OBJECTIVETo study the role of Mycoplasma pneumoniae (MP) load and antibody measurements in the diagnosis of MP pneumonia.

METHODSA total of 115 children with MP pneumonia and 400 healthy children were enrolled. The MP load and total antibody level were measured at different stages, and the MP load index (MPLI) was calculated.

RESULTSThe cut-off value of MPLI for MP infection was 6.12. MPLI and total antibody titer increased during the course of the disease, while MP-DNA decreased rapidly. Within the same time of blood collection, the group with a higher MP load had a significantly higher total antibody titer than the group with a lower MP load (P<0.05). Within 2 weeks of the course of the disease, the negative antibody group had a significantly higher MPLI than the positive antibody group (P<0.05).

CONCLUSIONSMPLI provides a standardized quantitative value of MP-DNA and plays an important role in the early diagnosis of MP infection.

Antibodies, Bacterial ; blood ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Early Diagnosis ; Female ; Humans ; Infant ; Male ; Pneumonia, Mycoplasma ; diagnosis ; microbiology

This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.
Aged ; Bacterial Infections/*diagnosis ; Calcitonin/*analysis/blood ; Diagnosis, Differential ; Female ; Humans ; Male ; Middle Aged ; Pleural Effusion/*diagnosis ; Pneumonia/*diagnosis ; Predictive Value of Tests ; Protein Precursors/*analysis/blood ; ROC Curve

OBJECTIVETo study the clinical value of the expression of neutrophil surface CD64 in the diagnosis of community acquired pneumonia in children.

METHODSNinety-eight children with community acquired pneumonia were recruited into the study and were classified into three groups according to pathogene: bacterial pneumonia (n=48), viral pneumonia (n=29) and Mycoplasmal pneumonia (n=21). Twenty healthy children were enrolled as controls. The bacterial infection group was subdivided into mild infection (n=36) and severe infection groups (n=12). The levels of peripheral blood neutrophil CD64 were measured using flow cytometry. Dynamic changes of C-reactive protein were also detected for each patient.

RESULTSThe CD64 index and CRP levels in the bacterial pneumonia group were significantly higher than in the other three groups (P<0.05). The CD64 index in the severe bacterial infection group was significantly higher than in the mild group (P<0.05). After antibiotic treatment, expression of CD64 in the severe bacterial infection group decreased significantly (P<0.05). The CD64 index was positively correlated with CRP value (r=0.545, P<0.01). ROC curve analysis showed that the threshold of CD64 and CRP was 2.8 and 8 mg/L respectively. Specificity of CD64 index (90%) was much higher than CRP (74%).

CONCLUSIONSThe determination of peripheral blood neutrophil CD64 contributes to the early diagnosis of pulmonary bacterial infection and the evaluation of anti-infection effect.

C-Reactive Protein ; analysis ; Child ; Child, Preschool ; Community-Acquired Infections ; blood ; diagnosis ; Female ; Humans ; Male ; Neutrophils ; chemistry ; Pneumonia, Bacterial ; blood ; diagnosis ; ROC Curve ; Receptors, IgG ; blood

BACKGROUND/AIMS: We investigated the utility of serum C-reactive protein (CRP) and procalcitonin (PCT) for differentiating pulmonary tuberculosis (TB) from bacterial community-acquired pneumonia (CAP) in South Korea, a country with an intermediate TB burden. METHODS: We conducted a prospective study, enrolling 87 participants with suspected CAP in a community-based referral hospital. A clinical assessment was performed before treatment, and serum CRP and PCT were measured. The test results were compared to the final diagnoses. RESULTS: Of the 87 patients, 57 had bacterial CAP and 30 had pulmonary TB. The median CRP concentration was 14.58 mg/dL (range, 0.30 to 36.61) in patients with bacterial CAP and 5.27 mg/dL (range, 0.24 to 13.22) in those with pulmonary TB (p<0.001). The median PCT level was 0.514 ng/mL (range, 0.01 to 27.75) with bacterial CAP and 0.029 ng/mL (range, 0.01 to 0.87) with pulmonary TB (p<0.001). No difference was detected in the discriminative values of CRP and PCT (p=0.733). CONCLUSIONS: The concentrations of CRP and PCT differed significantly in patients with pulmonary TB and bacterial CAP. The high sensitivity and negative predictive value for differentiating pulmonary TB from bacterial CAP suggest a supplementary role of CRP and PCT in the diagnostic exclusion of pulmonary TB from bacterial CAP in areas with an intermediate prevalence of pulmonary TB.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; C-Reactive Protein/*analysis ; Calcitonin/*blood ; Community-Acquired Infections/blood/*diagnosis ; Diagnosis, Differential ; Female ; Humans ; Male ; Middle Aged ; Pneumonia, Bacterial/blood/*diagnosis ; Prospective Studies ; Protein Precursors/*blood ; Severity of Illness Index ; Tuberculosis, Pulmonary/blood/*diagnosis

INTRODUCTIONThe aim of this study was to externally validate the Cham score for the prediction of bacteraemia in emergency department (ED) patients with non-hospital acquired pneumonia.

MATERIALS AND METHODSThis is a secondary analysis of a dataset collected to identify independent predictors of bacteraemia in adult ED patients with non-hospital acquired pneumonia. The primary outcome of interest was the predictive performance (sensitivity, specificity, negative predictive value) of the score with respect to bacteraemia. Secondary outcomes included the performance of the score in patients not known to be intravenous (IV) drug users, the predictive performance of pneumonia severity index (PSI) class IV/V and PSI class IV/V or IV drug use as predictors and the clinical impact of score application on test ordering. Data analysis was by clinical performance and receiver operator characteristic curve analysis.

RESULTSA total of 200 patients were studied; 14 true positive blood cultures (7%, 95% CI, 4% to 11%). The Cham score had a sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 26.3% (95% CI, 20.3% to 33.4%) and negative predictive value (NPV) of 98% (87.0% to 99.9%). Area under the receiver operating characteristic (ROC) curve was 0.71 (95% CI, 0.56 to 0.86). Using PSI class IV/V or known IV drug use as predictors had sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 51.1% (95% CI, 43.7% to 58.4%) and NPV of 99% (95% CI, 93.5% to 99.9%).

CONCLUSIONIn retrospective external validation, the Cham score performed better than in derivation with acceptable sensitivity and NPV. Simplified criteria (PSI class IV/V or known IV drug use), as yet not validated, had similar sensitivity and NPV but would avoid blood cultures in a higher proportion of patients.

Aged ; Aged, 80 and over ; Bacteremia ; blood ; diagnosis ; Bacteriological Techniques ; utilization ; Emergency Service, Hospital ; Female ; Hematologic Tests ; utilization ; Humans ; Male ; Middle Aged ; Pneumonia, Bacterial ; blood ; microbiology ; Retrospective Studies

OBJECTIVETo explore etiology, clinical manifestation and immunological changes of infectious pneumonia of neonates in Chengdu area.

METHODSSerum specimens were collected from 111 infants with infectious pneumonia. Eight viral and mycoplasmal specific serum IgM antibodies were detected by enzyme linked immunosorbent assay (ELISA); C reactive protein (CRP), total IgG and its subclasses, IgA and IgM were determined by rate scattered nephelometry; T lymphocyte subpopulations were detected by biotin-streptavidin-peroxidase method, and clinical and other laboratory data were analyzed.

RESULTS(1) Etiological agents: specific serum IgM antibodies were positive in 40 of 111 cases (36.0%) with pneumonias. All the 30 control infants were negative for the specific serum IgM antibodies. Among 111 infants with infectious pneumonia, 20.7% had single viral or mycoplasmal infection, 40.5% had bacterial infection, 15.3% had viral and mycoplasmal infection with bacterial infection; 23.4% had infection with unknown agents. (2) The most common clinical manifestations were tachypnea and cyanosis. The next were cough, milk choking, rales, retractions of the supraclavicular, intercostal and subcostal areas. Roentgenographic examination commonly revealed vague opacities, increased density and patchy infiltration. (3) Immune status: (1) CD(3), CD(4) cell counts of infants with pneumonias were lower than those of the controls while their serum IgA, IgM concentrations were higher than those of the control. (2) The CD(3) and CD(4) cell counts of the group with bacterial infection were lower than those of the control group. (3) The serum IgA concentration of the group with viral and mycoplasmal infection was higher than those of the control group and the group with unknown infection. (4) The serum IgM concentration of the group with bacterial infection was higher than those of the control group. (5) There were no significant differences in CD(8) cell counts, CD(4)/CD(8), concentration of serum IgG and IgG(1 - 4) between pneumonia group and the control group, and among various infectious groups and the control.

CONCLUSIONPathogens of neonatal infectious pneumonia in Chengdu area included single viral or mycoplasmic infection or bacterial infection, viral and mycoplasmal infection with bacterial infection, and unknown infection. Immunological changes of newborn infants suffered from infectious pneumonia included declined CD(3) and CD(4) cell counts, particularly in bacterial infection.

Antibodies, Bacterial ; blood ; Antibodies, Viral ; blood ; Bacterial Infections ; complications ; C-Reactive Protein ; analysis ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin M ; blood ; Infant, Newborn ; Male ; Pneumonia ; diagnosis ; etiology ; immunology ; T-Lymphocyte Subsets ; immunology ; metabolism ; Virus Diseases ; complications

PURPOSE: This study was performed to find the clinical significance in protein C as a differential marker in the beginning stage of infection and prognosis factor in severe infection among pediatric patients who were admitted due to fever. METHODS: A total of 40 pediatric patients who had temperatures higher than 37.5degrees C on admission at the Department of Pediatrics, Chungnam National University between December, 2002 and August, 2003 were enrolled. Total white blood cell count(WBC), erythrocyte sedimentation rate(ESR), C-reactive protein(CRP) and protein C were performed for those patients on admission. Clinical progress, diagnosis and prognosis were reviewed for these patients. The 40 patients were divided into two groups based on the diagnosis of bacterial and nonbacterial infections. RESULTS: Twenty patients(50%) were suspected of bacterial infections that showed positive results in blood, sputum, urine, and spinal cord fluid. There were eight cases with bacterial pneumonia, five with urinary tract infection, four with bacterial meningitis, two with cellulitis, and one with typhoid fever. The remaining 20 patients were diagnosed with nonbacterial infections because they had negative results in blood cultures. ESR and CRP were increased beyond normal range in both groups. However, protein C was significantly decreased in the bacterial infection group and yet normal range in the nonbacterial infection group(P<0.05). CONCLUSION: Protein C can be used as a differential marker in order to distinguish between bacterial and nonbacterial infections. In addition, protein C can possibly be used as a prognostic factor that can predict severe infection.
Bacterial Infections* ; Blood Sedimentation ; Cellulitis ; Chungcheongnam-do ; Diagnosis ; Fever* ; Humans ; Leukocytes ; Meningitis, Bacterial ; Pediatrics ; Pneumonia, Bacterial ; Prognosis ; Protein C* ; Reference Values ; Spinal Cord ; Sputum ; Typhoid Fever ; Urinary Tract Infections

OBJECTIVETo investigate the clinical features of Mycoplasma pneumoniae pneumonia (MPP) among children of different ages.

METHODSRetrospective analysis was performed on the clinical data of 112 children who were hospitalized due to MMP between January 2010 and December 2011. The children were divided into 3 groups according to their ages: infants (<3 years; n=20), preschool-aged children (≥3 years; n=41), and school-aged children (6-15.2 years; n=51). The three groups were compared in terms of their clinical symptoms, pulmonary signs, chest X-ray findings and laboratory test results.

RESULTSThe infant group presented mainly with expectoration and wheezing, accompanied by low fever. They showed gastrointestinal symptoms as the most common extra-pulmonary manifestation and had evident pulmonary signs. The majority of the school-aged children group presented with high fever and a severe dry cough, and wheezing was seen in several of them. They showed rash as the most common extra-pulmonary manifestation and had slight pulmonary signs. The symptoms of the preschool-aged children group were in between. In the infant and preschool-aged children groups, most showed bronchopneumonia on chest X-ray, while in the school-aged children group, chest X-rays mostly showed segmental parenchymatous infiltration. The infant group had a higher lymphocyte count than the school-aged children group, while the school-aged children group had a higher serum C-reactive protein level than the infant group.

CONCLUSIONSThe clinical features of MPP are different among children of different ages, especially between infants and school-aged children.

Adolescent ; Age Factors ; Antibodies, Bacterial ; blood ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Pneumonia, Mycoplasma ; diagnosis ; diagnostic imaging ; drug therapy ; Radiography, Thoracic ; Retrospective Studies

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R² = 0.033; P = 0.018), followed by acute kidney injury (AKI; R² = 0.032; P = 0.011) and plasma MIP-1β level (R² = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.
Acute Kidney Injury/complications* ; Bacteria/classification* ; Chemokine CCL4/blood* ; Community-Acquired Infections/microbiology* ; Humans ; Lung ; Microbiota/genetics* ; Pneumonia, Bacterial/diagnosis* ; Prognosis ; RNA, Ribosomal, 16S/genetics*

BACKGROUNDMycoplasma pneumoniae (M. pneumoniae) is a frequent cause of respiratory tract infections. However, there is deficient knowledge about the clinical manifestations of M. pneumoniae infection. We described the clinical and laboratory findings of M. pneumoniae pneumonia in hospitalized children who were all diagnosed by a ≥ fourfold increase in antibody titer.

METHODSM. pneumoniae antibodies were routinely detected in children admitted with acute respiratory infection during a one-year period. The medical history was re-collected from children whose M. pneumoniae antibody titer increased ≥ fourfold at the bedside by a single person, and their frozen paired serum samples were measured again for the M. pneumoniae antibody titer.

RESULTSOf the 635 children whose sera were detected for the M. pneumoniae antibody, paired sera were obtained from 82 and 29.3% (24/82) showed a ≥ fourfold increase in antibody titer. There were 24 cases, nine boys and 15 girls, aged from two to 14 years, whose second serum samples were taken on day 9 at the earliest after symptom onset; the shortest interval was three days. All children presented with a high fever (≥ 38.5°C) and coughing. Twenty-one had no nasal obstruction or a runny nose, and five had mild headaches which all were associated with the high fever. The disease was comparatively severe if the peak temperature was > 39.5°C. All were diagnosed as having pneumonia through chest X-rays. Four had bilateral or multilobar involvement and their peak temperatures were all ≤ 39.5°C. None of the children had difficulty in breathing and all showed no signs of wheezing.

CONCLUSIONSThe second serum sample could be taken on day 9 at the earliest after symptom onset meant that paired sera could be used for the clinical diagnosis of M. pneumoniae pneumonia in children at the acute stage. M. pneumoniae is a lower respiratory tract pathogen. Extrapulmonary complications were rare and minor in our study. High peak temperature (> 39.5°C) is correlated with the severity of M. pneumoniae pneumonia in children.

Acute Disease ; Adolescent ; Antibodies, Bacterial ; blood ; Child ; Child, Hospitalized ; Child, Preschool ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; immunology ; Pneumonia, Mycoplasma ; complications ; diagnosis ; drug therapy ; Radiography, Thoracic