Tomomichi Kurosaki

Japanese Guidelines for the Management of Respiratory Infectious Diseases in Children 2007 with focus on pneumonia

Members of the Japanese Society of Pediatric Pulmonology and the Japanese Society for Pediatric Infectious Diseases developed the Guidelines for the Management of Respiratory Infectious Diseases in Children with the objective of facilitating the appropriate diagnosis and treatment of childhood respiratory infections. To date, a first edition (2004) and a revised edition (2007) have been issued. Many problems complicate the diagnosis of the pathogens responsible for bronchopulmonary infections in children. The Guidelines were the first pediatric guidelines in the world to recommend treatment with antimicrobials suited to causative pathogens as identified from cultures of sputum and other clinical specimens collected from infection sites and satisfying assessment criteria. The major causative microorganisms for pneumonia in infants and children were revealed to be Streptococcus pneumoniae, Haemophilus influenzae and Mycoplasma pneumoniae. This manuscript describes the Guidelines for the Management of Respiratory Infectious Diseases in Children in Japan 2007, with a focus on pneumonia.

Incidence of childhood pneumonia and serotype and sequence-type distribution in Streptococcus pneumoniae isolates in Japan.

The 7-valent pneumococcal conjugate vaccine (PCV7) is reported to decrease the incidence of community-acquired pneumonia (CAP) in children. To determine the annual incidence of CAP before the introduction of PCV7, we counted the number of children hospitalized with CAP between 2008 and 2009 in Chiba City, Japan. We investigated serotype and multilocus sequence typing (MLST) for Streptococcus pneumoniae isolates in CAP cases. The annual incidence of hospitalized CAP in children aged <5 years was 17.6 episodes/1000 child-years. In 626 episodes, S. pneumoniae was dominant in 14.7% and 0.8% of sputum and blood samples, respectively. The most common serotypes were 6B, 23F and 19F. The coverage rates of PCV7 were 66.7% and 80% in sputum samples and blood samples, respectively. MLST analysis revealed 37 sequence types. Furthermore, 54.1% of the sputum isolates and 40% of the blood isolate were related to international multidrug-resistant clones.

The incidence of pediatric invasive pneumococcal disease in Chiba prefecture, Japan (2003–2005)

OBJECTIVES The purpose of the study is to evaluate the incidence, spectrum of clinical manifestations and outcome of invasive pneumococcal disease (IPD) in children in Chiba prefecture, Japan. METHODS To determine the precise incidence of IPD in Chiba prefecture, we implemented a retrospective survey of the period from 2003 to 2005. A written questionnaire was sent to 45 hospitals that have pediatric wards, and information was obtained from all hospitals. The questionnaire included the clinical diagnosis, patients age, underlying disease, prognosis and antimicrobial susceptibility of the isolated strains. RESULTS During the 3 study years, 130 patients were diagnosed with IPD. The mean annual incidence rates of IPD among children <2 and <5 years were 19.5-23.8 and 12.6-13.8 per 100,000, respectively. Among 130 patients with systemic infection, 66 patients had bacteremia, 39 had pneumonia and 16 had meningitis. Five patients had neurological sequelae and 2 patients died. Seventy-four out of 115 isolates (64.3%) exhibited resistance to penicillin G. CONCLUSIONS The annual incidence of pediatric IPD has remained constant during the study period. Two-third of isolated strains were at least partially resistant to penicillin G. Establishment of appropriate antibiotic therapy against IPD due to penicillin-resistant strains and the introduction of pneumococcal conjugate vaccines are emergent issues in Japan.

Intravenous immune globulin plus corticosteroids in refractory Kawasaki disease

Background:  The aim of the present study was to investigate the efficacy of i.v. immune globulin (IVIG) therapy combined with corticosteroids for additional treatment of acute Kawasaki disease (KD) unresponsive to initial IVIG treatment.

Intractable wheezing in infants with nasopharyngeal reflux

Two infants with intractable wheezing and moist cough were referred to Chiba Municipal Kaihin Hospital. Their symptoms were persistent even after the usual treatment for respiratory disease. No definite etiological agents were detected. They usually gagged while feeding and barium swallow tests revealed nasopharyngeal reflux and cricopharyngeal incoordination. One of the patients had remarkably high titers of IgE and IgE RAST of cows milk before she received treatment with thickened formula. She also had peripheral eosinophilia and nasal eosinophilia. These findings were thought to be caused by nasopharyngeal reflux. Four months after therapy commenced, those titers and symptoms were greatly reduced. The clinical and roentgenographic findings in these infants, and their response to therapy, strongly support a causal relationship between nasopharyngeal reflux and wheezing. Therefore, nasopharyngeal reflux should be considered when a baby has intractable wheezing, even when there is no developmental problem.

The clinical characteristics of Mycoplasma pneumoniae pneumonia in children younger than 6 years old

乳幼児のマイコプラズマ肺炎の臨床像を検討するため, 5歳以下43例を6歳以上40例と比較した。6歳以上に比べ5歳以下では咳噺の性状は湿性咳噺が90.0%を占め, 肺副雑音も83.7%に聴取し, 末梢血白血球数も10, 000/μL以上を示す症例がみられ成人市中肺炎診療ガイドラインに記載されている非定型肺炎の特徴とは異なる臨床像を認めた。また5歳以下の乳幼児では細気管支炎, 気管支喘息発作を合併する割合や, ウイルスや細菌の混合感染の割合が6歳以上より高率に認められ, 臨床像が成人と異なる要因と考えられた。年齢による微粒子凝集 (PA) 法による抗体価上昇の遅延は認めないが, 診断基準を満たす抗体価上昇に15日以上要した症例がみられた。以上より5歳以下のマイコプラズマ肺炎の臨床像は非典型的であり, 急性期に診断ができる感度のよい検査法もないため, 早期に有用な検査法の確立が望まれる。

Annual changes in antimicrobial susceptibility and macrolide resistance of Streptococcus pyogenes from 1995 through 2004

This aim of this study was to reveal annual changes in antibiotic susceptibility, especially the macrolide susceptibility of Streptococcus pyogenes. A total of 755 strains of S. pyogenes were clinicaly isolated from throat swabs of children from 1995 through 2004 in Chiba Municipal Kaihin Hospital. All isolates were fully susceptible to benzylpenicillin, cefotaxim and cefaclor. The rate of resistance to erythromycin (EM) was over 10% every year after 2001 and 19% in 2004, and the rate of high resistance (MIC > or =16 microg/mL) has been increasing. A significant increase in EM resistance was observed over a 10-year period. There were 118 strains (15.6%) that persisted after treatment with beta-lactams. In the past few years it has been discovered that some S. pyogenes can be internalized by human cells of respiratory tract origin and survive within them. Since beta-lactams do not reach high intracellular concentrations, this ability of S. pyogenes may be related to treatment failure. Since macrolides can enter eukaryotic cells and remain active in intracellular compartments, they will be effective for these S. pyogenes. In case of pharyngitis which againist treatment with beta-lactams, there is a possibility macrolides are effective. Macrolides may be effective in pharyngitis resistant to treatment with beta-lactams. However, macrolide resistance is not rare, susceptibility must be tested.

Effects of Intravenous Gammmaglobulin Therapy Combined with Dexamethasone for the Initial Treatment of Acute Kawasaki Disease

We studied effects of intravenous gammmaglobulin therapy (IVGG) combined with dexamethasone (DEX) for the initial treatment of acute Kawasaki disease(KD). Prospectively studied 33 KD patients received total of 2g/kg IVGG for consecutive 4-5days plus 0.3mg/kg DEX for consecutive 3days (group 1). Retrospectively studied 33 KD patients received standard IVGG therapy (2g/kg IVGG for consecutive 4-5days)(group 2) were compared to analyze the efficacy and safety of the new regimen. There were no differences in age, sex, body weight, duration of illness, or given doses of gammmaglobulin between those two groups. Clinical no responders to the initial treatment received additive IVGG treatment. Informed consent was obtained from childrens parents before therapy. No serious adverse effect was noted in both groups. The duration of high fever after the start of initial treatment in group1(1-12 days) was shorter than in group 2 (1-16 days)(p=0.07, by Mann-Whitney U-test). Two patients in group 1 and two patients in group 2 developed small coronary aneurysms. Although further analysis using larger numbers of patients are necessary to confirm the efficacy of this new regimen, we preriminaly demonstrated that IVGG combined with DEX in the initial treatment of acute KD was safe and may shorten the duration of fever.