Osamu Komiyama

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.

Effectiveness of Trivalent Inactivated Influenza Vaccine in Children Estimated by a Test-Negative Case-Control Design Study Based on Influenza Rapid Diagnostic Test Results

We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013–14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38°C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39–52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56–69), 77% (95% CI, 59–87), and 26% (95% CI, 14–36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B.

Trivalent inactivated influenza vaccine effective against influenza A(H3N2) variant viruses in children during the 2014/15 season, Japan.

The 2014/15 influenza season in Japan was characterised by predominant influenza A(H3N2) activity; 99% of influenza A viruses detected were A(H3N2). Subclade 3C.2a viruses were the major epidemic A(H3N2) viruses, and were genetically distinct from A/New York/39/2012(H3N2) of 2014/15 vaccine strain in Japan, which was classified as clade 3C.1. We assessed vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children aged 6 months to 15 years by test-negative case–control design based on influenza rapid diagnostic test. Between November 2014 and March 2015, a total of 3,752 children were enrolled: 1,633 tested positive for influenza A and 42 for influenza B, and 2,077 tested negative. Adjusted VE was 38% (95% confidence intervals (CI): 28 to 46) against influenza virus infection overall, 37% (95% CI: 27 to 45) against influenza A, and 47% (95% CI: -2 to 73) against influenza B. However, IIV was not statistically significantly effective against influenza A in infants aged 6 to 11 months or adolescents aged 13 to 15 years. VE in preventing hospitalisation for influenza A infection was 55% (95% CI: 42 to 64). Trivalent IIV that included A/New York/39/2012(H3N2) was effective against drifted influenza A(H3N2) virus, although vaccine mismatch resulted in low VE.

Three-season effectiveness of inactivated influenza vaccine in preventing influenza illness and hospitalization in children in Japan, 2013-2016

OBJECTIVES We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children 6 months to 15 years of age in 2015/16 season. In addition, based on the data obtained during the three seasons from 2013 to 2016, we estimated the three-season VE in preventing influenza illness and hospitalization. METHODS Our study was conducted according to a test-negative case-control design (TNCC) and as a case-control study based on influenza rapid diagnostic test results. RESULTS During 2015/16 season, the quadrivalent IIV was first used in Japan. The adjusted VE in preventing influenza illness was 49% (95% confidence interval [CI]: 42-55%) against any type of influenza, 57% (95% CI: 50-63%) against influenza A and 34% (95% CI: 23-44%) against influenza B. The 3-season adjusted VE was 45% (95% CI: 41-49%) against influenza virus infection overall (N = 12,888), 51% (95% CI: 47-55%) against influenza A (N = 10,410), and 32% (95% CI: 24-38%) against influenza B (N = 9232). An analysis by age groups showed low or no significant VE in infants or adolescents. By contrast, VE was highest in the young group (1-5 years old) and declined with age thereafter. The 3-season adjusted VE in preventing hospitalization as determined in a case-control study was 52% (95% CI: 42-60%) for influenza A and 28% (95% CI: 4-46%) for influenza B, and by TNCC design, it was 54% (95% CI: 41-65%) for influenza A and 34% (95% CI: 6-54%) for influenza B. CONCLUSION We demonstrated not only VE in preventing illness, but also VE in preventing hospitalization based on much larger numbers of children than previous studies.

Efficacy and safety of intravenous immunoglobulin plus prednisolone therapy in patients with Kawasaki disease (Post RAISE): a multicentre, prospective cohort study

BACKGROUND The RAISE study showed that additional prednisolone improved coronary artery outcomes in patients with Kawasaki disease at high risk of intravenous immunoglobulin (IVIG) resistance. However, no studies have been done to test the steroid regimen used in the RAISE study. We therefore aimed to verify the efficacy and safety of primary IVIG plus prednisolone. METHODS We did a multicentre, prospective cohort study at 34 hospitals in Japan. We included patients diagnosed with Kawasaki disease according to the Japanese diagnostic criteria, and excluded those who were treated at other hospitals before being transferred to a participating hospital. Patients who were febrile at diagnosis received primary IVIG (2 g/kg per 24 h) and oral aspirin (30 mg/kg per day) until the fever resolved, followed by oral aspirin (5 mg/kg per day) for 2 months after Kawasaki disease onset. We stratified patients using the Kobayashi score into predicted IVIG non-responders (Kobayashi score ≥5) or predicted IVIG responders (Kobayashi score <5). For predicted non-responders, each hospital independently decided whether to add prednisolone (intravenous injection of 2 mg/kg per day for 5 days) to the primary IVIG treatment, according to their respective treatment policy, and we further divided these patients based on the primary treatment received. The primary endpoint was the incidence of coronary artery abnormalities determined by two-dimensional echocardiography at 1 month after the primary treatment in predicted non-responders treated with primary IVIG plus prednisolone. Coronary artery abnormalities were defined according to the criteria of the Japanese Ministry of Health and Welfare and of the American Heart Association (AHA). This study is registered with the University Hospital Medical Information Network Clinical Trials Registry, number UMIN000007133. FINDINGS From July 1, 2012, to June 30, 2015, we enrolled 2628 patients with Kawasaki disease, of whom 724 (27·6%) were predicted IVIG non-responders who received IVIG plus prednisolone as primary treatment. 132 (18·2%) of 724 patients did not respond to primary treatment. Among patients with complete data, coronary artery abnormalities were present in 40 (incidence rate 5·9%, 95% CI 4·3-8·0) of 676 patients according to the AHA criteria or in 26 (3·8%, 2·5-5·6) of 677 patients according to the Japanese criteria. Serious adverse events were reported in 12 (1·7%) of 724 patients treated with primary IVIG plus prednisolone; two of these patients had hypertension and bacteraemia that was probably related to prednisolone. One patient died possibly due to severe inflammation from the Kawasaki disease itself. INTERPRETATION Primary IVIG plus prednisolone therapy in this study had an effect similar to that seen in the RAISE study in reducing the non-response rate and decreasing the incidence of coronary artery abnormalities. A primary IVIG and prednisolone combination therapy might prevent coronary artery abnormalities and contribute to lowering medical costs. FUNDING Tokyo Metropolitan Government Hospitals and the Japan Kawasaki Disease Research Center.

Spontaneous intramural duodenal hematoma as the manifestation of Noonan syndrome

1Medical Genetics Center, National Hospital Organization Tokyo Medical Center, Tokyo, Japan 2Department of Pediatrics, National Hospital Organization Tokyo Medical Center, Tokyo, Japan 3Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan 4Department of Pediatric Surgery, Keio University School of Medicine, Tokyo, Japan 5Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan

Continuous Nasogastric Infusion of Prostaglandin E2 in Ductus‐Dependent Congenital Heart Disease

Prostaglandin E2 (PGE2) was infused continuously through a nasogastric gavage tube in four infants with pulmonary atresia. The drug was given at a rate of 12.5–160 µg/kg/h. The duration of therapy was 7–123 days. The effects and side effects seen by this method were similar to those seen in the conventional multiple dose regimen. This method was an effective and simple way of maintaining the ductus arteriosus open, especially for a long period of time.