Recent trends in pediatric bacterial meningitis in Japan--a country where Haemophilus influenzae type b and Streptococcus pneumoniae conjugated vaccines have just been introduced.

To investigate the trends in incidence and the characteristics of bacterial meningitis in Japan where Haemophilus influenzae type b (Hib) vaccine and 7-valent pneumococcal conjugated vaccine (PCV7) were introduced in 2008 and 2010, respectively, which was 5-20 years after their introduction in western countries. The nationwide Japanese survey of pediatric and neonatal bacterial meningitis was performed in 2011 and 2012. We analyzed the epidemiological and clinical data, and compared the information obtained in the previous nationwide survey database. We also investigated the risk factors for disease outcome. In the 2011-2012 surveys, 357 patients were evaluated. H. influenzae, Streptococcus pneumoniae, Streptococcus agalactiae and Escherichia coli were the main organisms. The number of patients hospitalized with bacterial meningitis per 1000 admissions decreased from 1.31 in 2009 to 0.43 in 2012 (p < 0.001). The incidence of H. influenzae and S. pneumoniae meningitis also decreased from 0.66 to 0.08 (p < 0.001), and 0.30 to 0.06 (p < 0.001), respectively. Only 0-2 cases with Neisseria meningitidis were reported each year throughout 2001-2012. The median patient age was 10-12 months in 2001-2011, and became lower in 2012 (2 month old) (p < 0.001). The fatality rate for S. agalactiae is the highest (5.9% (11/187)) throughout 2001-2012 among the four organisms. Risk factors for death and sequelae were convulsions at onset, low CSF glucose, S. agalactiae etiology, and persistent positive CSF culture. Hib vaccine and PCV7 decreased the rate of bacterial meningitis. Earlier introduction of these vaccines may have prevented bacterial meningitis among Japanese children.

[Childhood bacterial meningitis trends in Japan from 2009 to 2010].

We conducted a pediatric survey of bacterial meningitis epidemiology from January 2009 to December 2010 in Japan, and obtained the following results for 314 cases (186 boys, 124 girls, and 4 with gender not reported). Children younger than one year old accounted for the majority of cases (51.2%, 161/314), and the incidence decreased with increasing age. Haemophilus influenzae (in children aged 1 month to 5 years old) was the most common cause of infection (53.2%), followed by Streptococcus pneumoniae (1 month to 12 years, 24.2%), Streptococcus agalactiae (0-4 months, 7.6%), and Escherichia coli (0-3 months, 3.2%). Susceptibility tests showed that 50.1% (78/153) of the H. influenzae isolates and 63.0% (46/73) of the S. pneumoniae isolates were drug-resistant. Combinations of ampicillin and cephem or carbapenem and other beta-lactams were mainly used as the initial antibiotics for patients under 4 months of age (77.8%, 42/54), and a carbapenem and other beta-lactam combination was used for patients aged 4 months and older (76.4%, 198/259). The final antibiotics for H. influenzae and S. pneumoniae were mainly cefotaxime (CTX) or ceftriaxone (CTRX) and carbapenem, respectively. The overall fatality rate was 2.0% (6/305). Since the Haemophilus influenzae type b vaccine (Hib vaccine) and the 7 valent pneumococcal conjugate vaccine (PCV7) are not widely used in Japan, only 5 patients in our cohort (all with meningitis not caused by H. influenzae) had been immunized with the Hib vaccine, and none had been immunized with the PCV7 vaccine. No remarkable changes in the characteristics of pediatric meningitis have been observed for several years in Japan.

Neonatal meningitis caused by Streptococcus gallolyticus subsp. pasteurianus.

We encountered a case of neonatal meningitis caused by Streptococcus gallolyticus subsp. pasteurianus. The patient was an 8-day-old boy. Gram staining of the cerebrospinal fluid (CSF) revealed gram-positive cocci in pairs or in short chains. In culture, γ-streptococcus-like colonies grew. The result of 16S rRNA sequence analysis identified S. gallolyticus subsp. pasteurianus. From these results, bacterial meningitis was diagnosed and, as a result of antimicrobial susceptibility testing, single-dose ampicillin therapy was given. Because inflammatory deterioration and spread was suspected from the CSF test results, this therapy was added by panipenem/betamipron. In response to his recovery, antibiotic treatment was stopped and the boy was discharged. This bacterium was classified as S. gallolyticus subsp. pasteurianus in the latest report in 2003. Since this change, there have only been a few cases of neonatal meningitis caused by this bacterium. Here we report this rare case.

[Peritonitis due to post-myomectomy Mycoplasma hominis infection].

A 36-year-old woman undergoing a myomectomy developed postoperative surgical-saite peritonitis and hematoma. Eight days postoperatively, she developed a 38 degrees C-plus fever and accumulated ascites, with fever unchanged despite antimicrobial beta-lactams therapy. Following transvaginal ascitic drainage, her fever disappeared. Recurrent 38 degrees C fever and inflammation were cured by clindamycin of 1.2 g/day. M. hominis detected from ascites drainage was considered the primary causative organism. Nongenito-urinary M. hominis infection is often difficult to detect, as in our case. Gram staining, for example, is not useful in ascertaining small organisms such as Mycoplasma spp. having no cell walls to stain. M. hominis grows slowly, requiring over three days to form colonies on blood agar plates, requiring time to identify pathogens. We report case showing the importance of suspecting M. hominis of causing gynecological surgical-site infection. When common bacterial pathogen cultures remain negative and when empiric beta-lactam antibiotic treatment is ineffective, M. hominis should be suspected. In conclusion, M. hominis should be considered a causative following myomectomy resection.

Trends in empirical chemotherapy of bacterial meningitis in children aged more than 4 months in Japan: a survey from 1997 through 2008.

Bacterial meningitis is a serious problem in pediatric clinics and, therefore, needs urgent and empirical chemotherapy. We investigated 1,116 cases of empirical chemotherapy of patients aged older than 4 months from 1997 through 2008 by sending questionnaires. A single antibiotic treatment was carried out in less than 30% of the cases throughout the years, whereas the combination of two antibiotics had been practiced in more than 70% of the cases. The main antibiotics used were cephalosporins, carbapenems, and ampicillin. Combinatory use of ampicillin and cephalosporin was carried out in 74.7-82.7% of cases in 1997-2000, but sharply declined thereafter to 0-13.8% in 2004-2008. However, the combination of carbapenem and cephalosporin compensated for the decline, increasing from 3.8-6.6% in 1998-1999 to 79.5-89.9% in 2005-2008. The breakdown in the use of cephalosporins, carbapenems, and ampicillin in two-drug combinatory therapy was as follows. (i) Use of cefotaxime was 61.8-75.3% in 1997-2001, but decreased to nearly 50%, equivalent to the level of ceftriaxone use in 2003-2008. (ii) Use of ampicillin dropped from 74.7-92.3% in 1997-2000 to 4.6% in 2008, and this decreased level was compensated for by the use of carbapenems. Overall, combinatory chemotherapy of the third-generation cephalosporins and carbapenems seems to be practical. The discussion in this report includes the difference between Japan and the United States in the prevalence of the causative agents and the use of antibiotics. These studies provide information on trends in the treatment of children's meningitis in Japan and will be useful for the design of future empirical chemotherapy.

[Childhood bacterial meningitis trends in Japan from 2007 to 2008].

We surveyed pediatrics bacterial meningitis epidemiology from January 2007 to December 2008 in Japan, with the following results: Cases numbered 287-160 male and 127 female-equivalent to 1.54-1.62 of 1,000 pediatric hospitalization per year. Children under 1-year-old accounted for the highest number of cases, which decreased with increasing age. Haemophilus influenzae was the most common cause of infection, followed by Streptococcus pneumoniae, group B streptococcus (GBS), and Escherichia coli. GBS and E. coli were major pathogens in children under 4 months of age, while H. influenzae and S. pneumoniae mainly accounted for those over 4 months of age. Susceptibility tests showed that 51% of H. influenzae isolates and 56.5% of S. pneumoniae isolates in 2008 were drug-resistant. Ampicillin combined with cephem antibiotics effective against GBS, E. coli, and Listeria, were mainly used to initially treat those under 4 months of age. In those over 4 months of age, carbapenem antibiotics are effective against PRSP and cephem antibiotics against H. influenza.

A comparative clinical study of macrolide-sensitive and macrolide-resistant Mycoplasma pneumoniae infections in pediatric patients.

In recent years, the increased prevalence of macrolide-resistant Mycoplasma pneumoniae (MR-M. pneumoniae) has become a significant issue in Japan. We isolated 94 strains of M. pneumoniae, and determined the minimum inhibitory concentrations (MICs) of macrolides and other antimicrobial agents for these strains. We also performed a comparative clinical evaluation of macrolide efficacy for cases of MR-M. pneumoniae infections and cases of macrolide-sensitive Mycoplasma pneumoniae infections (MS-M. pneumoniae). Of the 94 isolates of M. pneumoniae, 64 (68.1%) were classified as MS-M. pneumoniae and 30 (31.9%) as MR-M. pneumoniae strains. The clinical study included an assessment of 47 pediatric cases of MS-M. pneumoniae and 22 pediatric cases of MR-M. pneumoniae. The patient demographics, such as sex, age, the period from the onset of the infection to the first examination, laboratory findings, diagnosis, and the severity of symptoms, showed no significant difference between the two study groups. However, the efficacy of macrolide treatment was 91.5% for MS-M. pneumoniae and 22.7% for MR-M. pneumoniae, a statistically significant difference (P < 0.01). Although M. pneumoniae infection is generally considered a treatable condition, the increasing prevalence of macrolide-resistant strains of M. pneumoniae has become a significant clinical issue in pediatric patients, and it is therefore necessary to give careful consideration to the appropriate antimicrobial therapy for MR-M. pneumoniae infection.

[Childhood bacterial meningitis trends in Japan from 2005 to 2006].

We surveyed pediatric bacterial meningitis epidemiology from January 2005 to December 2006 in Japan, with the following results. Bacterial meningitis cases numbered 246 -138 boys and 108 girls-, equivalent to 1.7-1.72 children of 1,000 hospitalized in pediatrics per year. The age distribution for infection was highest in those under 1 year of age and decreased with increasing age, Haemophilus influenzae was the most common infection causing the pathogen, followed by Streptococcus pneumoniae, group B streptococcus, and Escherichia coli. The relationship between causative pathogens and age distribution was as follows: group B streptococcus and E. coli were major pathogens in patients under 4 months old and H. influenzae and S. pneumoniae in those over 4 months old. Susceptibility tests at individual facilities showed 59.3% of H. influen- zae isolates and 69.3% of S. pneumoniae isolates in 2004 to be drug-resistant. Ampicillin and cephem antibiotics are effective against GBS, E. coli, and Listeria, so combined of ampicillin and cephem antibiotics are used as first-line antibiotics in many facilities in patients under 4 month old and combined of carbapenem antibiotics effective against PRSP and cephem effective against H. influenzae were the first choice against childhood bacterial meningitis in patients over 4 month old.

[Detection of antibodies by immunoblotting using Chlamydia trachomatis serovars].

We compared reactivity between Chlamydia serovar antigens and sera from 18 patients using immunoblotting (IB) and enzyme-linked immunosorbent assay (ELISA). The antigens used were Chlamydia trachomatis serovar L2, D, E, and C organisms for IB and synthetic peptides derived from C, E, G, and L2-VDIV genes for ELISA. Eleven of 12 sera collected from Chlamydia antigen-positive women with cervicitis strongly reacted with C. trachomatis serovar E, as did one serum with serovar C in immunoblotting profiles. ELISA coated individually with peptides E and C strongly reacted with the sera of 6 different patients. The IB result between serovar L2, D, E, and C and sera from the 6 other women patients showed reactivity at E > or = D > or = L2 > or = C. ELISA using a synthetic peptide mixture including C, E, G and L2 peptides gave positive results for all 18 sera. These results indicate that IB sensitivity differes with the C. trachomatis serovar antigen used and that certain cases may produce inconsistent results between IB and ELISA. Results of ELISA and IB are thus not always consistent, indicating that different synthetic peptides should be used in ELISA for detecting of low-level C. trachomatis antibodies.

[Trends in pediatric bacterial meningitis in Japan (2003-2004)].

We surveyed the epidemiology of pediatric bacterial meningitis between January 2003 and December 2004 in Japan, with the following results: Bacterial meningitis cases numbered 233 (132 boys, 98 girls, and 3 unidentified), equivalent to 1.13-1.6 children of 1000 hospitalized in pediatrics per year. The age distribution for the infections was the highest under 1 year of age, decreasing with increasing age. Haemophilus influenzae was the most common pathogen, followed by Streptococcus pneumoniae, group B streptococcus, and Escherichia coli. The relationship between causactive pathogens and age distribution was as follows: group B. streptococcus and E. coli were major pathogens below 4 months of age and H. influenzae and S. pneumoniae were major pathogens above 4 months of age. Susceptibility tests at each facility demonstrated that 65.0% of H. influenzae isolates and 83.0% of S. pneumoniae isolates in 2004 were drug-resistant. Ampicillin and cephem antibiotics are currently effective against GBS, E. coli and Listeria so a combination of ampicillin and cephem antibiotics is used first line at many facilities for patients below 4 months of age. A combination of carbapenem which showed effective against PRSP and cephem which showed effective against H. influenzae is the first choice in childhood bacterial meningitis for patients above 4 months of age.

[The trend of childhood bacterial meningitis in Japan (2000-2002)].

We surveyed the epidemiology of bacterial meningitis in pediatrics between July 2000 and December 2002 in Japan and obtained the following results.: The number of cases of bacterial meningitis was 316 (182 boys and 134 girls), which was equivalent to 1.1-1.7 children out of 1,000 hospitalized those in pediatrics per year. The age-distribution for the infections was the highest under 1 year of age and it decreased as the age increased. Haemophilus influenzae was the most common pathogen causing the infections, followed by Streptococcus pneumoniae, group B streptococcus, and Escherichia coli. Relationship between causing pathogens and age-distribution was as follows: group B streptococcus and E. coli were major pathogens under 4 months of age and H. influenzae and S. pneumoniae were major pathogens over 4 months of age. Susceptibility tests performed at each facility demonstrated that 53.7% of H. influenzae isolates and 67.7% of S. pneumoniae isolates in 2003 were drug-resistant. As ampicillin and cephem antibiotics are effective against GBS, E. coli and Listeria at present, then the combination of ampicillin and cephem antibiotics was used as first line antibiotics in many facilities under 4 month of age and a combination of carbapenem which showed effective against PRSP and cephem which showed effective against H. influenzae is first choice against childhood bacterial meningitis over 4 month of age.

In vitro protein binding of teicoplanin to neonatal serum.

The protein-binding ability of teicoplanin (TEIC) to neonatal serum was investigated and the following results were obtained. (1) The protein binding ability of TEIC at concentrations ranging from 10 to 100 microg/ml, to neonatal serum was 80.5%-71.9% and was generally low as compared with that for adult serum. (2) The protein binding ability of TEIC (20 microg/ml) to albumin in neonatal serum was not concentration-dependent, and the correlation between the protein-binding ability and albumin concentration was low. Namely, it was suggested that the protein-binding ability of TEIC to neonatal serum was not dependent merely on the albumin concentration, and there was a possibility that the protein-binding ability also depended on qualitative changes in albumin. (3) The protein-binding ability of TEIC (20 microg/ml) to total bilirubin and free bilirubin was not concentration-dependent, and the correlation was extremely low, indicating that there is a low possibility that the protein-binding ability of TEIC induces an increase in free bilirubin.

[Analysis of an antigen in Chlamydia trachomatis infected-cell extract which reacts with sera of patients with C. trachomatis infection].

To find a new marker for sero-diagnosis of Chlamydia trachomatis infection, Western blot (WB) method was performed by using C. trachomatis infected HeLa229 cell extract (L2-ext) as antigen. Two series of sera of patients with pneumonia or cervicitis (4 sera each) were used for investigation and analysis of a band which fades earlier than others depending on weeks or antibody levels after therapeutic treatment. A 17 KDa band was found which tended to fade gradually, but did not completely disappear within the period of investigation. The band was also detected in sera of patients with cervicitis diagnosed by detection of C. trachomatis organisms (IDEIA-PCE Chlamydia (IDEIA) or Clearview test were positive at first visit to the clinic). Ten anti-C. pneumoniae antibody positive sera and five anti-Mycoplasma pneumoniae antibody positive sera were also tested as controls. The result was that a 17 KDa band was detected in 20 of 25 sera (80%) with IDEIA positive. 18 of 33 patients (54.5%) with Clearview positive-, and 12 of 16 (75%) sera with both tests positive. No band was found in the control sera. The frequency of antibody against 17 KDa antigen was almost completely identical with that obtained by microimmunofluorescence test and Peptide-Chlamydia-IgG test. These results show that a 17 KDa band may be used as a marker for detection of C. trachomatis antibody by the WB method. The antigen could be precipitated with salting out from the L2-ext with 60% saturation of ammonium sulfate of Hofmeister's method and it was digested with proteinase K. From the result of the amino acid sequence analysis, it was found that 17 KDa protein is the human nucleoside diphosphate kinase B.