A comparative study of general and severe mycoplasma pneumoniae pneumonia in children.

OBJECTIVES: The increasing prevalence of severe Mycoplasma pneumoniae pneumonia (SMPP) poses a significant threat to the health of children. This study aimed to characterise and assess the outcomes in children with SMPP. METHODS: We retrospectively analysed children hospitalised for M. pneumoniae pneumonia (MPP) between January and December 2022. Retrospectively, demographic, clinical, underlying diseases, laboratory and radiological findings, and treatment outcomes were collected and analysed. Disease severity was defined as severe or general according to the Guideline for diagnosis and treatment of community-acquired pneumonia in children (2019 version). RESULTS: Over a 12-month observation period, 417 children with MPP were enrolled, 50.6% (211/417) of whom had SMPP, with the peak incidence observed in winter. Of the 211 children with SMPP, 210 were treated and discharged with improvement, while one child with congenital heart disease died of cardioembolic stroke. A significantly higher proportion of patients with SMPP had underlying diseases, extrapulmonary complications (myocardial and digestive system involvement), and bacterial co-infection. A total of 25 (12%) children with SMPP received mechanical ventilation. The median duration of mechanical ventilation was 3 days. All children were treated with macrolide antibiotic. A significantly higher proportion of patients with SMPP received antibiotic other than macrolides, methylprednisolone sodium succinate, intravenous immunoglobulin and anticoagulation, compared with patients with general MPP (GMPP). Children with SMPP had significantly higher levels of white blood cells, neutrophil percentage, C-reactive protein, procalcitonin, interferon-γ, interleukin (IL)-2, IL-5, IL-6, IL-8, IL-10 and significantly lower percentages of lymphocytes, monocytes, and natural killer cells, compared with GMPP group. CONCLUSION: Our findings suggest that severely ill children have more pronounced inflammatory reaction and extrapulmonary complications. For effective management of children with SMPP, hormonal, prophylactic, anticoagulant therapy, as well as the use of antibiotics other than macrolides for bacterial co-infections, could be incorporated into treatment regimens.

Respiratory syncytial virus subtypes in children with bronchiolitis: does it correlate with clinical severity?

BACKGROUND: In this retrospective study, we aimed to evaluate the factors associated with the severity of respiratory syncytial virus (RSV) bronchiolitis in children aged under 2 years who were admitted to the Children's Hospital of Hebei between June 2018 and January 2019. METHODS: Sputum samples positive for RSV via multiplex PCR were subtyped using real-time PCR. Data collected included risk factors for disease severity, demographics, microbiology, and outcomes. RESULTS: Of the 82 children with RSV bronchiolitis, 79 were treated and discharged with improvement, while 3 died. All three patients had underlying medical conditions, including complex congenital heart disease and severe combined immunodeficiency. Further, disease severity was associated with preexisting underlying disease, fever duration, and bacterial co-infection, but not with the RSV subtype. CONCLUSIONS: Our findings suggest that an appropriate therapeutic regimen should include the detection of bacterial co-infections and the identification of underlying diseases for the effective management of severe RSV bronchiolitis.

Epidemiology and clinical severity of the serotypes of human parainfluenza virus in children with acute respiratory infection.

BACKGROUND: Acute respiratory infections (ARI) are a threat to human health and survival, resulting in many paediatric hospitalisations. However, the epidemiological and clinical severity characteristics of the human parainfluenza virus (PIV), one of the most prevalent respiratory viruses, are not well understood in children. METHODS: To identify the epidemiological features of PIV infection, in 2019, hospitalised children with ARI were screened using multiplex polymerase chain reaction (PCR) for PIV and 10 other common respiratory pathogens. Subtyping of randomly selected PIV-positive samples was performed using reverse transcription-PCR. Demographics, epidemiology, clinical manifestations, diagnosis, and outcomes were compared between PIV subtypes. RESULTS: The annual detection rate for PIV was 14.9%, with a peak from April to September. Children under one year of age had the highest rate of PIV infection (45.5%) compared to other age groups. Of the 121 sequenced samples, 58.7%, 36.4% and 4.9% were positive for PIV-3, PIV-1 and PIV-2, respectively, and no PIV-4 was detected. Severe infections were associated with pre-existing underlying diseases and co-infections, but not with PIV serotype. After excluding cases of co-infection, we found that PIV-2 infection was associated with upper respiratory tract infections, whereas PIV-1 and PIV-3 mainly caused lower respiratory tract infections. Apart from the proportion of patients with fever, there were no significant differences among the three subtypes in terms of clinical symptoms, severity, and outcome. CONCLUSION: Here, PIV was the main pathogen causing ARI in hospitalised children. Appropriate attention should be paid to children with underlying diseases and co-infections to prevent the worsening of severe PIV infection.

Comparative study of diagnostic efficacy of sputum and bronchoalveolar lavage fluid specimens in community-acquired pneumonia children treated with fiberoptic bronchoscopy.

BACKGROUND: Community-acquired pneumonia (CAP) is usually diagnosed in children, and the type of respiratory specimen is critical. Differences in pathogens detection between induced sputum (IS) and bronchoalveolar lavage fluid (BALF) have not been evaluated. METHODS: In 2018, paired sputum and BALF samples from CAP hospitalised children with indications for bronchoalveolar lavage (BAL) were subjected to multiplex PCR for the detection of 11 common respiratory pathogens. RESULTS: A total of 142 children with paired sputum and BALF were tested. The overall positivity rate was 85.9% (122/142) for sputum and 80.3% (114/142) for BALF. The two specimens presented almost perfect agreement between the detection on M. pneumoniae, influenza A, influenza B, bocavirus and RSV. In contrast, adenovirus had the lowest kappa value of 0.156, and a false negative rate (FNR) of 66.7%. Rhinovirus had the highest false positive rate (FPR) as 18.5%. The consistent rate was significantly higher in school-age children than those under 1 year old (p = .005). Bacterial co-infection in BALF specimens were observed in 14.8% (21/142). Of the 11 discordant pairs of specimens, 9 cases were sputum(+)/BALF(-) with adenovirus predominating. CONCLUSION: Our findings suggest that the consistency of results between sputum and BALF is pathogen specific. Careful consideration needs to be given to whether sputum can be used as a substitute for BALF when children are young or co-infections with bacteria are suspected.

[Epidemiological features of severe acute respiratory syndrome coronavirus 2 infection in children in Shijiazhuang, China: an analysis of 133 cases].

OBJECTIVE: To study the epidemiological features of children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Shijiazhuang, China. METHODS: Based on the information officially announced on the official website of the Health Commission of Hebei Province, epidemiological data were collected from 133 children, aged 0-18 years, who were diagnosed with SARS-CoV-2 infection in Shijiazhuang from January 2 to January 30, 2021. A statistical analysis was performed for general status, regional distribution, presence or absence of clusters, and results of SARS-CoV-2 nucleic acid tests. RESULTS: Among the 133 children with SARS-CoV-2 infection, there were 65 boys and 68 girls, with a male/female ratio of 0.96:1. The youngest age of onset was 3 months and 7 days, and the mean age of onset was (9±5) years. Of all the 133 children, 90(67.7%) were the first confirmed case of SARS-CoV-2 infection among their family members. Of all the children, 108(81.2%) came from the Gaocheng District in Shijiazhuang, among whom 38(28.6%) were from Xiaoguozhuang Village where the first patient with a confirmed diagnosis lived. SARS-CoV-2 nucleic acid test at week 2 after the outbreak showed positive results in 88 children (66.2%), and only 5 children had clinical symptoms before positive SARS-CoV-2 results were obtained. Of all the 133 children, 19(14.3%) were found positive in the first SARS-CoV-2 nucleic acid test after the outbreak, and 70(52.6%) had positive results for ≥4 times. There were 98 school students with infection, among whom 74(75.5%) were the first confirmed case in their family, and among 35 non-school students, 16(45.7%) were the first confirmed case in their family (P < 0.05). CONCLUSIONS: Among the children confirmed with SARS-CoV-2 infection in Shijiazhuang, there is a high proportion of children who are the first confirmed case in their family, and the children are mainly distributed in the rural areas of Gaocheng. Most of these children are students, so the prevention and control of cluster infection in schools should be taken seriously. There are often no symptoms before SARS-CoV-2 nucleic acid test, with a low positive rate of the first nucleic acid test, which increases the difficulty of early discovery of the epidemic.

[Efficacy of early treatment via fiber bronchoscope in children with Mycoplasma pneumoniae pneumonia complicated by airway mucus obstruction].

OBJECTIVE: To study the efficacy of early treatment via fiber bronchoscope in children with Mycoplasma pneumoniae pneumonia (MPP) complicated by airway mucus obstruction. METHODS: According to the time from admission to the treatment via fiber bronchoscope, the children with MPP who were found to have airway mucus obstruction under a fiber bronchoscope were randomly divided into early intervention group (≤3 days; n=40) and late intervention group (>3 days; n=56). The two groups were compared in terms of clinical data and imaging recovery.The children were followed for 1-3 months. RESULTS: Of the 96 children, 38 were found to have the formation of plastic bronchial tree, among whom 10 were in the early intervention group and 28 were in the late intervention group (P=0.01). Compared with the late intervention group, the early intervention group had a shorter duration of fever, length of hospital stay, and time to the recovery of white blood cell count and C-reactive protein (P<0.05), as well as a higher atelectasis resolution rate (P<0.05). Compared with the late intervention group, the early intervention group had a higher percentage of children with a ≥ 60% absorbed area of pulmonary consolidation at discharge. After 3 months of follow-up, the early intervention group had a higher percentage of children with a ≥ 90% absorbed area of pulmonary consolidation than the late intervention group (80% vs 55%; P=0.01), and the early intervention group had a lower incidence rate of atelectasis than the late intervention group (P<0.05). CONCLUSIONS: Early treatment via fiber bronchoscope can shorten the course of the disease and reduce complications and sequelae in MPP children with airway mucus obstruction.

The early examination of combined serum and imaging data under flexible fiberoptic bronchoscopy as a novel predictor for refractory Mycoplasma pneumoniae pneumonia diagnosis.

The treatment role of flexible bronchoscopy (FOB) for pediatric refractory Mycoplasma pneumoniae pneumonia (RMPP) has been well documented. Besides, the application indication of FOB is also studied in patients with general MPP (GMPP), especially in those with large pulmonary lesions. This study was designed to examine the diagnostic value of bronchoscopic features for RMPP.The FOB and bronchoalveolar lavage (BAL) were adopted for pediatric patients who showed clinical and radiograph indications. On the basis of the final diagnosis on discharge, patients were divided into general and refractory MPP groups. The clinical, laboratory, and bronchoscopic imaging features were retrospectively investigated between these 2 groups.From June 2012 to May 2014, a total of 62 RMPP and 101 GMPP patients were treated with therapeutic bronchoscopy. The comparison analysis showed that the CRP, HBDH, LDH were significantly different between RMPP and GMPP groups (all P < .001). In the bronchoscopic imaging, the mucus plug was significantly more commonly seen in the RMPP group (P < .001). Receiver operating characteristic (ROC) analysis revealed that the combined serum, clinical, and FOB imaging data possessed greater specificity and sensitivity than serum and clinical data alone.Our data suggest that the combined serum, clinical, and bronchoscopic imaging data might serve as a promising predictor for early RMPP diagnosis for pediatric patients with large pulmonary lesions.

Amplification of 16S rDNA by nested PCR for measurement of Mycoplasma pneumoniae DNA over time: clinical application.

Mycoplasma pneumoniae (MP) is the most common atypical pathogen that causes respiratory infections in children. Such infections are typically treated by macrolide antibiotics, but the duration of treatment is variable. In this study, we used nested PCR to amplify the 16S rDNA (16S rRNA gene) of MP at different stages of MP pneumonia (MPP) in 100 children who were admitted for lower respiratory tract infections and diagnosed with MPP. Our results indicate that the median duration of MP-DNA positivity was 5 weeks, and 78 % of cases tested positive for 3-6 weeks. Patients with severe disease were positive for MP-DNA for a significantly longer time (median of 6 weeks) than those with mild disease (median of 4 weeks). Thirty-one patients with severe disease who received intravenous immunoglobulin were MP-DNA positive for significantly less time than patients with severe disease who did not receive this treatment. The duration of MP-DNA positivity was prolonged when MP antibody levels were high and treatment was started at a later stage. Therefore, nested PCR can be used for early diagnosis of MP and the duration of MP-DNA reflects the clinical stage of MPP. Early treatment of MPP and the administration of intravenous immunoglobulin during the acute phase of severe MPP shorten the duration of MP-DNA positivity.