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Background Japanese encephalitis (JE) is the leading cause of viral encephalitis with high mortality and morbidity in Asia. In Japan, however, the active recommendation of JE vaccine was retracted in 2005 because of the potential risk of acute disseminated encephalomyelitis. We aimed to determine the recent incidence of childhood-onset JE after the domestic change of vaccination policy in Japan, and to analyze the clinical features of affected children. Methods A retrospective nationwide survey was conducted for pediatric patients with JE in Japan from 1995 to 2015. The national surveillance system was used to identify the pediatric patients with JE. Follow-up questionnaires were sent to analyze their clinical and neuroimaging profiles. Results Among a total of 109 patients registered to the national surveillance, 10 (9%) were less than age 15 years. The annual incidence rate of childhood-onset JE was higher during 2005–15 than that during 1995–2004 (4.3 × 10–3 vs 1.1 × 10–3 per 100000, respectively; P =.04). Endemic regions overlapped with prefectures that farmed pigs harboring antibodies against JE virus with high prevalence. Detailed clinical data were collected from 9 patients. None of them died, but 5 of 9 patients (56%) had neurological sequelae after recovery. One patient who was partially vaccinated with 2 doses of JE vaccine fully recovered from a coma. The age of 3 years or less was associated with unfavorable neurological prognosis. Conclusions Our data provide evidence for the importance and prophylactic effect of the JE vaccine in young children in the endemic area. [ABSTRACT FROM AUTHOR]

Background: Young infants with influenza virus infection are frequently hospitalized, and are at risk of serious complications including death. With the emergence of pandemic influenza A/H1N1 2009, oseltamivir was approved for use in Europe and the USA, including use in infants aged < 3 months. However, few data are available regarding the safety of oseltamivir treatment for influenza in infants aged < 3 months. Methods: The clinical data from Japanese infants aged < 3 months with laboratory-confirmed influenza virus infections, who were treated with oseltamivir between October 2009 and April 2011, were collected and analyzed. Results: Forty-four infants were included in the study. The median age was 1 month (range 4 days to 2 months) and median body weight was 4.5 kg (range 2.6-7.6 kg). Thirty-eight infants (86%) had no underlying diseases. The most common presenting symptom was fever (42 infants, 95%). There were no cases of influenza-associated encephalopathy or myocarditis. The median time between the onset of influenza symptoms and initiation of oseltamivir treatment was 0 days (range 0-7 days), with treatment initiated within 1 day in 40 infants (91%). The oseltamivir dose was 1.5-2 mg/kg twice daily in 98% of infants. No serious adverse events were identified during treatment. All infants recovered completely. Conclusions: Treatment of influenza with oseltamivir 1.5-2 mg/kg twice daily may be safe in infants aged < 3 months. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Highlights • An active surveillance through a phased introduction of the Hib vaccine in Japan was studied. • Hib disease incidence decreased significantly after vaccine introduction. • Hif and non-typeable H. influenzae were isolated from a few cases. • Serotype replacement was not observed after the introduction of the Hib vaccine. • Continuous capsular typing and strain identification surveillance is important. Abstract Background Haemophilus influenzae type b (Hib) vaccine was introduced as a voluntary vaccine in December 2008 and was included in the national routine immunization program in April 2013 in Japan. Currently, no nationwide data are available to evaluate the effectiveness of Hib vaccine in Japan. Methods To evaluate the effectiveness of Hib vaccine in Japan, nationwide active population-based surveillance of culture-proven invasive infections caused by H. influenzae in children was performed in 2008–2017 in 10 prefectures in Japan (covering approximately 23% of the total Japanese population). Clinical data were recorded on a standardized case report form. Capsular type and antimicrobial susceptibility of the H. influenzae isolates were examined. The incidence rate ratio (IRR) and its confidence interval (CI) were calculated to compare data from 5 years before and that from after the introduction of the national routine Hib vaccine immunization program. Results During the 10-year study period, 566 invasive H. influenzae disease cases including 336 meningitis cases were identified. The average number of invasive H. influenzae disease cases among children <5 years of age during 2013–2017 decreased by 93% (IRR: 0.07, 95%CI 0.05–0.10, p < 0.001) compared with those occurring during 2008–2012. Hib strains have not been isolated from invasive H. influenzae disease cases since 2014; however, non-typeable H. influenzae and H. influenzae type f isolates have been noted as causes of invasive H. influenzae diseases among children <5 years in the post-Hib vaccine era. Conclusions After the governmental subsidization of the Hib vaccine, invasive Hib disease cases decreased dramatically in the study population, as per our surveillance. Continuous surveillance is necessary to monitor the effectiveness of Hib vaccine and for detecting any emerging invasive capsular types. [ABSTRACT FROM AUTHOR]

Background In Japan, the seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2010. PCV13 has replaced PCV7 since November 2013. Methods The effectiveness of PCV7 in protecting against invasive pneumococcal disease (IPD) in children aged <5 years was evaluated in a nationwide active population-based surveillance of IPD in 2008–2013 in 10 prefectures in Japan. Results 1181 cases were identified; 711 pneumococcal strains were analyzed for serotyping and antimicrobial resistance. Compared with the baseline IPD incidence (25.0 per 100,000), a 98% decline in IPD caused by PCV7 serotypes was found after the introduction of PCV7. This was partially offset by an increased incidence of IPD caused by PCV13 minus PCV7 and non-PCV13 serotypes, resulting in a 57% decline in overall IPD incidence. Absolute increases in the incidence rates of IPD caused by PCV13 minus PCV7 and non-PCV13 serotypes were 2.1 and 2.8 per 100,000 during the study period, respectively. The proportion of meropenem-nonsusceptible strains, especially with serotypes 19A and 15A, increased significantly after PCV7 introduction. Conclusions Our data confirmed a 98% decline in IPD incidence caused by PCV7 serotypes in children aged <5 years and serotype replacement after PCV7 introduction. This shows the importance of continuing surveillance of serotypes responsible for IPD and their antimicrobial resistance in Japan. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Palivizumab effectively prevents severe respiratory syncytial virus (RSV) disease in preterm infants. Our objective was to test whether palivizumab prophylaxis given to preterm infants during the first RSV season reduces the incidence of subsequent recurrent wheezing up to 3 years of life. METHODS: We conducted an observational prospective multicenter (52 registered hospitals in Japan) case-control study in preterm infants with a gestational age between 33 and 35 weeks followed for 3 years. During the 2007-2008 RSV season, the decision to administer palivizumab was made based on standard medical practice. In April 2008, 52 hospitals were recruited. Study participants were pro- spectively followed to the age of 3 years. Parents of study subjects reported the infants' physician's assessment of recurrent wheezing, used a report card and a novel mobile phone-based reporting system by using the Internet. The primary end point was the incidence of physician-diagnosed recurrent wheezing. RESULTS: Of 444 preterm infants enrolled, 349 received palivizumab during the first 6 months of life and 95 infants did not. Physician- diagnosed recurrent wheezing was observed in 6.4% and 18.9% of infants in the treated and untreated groups, respectively (P < .001). This difference remained significant after adjustment for known risk factors of recurrent wheezing (P < .001). CONCLUSIONS: Palivizumab prophylaxis administered to preterm infants 33 to 35 weeks' gestational age is associated with a significantly lower incidence of recurrent wheezing during the first 3 years of life. [ABSTRACT FROM AUTHOR]