Antibiotics Susceptability of Streptococcus pneumoniae Isolated from Pharynx in Healthy Korean Children and Choice of Proper Empirical Oral Antibiotics Using Pharmacokinetics/Pharmacodynamics Model / 소아감염

PURPOSE: Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. METHODS: Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for beta-lactams and macrolide. For the beta-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. RESULTS: Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC 90% at MIC < or =1.0 microg/mL but PTA decreased to 52% at MIC 2 microg/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 microg/mL. Overall, oral amoxicillin 90 mg/kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. CONCLUSION: Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.

Epidemiologic Characteristics of Human Bocavirus-Associated Respiratory Infection in Children / 소아감염

PURPOSE: This study was performed to investigate the epidemiologic characteristics of human bocavirus (HBoV)-associated lower respiratory tract infections (LRTIs) in children. METHODS: Nasopharyngeal aspirate samples were obtained from 658 children who had been hospitalized for LRTIs in Seoul National University (SNU) Children's Hospital and SNU Bundang Hospital from March 2000 to September 2005. Multiplex RT-PCR was performed to detect 11 respiratory viruses including respiratory syncytial virus, adenovirus, rhinovirus, parainfluenza viruses 1 and 3, influenza viruses A and B, human metapneumovirus, HBoV, human coronavirus (HCoV) OC43/229E, and HCoV-NL63. Clinical data were reviewed retrospectively. RESULTS: Overall, respiratory viruses were detected in 325 (49.4%) among 658 patients. HBoV was detected in 62 cases (9.4%) and was responsible for 19.1% of virus-positive cases. HBoV was prevalent among infants and young children aged from 3 months to 5 years with the mean age of 25.3 months. Co-detection of HBoV and other respiratory viruses was observed in 37.1% which is significantly higher than average co-detection rate (12.3%) among overall virus-positive cases (P=0.000). HBoV was identified mainly in late spring and early summer from May to July. CONCLUSION: This study describes epidemiologic features of HBoV in Korean children compared with those associated with other respiratory viruses. HBoV was prevalent among LRTIs in childhood, especially in late spring and early summer season in Korea.

A Case of Disseminated Mycobacterium bovis Infection after BCG Vaccination (Tokyo strain) in an Apparently Immunocompetent Infant / 소아감염

Bacille Calmette-Guerin (BCG) vaccine is a live attenuated vaccine derived from Mycobacterium bovis. Frequent complications after BCG vaccination are localized ulcer formation and regional lymphadenitis, but there could be rarely severe systemic reactions to BCG vaccine such as osteomyelitis and disseminated BCG infection. Although disseminated BCG infection can be complicated in infants with underlying immunodeficiency after BCG vaccination, it is very unlikely to develop in immunocompetent infants or children. We report a 13-month-old infant who presented with fever, skin nodules, and multiple enlarged lymph nodes 5 months following BCG vaccination. She was diagnosed with disseminated BCG infection by PCR-confirmed M. bovis BCG infection at > or =2 anatomical sites beyond the region of vaccination. The patient showed no obvious evidence of immunodeficiency as judged on the basis of previous disease history, plasma immunoglobulin levels, B and T lymphocytes counts in peripheral blood, DHR (dihydrorhodamine 123 fluorescence) test and HIV test. She started antituberculous treatment with isoniazid and rifampin, and now, apparently her symptoms have been improved.