP-HP (CRC180159). A financial support for the multiplex PCR kits used in this study was partially provided by bioMérieux.

Nonbacterial Respiratory Pathogens Following the Easing of COVID-19 Restrictive Measures

Nonbacterial respiratory pathogens are major acute respiratory infection (ARI) agents in children. We aimed to characterize the epidemiological changes in 11 common nonbacterial pathogens after easing COVID-19 restrictions in Zhejiang, China, to guide prevention and treatment. A retrospective study was conducted on children with ARIs at Children's Hospital, Zhejiang University School of Medicine in 2023, and epidemiological characteristics were analyzed for gender, age, month, sampling method, and immune status. In total, 59.48% of the children identified pathogens, and Mycoplasma pneumoniae ranked first. Various pathogens showed new features regarding detection rates, seasonal patterns, and susceptible populations. The host age, onset time, sampling method, and immunity status affected the mixed infection rate and unusual coinfection pairs emerged. The epidemiology of respiratory pathogens among children in Zhejiang has changed with local characteristics, and possible preventive actions are needed.

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.

Mycoplasma pneumoniae detections in children with acute respiratory infection, 2010-2023: a large sample study in China

BACKGROUND

This study aimed to describe the epidemiological trends of Mycoplasma pneumoniae (MP) infection among children with acute respiratory tract infections (ARTIs) before, during and after the COVID-19 pandemic, and evaluating the impact of non-pharmaceutical interventions (NPIs) on the epidemiology of MP infection.

METHODS

Children with ARTIs admitted to the Children's Hospital of Soochow University (SCH) from January 2010 to December 2023 and underwent MP nucleic acid PCR assay were included. Clinical data on age, sex, onset time and detection result were collected and analyzed.

RESULTS

All of the 122,984 inpatients were enrolled, in which 20.8% (25659/122984) of the children with MP tested positive, including 19.4% (14139/72662) for male and 22.9% (11520/50322) for female. It was a statistically significant difference between the two genders (p < 0.05). In addition, the positive rate of MP was the highest in the age group > 6 years old each year (p < 0.05). During 14-year period, the detection rate of MP has experienced four peaks in 2012, 2013, 2019, and 2023. Before the NPIs the prevalence of MP showed seasonality, and the number and rate of MP positivity reached their peak in August. However, the rate of MP positivity remained at a low level during the NPIs. After the abolition of NPIs, the MP positivity rate obviously increased and remained at a high level.

CONCLUSIONS

The NPIs could reduce the spread of MP infection and change its epidemic season, but it has not changed the susceptible population of MP infection.

The prevalence of Mycoplasma pneumoniae in children in Shandong, China before, during, and after COVID-19

Background

The multifaceted non-pharmaceutical interventions after the outbreak of the COVID-19 pandemic not only limited the spread of SARS-CoV2 but also had an impact on the prevalence of other pathogens.

Methods

In this work, we retrospectively analyzed the epidemiological characteristics of Mycoplasma pneumoniae (MP) in children before and after the COVID-19 pandemic in Shandong, China. From 2019-2023, there were 29,558 visits of pediatric patients (1 month to 15 years old) with respiratory tract infection (RTI) symptoms at a tertiary hospital in Shandong Province, 10,039 of which were positive for MP according to a passive agglutination assay of the serum IgM antibodies. Conduct statistical analysis and epidemiological investigation of the test results categorized by years, months, ages, genders and clinical diagnosis. Utilize the χ 2 test to analyze the differences in incidence rates.

Results

Compared to 2019, the number of visits and the positive cases both decreased substantially in 2020, but the positivity rate increased. Both 2021 and 2023 were peak years of MP infection. The peak seasons of MP infection were fall and winter, female patients had higher positivity rate than male patients, and school-age children (>6 years) had higher positivity rate than the children in other age groups. In terms of the clinical manifestation of MP infection, compared to 2019, in 2023, the proportion of bronchopneumonia and upper RTI decreased significantly.

Conclusions

The ongoing surveillance of the epidemiology of MP is critical for effective disease management and provides a basis for diagnosis, treatment, and the corresponding prevention and control strategies. This work for the first time characterized the epidemiology of MP in Shandong before and after the COVID-19 pandemic, thus providing valuable information for monitoring and preventing MP infection in the post-epidemic era.

Epidemic features and megagenomic analysis of childhood Mycoplasma pneumoniae post COVID-19 pandemic: a 6-year study in southern China

With the atypical rise of Mycoplasma pneumoniae infection (MPI) in 2023, prompt studies are needed to determine the current epidemic features and risk factors with emerging trends of MPI to furnish a framework for subsequent investigations. This multicentre, retrospective study was designed to analyse the epidemic patterns of MPI before and after the COVID-19 pandemic, as well as genotypes and the macrolide-resistance-associated mutations in MP sampled from paediatric patients in Southern China. Clinical data was collected from 1,33,674 patients admitted into investigational hospitals from 1 June 2017 to 30 November 2023. Metagenomic next-generation sequencing (mNGS) data were retrieved based on MP sequence positive samples from 299 paediatric patients for macrolide-resistance-associated mutations analysis. Pearson's chi-squared test was used to compare categorical variables between different time frames. The monthly average cases of paediatric common respiratory infection diseases increased without enhanced public health measures after the pandemic, especially for influenza, respiratory syncytial virus infection, and MPI. The contribution of MPI to pneumoniae was similar to that in the outbreak in 2019. Compared to mNGS data between 2019-2022 and 2023, the severity of MP did not grow stronger despite higher rates of macrolide-resistance hypervariable sites, including loci 2063 and 2064, were detected in childhood MP samples of 2023. Our findings indicated that ongoing surveillance is necessary to understand the impact of post pandemic on MP transmission disruption during epidemic season and the severity of clinical outcomes in different scenarios.

Reemergence of Mycoplasma pneumoniae disease: Pathogenesis and new approaches

The review discusses the recurrence of Mycoplasma pneumoniae (M. pneumoniae), a bacterium causing atypical pneumonia, primarily affecting Europe and Asia due to climate change, immunity decline, antibiotic resistance, and genetic heterogeneity. The COVID-19 pandemic initially reduced M. pneumoniae cases due to preventative measures, but its reemergence suggests different transmission dynamics and exacerbates clinical severity with co-infections with other viruses. The pathogenicity of M. pneumoniae is attributed to its intracellular changes, toxin release, and adhesion processes, which can result in a variety of symptoms and problems. Antibiotics and immunomodulators are used in treatment, and attempts are being made to create vaccines. Effective management of its reappearance necessitates surveillance and preventative measures, especially in the context of co-infections and potential outbreaks. M. pneumoniae's resurgence highlights its reliance on a polarized cytoskeletal architecture for host cell attachment and pathogenicity through cytoadherence and cytotoxic agent synthesis. M. pneumoniae has returned even though the COVID-19 pandemic originally reduced incidence; this might be because of things like declining immunity and particular pathogenic characteristics. Meteorological factors like temperature and humidity, along with air quality, including pollutants like PM2.5 and NO2, increase susceptibility to environmental hazards. During the pandemic, non-pharmaceutical measures decreased transmission but did not eradicate the infection. Epidemics typically occur three to five years apart, emphasizing the need for ongoing study and observation. Antimicrobial resistance is a serious issue, necessitating caution and alternative therapies, especially in macrolides. COVID-19 pandemic lessons, such as mask use and hand hygiene, may help limit M. pneumoniae transmission.

New Insights into the Epidemiological Characteristics of Mycoplasma pneumoniae Infection before and after the COVID-19 Pandemic

Mycoplasma pneumoniae (M. pneumoniae), a prevalent respiratory pathogen affecting children and adolescents, is known to trigger periodic global epidemics. The most recent significant outbreak commenced in the first half of 2023 and reached its peak globally during the autumn and winter months. Considering the worldwide repercussions of the COVID-19 pandemic, it has become increasingly essential to delve into the epidemiological characteristics of M. pneumoniae both before and after the pandemic. This review aims to provide a comprehensive analysis of the key features of M. pneumoniae epidemics in the pre-and post-COVID-19 contexts, including but not limited to shifts in the susceptible population, the molecular genotypes of the pathogen, the clinical manifestations, and potential new trends in drug resistance. Additionally, we will introduce the latest advancements in the diagnosis of M. pneumoniae.

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.

Post-Pandemic Epidemiology of Respiratory Infections among Pediatric Inpatients in a Tertiary Hospital in Shanghai, China

BACKGROUND

After the removal of the three-year epidemic control restrictions, Chinese children were confronted with heightened risks of respiratory infections. We aimed to investigate the post-pandemic (2023) epidemiology of respiratory infections among pediatric inpatients in a tertiary hospital in Shanghai, China, and compare it with the pre-pandemic (2019) levels.

METHODS

A total of 2644 pediatric inpatients were enrolled based on discharge time and divided into group 2019 (n = 1442) and group 2023 (n = 1202). Information on the demographic characteristics, diagnoses, and pathogen test results (Mycoplasma pneumoniae, MP; Chlamydia pneumoniae, CP; Legionella pneumophila, LP; Influenza A, IFA; Influenza B, IFB; Parainfluenza virus, PIV; respiratory syncytial virus, RSV; Coxsackie virus, COX; Adenovirus, ADV; Epstein-Barr virus, EBV) was collected and analyzed.

RESULTS

Significant increases were found in the overall test positivity rates (64.6% vs. 46.7%), mixed infection rates (17.4% vs. 9%), and proportion of severe cases (25.5% vs. 3.7%) after the pandemic than those before it. Compared with 2019, the incidences of MP, IFA, LP, RSV, and ADV remarkably increased, while those of IFB and COX decreased, with no obvious differences noted for CP, PIV, and EBV in 2023. A significantly higher MP-positive detection rate was noticed in children aged 1-6 years in 2023 than in 2019. The incidence of RSV infection began to rise in August 2023, earlier than the conventional epidemic season.

CONCLUSIONS

Compared with the pre-pandemic levels, the overall test positivity rates of atypical pathogens and viruses among pediatric inpatients significantly increased, and alterations in the disease spectrum, epidemic season, and age of prevalence were observed after the COVID-19 pandemic.

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.

Epidemiologic trends and changes in humoral immunity and lymphocyte subsets levels among hospitalized children with Mycoplasma pneumoniae infection during 2019-2023

PURPOSE

To understand the changes in humoral immunity and lymphocyte subsets levels among hospitalized children with Mycoplasma pneumoniae (MP) infection from 2019 to 2023.

METHODS

This study retrospectively analyzed inpatients aged 0-14 years who were diagnosed with MP infection or MP pneumonia in a tertiary hospital from January 2019 to December 2023. The children were divided into three groups: before the implementation of nonpharmaceutical interventions (NPIs), during the implementation of NPIs, and after the NPIs being lifted.

RESULTS

A total of 4103 patients were enrolled in this study, of whom 2125 were diagnosed with MP infection and 1978 were diagnosed with MP pneumonia. The number of MP infection cases dramatically decreased early during the implementation of NPIs, and the previous epidemic trend resumed after the NPIs were lifted, with the number of cases during the period 2019-2023 peaked in November 2023. In children aged < 5 years, the levels of IgA and IgM and the percentages of total T cells and cytotoxic T cells in the "before the implementation of NPIs" group were greater than those in the other groups, and the percentage of total B cells was lower than that in the other groups. In children aged ≥ 5 years, the IgM level in the "before the implementation of NPIs" group was greater than that in the other groups.

CONCLUSION

The number of MP-infected hospitalized children decreased significantly after NPI implementation and reached its highest peak during 2019-2023 in November 2023. After the NPIs were lifted, the level of humoral immunity was decreased and balance lymphocyte subsets were disrupted, especially in children aged < 5 years. We should pay close attention to and prevent MP infection in a timely manner after epidemics caused by large respiratory pathogens.

Influence of non-pharmaceutical interventions on epidemiological characteristics of Mycoplasma pneumoniae infection in children during and after the COVID-19 epidemic in Ningbo, China

Background

Since the outbreak of COVID-19, China has implemented a series of non-pharmaceutical interventions (NPIs), effectively containing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as various respiratory pathogens. With the continuous relaxation of restrictions, China has entered a new phase of the post-pandemic era. However, the epidemiological differences of Mycoplasma pneumoniae (MP) between the two phases in Ningbo and even in China remain unclear.

Methods

Data of children aged 0-14 years who visited the Ningbo Medical Center LiHuiLi Hospital due to acute respiratory tract infections from January 2020 to December 2023 were collected. PCR was used to detect 13 respiratory pathogens and the macrolide-resistance of Mycoplasma pneumoniae.

Results

Among 10,206 children, 2,360 were infected with MP (23.12%). Among the total, the MP positive rate during the NPI phase (6.35%) was significantly lower than that during the non-NPI phase (34.28%), while the macrolide resistance rate increased from 62.5% (NPI phase) to 81.1% (non-NPI phase). The rate of MP co-infection increased from 11.2% (NPI phase) to 30.3% (non-NPI phase). MP infection exhibited obvious seasonality, with the highest prevalence in autumn (30.0%) followed by summer (23.6%). There were differences in MP positivity rates among different age groups, with the highest among school-age children at 39.5%. During the NPI phase, all age groups were less susceptible to MP, while during the non-NPI phase, the susceptible age for MP was 4-12 years, with 8 years being the most susceptible. The susceptible age for MP co-infection was 0-6 years. MP exhibited antagonistic effects against numerous pathogens. Compared to MP single infection, the proportion of pneumonia was higher in MP co-infection cases.

Conclusion

The removal of NPIs significantly impacted the spread of MP, altering population characteristics including age, seasonality, macrolide resistance, and MP co-infection rates.

CRISPR/Cas9 gene editing: a novel strategy for fighting drug resistance in respiratory disorders

Respiratory disorders are among the conditions that affect the respiratory system. The healthcare sector faces challenges due to the emergence of drug resistance to prescribed medications for these illnesses. However, there is a technology called CRISPR/Cas9, which uses RNA to guide DNA targeting. This technology has revolutionized our ability to manipulate and visualize the genome, leading to advancements in research and treatment development. It can effectively reverse epigenetic alterations that contribute to drug resistance. Some studies focused on health have shown that targeting genes using CRISPR/Cas9 can be challenging when it comes to reducing drug resistance in patients with respiratory disorders. Nevertheless, it is important to acknowledge the limitations of this technology, such as off-target effects, immune system reactions to Cas9, and challenges associated with delivery methods. Despite these limitations, this review aims to provide knowledge about CRISPR/Cas9 genome editing tools and explore how they can help overcome resistance in patients with respiratory disorders. Additionally, this study discusses concerns related to applications of CRISPR and provides an overview of successful clinical trial studies.

Mycoplasma pneumoniae detections in children with lower respiratory infection before and during the COVID-19 pandemic: a large sample study in China from 2019 to 2022

BACKGROUND

Nonpharmaceutical interventions (NPIs) implemented to reduce the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have suppressed the spread of other respiratory viruses during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to explore the epidemiological trends and clinical characteristics of Mycoplasma pneumoniae (MP) infection among inpatient children with lower respiratory tract infection (LRTI) before and during the COVID-19 pandemic, and investigate the long-term effects of China's NPIs against COVID-19 on the epidemiology of MP among inpatient children with LRTI.

METHODS

Children hospitalised for LRTI at the Department of Pulmonology, The Children's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between January 2019 and December 2022 were tested for common respiratory pathogens, including Mycoplasma pneumoniae (MP), Chlamydia trachomatis (CT) and other bacteria. Clinical data on age, sex, season of onset, disease spectrum, and combined infection in children with MP-induced LRTI in the past 4 years were collected and analysed.

RESULTS

Overall, 15909 patients were enrolled, and MP-positive cases were 1971 (34.0%), 73 (2.4%), 176 (5.8%), and 952 (20.6%) in 2019, 2020, 2021, and 2022, respectively, with a significant statistical difference in the MP-positive rate over the 4 years (p <0.001). The median age of these children was preschool age (3-6 years), except for 2022, when they were school age (7-12 years), with statistical differences. Comparing the positive rates of different age groups, the school-age children (7-12 years) had the highest positive rate, followed by the preschoolers (3-6 years) in each of the 4 years. Compared among different seasons, the positive rate of MP in children with LRTI was higher in summer and autumn, whereas in 2020, it was highest in spring. The monthly positive rate peaked in July 2019, remained low from 2020 to 2021, and rebounded until 2022. Regarding the disease spectrum, severe pneumonia accounted for the highest proportion (46.3%) pre-pandemic and lowest (0%) in 2020.

CONCLUSION

Trends in MP detection in children with LRTIs suggest a possible correlation between COVID-19 NPIs and significantly reduced detection rates. The positivity rate of MP gradually rose after 2 years. The epidemic season showed some differences, but school-age children were more susceptible to MP before and during the COVID-19 pandemic.

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.

Childhood Mycoplasma pneumoniae: epidemiology and manifestation in Northeast and Inner Mongolia, China

Mycoplasma pneumoniae (MP) is commonly detected in children. However, the epidemiological trends of MP in Northeast (NE) China are unclear. This retrospective study aimed to investigate the prevalence of MP infections in this understudied region. The clinical manifestations and bronchoscopic findings observed in hospitalized patients with severe Mycoplasma pneumoniae pneumonia (SMPP) were collected from comprehensive data obtained from six tertiary hospitals in NE and Inner Mongolian (IM) China, from 1 January 2017 to 31 December 2023. A total of 5,593,530 children who visited the outpatient and emergency departments, and 412,480 inpatient hospitalized children were included in the study. The positivity rate of MP immunoglobulin M (IgM) in the children who visited the outpatient and emergency departments varied from 7.80% to 10.12%, whereas that of MP infection in hospitalized children ranged from 27.18% to 30.10%. Children hospitalized for MP infection were mainly concentrated in the 1- to 4-year (41.39%) and 4- to 7-year (24.25%) age groups. Before 2020, the season with the highest incidence of MP was winter. After the implementation of non-pharmaceutical interventions (NPIs), the MP epidemic season changed, and the number of children with MP infections decreased; however, the proportion of MP infections in hospitalized children did not change significantly. Starting from August 2023, the MP infection rate in outpatient, emergency, and hospitalized children increased sharply, with SMPP and its complications (e.g., plastic bronchitis and pleural effusion) increasing significantly. MP is prevalent in NE and IM, China. When the NPIs ended, MP infection showed a delayed outbreak trend, and the number of children with severe infection increased significantly.

IMPORTANCE

In Northeastern (NE) and Inner Mongolia (IM), the incidence of Mycoplasma pneumoniae (MP) infections, including severe Mycoplasma pneumoniae pneumonia (SMPP), is high, posing health risks and imposing substantial economic burdens on the local population. Therefore, it is imperative to prioritize the study of MP prevalence and address the research gaps in MP epidemiology in these areas of China. We obtained a comprehensive collection of pediatric outpatient, emergency, and inpatient data from six public Grade III hospitals. We believe that our study makes a significant contribution to the literature because understanding regional variations in MP infections can help healthcare professionals tailor prevention and treatment strategies, and studying bronchoscopic manifestations can provide insights into the impact of the disease on the respiratory system, potentially leading to a more effective clinical management.

Apolipoprotein C3 (ApoC3) facilitates NLRP3 mediated pyroptosis of macrophages through mitochondrial damage by accelerating of the interaction between SCIMP and SYK pathway in acute lung injury

Respiratory failure caused by severe acute lung injury (ALI) is the main cause of mortality in patients with COVID-19.This study aimed to investigate the effects and underlying biological mechanism of Apolipoprotein C3 (ApoC3) in ALI. To establish an in vivo model, C57BL/6 mice were exposed by lipopolysaccharide (LPS). For the in vitro model, murine bone marrow-derived macrophages (BMDMs) or RAW264.7 cells were stimulated with LPS + adenosine triphosphate (ATP). Serum levels of ApoC3 were found to be upregulated in patients with COVID-19 or pneumonia-induced ALI. Inhibition of ApoC3 reduced lung injury in an ALI model, while overexpression of ApoC3 promoted lung injury. ApoC3 induced mitochondrial damage-mediated pyroptosis in ALI through the activation of the NOD-like receptorprotein 3 (NLRP3) inflammasome. ApoC3 recombinant protein significantly increased SCIMP expression in the lung tissue of mice models with ALI. ApoC3 also facilitated the interaction between the SLP adapter and CSK-interacting membrane protein (SCIMP) protein and Spleen tyrosine kinase (SYK) protein in the ALI model. Moreover, ApoC3 accelerated calcium-dependent reactive oxygen species (ROS) production in the ALI model. The effects of ApoC3 on pyroptosis were mitigated by the use of a pyroptosis inhibitor or an ROS inhibitor in the ALI model. Furthermore, ApoC3 activated the expression of SYK, which in turn induced NLRP3 inflammasome-regulated pyroptosis in the ALI model. METTL3 was found to mediate the m6A mRNA expression of ApoC3. Overall, our study highlights the crucial role of ApoC3 in promoting macrophage pyroptosis in ALI through calcium-dependent ROS production and NLRP3 inflammasome activation via the SCIMP-SYK pathway, providing a potential therapeutic strategy for ALI and other inflammatory diseases.

Chlamydophila pneumoniae-associated community-acquired pneumonia in paediatric patients of a tertiary care hospital in Mexico: molecular diagnostic and clinical insights

Chlamydophila pneumoniae is a cause of community-acquired pneumonia (CAP) and responsible for 1-2% of cases in paediatric patients. In Mexico, information on this microorganism is limited. The aim of this study was to detect C. pneumoniae using two genomic targets in a real-time PCR and IgM/IgG serology assays in paediatric patients with CAP at a tertiary care hospital in Mexico City and to describe their clinical characteristics, radiological features, and outcomes. A total of 154 hospitalized patients with diagnosis of CAP were included. Detection of C. pneumoniae was performed by real-time PCR of the pst and arg genes. Complete blood cell count, C-reactive protein measurement and IgM and IgG detection were performed. Clinical-epidemiological and radiological data from the patients were collected. C. pneumoniae was detected in 25 patients (16%), of whom 88% had underlying disease (P = 0.014). Forty-eight percent of the cases occurred in spring, 36% in girls, and 40% in children older than 6 years. All patients had cough, and 88% had fever. Interstitial pattern on chest-X-ray was the most frequent (68%), consolidation was observed in 32% (P = 0.002). IgM was positive in 7% and IgG in 28.6%. Thirty-six percent presented complications. Four percent died. A high proportion showed co-infection with Mycoplasma pneumoniae (64%). This is the first clinical report of C. pneumoniae as a cause of CAP in Mexican paediatric patients, using two genomic target strategy and serology. We found a frequency of 16.2% with predominance in children under 6 years of age. In addition; cough and fever were the most common symptoms. Early detection of this pathogen allows timely initiation of specific antimicrobial therapy to reduce development of complications. This study is one of the few to describe the presence of C. pneumoniae in patients with underlying diseases.

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.

Comparison of respiratory pathogens in children with community-acquired pneumonia before and during the COVID-19 pandemic

BACKGROUND

Multifaceted non-pharmaceutical interventions during the COVID-19 pandemic have not only reduced the transmission of SARS-CoV2, but have had an effect on the prevalence of other pathogens. This retrospective study aimed to compare and analyze the changes of respiratory pathogens in hospitalized children with community-acquired pneumonia.

METHODS

From January 2019 to December 2020, children with community-acquired pneumonia were selected from the Department of Respiratory Medicine, Shanghai Children's Medical Center. On the first day of hospitalization, sputum, throat swabs, venous blood samples from them were collected for detection of pathogens.

RESULTS

A total of 2596 children with community-acquired pneumonia were enrolled, including 1871 patients in 2019 and 725 in 2020. The detection rate in 2020 was lower than in 2019, whether single or multiple pathogens. Compared with 2019, the detection rate of virus, especially parainfluenza virus, influenza virus and respiratory syncytial virus, all decreased in 2020. On the contrary, the prevalence of human rhinovirus was much higher than that in 2019. In addition, the positivity rate for bacteria did not change much over the two years, which seemed to be less affected by COVID-19. And Mycoplasma pneumoniae which broke out in 2019 has been in low prevalence since March 2020 even following the reopening of school.

CONCLUSIONS

Strict public health interventions for COVID-19 in China have effectively suppressed the spread of not only SARS-CoV2 but parainfluenza virus, influenza virus and Mycoplasma pneumonia as well. However, it had a much more limited effect on bacteria and rhinovirus. Therefore, more epidemiological surveillance of respiratory pathogens will help improve early preventive measures.

miRNA, lncRNA and circRNA: targeted molecules with therapeutic promises in Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) is primarily recognized as a respiratory pathogen that causes community-acquired pneumonia, which can lead to acute upper and lower airway inflammation and extrapulmonary syndrome. Refractory pneumonia caused by MP can cause severe complications and even be life-threatening, particularly in infants and the elderly. It is well-known that non-coding RNAs (ncRNAs) represented by miRNAs, lncRNAs and circRNAs have been manifested to be widely involved in the regulation of gene expression. Growing evidence indicates that these ncRNAs have distinct differentiated expression in MP infection and affect multiple biological processes, playing an indispensable role in the initiation and promotion of MP infection. However, the epigenetic mechanisms involved in the development of MP infection remain unclear. This article reviews the mechanisms by which miRNAs, lncRNAs, and circRNAs mediate MP infection, such as inflammatory responses, apoptosis and pulmonary fibrosis. Focusing on miRNAs, lncRNAs and circRNAs associated with MP infection could provide new insights into this disease's early diagnosis and therapeutic approaches.

Effect of Past Chlamydophila pneumoniae Infection on the Short-Time Mortality of COVID-19: A Retrospective Cohort Study

BACKGROUND

Although Chlamydophila pneumoniae (CP)is known to play a role in atherosclerosis and endothelial injury, its past infection on the mortality of coronavirus disease 2019 (COVID-19), which was also reported to be a vascular disease, remains unknown.

METHODS

In this retrospective cohort study, we examined 78 COVID-19 patients and 32 bacterial pneumonia patients who visited a tertiary emergency center in Japan between April 1, 2021, and April 30, 2022. CP antibody levels, including IgM, IgG, and IgA, were measured.

RESULTS

Among all patients, the CP IgA-positive rate was significantly associated with age (P = 0.002). Between the COVID-19 and non-COVID-19 groups, no difference in the positive rate for both CP IgG and IgA was observed (P = 1.00 and 0.51, respectively). The mean age and proportion of males were significantly higher in the IgA-positive group than in the IgA-negative group (60.7 vs. 75.5, P = 0.001; 61.5% vs. 85.0%, P = 0.019, respectively). Smoking and dead outcomes were significantly higher both in the IgA-positive group and IgG-positive group (smoking: 26.7% vs. 62.2, P = 0.003; 34.7% vs. 73.1%, P = 0.002, dead outcome: 6.5% vs. 29.8%, P = 0.020; 13.5% vs. 34.6%, P = 0.039, respectively). Although the log-rank test revealed higher 30-day mortality in the IgG-positive group compared to the IgG-negative group (P = 0.032), Cox regression analysis demonstrated no significant difference between the IgG-positive and negative groups (hazard ratio (HR) = 4.10, 95%CI = 0.94-18.0, P = 0.061).

CONCLUSION

The effect of past CP infection on 30-day mortality in COVID-19 patients was not obvious.

Nonpharmaceutical interventions for COVID-19 disrupt the dynamic balance between influenza A virus and human immunity

During the COVID-19 epidemic, nonpharmaceutical interventions (NPIs) blocked the transmission route of respiratory diseases. This study aimed to investigate the impact of NPIs on the influenza A virus (IAV) outbreak. The present study enrolled all children with respiratory tract infections who came to the Children's Hospital of Zhejiang University between January 2019 and July 2022. A direct immunofluorescence assay kit detected IAV. Virus isolation and Sanger sequencing were performed. From June to July 2022, in Hangzhou, China, the positive rate of IAV infection in children has increased rapidly, reaching 30.41%, and children over 3 years old are the main infected population, accounting for 75% of the total number of infected children. Influenza A (H3N2) viruses are representative strains during this period. In this outbreak, H3N2 was isolated from a cluster of its own and is highly homologous with A/South_Dakota/22/2022 (2021-2022 Northern Hemisphere). Between isolated influenza A (H3N2) viruses and A/South_Dakota/22/2022, the nucleotide homology of the HA gene ranged from 97.3% to 97.5%; the amino acid homology was 97%-97.2%, and the genetic distance of nucleotides ranged from 0.05 to 0.052. Compared with A/South_Dakota/22/2022, the isolated H3N2 showed S156H, N159Y, I160T, D186S, S198P, I48T, S53D, and K171N mutations. There was no variation in 13 key amino acid sites associated with neuraminidase inhibitor resistance in NA protein. Long-term NPIs have significantly affected the evolution and transmission of the influenza virus and human immunity, breaking the dynamic balance between the IAV and human immunity.

Seroprevalence of Epstein-Barr virus infection in children during the COVID-19 pandemic in Zhejiang, China

AIM

We aimed to investigate the seroprevalence of Epstein-Barr virus (EBV) infection in children before and during the COVID-19 pandemic.

METHODS

All children admitted to the Children's Hospital Affiliated to Zhejiang University from January 2019 to December 2021 with suspected EBV-associated disease and EBV antibodies were detected by a two-step indirect method of chemiluminescence technology. A total of 44,943 children were enrolled in this study. The seroprevalence of EBV infections was compared from January 2019 to December 2021.

RESULTS

The total seropositive rate of EBV infections was 61.02% between January 2019 and December 2021, and the seropositive trend decreased year by year. The total number of seropositive EBV infections in 2020 was reduced by 30% compared to that in 2019. In particular, nearly 30% and 50% reductions in the number of acute EBV infections and EBV reactivations or late primary infections from 2019 to 2020 were found, respectively. The number of acute EBV infections in children aged 1-3 years and EBV reactivation or late primary infection in children aged 6-9 years in 2020 sharply dropped by approximately 40% and 64% compared to that in 2019.

CONCLUSIONS

Our study further demonstrated that the prevention and control measures for COVID-19 in China had a certain effect on containing acute EBV infections and EBV reactivations or late primary infections.

Long COVID and the Neuroendocrinology of Microbial Translocation Outside the GI Tract: Some Treatment Strategies

Similar to previous pandemics, COVID-19 has been succeeded by well-documented post-infectious sequelae, including chronic fatigue, cough, shortness of breath, myalgia, and concentration difficulties, which may last 5 to 12 weeks or longer after the acute phase of illness. Both the psychological stress of SARS-CoV-2 infection and being diagnosed with COVID-19 can upregulate cortisol, a stress hormone that disrupts the efferocytosis effectors, macrophages, and natural killer cells, leading to the excessive accumulation of senescent cells and disruption of biological barriers. This has been well-established in cancer patients who often experience unrelenting fatigue as well as gut and blood–brain barrier dysfunction upon treatment with senescence-inducing radiation or chemotherapy. In our previous research from 2020 and 2021, we linked COVID-19 to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) via angiotensin II upregulation, premature endothelial senescence, intestinal barrier dysfunction, and microbial translocation from the gastrointestinal tract into the systemic circulation. In 2021 and 2022, these hypotheses were validated and SARS-CoV-2-induced cellular senescence as well as microbial translocation were documented in both acute SARS-CoV-2 infection, long COVID, and ME/CFS, connecting intestinal barrier dysfunction to disabling fatigue and specific infectious events. The purpose of this narrative review is to summarize what is currently known about host immune responses to translocated gut microbes and how these responses relate to fatiguing illnesses, including long COVID. To accomplish this goal, we examine the role of intestinal and blood–brain barriers in long COVID and other illnesses typified by chronic fatigue, with a special emphasis on commensal microbes functioning as viral reservoirs. Furthermore, we discuss the role of SARS-CoV-2/Mycoplasma coinfection in dysfunctional efferocytosis, emphasizing some potential novel treatment strategies, including the use of senotherapeutic drugs, HMGB1 inhibitors, Toll-like receptor 4 (TLR4) blockers, and membrane lipid replacement.