[Value of anti-neutrophil cytoplasmic antibody in assessing the severity of bronchiolitis obliterans in children].

OBJECTIVE: To study the value of anti-neutrophil cytoplasmic antibody (ANCA) in assessing the severity of bronchiolitis obliterans (BO) in children. METHODS: A prospective analysis was performed on 59 children who were diagnosed with BO from June 2009 to October 2014. ELISA was used to measure the concentrations of myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA in serum. According to the results of ELISA, the children were divided into three groups: double-negative ANCA (n=22), single-positive ANCA (n=17), and double-positive ANCA (n=20). The three groups were compared in terms of the scores of BO risk factors, clinical symptoms, chest high-resolution computed tomography (HRCT), and lung pathology on admission, as well as the changes in the expression level of ANCA and the scores of clinical symptoms and chest HRCT over time. RESULTS: Compared with the double-negative ANCA group, the double-positive ANCA group had a significantly higher score of BO risk factors (P<0.05), and the single-positive ANCA group and the double-positive ANCA group had significantly higher scores of clinical symptoms, chest HRCT, and lung pathology (P<0.05). The children were followed up for 6 months after discharge, and there were significant reductions in MPO-ANCA and PR3-ANCA titers from admission and discharge to the end of follow-up (P<0.05), as well as a significant reduction in the score of clinical symptoms from admission to the end of follow-up (P<0.05), while there was no significant change in the score of chest HRCT from admission to the end of follow-up (P>0.05). The single-positive ANCA and double-positive ANCA groups still had a significantly higher score of clinical symptoms than the double-negative ANCA group (P<0.05). CONCLUSIONS: The expression level of ANCA is correlated with the severity of BO in children and thus has certain clinical significance in disease evaluation.

Paramyxoviruses respiratory syncytial virus, parainfluenza virus, and human metapneumovirus infection in pediatric hospitalized patients and climate correlation in a subtropical region of southern China: a 7-year survey.

To investigate the features of paramyxovirus respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (HMPV) infection and determine the effect of meteorological conditions in Guangzhou, a subtropical region of southern China. We collected 11,398 respiratory samples from hospitalized pediatric patients with acute respiratory illness between July 2009 and June 2016 in Guangzhou. The samples were tested simultaneously for 18 respiratory pathogens using real-time PCR. Local meteorological data were also collected for correlation analysis. Of 11,398 patients tested, 5606 (49.2%) patients tested positive for one or more pathogens; RSV, PIV, and HMPV were the first, sixth, and ninth most frequently detected pathogens, in 1690 (14.8%), 502 (4.4%), and 321 (2.8%) patients, respectively. A total 17.9% (4605/5606) of patients with positive results had coinfection with other pathogens. Significant differences were found in the prevalence of RSV, PIV, and HMPV among all age groups (p < 0.001). RSV and HMPV had similar seasonal patterns, with two prevalence peaks every year. PIV appeared alternatively with RSV and HMPV. Multiple linear regression models were established for RSV, PIV, and HMPV prevalence and meteorological factors (p < 0.05). RSV and PIV incidence was negatively correlated with monthly mean relative humidity; RSV and HMPV incidence was negatively correlated with sunshine duration; PIV incidence was positively correlated with mean temperature. We described the features of paramyxovirus infection in a subtropical region of China and highlighted the correlation with meteorological factors. These findings will assist public health authorities and clinicians in improving strategies for controlling paramyxovirus infection.

Epidemiology and clinical characteristics of human coronaviruses OC43, 229E, NL63, and HKU1: a study of hospitalized children with acute respiratory tract infection in Guangzhou, China.

Human coronaviruses (HCoV) OC43, 229E, NL63, and HKU1 are common respiratory viruses which cause various respiratory diseases, including pneumonia. There is a paucity of evidence on the epidemiology and clinical manifestations of these four HCoV strains worldwide. We collected 11,399 throat swabs from hospitalized children with acute respiratory tract infection from July 2009 to June 2016 in Guangzhou, China. These were tested for four strains of HCoV infection using real-time polymerase chain reaction (PCR). HCoV-positive patients were then tested for 11 other respiratory pathogens. 4.3% (489/11399) of patients were positive for HCoV, of which 3.0% were positive for OC43 (346/11399), 0.6% for 229E (65/11399), 0.5% for NL63 (60/11399), and 0.3% for HKU1 (38/11399). Patients aged 7-12 months had the highest prevalence of HCoV and OC43 when compared with other age groups (p < 0.001). The peak seasons of infection varied depending on the HCoV strain. Patients infected with a single strain of HCoV infection were less likely to present fever (≥ 38 °C) (p = 0.014) and more likely to present pulmonary rales (p = 0.043) than those co-infected with more than one HCoV strain or other respiratory pathogens. There were also significant differences in the prevalence of certain symptoms, including coughing (p = 0.032), pneumonia (p = 0.026), and abnormal pulmonary rales (p = 0.002) according to the strain of HCoV detected. This retrospective study of the prevalence of four HCoV strains and clinical signs among a large population of pediatric patients in a subtropical region of China provides further insight into the epidemiology and clinical features of HCoV.

Epidemiology of HBoV1 infection and relationship with meteorological conditions in hospitalized pediatric patients with acute respiratory illness: a 7-year study in a subtropical region.

BACKGROUND: Human bocavirus 1 (HBoV1) is an important cause of acute respiratory illness (ARI), yet the epidemiology and effect of meteorological conditions on infection is not fully understood. To investigate the distribution of HBoV1 and determine the effect of meteorological conditions, hospitalized pediatric patients were studied in a subtropical region of China. METHODS: Samples from 11,399 hospitalized pediatric patients (≤14 years old), with ARI were tested for HBoV1 and other common respiratory pathogens using real-time PCR, between July 2009 and June 2016. In addition, local meteorological data were collected. RESULTS: Of the 11,399 patients tested, 5606 (49.2%) were positive for at least one respiratory pathogen. Two hundred forty-eight of 11,399 (2.2%) were positive for HBoV1 infection. Co-infection was common in HBoV1-positive patients (45.2%, 112/248). A significant difference in the prevalence of HBoV1 was found in patients in different age groups (p < 0.001), and the peak prevalence was found in patients aged 7-12 months (4.7%, 56/1203). Two HBoV1 prevalence peaks were found in summer (between June and September) and winter (between November and December). The prevalence of HBoV1 was significantly positively correlated with mean temperature and negatively correlated with mean relative humidity, and the mean temperature in the preceding month had better explanatory power than the current monthly temperature. CONCLUSIONS: This study provides a better understanding of the characteristics of HBoV1 infection in children in subtropical regions. Data from this study provide useful information for the future control and prevention of HBoV1 infections.

[Association of ORMDL3 single nucleotide polymorphisms with lysophosphatidylcholine and apolipoprotein B levels in children with asthma].

OBJECTIVE: To study the association of ORMDL3 single nucleotide polymorphisms (SNP) with lysophosphatidylcholine (LysoPC) and apolipoprotein B (apoB) levels. METHODS: A total of 300 children diagnosed with bronchial asthma between January 2010 and December 2012 were selected for the asthma group, and 298 children diagnosed with upper respiratory tract infection in the same period were selected for the control group. Serum LysoPC and apoB levels were measured using enzyme-linked immunosorbent assay. Genotype analysis was performed using the TaqMan probe. RESULTS: LysoPC and apoB levels were significantly higher in the asthma group than in the control group (P<0.01). Among children with various genotypes of ORMDL3 gene at locus rs12603332, the asthma group had significantly higher LysoPC and apoB levels than the control group (P<0.01). Among the children with asthma, those with CC genotype had significantly higher LysoPC and apoB levels than those with CT and TT genotypes (P<0.01). CONCLUSIONS: LysoPC and apoB may intervene in the pathological process of asthma. Pro-inflammatory gene ORMDL3 SNP rs12603332 may be associated with high LysoPC and apoB levels, which leads to the occurrence of childhood asthma.

Allergy-related evidences in relation to serum IgE: data from the China state key laboratory of respiratory disease, 2008-2013.

OBJECTIVE: To investigate the serum total IgE (tIgE) and specific IgE (sIgE) to common allergens among allergic patients in Guangzhou, China. METHODS: 7 085 patients were examined for tIgE and sIgE to 15 allergens, based on the protocols of reversed enzyme allergosorbent test and the sandwich enzyme-linked immunosorbent assay. RESULTS: 3 758 (53.04%) patients tested positive for tIgE, and 4 640 (65.49%) for sIgE. Der pteronyssinus, Der farinae, eggs, and cow's milk were the most common allergens leading to higher positive rates of sIgE responses. Several peaks of sensitization were: Der pteronyssinus, Der farinae, and Blomia tropicalis at age 10-12; cow's milk at age below 3; eggs at age 4-6. The mean level and positive rate of tIgE tended to increase in subjects sensitized to more allergens. Sensitization to Der pteronyssinus (OR, 1.6; P<0.05), Der farinae (OR, 1.5; P<0.05), Blomia tropicalis (OR, 1.4; P<0.05), Blattella germanica (OR, 1.5; P<0.05), cow's milk (OR, 1.3; P<0.05), and soy beans (OR, 2.0; P<0.05) were independently correlated with allergy-related conditions in preliminary diagnosis. CONCLUSION: The major allergens in Guangzhou include Der pteronyssinus, Der farinae, cow's milk, and eggs. Sensitization to these allergens appears to be predictors of allergy-related disorder.

Automated lepidopteran pest developmental stages classification via transfer learning framework.

The maize crop is highly susceptible to damage caused by its primary pests, which poses considerable challenges in manually identifying and controlling them at various larval developmental stages. To mitigate this issue, we propose an automated classification system aimed at identifying the different larval developmental stages of 23 instars of 4 major lepidopteran pests: the Asian corn borer, Ostrinia furnacalis (Guenée; Lepidoptera: Crambidae), the fall armyworm, Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae), the oriental armyworm, Mythimna separata (Walker; Lepidoptera: Noctuidae), and the tobacco cutworm, Spodoptera litura (Fabricius; Lepidoptera: Noctuidae). Employing 5 distinct Convolutional Neural Network architectures-Convnext, Densenet121, Efficientnetv2, Mobilenet, and Resnet-we aimed to automate the process of identifying these larval developmental stages. Each model underwent fine-tuning using 2 different optimizers: stochastic gradient descent with momentum and adaptive moment estimation (Adam). Among the array of models tested, Densenet121, coupled with the Adam optimizer, exhibited the highest classification accuracy, achieving an impressive 96.65%. The configuration performed well in identifying the larval development stages of all 4 pests, with precision, recall, and F1 score evaluation indicators reaching 98.71%, 98.66%, and 98.66%, respectively. Notably, the model was ultimately tested in a natural field environment, demonstrating that Adam_Densenet121 model achieved an accuracy of 90% in identifying the 23 instars of the 4 pests. The application of transfer learning methodology showcased its effectiveness in automating the identification of larval developmental stages, underscoring promising implications for precision-integrated pest management strategies in agriculture.

Epidemiology and clinical presentation of the four human parainfluenza virus types.

BACKGROUND: Human parainfluenza viruses (HPIVs) are important causes of upper respiratory tract illness (URTI) and lower respiratory tract illness (LRTI). To analyse epidemiologic and clinical characteristics of the four types of human parainfluenza viruses (HPIVs), patients with acute respiratory tract illness (ARTI) were studied in Guangzhou, southern China. METHODS: Throat swabs (n=4755) were collected and tested from children and adults with ARTI over a 26-month period, and 4447 of 4755 (93.5%) patients' clinical presentations were recorded for further analysis. RESULTS: Of 4755 patients tested, 178 (3.7%) were positive for HPIV. Ninety-nine (2.1%) samples were positive for HPIV-3, 58 (1.2%) for HPIV-1, 19 (0.4%) for HPIV-2 and 8 (0.2%) for HPIV-4. 160/178 (88.9%) HPIV-positive samples were from paediatric patients younger than 5 years old, but no infant under one month of age was HPIV positive. Seasonal peaks of HPIV-3 and HPIV-1 occurred as autumn turned to winter and summer turned to autumn. HPIV-2 and HPIV-4 were detected less frequently, and their frequency of isolation increased when the frequency of HPIV-3 and HPIV-1 declined. HPIV infection led to a wide spectrum of symptoms, and more "hoarseness" (p=0.015), "abnormal pulmonary breathing sound" (p<0.001), "dyspnoea" (p<0.001), "pneumonia" (p=0.01), and "diarrhoea" (p<0.001) presented in HPIV-positive patients than HPIV-negative patients. 10/10 (100%) HPIV-positive adult patients (≥14 years old) presented with systemic influenza-like symptoms, while 90/164 (54.9%) HPIV-positive paediatric patients (<14 years old) presented with these symptoms (p=0.005). The only significant difference in clinical presentation between HPIV types was "Expectoration" (p<0.001). Co-infections were common, with 33.3%-63.2% of samples positive for the four HPIV types also testing positive for other respiratory pathogens. However, no significant differences were seen in clinical presentation between patients solely infected with HPIV and patients co-infected with HPIV and other respiratory pathogens. CONCLUSIONS: HPIV infection led to a wide spectrum of symptoms, and similar clinical manifestations were found in the patients with four different types of HPIVs. The study suggested pathogenic activity of HPIV in gastrointestinal illness. The clinical presentation of HPIV infection may differ by patient age.

[The efficacy of nebulized budesonide in acute moderate to severe exacerbations of asthma in children].

OBJECTIVE: To evaluate the effect of nebulized budesonide (BUD) in acute moderate to severe exacerbations of asthma in children. METHODS: Forty children, 5 to 15 years of age, with acute moderate to severe attacks of asthma, were randomized into BUD group and control group, receiving nebulized 0.5% salbutamol (150 µg/kg) + 0.025% ipratropium bromide (1 ml) + 0.05% budesonide (2 ml) or nebulized 0.5% salbutamol (150 µg/kg) + 0.025% ipratropium bromide (1 ml) + saline (2 ml) at half-hourly intervals for 3 doses respectively. Lung function, respiratory rate (RR), heart rate(HR), oxygen saturation (SaO2) and clinical score (CS) were monitored. RESULTS: The baseline characteristics of the 2 groups were similar. After 3 doses of nebulization, CS, RR, SaO2, FEV(1) and FEV(1)% were significantly improved in both groups (P < 0.05). The CS in BUD group was significantly lower than that in control group at the end of 2 h after the third dose of nebulization 0 (0) vs 0 (1), Z = 2.522, P = 0.012. There were no significant differences in RR, HR and SaO2 between 2 groups (P > 0.05). The improvement of FEV(1)% in the first hour and the second hour after 3 doses of nebulization was 8.0 (6.8)% and 5.5 (6.5)% in BUD group, and 6.0 (8.5)% and 1.0 (6.5)% in control group, the improvement in BUD group being significantly greater than that in control group (Z = 2.270 and 2.686, P = 0.023 and 0.007 respectively). The improvement of FEV(1) in the second hour after 3 doses of nebulization was significantly greater in BUD group than in control group 0.07 (0.12) L vs 0.01 (0.10) L, Z = 2.455, P = 0.014. The full recovery rate in BUD group at the end of 2 h after completion of nebulization was significantly higher than that in control group (17/20, 85.0% vs 9/18, 50.0%, χ(2) = 5.371, P = 0.024). The proportion of patients who needed to use oral corticosteroids was significantly lower in BUD group than in control group (3/20, 15.0% vs 8/18, 44.4%, χ(2) = 3.993, P = 0.046). The hospitalization rate was 5% (1/20) in BUD group, and 17% (3/18) in control group, but the difference was not statistically significant (P > 0.05). CONCLUSION: Nebulized BUD in high dose and at short intervals combined with rapid-acting bronchodilators has an additional bronchodilator response, associated with more rapid and better improvement in clinical symptoms and lung function, indicating that it is preferred in the early management of acute moderate to severe exacerbation of asthma in children.

Detection of human bocavirus from children and adults with acute respiratory tract illness in Guangzhou, southern China.

BACKGROUND: Human bocavirus (HBoV) is a newly discovered parvovirus associated with acute respiratory tract illness (ARTI) and gastrointestinal illness. Our study is the first to analyze the characteristics of HBoV-positive samples from ARTI patients with a wide age distribution from Guangzhou, southern China. METHODS: Throat swabs (n=2811) were collected and analyzed from children and adults with ARTI over a 13-month period. The HBoV complete genome from a 60 year-old female patient isolate was also determined. RESULTS: HBoV DNA was detected in 65/2811 (2.3%) samples, of which 61/1797 were from children (<18 years old) and 4/1014 from adults (≥18 years old). Seasonal peaks of 4.8% and 7.7% were detected in May and June, respectively. 28 of 65 (43.1%) HBoV-positive samples were co-detected with 11/16 other potential pathogens. Mycoplasma pneumoniae had the highest frequency of 16.9% (11/65). Upper and lower respiratory tract illness were common symptoms, with 19/65 (29.2%) patients diagnosed with pneumonia by chest radiography. All four adult patients had systemic influenza-like symptoms. Phylogenetic analysis of the complete genome revealed a close relationship with other HBoVs, and a more distant relationship with HBoV2 and HBoV3. CONCLUSIONS: HBoV was detected from children and adults with ARTI from Guangzhou, southern China. Elderly people were also susceptive to HBoV. A single lineage of HBoV was detected among a wide age distribution of patients with ARTI.

[The level and clinical significance of Toll-like receptor 4 in children with severe sepsis].

OBJECTIVE: To study the clinical significance of Toll-like receptor 4 (TLR4) in children with severe sepsis. METHODS: A prospective control study was performed. All cases were enrolled from pediatric department of the First Affiliated Hospital of Guangzhou Medical College, and they were divided into severe sepsis group (14 patients) who were diagnosed to have severe sepsis or septic shock in intensive care unit (ICU), pneumonia group (10 cases) with diagnosis of bronchial pneumonia, and healthy control group (10 healthy children). Venous blood samples of 2 ml were collected at admission, the level of TLR4 was detected by flow cytometry .At the same time, the changes in serum interleukin (IL-6, IL-10 ) and tumor necrosis factor-α (TNF-α) levels were determined by enzyme linked immunoadsorbent assay (ELISA). RESULTS: In severe sepsis group, the contents of TLR4 [(71.56±15.32)%], IL-6 [(1.98±1.55) ng/L], IL-10 [(88.20±61.23) ng/L] and TNF-α [(104.08±85.36) ng/L] were significantly higher than those in pneumonia group [(50.07±26.36)%, (0.93±0.16) ng/L, (41.42±7.02) ng/L, (48.96±6.40) ng/L] and healthy control group [(39.43±17.43)%, (0.94±0.43) ng/L,(43.73±22.68) ng/L, ( 49.94± 18.47) ng/L, all P<0.05). But there was no significant difference in the contents of TLR4, IL-6, IL-10 and TNF-α between pneumonia group and healthy control group (all P>0.05). CONCLUSION: This study suggests that TLR4 might be critically involved in the development of sepsis, and changes in TLR4 expression are parallel with levels of proinflammatory cytokines, including IL-6, TNF-α, and IL-10. The combination of TLR4 and proinflammatory cytokines would serve as the predictive parameters in early diagnosis and severity evaluation of sepsis in children.

An analysis of 20 clinical cases of refractory mycoplasma pneumonia in children.

BACKGROUND: Refractory mycoplasma pneumonia (RMPP) is one of the important pathogens of community-acquired pneumonia (CAP) in children. Its treatment is difficult. The aims of this study were to analyze the clinical manifestations, diagnosis, and treatment of 20 cases of RMPP in children in order to provide a reference for the diagnosis and treatment of RMPP. METHODS: The clinical data of 20 patients with RMPP admitted to the Pediatrics Department of the First Affiliated Hospital of Guangzhou Medical University in the recent three years were retrospectively analyzed. The clinical data of 36 patients with common mycoplasma pneumonia in the same period were compared. The clinical manifestations, laboratory examinations, and imaging characteristics of RMPP were discussed. Intrapulmonary and extrapulmonary complications and treatment were also analyzed in order to provide assistance in the diagnosis and treatment of RMPP. RESULTS: There were significant differences between the refractory group and the general group in terms of heat duration, hospitalization time, hypoxemia, lung rales, CRP, ESR, PCT, LDH, ALT, PLT, WBC, D dimer and other laboratory examinations, intrapulmonary and extrapulmonary complications, and treatment (all P<0.05). There was no significant difference in the age, sex, and wheezing between the two groups (P>0.05). CONCLUSIONS: Long duration of fever, tachycardia, and lung rale protrusion may be the clinical characteristics of RMPP. Unilateral pulmonary shadow and atelectasis should be paid more attention, which may be a high-risk factor for the development of RMPP. The inflammation index of RMPP cases increased and there were many complications inside and outside the patients' lungs. It was necessary to give enough macrolides to fight the infection by using Glucocorticoid and Intravenous immunoglobulin reasonably while liver, heart, and fiberoptic bronchoscopy was completed to improve the effectiveness of the diagnosis and treatment.

Effects of Intranasal Cellulose Powder on Asthma Control in Children With Mild-to-Moderate Perennial Allergic Rhinitis: A Randomized, Placebo-Controlled Trial.

BACKGROUND: Perennial allergic rhinitis (PAR) often coexists in asthmatic patients. Intranasal cellulose powder (ICP) was reportedly effective in ameliorating PAR. OBJECTIVE: We investigated whether ICP is equally effective compared with intranasal corticosteroids in improving asthma control as well as nasal symptoms among children with PAR and allergic asthma (AA). METHODS: Between July 2015 and September 2016, we did a single-center, randomized, placebo-controlled trial. Asthmatic children aged 6 to 11 years with mild-to-moderate PAR were randomly assigned to formoterol/budesonide inhalation (4·5 µg/80 µg, twice daily) plus intranasal budesonide 64 µg twice daily (group A), ICP 250 µg thrice daily (group B), or intranasal placebo 250 µg thrice daily (group C) for 8 weeks. The primary outcome was change in asthma control test for children (C-ACT) score from baseline to week 8 posttreatment. Changes in spirometry, peak expiratory flow (PEF), fractional exhaled nitric oxide (FeNO), and visual analog scale (VAS) for nasal and ocular symptoms were detected as secondary outcomes. RESULTS: We included 121 patients (38 in group A, 41 in group B, and 42 in group C) in full-analysis set. C-ACT score was markedly higher at week 8 compared with baseline (mean difference: 5.11, 6.05, and 4.85 points in groups A, B, and C, respectively; P < .05). There were interactions between baseline and treatment in C-ACT scores ( P < .05). Group B demonstrated greater improvement in C-ACT score than group C among children with baseline C-ACT score of 6 to 18. 95% confidence intervals of group A at baseline overlapped with those of groups B and C. The treatment achieved reduced VAS symptoms in groups A and B but not in group C. Incidence of adverse events was comparable. No serious adverse event was reported. CONCLUSIONS: ICP could be recommended for children with PAR and AA who have poorer asthma control.

Surveillance for seasonal influenza virus prevalence in hospitalized children with lower respiratory tract infection in Guangzhou, China during the post-pandemic era.

BACKGROUND: Influenza A(H1N1)pdm09, A(H3N2) and B viruses have co-circulated in the human population since the swine-origin human H1N1 pandemic in 2009. While infections of these subtypes generally cause mild illnesses, lower respiratory tract infection (LRTI) occurs in a portion of children and required hospitalization. The aim of our study was to estimate the prevalence of these three subtypes and compare the clinical manifestations in hospitalized children with LRTI in Guangzhou, China during the post-pandemic period. METHODS: Children hospitalized with LRTI from January 2010 to December 2012 were tested for influenza A/B virus infection from their throat swab specimens using real-time PCR and the clinical features of the positive cases were analyzed. RESULTS: Of 3637 hospitalized children, 216 (5.9%) were identified as influenza A or B positive. Infection of influenza virus peaked around March in Guangzhou each year from 2010 to 2012, and there were distinct epidemics of each subtype. Influenza A(H3N2) infection was more frequently detected than A(H1N1)pdm09 and B, overall. The mean age of children with influenza A virus (H1N1/H3N2) infection was younger than those with influenza B (34.4 months/32.5 months versus 45 months old; p<0.005). Co-infections of influenza A/ B with mycoplasma pneumoniae were found in 44/216 (20.3%) children. CONCLUSIONS: This study contributes the understanding to the prevalence of seasonal influenza viruses in hospitalized children with LRTI in Guangzhou, China during the post pandemic period. High rate of mycoplasma pneumoniae co-infection with influenza viruses might contribute to severe disease in the hospitalized children.

Epidemiology of acute respiratory infections in children in Guangzhou: a three-year study.

Acute Respiratory Infections (ARI) are some of the most common human diseases worldwide. However, they have a complex and diverse etiology, and the characteristics of the pathogens involved in respiratory infections in developing countries are not well understood. In this work, we analyzed the characteristics of 17 common respiratory pathogens in children (≤14 years old) with ARI in Guangzhou, southern China over a 3-year period using real-time polymerase chain reaction. Pathogens were identified in 2361/4242 (55.7%) patients, and the positivity rate varied seasonally. Ten of the 17 pathogens investigated showed positivity rates of more than 5%. The most frequently detected pathogens were respiratory syncytial virus (768/2361, 32.5%), influenza A virus (428/2361, 18.1%), enterovirus (138/2361, 13.3%), Mycoplasma pneumoniae (267/2361, 11.3%) and adenovirus (213/2361, 9.0%). Co-pathogens were common and found in 503 of 2361 (21.3%) positive samples. When ranked according to frequency of occurrence, the pattern of co-pathogens was similar to that of the primary pathogens, with the exception of human bocavirus, human coronavirus and human metapneumovirus. Significant differences were found in age prevalence in 10 of the 17 pathogens (p≤0.009): four basic patterns were observed, A: detection rates increased with age, B: detection rates declined with age, C: the detection rate showed distinct peaks or D: numbers of patients were too low to detect a trend or showed no significant difference among age groups (p>0.05). These data will be useful for planning vaccine research and control strategies and for studies predicting pathogen prevalence.

Prevalence of allergen sensitization among patients with allergic diseases in Guangzhou, Southern China: a four-year observational study.

BACKGROUND: The distribution of allergens may vary with different geographic areas, suggesting the importance of local epidemiological data to support evidence-based prevention and management of allergic diseases. We investigated the distribution of common allergens in allergic patients in Guangzhou, southern China. METHODS: 7,047 patients with allergic symptoms were examined for serum sIgE to 15 common allergens in this region, based on the protocol of reversed enzyme allergosorbent test. RESULTS: 4,869 (69.09%) of the subjects tested positive for sIgE to at least one of the 15 common allergens. There was no statistical difference in the overall rate of positive sIgE detection between males (3128/4523, 69.16%) and females (1741/2524, 68.98%). Der pteronyssinus and Der farinae were the most common aeroallergens, while eggs and cow's milk the most common food allergens, responsible for higher positive rates of sIgE responses. A good correlation in positive sIgE response was found between Der pteronyssinus and Der farinae. By age-group analysis, we noted several peaks of sensitization to certain allergens: Der pteronyssinus, Der farinae, and Blomiatropicalis at age between 9 and 12; Blattellagermanica and mosquito at age between 15 and 18, cow's milk before age 3; eggs and flour at age between 3 and 6; crabs and shrimps at age between 12 and 15. Along with older age, there was an ascending tendency in the overall positive rate of sIgE response to house dust mites among subjects who tested positive for sIgE to eggs or cow's milk. CONCLUSIONS: Der pteronyssinus, Der farinae, cow's milk, and eggs are major allergens in Guangzhou. Sensitization to eggs and cow's milk is more common at younger age, and then gives place to the increasing prevalence of sensitization to Der pteronyssinus and Der farinae at older age. Such a sequence of events may be a result of allergy march. Knowledge on the prevalence of allergen sensitization in different age groups would help early diagnosis and intervention of allergic diseases in this large geographical region.

Reference values of induced sputum cytology in healthy children in guangzhou, southern china.

OBJECTIVE: To establish normal reference values of induced sputum cytology in healthy children in southern China. METHODS: During a period from January 2010 to December 2011, a total of 580 healthy children (5-16 years of age) were approached. A total of 266 children (137 boys and 129 girls) participated in the study. Sputum induction was carried out by using 5% hypertonic saline. Cell types in the sputum were examined by using routine methods. RESULTS: Sputum induction was completed in 175 of the 266 subjects (65.79%), but 16 sputum samples were disqualified. The overall success rate was 59.77% (159/266). Macrophages and neutrophils were the predominant cell types: macrophages: median, 76.14%; interquartile range (IQR), 32.68%; and 2.5% to 97.5% percentile, 1.00% to 94.50%; neutrophils: median, 20.67%; IQR, 33.0%; and 2.5% to 97.5% percentile, 4.00% to 92.75%; eosinophils: median, 0.39%; IQR, 1.93%; and 2.5% to 97.5% percentile, 0.00% to 6.50%; and lymphocytes: median, 1.22%; IQR, 2.04%; and 2.5% to 97.5% percentile, 0.00% to 5.00%. The cell types did not differ among different age, gender, and passive smoking groups. Adverse events occurred in 4.4% (7/159) of the participants who completed the procedures but required no specific treatment to dissipate. Peak expiratory flow did not differ between those who completed the procedures compared with those who did not, suggesting that the procedure is safe and feasible in children. CONCLUSIONS: The current study represents the first attempt to develop normal reference values of induced sputum cytology in Chinese children, and could be used as a control for future studies.

[Clinical characteristics of bronchiolitis obliterans in pediatric patients].

OBJECTIVE: To analyze the clinical characteristics, image findings, laboratory examination, the therapeutic methods and clinical outcomes of bronchiolitis obliterans (BO) in pediatric patients. METHOD: Twenty-six pediatric patients with BO were reported. All data were collected from cases who were hospitalized in the Department of Pediatrics, First Affiliated Hospital of Guangzhou Medical College from June 1(st), 2009 to the April 30(th), 2011, and infectious agents, clinical manifestations, risk factors, changes in imageology, laboratory examination, therapeutic methods and treatment responses were analyzed. RESULT: The ranges of age at onset was 4.5 months-8 years in 26 cases (18 boys and 8 girls). The course of disease was (6.2 ± 3.5) months. The period of followed-up ranged from 2 to 24 months. The common clinical characteristics were persistent wheezing of different severity (26 cases, 100%), cough (24 cases, 92%), intolerance to exercise (22 cases, 85%), short of breath (21 cases, 81%), retraction (20 cases, 77%), wheezy phlegm (16 cases, 62%), keeping with crackles (10 cases, 38%), cyanosis around the mouth (3 cases, 12%) and no clubbed fingers (toes). In 18 cases the etiology was detected, mycoplasma (11 cases, 42%), respiratory syncytial virus (4 cases, 15%), parainfluenza virus (2 cases, 8%), influenza virus A (2 cases, 8%) and influenza virus B (2 cases, 8%), human bocavirus (HBoV) (1 case, 4%). There were 8 cases (31%) with combined infection. Chest X-ray in 10 cases indicated changes suggestive of bronchopneumonia (38%), in only 1 case there was an image of interstitial pneumonia disease (4%). All the patients were diagnosed by high-resolution computerized tomography (HRCT). All cases were demonstrated to have air retention, poor blood perfusion in lung, just like "Westemark sign" with HRCT. In 19 cases antineutrophil cytoplasmic antibody (ANCA) was determined and 10 patients (53%) were positive for P-ANCA, and 8 cases (42%) were positive for C-ANCA. All patients received oral corticosteroid and low doses azithromycin. In 13 cases (50%) the treatment effectively reduced the severity of disease and the frequency of cough and wheezing. The average number of days for symptom improvement was (7.1 ± 4.8) days. CONCLUSION: Respiratory infection plays an important role in BO in children. The chronic and persistent wheezing, cough, intolerance to exercises, short breath, retraction were the main clinical manifestations. But these symptoms are non-specific. Chest X-ray can not provide enough information for diagnosis. Classical "Westemark sign" with HRCT is an important sign. ANCA with a high positive rate (approximately 50%) suppose immuno-lesion in BO. Oral corticosteroid and methotrexate may relieve clinical symptoms.