Pulmonary Nocardia infection in a child with idiopathic pulmonary hemosiderosis.

BACKGROUND: Idiopathic pulmonary hemosiderosis (IPH) encompasses a rare and agnogenic group of diffuse alveolar capillary hemorrhagic diseases. Corticosteroid treatment is the globally preferred therapeutic strategy for IPH; however, it can cause immunodeficiency. Nocardia infection often occurs in immunocompromised patients and primarily involves the pleura and lungs. Herein, we describe a case of pediatric pulmonary Nocardia infection after the corticosteroid treatment of IPH. CASE PRESENTATION: A 7-year-old girl presented with chief complaints of pale complexion persisting for 1 year and a cough for 20 days. Abundant hemosiderin-laden macrophages were detected in the gastric juice, which supported the diagnosis of IPH. Uninterrupted doses of corticosteroids were administered during the last hospitalization. After nearly 2 months of corticosteroids therapy, the patient began to cough and produce a purulent sputum. Next-generation sequencing of the bronchoalveolar lavage fluid revealed Nocardia abscessus (N. abscessus) DNA. Linezolid was administered with good response, and the patient was discharged after 18 days of hospitalization. Her symptoms and pulmonary lesions had recovered, and the IPH appeared to be well-controlled with low dose of corticosteroids in follow-up. CONCLUSIONS: Nocardia infection should be considered in the differential diagnoses for IPH patients receiving corticosteroid therapy, especially in patients with poor response to conventional empirical antibiotic therapy. Next-generation sequencing of bronchoalveolar lavage fluid may be used to quickly identify the Nocardia. Sulfonamides or linezolid are effective for pediatric pulmonary Nocardia infection.

In vitro activity and clinical efficacy of macrolides, cefoperazone-sulbactam and piperacillin/piperacillin-tazobactam against Bordetella pertussis and the clinical manifestations in pertussis patients due to these isolates: A single-centre study in Zhejiang Province, China.

BACKGROUND AND OBJECTIVE: Macrolides are the recommended antibiotics for treating pertussis and preventing transmission. The causative bacterium, Bordetella pertussis, has high macrolide resistance and has recently circulated in China. The objective of this study was to find effective alternative antibiotics for treatment by assessing the in vitro activity and clinical efficacy of antibiotics against Bordetella pertussis. METHODS: Bordetella pertussis was confirmed by agglutination with specific antisera and mass spectrometry. The MICs of antibiotics against isolates were determined using the Etest method. Treatment outcomes were clinically and microbiologically evaluated. RESULTS: A total of 126 pertussis patients were diagnosed based on culture, 69.8% of whom were aged ≤6 months and 72.1% were treated with previous macrolides. Leucocytosis and lymphocytosis were observed in 29.4% and 54.8% of all patients, respectively. Both MIC50 and MIC90 of erythromycin, azithromycin, and clindamycin were >256mg/L, and 75.4% were highly macrolide resistant. The MIC90 of trimethoprim-sulfamethoxazole, ampicillin, ampicillin-sulbactam, cefuroxime, ceftriaxone and cefoperazone-sulbactam were 0.38mg/L, 0.25mg/L, 0.19mg/L, 12mg/L, 0.19mg/L and 0.047mg/L, respectively. The MICs of piperacillin in all of the isolations were <0.016mg/L. Of the patients treated with single cefoperazone-sulbactam or piperacillin-tazobactam, 30 of 32 (93.8%) had significantly improved clinical symptoms and 24 of 25 (96%) had negative culture results after 2 weeks of therapy. CONCLUSION: Macrolide resistance in Bordetella pertussis is a serious problem in Zhejiang Province, China. Piperacillin/piperacillin-tazobactam and cefoperazone-sulbactam have potent antibacterial activity in vitro and in vivo, and may become the alternative choice for treating pertussis caused by macrolide-resistant isolates.

Epidemiological characteristics and meteorological factors of childhood Mycoplasma pneumoniae pneumonia in Hangzhou.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of pediatric respiratory infections and the relation of M. pneumoniae pneumonia (MPP) with meteorological factors remains obscure. This study aims to investigate the epidemiological characteristics of childhood MPP and observe if there is a relationship between epidemiological characteristics and meteorological factors in Hangzhou. METHODS: M. pneumoniae DNA in nasopharyngeal aspirates of hospitalized pneumonia children were detected by polymerase chain reaction from January 1, 2007 to December 31, 2009. The positive rates of MPP (MPP rates) in different years, seasons and ages were compared. The relationship between MPP rates and meteorological data, including mean air temperature (°C), mean relative humidity (%), monthly precipitation (mm) and raining days were analyzed. RESULTS: In 14 799 pneumonia cases found from 2007 to 2009, the MPP rate was 18.5%. Altogether 1610 boys (16.9%) and 1134 girls (21.4%) suffered from MPP with a significant difference between both genders (χ(2)=45.68, P<0.001). In children younger than 1 year, 1-2 years, 3-6 years, and older than 7 years, the MPP rates were 9.8%, 21.1%, 44.4% and 61.6%, respectively. The MPP rates were significantly higher in older children than in younger ones (trends test χ(2)=46.72, P<0.001). In a descending order, the MPP rates in summer, autumn, spring, and winter were 27.8%, 23.9%, 18.0% and 11.6%, respectively (χ(2)=372.75, P<0.001). The MPP rates in 2007 to 2009 were 12.9%, 19.3% and 23.6%, respectively (trends test χ(2)=13.72, P<0.001). Of the four meteorological factors, only monthly mean air temperature was included in the multiple linear regression model (P<0.001). CONCLUSIONS: This study showed that the MPP rate was higher in older children than in younger ones. Girls had a higher positive rate of MPP than boys. In Hangzhou, MPP was more prevalent in summer and autumn. Air temperature was the only meteorological factor affecting the prevalence of MPP.