[Comparison of clinical features and co-infection between pneumonia caused by influenza virus A and pneumonia caused by influenza virus B among children].

OBJECTIVE: To compare the clinical features and co-infection between pneumonia caused by influenza virus A (IVA) and pneumonia caused by influenza virus B (IVB) among children. METHODS: A total of 165 children with pneumonia caused by influenza virus (IV) were included in the study. These subjects were divided into IVA(n=71) and IVB pneumonia groups (n=94) according to the subtypes of IV. The IVA pneumonia group was further divided into simple infection (n=14) and co-infection subgroups (n=57), and the IVB pneumonia group was also further divided into simple infection (n=27) and co-infection subgroups (n=67). Co-infection rate and pathogen spectrum were analysed in children with IV pneumonia. RESULTS: The IVB pneumonia group had significantly increased mean age of onset and significantly prolonged mean duration of fever compared with the IVA pneumonia group (P<0.05). Co-infection rate among children with IV pneumonia was 75.2%, who were co-infected with bacteria (44.2%), Mycoplasma pneumoniae (MP, 21.8%) and other viruses (45.5%). Respiratory syncytial virus (RSV) was most common in children co-infected viruses (89% ). The rate of co-infection with RSV was significantly higher in the IVA pneumonia group than in the IVB pneumonia group. There were no significant differences in age, length of hospital stay, duration of fever, percentage of neutrophils, prealbumin, C-reactive protein, alanine aminotransferase, and creatine kinase-MB between the simple infection and co-infection subgroups of each group. CONCLUSIONS: Children with IVB pneumonia have prolonged duration of fever and increased age of onset compared with those with IVA pneumonia. Co-infection rate is high among children with IV pneumonia, who may be co-infected with bacteria, viruses and MP. Co-infection with RSV is more common in children with IVA pneumonia. It is difficult to identify the presense of co-infection using clinical indices.

[Monitoring of influenza virus B and clinical features of pediatric pneumonia caused by influenza virus B only].

OBJECTIVE: To investigate the epidemiological features of influenza virus B (IVB) in the winter and the clinical features of pediatric pneumonia caused by IVB only. METHODS: A retrospective study was performed on the clinical data of children with respiratory infection who received pathogen testing and therapy at Soochow University Affiliated Children's Hospital during the winters of 2008, 2009, 2010 and 2011. RESULTS: The positive rates of influenza viruses A and B in the winters of 2008, 2009, and 2010 were 0.89%, 5.49%, and 6.24% respectively; the positive rate of influenza viruses A and B in the winter of 2011 was 8.72%, significantly higher than those in 2008-2010. The positive rates of IVB in the winters of 2008, 2009, and 2010 were 0%, 0%, and 0.21% respectively; the positive rate of IVB in the winter of 2011 was 5.36%, which was significantly higher than in the years 2008 to 2010. Pneumonia caused by IVB was confirmed in 94 children during the winter of 2011, including 27 cases of pneumonia caused by IVB only. Most of children with pneumonia caused by IVB only were aged over 6 months. The common symptoms in the 27 children caused by IVB only were fever (85%), runny nose (89%), and cough (100%). Wheezing (26%) and dyspnea (7%) were also seen in some cases. Among the 27 children, 19% showed abnormal white blood cell count, 30% showed increased C-reactive protein, 70% showed decreased prealbumin, and none showed visible organ dysfunction. No specific imaging findings were seen in the children with pneumonia caused by IVB only. However, many abnormal humoral and cellular immunological parameters were found in the majority of these children. The average length of hospital stay was approximately one week, there were no critical patients and the prognosis was good. CONCLUSIONS: Influenza viruses were at a peak level in inpatient children in the winter of 2011. IVB infection rate was gradually increasing. In children with pneumonia caused by IVB only, there are few critical patients, the symptoms are nonspecific and the prognosis is good.

[Study on low density lipoprotein receptor of adult Schistosoma japonicum].

OBJECTIVE: To provide a theoretical basis for the study of vaccines against Schistosoma japonicum, the receptor for human LDL in the tegument of adult Schistosoma japonicum was investigated. METHODS: Proteins existed in adult Schistosoma japonicum membrane were extracted by Triton X-100 and purified through reverse-phase high performance liquid chromatography (HPLC), and the main protein peaks were then collected separately. 125I-LDL of human plasma as the ligand, through the radioautography and radioligand binding assay, the protein which can bind human serum 125I-LDL specifically was identified. The molecular weight and IEF were detected by SDS-PAGE. RESULTS: According to the radioautography and radioligand binding assay, a protein with retention time of 10.5 min was proved to be able to bind human serum 125I-LDL specifically. SDS-PAGE revealed that the molecular weight of the purified protein is 60-65 kDa, and its IEF is 6.7. CONCLUSION: LDL binding protein may exist on the surface of both male and female adult Schistosoma japonicum with the function of obtaining cholesterol from host circulating system.

Mortality and morbidity of acute hypoxemic respiratory failure and acute respiratory distress syndrome in infants and young children.

BACKGROUND: Acute hypoxemic respiratory failure (AHRF) often develops acute respiratory distress syndrome (ARDS), and its incidence and mortalities in critically ill pediatric patients in China were 2% and 40% respectively. This study aimed at prospectively investigating incidence, causes, mortality and its risk factors, and any relationship to initial tidal volume (V(T)) levels of mechanical ventilation, in children £5 years of age with AHRF and ARDS. METHODS: In 12 consecutive months in 23 pediatric intensive care units (PICU), AHRF and ARDS were identified in those requiring > 12 hour intratracheal mechanical ventilation and followed up for 90 days or until death or discharge. ARDS was diagnosed according to the American-European Consensus definitions. The mortality and ventilation free days (VFD) were measured as the primary outcome, and major complications, initial disease severity, and burden were measured as the secondary outcome. RESULTS: In 13 491 PICU admissions, there were 439 AHRF, of which 345 (78.6%) developed ARDS, resulting in incidences of 3.3% and 2.6%, and corresponding mortalities of 30.3% and 32.8% respectively along with 8.2 and 6.7 times of relative risk of death in those with pneumonia (62.9%) and sepsis (33.7%) as major underlying diseases respectively. No association was found in V(T) levels during the first 7 days with mortality, nor for V(T) at levels < 6, 6 - 8, 8 - 10, and > 10 ml/kg in the first 3 days with mortality or length of VFD. By binary Logistic regression analyses, higher pediatric risk of mortality score III, higher initial oxygenation index, and age < 1 year were associated with higher mortality or shorter VFD in AHRF. CONCLUSIONS: The incidence and mortalities of AHRF and ARDS in children £5 years were similar to or lower than the previously reported rates (in age up to 15 years), associated with initial disease severity and other confounders, but causal relationship for the initial V(T) levels as the independent factor to the major outcome was not found.

[Clinical characteristics of 14 critically ill children with 2009 influenza A (H1N1)].

OBJECTIVE: To summarize characteristics and outcomes of critically ill children with 2009 influenza A (H1N1). METHOD: A prospective observational study of 14 critically ill children with 2009 influenza A (H1N1) in pediatric intensive care unit (PICU) in Suzhou between Oct. 1(st) 2009 and Dec. 25(th) 2009. The primary outcome measures included frequency and duration of mechanical ventilation and duration of ICU stay. RESULT: Critical illness occurred in 14 patients with confirmed (n = 14), community-acquired 2009 influenza A virus (H1N1) infection. The mean (SD) age of the 14 patients with confirmed 2009 influenza A (H1N1) was (4.91 ± 4.14) years, 7 were female (50.0%). The median duration from symptom onset to hospital admission was (3.09 ± 1.30) days and from hospitalization to ICU admission was (0.95 ± 0.96) day. All the patients were severely hypoxemic [mean (SD) ratio of PaO2/FiO2 was (191.27 ± 80.58) mm Hg] at ICU admission. ARDS occurred in 11 cases (78.6%). Mechanical ventilation was applied for 10 patients (71.4%). The median duration of ventilation was (12.51 ± 10.03) days and ICU stay was (12.58 ± 10.65) days. The median length of time during which the real-time RT-PCR test results were positive was (17.27 ± 5.57) days; Comorbidities such as iron deficiency anemia, cerebral palsy and congenital heart disease were found in 8 cases (57.1%). The longer length of mechanical ventilation and ICU stay were found in cases with higher admission PRISM III Score and lower Pediatrics Critical Illness Score. CONCLUSION: Critical illness due to 2009 influenza A (H1N1) in Suzhou occurred rapidly after hospital admission and was associated with severe hypoxemia, ARDS, a condition that required prolonged mechanical ventilation. There were myocardial damages in critically ill children with severe 2009 influenza A (H1N1).

The epidemiology of acute respiratory distress syndrome in pediatric intensive care units in China.

OBJECTIVE: To assess the incidence of, predisposing factors for, and the rates and relative risks of mortality from acute respiratory distress syndrome (ARDS) in pediatric patients. DESIGN: A prospective study in 12 consecutive months from 2004 to 2005 in 25 pediatric intensive care units (PICUs). PATIENTS AND SETTING: ARDS was diagnosed according to the 1994 American-European Consensus Conference definitions, applied to all severely ill admissions between 1 month and 14 years of age. The PICUs were in major municipalities and provincial cities, and half were university affiliated. MEASUREMENTS AND RESULTS: From a total of 12,018 admissions, 7,269 were severely ill. One hundred and five (1.44%) patients developed ARDS and 64 (61.0%) died, which accounts for 13.2%, of the total ICU death (n = 485, 6.7%) or a nine times relative risk of dying. The median age at onset of ARDS was 24 months and 40% were less than 12 month old. Median time from PICU admission to the onset of ARDS was 16 h, and in 63% <24 h. Pneumonia (55.2%) and sepsis (22.9%) were the major predisposing factors for ARDS. These were respectively 14 and 5 times as high a death rate as those of the severely ill patients without ARDS. CONCLUSIONS: ARDS has a high mortality in these Chinese PICUs, especially in those with pneumonia and sepsis, and adequate management including lung protective ventilation strategy is required.