The epidemiology of paediatric Mycoplasma pneumoniae pneumonia in North China: 2006 to 2016.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2-3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2-3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Clinical and genetic characteristics of Chinese pediatric patients with chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare disease in China, and very little large-scale studies have been conducted to date. We aimed to investigate the clinical and genetic features of CGD in Chinese pediatric patients. METHODS: Pediatric patients with CGD from Beijing Children's Hospital, Capital Medical University, China, were enrolled from January 2006 to December 2016. RESULTS: A total of 159 pediatric patients with CGD were enrolled. The median age of clinical onset was 1.4 months, and 73% (116/159) had clinical onset symptoms before the 1 year of age. The most common site of invasion was the lungs. The lymph nodes, liver, and skin were more frequently invaded in X-linked (XL) CGD patients than in autosomal recessive (AR) CGD patients (P < 0.05). Approximately 64% (92/144) of the pediatric patients suffered from abnormal response to BCG vaccination. The most frequent pathogens were Aspergillus and Mycobacterium tuberculosis. Gene analysis indicated that 132 cases (89%, 132/147) harbored CYBB pathogenic variants, 7 (5%, 7/147) carried CYBA pathogenic variants, 4 (3%, 4/147) had NCF1 pathogenic variants, and 4 (3%, 4/147) had NCF2 pathogenic variants. The overall mortality rate in this study was 43%, particularly the patients were males, with CYBB mutant and did not receive HSCT treatment. CONCLUSIONS: Chronic granulomatous disease is a rare disease affecting Chinese children; however, it is often diagnosed at a later age, and thus, the mortality rate is relatively high. The prevalence and the severity of disease in XL-CGD are higher than AR-CGD.

[Clinical characteristics of primary ciliary dyskinesia in children].

OBJECTIVE: Although primary ciliary dyskinesia (PCD) is a group of inherited diseases, accurate diagnosis and appropriate clinical care to prevent and treat the complications could maintain patients' quality of life and normal life span. The diagnosis of PCD may often be delayed because it is frequently misdiagnosed as bronchitis, sinusitis and otitis. This study aimed to analyze and summarize the clinical features of PCD and explore diagnostic and differential diagnostic procedures in children. METHODS: Patients were all chosen from the inpatient department of Beijing Children's Hospital, Capital Medical University between 1990 - 2006. The tunica mucosa bronchiorum and/or nasal mucous membrane were gained through bronchoscope in children suspected to have PCD. The ciliary ultrastructures were analyzed through the electron microscope. The clinical features and procedures of the diagnosis and differential diagnosis in children with PCD were analyzed. RESULTS: There were totally 26 children diagnosed as PCD with 10 (38.5%) Kartagener syndrome. All Kartagener syndrome children had mirror image dextrocardia with normal cardiac structure and situs inversus viscerum. The bronchoscopy performed in eight of 10 Kartagener syndrome children showed bronchus transposition. Twenty-six children came from twenty-five families. Although the siblings of four probands also had the symptoms of chronic cough with sputum, running nose and recurrent respiratory infections, only a boy and his sister were diagnosed as Kartagener syndrome simultaneously. Their parents and the other family members were healthy. Of the 26 patients, 11 were boys and 15 were girls. The median age at diagnosis was 8.7 years. The age of onset was between the second day after delivery and fifteen years old, median age was 3 years. The course of disease before diagnosis was eleven days to twelve years (median 3.5 years). All the children had the symptom of cough, 24 of which had productive cough. Seven cases were found to have clubbing fingers. Dynein arm defect was found in 10 children, 6 of them had total absence of dynein arms and 4 had decreased dynein arm numbers. Microtube derangements were found in 8 children. One Kartagener syndrome child had a normal cilia structure. Bronchiectasis, consolidation and increased lung markings were found in 8, 6 and 7 patients separately on the radiographic study. Twenty patients had sinusitis. Nine of sixteen children had decreased PEF, FEV1 and/or FEF 25 - 75 on the pulmonary function test. Fifteen culture samples obtained from 6 children's sputum and/or bronchoalveolar lavage fluid were positive for 8 strains of Pseudomonas aeruginosa, 5 strains of Streptococcus pneumoniae and 2 strains of Candida albicans. In 1 subject more than one organism were found in the same sample. Hearing lost and gastroesophageal reflux were detected in 3 of 4 and 3 of 5 examined children respectively. CONCLUSIONS: The onset of PCD can occur from neonate to adolescence and usually has a chronic course. The common symptom of pediatric PCD was productive cough and significant growth retardation. The most common ultrastructural abnormalities associated with PCD were the total absence of dynein arms, decreased dynein arm numbers and microtube derangement. Some patients have normal ciliary structures. Bronchiectasis, consolidation and sinusitis were usually seen on the radiography. Pseudomonas aeruginosa and Streptococcus pneumoniae were the two common bacterial organisms obtained from sputum and/or bronchoalveolar lavage fluid of PCD children. Some patients have mixed infections. PCD children have high percentages of hearing lost and gastroesophageal reflux.

[Clinical analysis of pediatric SARS cases in Beijing].

OBJECTIVE: To study clinical characteristics of pediatric SARS cases in Beijing. METHODS: Eighteen pediatric cases with SARS diagnosed on admission were analyzed. The cases were admitted to Beijing Children's Hospital and Ditan Hospital (pediatric ward) from April 8 to May 12. RESULTS: The 18 children aged 5 months to 15 years (10 male and 8 female) had epidemiologically linked findings. Fourteen cases had close contact with SARS patients. Four cases were living in the community where adult SARS patients were found. All the 18 patients but one presented with fever and cough. Most of them had high fever, 2 cases had bradycardia, 2 had diarrhea, and another 2 had tachypnea. Malaise and headache were noted only in 3 cases respectively which were much less frequently seen than in adult patients. Symptoms and signs of the children were much less severe and aggressive than adults cases. Thirteen children had chest radiographic consolidation. Of them, 9 cases had progressive changes after admission, then improved quickly. We did not find significant lower hemoglobin and platelet levels. Most patients had leukopenia and lymphopenia. Serologic test was performed for 15 cases and 8 were positive for SARS virus-IgG and 6 for IgM antibody. Of the 4 cases who had close contact with SARS adults and without chest radiograph abnormal findings, 3 were negative for SARS virus-antibodies. Part of the patients had temporary abnormality of myocardial enzyme and liver function. All these children finally had rapid improvement on chest radiograph. The patients were treated with antiviral agents and corticosteroid. Only two cases required oxygen therapy. No child needed assisted ventilation and no death, nor lung fibrosis occurred. After hospitalization, all patients were improved and discharged when this paper was being written. The average hospital stay of these patients was 14.6 days (6 - 22 days). CONCLUSION: Compared with adults, pediatric SARS patients seemed to have their own clinical characteristics. The disease in children had lower severity and infectivity than that in adults. The mechanisms of the disease in children should be studied in well-designed clinical trials. Cases like the 4 children who had close contact with SARS adult patients but without chest radiographic changes deserve further studies with the help of more reliable and sensitive etiologic tests.