Isolation Rate of Neisseria meningitidis in Japanese Children with Respiratory Tract Infections.

Although invasive meningococcal disease is rare in Japan (0.028 cases per 100,000 population), its incidence is 10 times greater in many other countries. Colonization is a prerequisite for invasive meningococcal disease. However, no study in Japan has involved specifically analyzing the carriage rate of Neisseria meningitidis in children. During 5 months in 2015, the respiratory tract specimens of patients who presented to 3 hospitals with respiratory symptoms were cultured. The bacteria were identified in selective media using a meningococcal detection kit and the serogroup was identified using polymerase chain reaction analysis. In 389 patients aged ≤15 years with respiratory symptoms, the N. meningitidis isolation rate was 0.26% (1/389). The serogroup of the only child who tested positive was Y. In this study, we detected a low meningococcal isolation rate in pediatric patients. Due to increasing globalization, the risk of invasive meningococcal disease is likely increasing in Japan. Accordingly, invasive meningococcal diseases should be continuously monitored in Japan. Future large-scale studies should assess meningococcal isolation rates and corresponding serogroups.

[Bacterial meningitis caused by beta-lactamase-negative, ampicillin-resistant nontypeable Haemophilus influenzae in a 1-year-old girl: a case report].

We present herein the case report of bacterial meningitis caused by nontypeable Haemophilus influenzae (NTHi) in a 1-year-7-month-old girl with no medically significant history. NTHi from cerebrospinal fluid (CSF) was the beta-lactamase non-producing ampicillin resistant strain (BLNAR). Some beta-lactams were administrated, but fever was prolonged. Finally, rifampicin seemed to be effective. In NTHi, compared with H. influenzae type b (Hib), the prevalence of BLNAR is high. Hence, complicated cases may increase in the near future if the use of the Hib vaccine becomes widespread, and meningitis caused by NTHi increases. It may be necessary to consider combination therapy or use of non-beta-lactams that have a different antimicrobial mechanism from beta-lactams. PCR analysis revealed the possibility that the CSF isolate lacked the P5 protein gene. Though deficiency of P5 fimbriae is known to reduce the affinity of NTHi for the human respiratory epithelium, determining whether P5 deficient NTHi induced meningitis will require further study.

Myocarditis in a pediatric case of pandemic 2009H1N1 influenza.

We report a 6-year-old boy with no major disease history or allergic conditions initially presented with pneumonia, progressed to acute respiratory distress syndrome and acute myocarditis caused by pandemic 2009H1N1 influenza diagnosed with RT-PCR testing, successfully managed with mechanical ventilation and percutaneous cardiopulmonary support system. Marked transient elevation of IgE in acute phase of the disease and the subsequent diagnosis of atopic asthma in our patient suggested a possible role of an underlying allergic condition in the clinicopathological process. Critically ill 2009H1N1-infected patient with acute respiratory failure should carefully be physiologically monitored together with serial assessment of biomarkers aiming at a favorable cardiac outcome by giving the timely diagnosis and intervention.

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. METHODS: In 50 prospective KD patients, six IVIG non-responders without clinical improvement within 24-48 h after completion of initial IVIG, received 2 g/kg IVIG concurrently with 2 mg/kg i.v. prednisolone sodium succinate (PSL) until normalization of C-reactive protein level. Treatment was then changed to oral PSL, which was tapered over time. Clinical and coronary artery lesion (CAL) outcomes were compared with those of 13 IVIG non-responders who received additional heterogeneous therapies in 125 retrospective KD patients. In addition, the scoring system of Kobayashi et al. for prediction of non-responsiveness to initial IVIG treatment was retrospectively verified in 175 KD subjects, consisting of 50 prospective and 125 retrospective patients in order to evaluate the efficacy of the re-treatment regimen. RESULTS: Incidence of CAL in the study patients was lower than in the control patients, although differences were not significant both in the acute stage (within 1 month: 1/6, 16.7% vs 7/13, 53.8%; P= 0.177) and in the convalescent stage (after 1 month: 0/6, 0.0% vs 4/13, 30.8%; P= 0.255). According to the non-responder prediction system, the scores of six study and 13 control patients before initial IVIG treatment were similar (7.2 ± 1.9 vs 5.3 ± 3.1; P= 0.200). No serious adverse effects related to each treatment were noted in patients of either group. CONCLUSIONS: Additional IVIG combined with concurrent PSL appears to be safe and worth evaluation for the treatment of acute KD unresponsive to initial IVIG treatment.

Incidence of bacterial coinfection with respiratory syncytial virus bronchopulmonary infection in pediatric inpatients.

Bacterial coinfection occurs in pediatric bronchopulmonary infections caused by respiratory syncytial virus (RSV), but the incidence is uncertain. Our subjects are 188 pediatric inpatients having RSV bronchopulmonary infection in two hospitals in Chiba Prefecture between 2005 and 2007. On admission, antigen detection kits using nasopharyngeal aspirate were performed to detect RSV infection and washed sputum bacterial culture was performed to detect bacterial infection. Of the 188 pediatric inpatients with RSV bronchopulmonary infection, 95 (50.5%) patients were aged less than 1 year, 57 (30.3%) were aged 1-2 years, and 36 (19.1%) were aged 2 years or more. Thirty-six (19.1%) patients were associated with bronchial asthma attacks. Pathogenic bacteria were predominantly isolated from 43.6% of the patients. The three most frequently isolated bacteria were Haemophilus influenzae (43.9%), Streptococcus pneumoniae (36.6%), and Moraxella catarrhalis (29.3%). We found that 38.9% of H. influenzae strains were ß-lactamase-nonproducing ampicillin-resistant strains. All S. pneumoniae strains were penicillin G (PcG) sensitive. However, 21.9% of S. pneumoniae strains showed PcG minimum inhibitory concentration values of 2 µg/ml. RSV bronchopulmonary infections in hospitalized children are often associated with antimicrobial-resistant bacterial infection in their lower airways. These results indicate that we should be aware of bacterial coinfections in the management of pediatric inpatients with RSV bronchopulmonary infection.

Unique phenotypes of C1s deficiency and abnormality caused by two compound heterozygosities in a Japanese family.

A deficiency in the early components of complement is associated with an increased susceptibility to pyrogenic infections and multiple autoimmune diseases. We previously reported a Japanese case of selective C1s deficiency resulting from a compound heterozygosity for a 4-bp deletion in exon X and a nonsense mutation Glu597X in exon XII of the C1s gene. In this previous case, the patient suffered from unique symptoms including virus-associated hemophagocytic syndrome and died after a long period of loss of consciousness. In the present study, we report another patient from the same family, with C1s abnormality caused by a distinct compound-heterozygous genotype and who had a novel missense mutation Gly630Glu transmitted from the mother's side and a previously identified nonsense mutation Glu597X from the father's side. Thus three distinct mutations of the C1s gene were clustered and resulted in two distinct genotypes for C1s deficiency and C1s abnormality within this one family. The present patient showed symptoms that were similar in part to our previous patient, which were different from those of the cases reported in other families. The biochemical properties of C1s in the patient's serum and the recombinant form were closely related to the undetectable or very low activity of complement activation. These results suggested that the uniqueness and severity of the symptoms observed here in the two patients might be under the control of a common C1s allele and distinct counterparts, respectively.

[Clinical and bacterial analysis of pediatric urinary tract infection].

We analyzed the clinical and bacterial backgrounds of 120 patients with pediatric urinary tract infection (UTI). Escherichia coli was the main pathogen recovered from 98 patients (81.7%). All causative agents isolated from 50 uncomplicated UTI cases were E. coli. Of 98 cases of E. coli UTI, 71 were treated with second-generation cephems, whose therapeutic effect was equal to that of third and fourth-generation cephems. MIC50 and MIC90 (microg/mL) for E. coli were as follows: cefazolin :2, 4; cefmetazole: < or = 0.5, 2; and ceftazidime: < or = 0.25, < or = 0.25. Yearly decline in susceptibility was not observed, but MIC elevation for third generation cephems (< or = 2 microg/mL) including ceftazidime was seen in six isolates. Careful monitoring of susceptibility trends is therefore necessary for appropriate antimicrobial therapy.

[Studies of treatment for Haemophilus influenzae type b meningitis in children].

We summarize 41 cases of bacterial meningitis in the last 11 years caused by Haemophilus influenzae. All isolates were serotype b strain (Hib). Initial chemotherapy was started with ceftriaxone (CTRX) in 22 cases, ampicillin plus cefotaxime (CTX) in 9, CTRX plus panipenem/betamipron in 5, and CTX in 2. Some 31 cases were treated mainly with CTRX. Although therapeutic antibiotics showed good susceptibility for isolates, 8 complicated cases (19.5%) occurred. Sequalae were observed in 7 (17.1%) but none were fatal. Five strains with elevated MIC of CTX (0.12 to 1 microg/mL) recovered after 2001, and 3 of 5 strains also showed elevated MIC of CTRX (0.12 to 0.5 microg/mL), but all were cured completely with CTRX. At present, no treatment failures due to antibiotic resistance have been observed, and CTRX remains suitable as initial therapy for Hib meningitis. A decline in susceptibility for third-generation cephalosporin against beta-lactamase-nonproducing ampicillin-resistant H. influenzae is emerging, however, so it will be necessary to consider combination therapy with CTRX given the foreseeable trend in MICs.

[Two cases of meningitis caused by the same Haemophilus influenzae type B strain in a nursery at a 3-month interval].

We present 2 cases of meningitis caused by the same Haemophilus influenzae type b (Hib) strain in a nursery at a 3-month interval. Causative agents isolated showed good susceptibility to beta-lactams and both patients recovered without any sequelae. Survey culture at each occurrence of meningitis showed 10 asymptomatic nasopharyngeal carriers. Oral rifampin was administrated to all staff and infants, but 2 carriers were found a month later from chemoprophylaxis. Pulsed-field gel electrophoresis analysis showed that the two strains isolated from meningitis patients and 12 from asymptomatic carriers were apparently identical. When systemic Hib infection occurs in a nursery, other infants may be at high risk for secondary disease. It is difficult, however, to eliminate Hib carriage by chemoprophylaxis, indicating that Hib vaccination to prevent systemic Hib infection is necessary in Japan.