Detection of Mycoplasma pneumoniae by loop-mediated isothermal amplification (LAMP) assay and serology in pediatric community-acquired pneumonia.

Rapid diagnosis of Mycoplasma pneumoniae pneumonia is required for treatment with effective antimicrobial agents without delay; however, this capacity has not yet been established in clinical practice. Recently, a novel nucleic acid amplification method termed loop-mediated isothermal amplification (LAMP) has been used to rapidly diagnose various infectious diseases. In this study, we prospectively evaluated the efficacy of the LAMP assay to rapidly diagnose M. pneumoniae pneumonia in clinical practice. Three hundred sixty-eight children (median age, 3.8 years; range, 0.1-14.3 years) admitted to our hospital between April 2009 and March 2010 for community-acquired pneumonia were enrolled in this study. We obtained throat swabs on admission to detect M. pneumoniae DNA and paired serum samples on admission and at discharge to assay M. pneumoniae antibody titers. M. pneumoniae pneumonia was diagnosed by either a positive LAMP assay or a fourfold or greater increase in antibody titer. Overall, 46 children (12.5% of the patients with pneumonia) were diagnosed with M. pneumoniae pneumonia; of these, 27 (58.7%) were aged less than 6 years. Of the aforementioned 46 children, 38 (82.6%) and 37 (80.4%) were identified by LAMP and serology, respectively. When the results of serology were taken as the standard, the sensitivity and specificity and positive and negative predictive values of the LAMP assay were 78.4%, 97.3%, 76.3%, and 97.6%, respectively. We concluded the LAMP assay may be useful for rapid diagnosis of M. pneumoniae pneumonia.

Relationship between lower respiratory tract infections caused by respiratory syncytial virus and subsequent development of asthma in Japanese children.

Several studies in Western countries have found that lower respiratory tract infections (LRTIs) caused by the respiratory syncytial virus (RSV) in infancy may subsequently trigger the development of asthma. In this study, we enrolled 262 infants under the age of 3 who had been admitted to our hospital with LRTI between September 2002 and August 2003. RSV infection was diagnosed in these patients using an RSV rapid diagnostic kit and by measuring antibody titers in paired serum samples. In March 2009, we sent questionnaires on post-discharge allergic conditions to the families of the 249 patients, excluding 13 who had a prior history of asthma. A total of 133 responses were received (response rate, 53.4%); RSV was detected in 36 patients of the RSV group and 97 patients of the non-RSV group. Wheezing was experienced post-discharge by 10 patients in the RSV group (27.8%) and 32 in the non-RSV group (33.0%) (P = 0.57). Four patients in the RSV group (11.1%) and 6 in the non-RSV group (6.2%) (P = 0.34) were treated for asthma. This study revealed that RSV LRTI in infancy does not predispose children to subsequent development of asthma at the age of 7 years and 7 months. We believe that this is the first Japanese survey that has examined the relationship between RSV LRTI in infancy and the subsequent development of asthma.

Community-acquired Acinetobacter baumannii meningitis in a previously healthy 14-month-old boy.

We report a previously healthy 14-month-old boy who developed community-acquired Acinetobacter baumannii meningitis. He had no history of immunodeficiency, and was brought to Konan Kosei Hospital with a high fever and vomiting. His consciousness was clear, but neck stiffness was noted. Examination of the cerebrospinal fluid (CSF) revealed a cell count of 10 112/microl; protein, 216 mg/dl; and glucose, 9 mg/dl. A CSF test kit for bacterial capsular antigens (Pastorex Meningitis; Bio-Rad Laboratories) was positive for Haemophilus influenzae type b antigen. On day 3 of admission, the microorganism isolated by CSF culture was identified as A. baumannii. Therefore, his treatment was changed to meropenem hydrate from the initial therapy with panipenem/betamipron and ceftriaxone sodium hydrate. Because the CSF cell count remained elevated, meropenem hydrate was administered for a total of 19 days. The meningitis resolved with no sequelae.