Comparison design and evaluation power in cohort and self-controlled case series designs for post-authorization vaccine safety studies

Background

Post-authorization safety studies (PASSs) of vaccines are important. PASSs enable the evaluation of association between vaccination and adverse events following immunization through common study designs. Clinical trials during vaccine development typically include a few thousand to 10,000 participants while a PASS might aim to detect a few adverse events per 100,000 vaccine recipients. While all available data may be utilized, prior consideration of power analyses are nonetheless crucial for interpretation in cases where statistically significant differences are not found.

Methods

This research primarily examined cohort study design and self-controlled case series (SCCS) design, estimating the power of a PASS under plausible conditions.

Results

Both the cohort study and SCCS designs necessitated large sample sizes or high event counts to guarantee adequate power. The SCCS design is particularly suited to evaluating rare adverse events. However, extremely rare events may not yield sufficient occurrences, thereby resulting in low power. Although the SCCS design can more efficiently control for time-invariant confounding in principle, it solely estimates relative measures. A cohort study design might be preferred if confounding can be adequately managed as it also estimates absolute measures. It may be an easy decision to use all the data at hand for either design. We found it necessary to estimate the sample size and number of events to be used in the study based on a priori information and anticipated results.

Immune thrombocytopenic purpura and Guillain-Barré syndrome after 23-valent pneumococcal polysaccharide vaccination in Japan: The vaccine effectiveness, networking, and universal safety (VENUS) study

BACKGROUND

To address the lack of an active vaccine safety surveillance system in Japan, the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study was initiated in 2021 as a pilot system using existing health insurance claims data and vaccination records.

METHODS

This study evaluated the value of the VENUS study by assessing the incidence of immune thrombocytopenic purpura (ITP) and Guillain-Barré syndrome (GBS) following vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using a self-controlled case series (SCCS) design.

RESULTS

Incidence rate ratios for ITP during 28-day and 42-day risk periods were 0.89 (95% confidence interval [CI], 0.12-6.4), and 0.58 (95% CI, 0.081-4.2), respectively. Neither was statistically significant. Incidence rate ratios could not be estimated for GBS due to the limited sample size.

CONCLUSION

The VENUS study can provide valuable insights to facilitate the establishment of an advanced vaccine monitoring system in Japan.

Laryngo-Esophageal Dysfunction Free Survival of Chemoradiation for Cervical Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Chemoradiotherapy is often the treatment of choice for cervical esophageal cancer due to the invasiveness of surgery. However, toxicity after chemoradiotherapy often affects the quality of life related to swallowing and speech. This study evaluated laryngoesophageal dysfunction-free survival (LEDFS) in patients with cervical esophageal cancer, which has recently been used in head and neck cancer.

MATERIALS/METHODS

We analyzed 59 patients with cervical esophageal cancer without distant metastases other than supraclavicular lymph node metastases who received radical chemoradiotherapy with 5-fluorouracilplus platinum between 2002 and 2018. Loco-regional control (LRC), overall survival (OS), LEDFS, metachronous esophageal cancer incidence rates, and late toxicities were evaluated. LEDFS events were defined as death, local recurrence, total or partial laryngectomy, tracheostomy for more than 2 years, and feeding tube use for more than 2 years, as recommended by the Larynx Preservation Consensus Panel. The Kaplan-Meier method was used to calculate survival rates. The generalized Wilcoxon test was used to compare the two groups. The Common Terminology Criteria for Adverse Events v5.0 was used to assess toxicities.

RESULTS

The median age was 66 years (range, 38-83). There were 13 women and 46 men. Stage I, II, III, IVA, and IVB disease according to UICC 8th staging were 15, 9, 9, 10, and 16 patients, respectively. 22 received conventional radiotherapy and 37 received volumetric modulated arc therapy. The median total irradiation dose was 66 Gy. Platinum plus 5-fluorouracil chemotherapy was administered to all patients. The median follow-up for survivors was 87.5 months. The 5-year LRC, OS, and LEDFS rates were 54.2%, 48.9%, and 41.9%, respectively. The prognostic factors for OS were performance status (PS), hypopharyngeal extension, and clinical stage in univariate analysis and only clinical stage (hazard ratio [HR] 3.87, 95% Confidence interval [CI]: 1.52-9.87, p<0.01) in multivariate analysis; the prognostic factors for LEDFS were PS, hypopharyngeal extension and clinical stage in univariate analysis and hypopharyngeal extension (HR 2.38, 95% CI: 1.12-5.03, p = 0.02) and clinical stage (HR 4.07, 95% CI: 1.48-11.06, p<0.02) in multivariate analysis. Metachronous esophageal cancer was observed in 28.6% of patients at 5 years. As severe late toxicities, grade 3 pneumonitis, esophageal stricture, esophageal fistula, laryngeal stricture, and laryngeal edema were observed in 1 (2%), 1 (2%) and 4 (7%), 1 (2%) and 1 (2%), respectively. Grade 2 hypothyroidism was observed in 31 (53%) patients.

CONCLUSION

Chemoradiation for cervical esophageal cancer showed good results. The prognostic factors for LEDFS were pharyngeal extension and clinical stage. Late esophageal and laryngeal toxicity, hypothyroidism, and metachronous esophageal cancer should be noted.

Impact of the G8 Score on Treatment Strategies and Outcome in Definitive Radiotherapy for the Elderly Esophageal Cancer Patients

PURPOSE/OBJECTIVE(S)

Although chemoradiotherapy (CRT) is widely used as a curative treatment for esophageal cancer, it is often difficult to perform standard CRT for the elderly in the real world. This study aimed to investigate the impact of the Geriatric 8 (G8) score on treatment strategies and outcome in definitive radiotherapy (RT) for elderly esophageal cancer patients.

MATERIALS/METHODS

We analyzed 81 esophageal cancer patients aged ≥65 years who received definitive RT between 2018 and 2021. The G8 score was acquired at the first visit to the radiation oncology department. The treatment strategy was decided by a multi-disciplinary conference, and the G8 score was not used to determine the treatment strategy. Standard treatment (standard CRT) was defined as RT with elective nodal irradiation and a total dose ≥50 Gy, and chemotherapy with two cycles of platinum (70 mg/m2) and 5FU (700 mg/m2 for 4 days) concurrently. The Kaplan-Meier method was used to generate actual survival curves. The Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 was used to assess toxicities. The Mann-Whitney U test was used to compare the two groups, and statistical significance was set at p<0.05. The Receiver Operating Characteristic (ROC) curve was used to calculate the cutoff value.

RESULTS

The Median follow-up time was 30 months (range: 8-51) for survivors. The mean G8 scores by treatment strategy were 13.9 (range: 9-17) for standard CRT group (n = 26), 12.1 (range: 7-16) for reduced CRT group (n = 30), and 9.7 (range: 4.5-14) for RT alone group (n = 25). G8 score was significantly higher for standard CRT (p = 0.017) and significantly lower for RT alone (p<0.01). The cut-off value of the G8 score for standard treatment, calculated by the ROC curve, was 12.5 points. In the non-standard treatment group, the cut-off value of the G8 score for RT alone, calculated by the ROC curve, was 10.5 points. The 2-year overall survival (OS) rates for standard CRT, reduced CRT and RT alone were 74%, 71% and 35%, respectively, and significantly lower in RT alone (p<0.001). The 2-years OS rates for G8 score >10.5 points and ≤10.5 points were 69% and 48%, respectively (p = 0.039). Grade 3 or higher acute toxicities were observed in 33 patients (41%); 14 (54%) in standard CRT, 17 (57%) in reduced CRT and 2 (8%) in RT alone. Grade 5 acute toxicity was not observed. G8 scores tended to be higher in the patients with grade 3 or higher acute toxicities, but the difference was not statistically significant (p = 0.057). Grade 3 or higher late toxicities were observed in 7 patients.

CONCLUSION

Our results suggest that there is an association between the G8 score and clinicians' treatment decisions. Although RT alone could be safely performed even in patients with low G8 scores, administration of chemotherapy strongly affected prognosis. These results suggest the importance of developing less toxic systemic therapy regimens for patients with low G8 scores.

Predictive Modeling of Radiation Pneumonitis Induced by Chemoradiotherapy for Locally Advanced Non-Small Cell Lung Cancer Using Radiomics and Clinical Features

PURPOSE/OBJECTIVE(S)

The purpose of this study is to establish a prediction model for the development of grade 2 or higher radiation pneumonitis (RP) using radiomics analysis of pretreatment CT images, PET images, and dose distribution, in addition to clinical factors, in patients with locally advanced non-small cell lung cancer (NSCLC) treated with radical chemoradiotherapy.

MATERIALS/METHODS

We retrospectively evaluated 128 cases of locally advanced NSCLC treated with radical radiotherapy at our institution from 2008 to 2021. Clinical factors included age, sex, performance status (PS), KL-6, smoking history, histological type, clinical stage, and total radiation dose. Radiomics analysis was performed by analyzing treatment planning CT images, PET images, and dose distribution, and Rad-score (Radiomics-score) was calculated for the extracted features using Lasso-Cox regression. Rad-score (Radiomics-score) was calculated by Lasso-Cox regression for the extracted features. Risk factors were selected by univariate/multivariate analysis of clinical factors and Rad-score. Three models for predicting RP were developed from the identified risk factors using Nomogram: Clinical, Rad-score, and Combined model. The model was evaluated using area under the curve (AUC) based on receiver operating characteristic (ROC) curves and concordance index (C-index). RP was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The cumulative incidence of Grade 2 or higher RP was evaluated using the Kaplan-Meier method.

RESULTS

Of the 128 cases, grade 2 or higher RP was observed in 50 cases (39%). Regarding clinical factors, gender, smoking status, and histology were selected as significant predictors of RP. Lasso-Cox analysis of radiomics features selected 11 features from CT images, 7 features from PET images, and 16 features from dose distribution as predictors of RP, yielding a total of 34 factors. The combined model (C-index: 0.96, AUC: 0.92) showed the best discrimination performance compared to the clinical model (C-index: 0.73, AUC: 0.56) and the Rad-score model (C-index: 0.87, AUC: 0.92). Risk classification using the combined model showed that the 1-year cumulative incidence of grade 2 or higher RP was 65% in the high-risk group, significantly higher than 15% in the low-risk group (p<0.001).

CONCLUSION

The combined model with Rad-score and clinical factors can predict grade 2 or higher RP in NSCLC patients with high accuracy.

Acute and Postacute Clinical Characteristics of Coronavirus Disease 2019 in Children in Japan

BACKGROUND

The clinical features of coronavirus disease 2019 (COVID-19) in children have been changing because of the emergence and rapid spread of variants of concern (VOC). The increase in cases infected with VOC has brought concern with persistent symptoms after COVID-19 in children. This survey aimed to analyze the clinical manifestations and persistent symptoms of pediatric COVID-19 cases in Japan.

METHODS

We analyzed the clinical manifestations of pediatric COVID-19 cases reported between February 2020 and April 2022 in Japan, using a dedicated database updated voluntarily by the members of the Japan Pediatric Society. Using the same database, we also analyzed persistent symptoms after COVID-19 in children who were diagnosed between February 2020 and November 2021.

RESULTS

A total of 5411 and 1697 pediatric COVID-19 cases were included for analyzing clinical manifestations and persistent symptoms, respectively. During the Omicron variant predominant period, the percentage of patients with seizures increased to 13.4% and 7.4% in patient groups 1-4 and 5-11 years of age, respectively, compared with the pre-Delta (1.3%, 0.4%) or Delta period (3.1%, 0.0%). Persistent and present symptoms after 28 days of COVID-19 onset were reported in 55 (3.2%).

CONCLUSIONS

Our survey showed that the rate of symptomatic pediatric COVID-19 cases increased gradually, especially during the Omicron variant predominant period, and a certain percentage of pediatric cases had persistent symptoms. Certain percentages of pediatric COVID-19 patients had severe complications or prolonged symptoms. Further studies are needed to follow such patients.

The clinical characteristics of pediatric coronavirus disease 2019 in 2020 in Japan

BACKGROUND

The COVID-19 pandemic has affected the lives of people of all ages. Most reports on pediatric cases suggest that children experience fewer and milder symptoms than do adults. This is the first nationwide study in Japan focusing on pediatric cases reported by pediatricians, including cases with no or mild symptoms.

METHODS

We analyzed the epidemiological and clinical characteristics and transmission patterns of 840 pediatric (<16 years old) COVID-19 cases reported between February and December 2020 in Japan, using a dedicated database which was maintained voluntarily by members of the Japan Pediatric Society.

RESULTS

Almost half of the patients (47.7%) were asymptomatic, while most of the others presented mild symptoms. At the time of admission or first outpatient clinic visit, 84.0% of the cases were afebrile (<37.5°C). In total, 609 cases (72.5%) were exposed to COVID-19-positive household members. We analyzed the influence of nationwide school closures that were introduced in March 2020 on COVID-19 transmission routes among children in Japan. Transmission within households occurred most frequently, with no significant difference between the periods before and after declaring nationwide school closures (70.9% and 74.5%, respectively).

CONCLUSIONS

COVID-19 symptoms in children are less severe than those in adults. School closure appeared to have a limited effect on transmission. Controlling household transmission from adult family members is the most important measure for prevention of COVID-19 among children.

Comparative Analysis of Pediatric COVID-19 Infection in Southeast Asia, South Asia, Japan, and China

There is a scarcity of data regarding coronavirus disease 2019 (COVID-19) infection in children from southeast and south Asia. This study aims to identify risk factors for severe COVID-19 disease among children in the region. This is an observational study of children with COVID-19 infection in hospitals contributing data to the Pediatric Acute and Critical Care COVID-19 Registry of Asia. Laboratory-confirmed COVID-19 cases were included in this registry. The primary outcome was severity of COVID-19 infection as defined by the World Health Organization (WHO) (mild, moderate, severe, or critical). Epidemiology, clinical and laboratory features, and outcomes of children with COVID-19 are described. Univariate and multivariable logistic regression models were used to identify risk factors for severe/critical disease. A total of 260 COVID-19 cases from eight hospitals across seven countries (China, Japan, Singapore, Malaysia, Indonesia, India, and Pakistan) were included. The common clinical manifestations were similar across countries: fever (64%), cough (39%), and coryza (23%). Approximately 40% of children were asymptomatic, and overall mortality was 2.3%, with all deaths reported from India and Pakistan. Using the multivariable model, the infant age group, presence of comorbidities, and cough on presentation were associated with severe/critical COVID-19. This epidemiological study of pediatric COVID-19 infection demonstrated similar clinical presentations of COVID-19 in children across Asia. Risk factors for severe disease in children were age younger than 12 months, presence of comorbidities, and cough at presentation. Further studies are needed to determine whether differences in mortality are the result of genetic factors, cultural practices, or environmental exposures.

Changes in childhood vaccination during the coronavirus disease 2019 pandemic in Japan

Background

The coronavirus disease 2019 (COVID-19) pandemic has greatly affected daily life. COVID-19 often causes asymptomatic or mild disease in children; however, delayed routine childhood immunization is a concern, as it could increase the risk of vaccine-preventable disease. No study has evaluated the status of childhood vaccinations in Japan during the COVID-19 pandemic.

Methods

This retrospective observational study evaluated the number of vaccine doses administered to children in 4 Japanese cities (2 cities in the Tokyo metropolitan area and 2 cities far from Tokyo) during the period from 2016 to 2020. Vaccine doses administered between January and September 2020 during the COVID-19 pandemic were compared, by month, with those given during 2016–2019. Age-stratified demographic data were collected to determine whether factors other than change in the child population over time affected vaccination trends.

Results

In all cities the decrease in vaccine doses administered was most apparent in March and April 2020, i.e., just before or coincident with the declaration of a nationwide COVID-19 emergency on April 7, 2020. The decrease started as early as February in the Tokyo metropolitan area. As child age increased, the decrease became more apparent. Before the lift of national emergency on May 25, catch-up of the vaccination was observed in all age groups in all cities. Vaccine doses persistently increased in older age groups but not in infants. The overall vaccination trends did not differ significantly among the 4 cities.

Conclusions

The COVID-19 pandemic significantly affected routine childhood immunization in Japan. Thus, a nationwide electronic surveillance system and announcements for guardians to encourage timely routine immunization are warranted.

Willingness to Vaccinate Children against Influenza after the Coronavirus Disease 2019 Pandemic

OBJECTIVES

To determine factors associated with parents who plan to vaccinate their children against influenza next year, especially those who did not vaccinate against influenza last year using a global survey.

STUDY DESIGN

A survey of caregivers accompanying their children aged 1-19 years old in 17 pediatric emergency departments in 6 countries at the peak of the coronavirus disease 2019 (COVID-19) pandemic. Anonymous online survey included caregiver and child demographic information, vaccination history and future intentions, and concern about the child and caregiver having COVID-19 at the time of emergency department visit.

RESULTS

Of 2422 surveys, 1314 (54.2%) caregivers stated they plan to vaccinate their child against influenza next year, an increase of 15.8% from the previous year. Of 1459 caregivers who did not vaccinate their children last year, 418 (28.6%) plan to do so next year. Factors predicting willingness to change and vaccinate included child's up-to-date vaccination status (aOR 2.03, 95% CI 1.29-3.32, P = .003); caregivers' influenza vaccine history (aOR 3.26, 95% CI 2.41-4.40, P < .010), and level of concern their child had COVID-19 (aOR 1.09, 95% CI 1.01-1.17, P = .022).

CONCLUSIONS

Changes in risk perception due to COVID-19, and previous vaccination, may serve to influence decision-making among caregivers regarding influenza vaccination in the coming season. To promote influenza vaccination among children, public health programs can leverage this information.

Effect of a vaccine information statement (VIS) on immunization status and parental knowledge, attitudes, and beliefs regarding infant immunization in Japan

BACKGROUND

Because of the overabundance of vaccination information on the internet, in the media, and on social media, providing clear and correct information on immunization is critical for parental decision-making. In 2018, the Japan Pediatric Society created and distributed a Vaccine Information Statement (VIS) to provide appropriate immunization information to caregivers. The objectives of the present study were to evaluate the effect of the VIS on immunization rates, adherence to schedule, and parental understanding of immunization in Japan.

METHODS

This cross-sectional study was conducted at 18 centers in 2 prefectures in Japan. Caregivers were assigned to an intervention group, which received the VIS and a questionnaire when their child reached the age of 1 month, and a control group, which received only the questionnaire. Using the self-reported questionnaires, we evaluated vaccination rates and schedule adherence at age 2 months, and parental knowledge, attitudes, and beliefs regarding immunization. Three months later, the questionnaires were returned, and the findings were compared between the 2 groups.

RESULTS

We contacted 422 and 428 persons in the intervention and control groups, respectively, and 111/422 (26.3%) and 119/428 (27.8%) returned the surveys. Vaccination rates and adherence rates for the first dose of 4 recommended vaccines did not differ significantly (P > 0.25); however, there were some positive effects on items related to vaccine knowledge (P = 0.03), perceived benefits (P = 0.02), perceived barriers (P < 0.001), and perceived behavioral control (P = 0.01).

CONCLUSION

The VIS improved parent comprehension of infant immunization. Future studies should examine if the effects of such an intervention persist and affect vaccine uptake throughout childhood.

Comparison of immunization systems in Japan and the United States - What can be learned?

Recently, efforts have been made to fill a so-called "vaccine gap" between Japan and other countries; however, more work remains. Concerns about adverse events following immunization (AEFI) resulted in an historically passive approach to policy making in the National Immunization Program (NIP). For example, reports of AEFI following human papillomavirus vaccine (HPVV) in 2013 led the Japanese government to withdraw its proactive recommendations, resulting in a sharp drop in HPVV coverage rate to less than 1.0%. In this report, we review key historical incidents that led to the current immunization system in Japan, compare it to that in the United States, and discuss strategies for improving the Japanese immunization system. By strengthening existing policies and programs, such as National Immunization Technical Advisory Groups and AEFI reporting, compensation laws, and immunization education, the remaining vaccine gap in Japan could be filled.

Japanese physicians' attitudes and intentions regarding human papillomavirus vaccine compared with other adolescent vaccines

INTRODUCTION

Japan has experienced extremely low human papillomavirus vaccine (HPVV) coverage following the suspension of proactive governmental recommendations in 2013. Several studies have reported that recommendations from physicians increase adolescents' vaccine acceptance. In this survey, we evaluated the attitudes and intentions of Japanese physicians related to adolescent immunizations, particularly HPVV.

METHODS

We conducted a cross-sectional study using a mailed questionnaire targeting 330 Japanese physicians including 78 pediatricians, 225 internists and 27 obstetricians and gynecologists (OB/GYNs) in Kawasaki City, Japan in 2016. The survey measured physicians' reported frequency of educating adolescents about vaccines as well as their own perceptions and intentions related to adolescent immunizations.

RESULTS

Valid responses were obtained from 148 (45%) physicians. Though 53% agreed that the HPVV should be recommended, only 21% reported educating about HPVV. The majority of respondents (90%) agreed that they would restart HPVV for adolescents if the government reinstated its recommendation.

CONCLUSIONS

Although Japanese physicians reported support for adolescent immunizations, they were less likely to recommend or discuss HPVV compared with other adolescent vaccines. Responses indicated this was, at least in part, due to the lack of governmental support for HPVV, indicating that their recommendations would improve with government endorsement of the vaccine.

An intersection network based on combining SNP coassociation and RNA coexpression networks for feed utilization traits in Japanese Black cattle

Genome-wide association studies (GWAS) of quantitative traits have detected numerous genetic associations, but they encounter difficulties in pinpointing prominent candidate genes and inferring gene networks. The present study used a systems genetics approach integrating GWAS results with external RNA-expression data to detect candidate gene networks in feed utilization and growth traits of Japanese Black cattle, which are matters of concern. A SNP coassociation network was derived from significant correlations between SNPs with effects estimated by GWAS across 7 phenotypic traits. The resulting network genes contained significant numbers of annotations related to the traits. Using bovine transcriptome data from a public database, an RNA coexpression network was inferred based on the similarity of expression patterns across different tissues. An intersection network was then generated by superimposing the SNP and RNA networks and extracting shared interactions. This intersection network contained 4 tissue-specific modules: nervous system, reproductive system, muscular system, and glands. To characterize the structure (topographical properties) of the 3 networks, their scale-free properties were evaluated, which revealed that the intersection network was the most scale-free. In the subnetwork containing the most connected transcription factors (URI1, ROCK2, and ETV6), most genes were widely expressed across tissues, and genes previously shown to be involved in the traits were found. Results indicated that the current approach might be used to construct a gene network that better reflects biological information, providing encouragement for the genetic dissection of economically important quantitative traits.

Treatment With Quadrivalent Human Papillomavirus Vaccine for Juvenile-Onset Recurrent Respiratory Papillomatosis: Case Report and Review of the Literature

Although juvenile-onset recurrent respiratory papillomatosis (JoRRP) generally involves a benign tumor on the larynx and other respiratory tract areas, almost all patients with this disease require repeated surgical intervention (to prevent airway obstruction during the course of illness) and various adjuvant therapies such as interferon, cidofovir, acyclovir, ribavirin, indole-3-carbinol, HspE7, mumps vaccine, photodynamic therapy, propranolol, cimetidine, and bevacizumab. Some case reports recently described the effectiveness of the quadrivalent human papillomavirus vaccine (HPV4) as an adjuvant therapy. On the basis of these reports, we administered HPV4 to a 2-year-old boy with JoRRP. However, no therapeutic effect was found. A review of the available literature revealed that current evidence for the effectiveness of therapeutic HPV4 and other adjuvant therapies for JoRRP is inconsistent. Therefore, the prophylactic use of currently available HPV vaccine for adolescents is the most effective strategy for preventing not only anogenital cancers but also genital warts, which might be a risk factor for JoRRP among their children in the future.

Perception of Japanese Physicians about Human Papillomavirus Vaccine

Background

Current vaccination coverage of Human Papillomavirus vaccine (HPVV) in Japan is less than 1% because the Ministry of Health, Labour and Welfare (MHLW) suspended its proactive recommendations for HPVV in 2013 after some reports of possible adverse events following immunization. We evaluated the perception of Japanese physicians about HPVV in order to consider the appropriate countermeasure to improve HPVV coverage in Japan.

Methods

We conducted a cross-sectional study using a postal questionnaire targeting 330 Japanese physicians (78 pediatricians, 225 internists and 27 obstetricians-gynecologists (OB-GYNs)) in Kawasaki, Japan in 2016. The questionnaire comprised questions about education frequency, physicians’ perception and recommendation behavior related to adolescent vaccines (HPVV, diphtheria tetanus toxoid (DT) and inactivated influenza vaccine (IIV)).

Results

Valid responses were obtained from 148 (44.9%) physicians (pediatricians 80.8%, internists 31.6% and OB-GYNs 51.9%). Very few (8.0%) of physicians provided HPVV during the past month. Only 21.3% of physicians educated aggressively about HPVV, which was significantly less frequently than DT (61.7%) and IIV (88.6%). Similarly, 53.1% of physicians recommended HPVV aggressively, which was significantly less frequently than DT (83.1%) and IIV (80.3%). We found no significant differences in the frequency of HPVV education or recommendation by pediatricians, internists and OB/GYNs (22.4% vs. 16.9% vs. 35.7% and 54.8% vs. 47.9% vs. 71.5%, respectively). However, 90.0% of physicians answered that if MHLW were to reinstate its HPVV recommendation, they would more aggressively recommend HPVV for adolescents.

Conclusion

Although Japanese physicians were cautious about HPVV and infrequently provided education or made a recommendation for HPVV compared with other adolescent vaccines, our survey suggested such a passive attitude could be improved by the MHLW resuming its proactive recommendation in Japan.

Disclosures

All authors: No reported disclosures.

An infant with human parechovirus type 3 infection with a distinctive rash on the extremities

Human parechovirus type 3 (HPeV3) is known to cause sepsis-like syndrome and meningoencephalitis in neonates and young infants. We herein report a neonatal case of sepsis-like syndrome due to HPeV3 infection, diagnosed using polymerase chain reaction (PCR), with a distinctive erythematous rash present mainly on the soles and palms that helped in the diagnosis of the disease. Combining the unique characteristics of rash and confirmation by PCR at the early stage of the disease led to the diagnosis of HPeV3, distinguishing it from sepsis and other critical disease conditions, and allowing for appropriate, rapid management.

The value of radiographic findings for the progression of pandemic 2009 influenza A/H1N1 virus infection

Background

Most illnesses caused by pandemic influenza A (H1N1) pdm09 virus (A/H1N1) infection are acute and self-limiting among children. However, in some children, disease progression is rapid and may require hospitalization and transfer to a pediatric intensive care unit (PICU). We investigated factors associated with rapid disease progression among children admitted to hospital for A/H1N1 infection, particularly findings on initial chest radiographs.

Methods

In this retrospective study, we investigated the records of children who had received a laboratory or clinical diagnosis of A/H1N1 infection and were admitted to the largest children’s hospital in Japan between May 2009 and March 2010. The medical records were reviewed for age, underlying diseases, vital signs on admission, initial chest radiographic findings, and clinical outcomes. According to chest radiographic findings, patients were classified into 4 groups, as follows: [1] normal (n = 46), [2] hilar and/or peribronchial markings alone (n = 64), [3] consolidation (n = 64), and [4] other findings (n = 29). Factors associated with clinical outcomes were analyzed using logistic regression.

Results

Two hundreds and three patients (median 6.8 years) were enrolled in this study. Fifteen percent (31/203) of patients were admitted to PICU. Among 31 patients, 39% (12/31) of patients required mechanical ventilation (MV). When the initial chest radiographic findings were compared between patients with consolidation (n = 64) and those without consolidation (n = 139), a higher percentage of patients with consolidation were admitted to PICU (29.7% vs.8.6%, P < 0.001) and required MV (17.2% vs. 0.7%, P < 0.001). These findings remain significant when the data were analyzed with the logistic regression (P < 0.001, P < 0.001, respectively).

Conclusions

Consolidation on initial chest radiographs was the most significant factor to predict clinical course of hospitalized children with the 2009 A/H1N1 infection.

[Haemophilus influenzae type b vaccine]

Haemophilus influenzae type b (Hib) vaccine has been included in the national Immunization Program in more than 120 countries around the world and its effectiveness and safety have been confirmed. In Japan, Hib vaccine was recently licensed in December 2008. Because it has included in the category of voluntary vaccine and the burden of out-of-pocket expense is a major concern for caregivers, payment coverage through the local government funded by the temporal national budget has been initiated since November 2010. It is important to make an effort to fill the "vaccine gap" between Japan and other developed countries and increase a vaccine coverage rate including Hib vaccine to decrease vaccine preventable diseases in Japanese children.

Microsurgical anatomy for lateral approaches to the foramen magnum with special reference to transcondylar fossa (supracondylar transjugular tubercle) approach

Microsurgical anatomy for lateral approaches to the foramen magnum, especially for transcondylar fossa (supracondylar transjugular tubercle) approach, was studied using cadavers. The transcondylar fossa approach is an approach in which extradural removal of the posterior portion of the jugular tubercle through the condylar fossa is added to the far lateral approach. Some differences between this approach and the transcondylar approach are demonstrated. The atlanto-occipital joint and the jugular tubercle are obstacles for the lateral approaches. The condylar fossa forming the external occipital surface of the jugular tubercle is located supero-posterior to the occipital condyle. The fossa is limited laterally by the sigmoid sulcus and the jugular foramen. The posterior condylar canal communicating anteriorly with the distal end of the sigmoid sulcus, the jugular foramen, or the hypoglossal canal opens at the bottom of the fossa. The condyle is situated inferior to the posterior condylar and hypoglossal canals, and the jugular tubercle is located superior to them. In the transcondylar fossa approach the posterior part of the jugular tubercle is extradurally removed, but the condyle and the atlanto-occipital joint are untouched. On the other band, in the transcondylar approach the medial parts of the condyle and the lateral mass of Cl are removed. The latter approach offers better visualization of the inferior part of the foramen magnum. The essential difference of the two approaches is in the direction of looking and the extent of resection of the atlanto-occipital joint. Both approaches offer excellent view of the ventral dural space in the lower clivus and the foramen magnum, but the level of exposure differs somewhat between them. In the lateral approaches to the foramen magnum, the condylar fossa, the posterior condylar canal, and the posterior condylar emissary vein all play an important role as intraoperative anatomical landmarks.

The architecture of the arcuate eminence-a microanatomical study and its application to the transpetrosal approach

This study was performed to determine if the arcuate eminence can be drilled down without opening the semicircular canal to obtain a flatter operative field during an anterior or posterior transpetrosal approach. The depth of the superior semicircular canal from the top of the arcuate eminence was measured in 43 dry temporal bones. We found that the arcuate eminence was situated approximately 20 mm from the petrosigmoid intersection, and the superior semicircular canal was located 2.0 mm deep from the top of the arcuate eminence (range, 0.2 mm to 4.2 mm). The arcuate eminence consists of either (1) the otic capsule and additional overlying bone, (2) the naked otic capsule of normal thickness, or (3) the thinned otic capsule. In cases strictly selected by preoperative computed tomography, it may be possible to drill down the arcuate eminence with meticulous manipulation. The relationship between opening the semicircular canal and hearing preservation is also discussed.

Marked difference between adults and children in Bordetella pertussis DNA load in nasopharyngeal swabs

Bordetella pertussis is the aetiologic agent of whooping cough, a common cause of severe respiratory illness in children and prolonged mild cough in adults. To understand some of the reasons for differences in clinical symptoms between adults and children, we measured B. pertussis DNA loads in nasopharyngeal swabs (NPS) from 19 adults and 40 children (including 14 infants) by quantitative IS481 real-time PCR. All cases had been pre-diagnosed with the B. pertussis-specific loop-mediated isothermal amplification method. The mean PCR threshold cycles for adult and child NPS were 34.9 and 27.1, respectively, indicating a significantly lower B. pertussis DNA load in adults than in children (p <0.001). Moreover, adults had very low DNA loads during both early and later stages of the disease. When corresponding bacterial loads in NPS were calculated for B. pertussis Tohama cells using a standard curve, the mean number of bacterial cells taken with a rayon-tipped swab from an adult, older child and infant was estimated to be 320 (95% CI 120-910), 2.1 × 10⁴(95% CI 5.3 × 10³ to 8.3 × 10⁴) and 1.1 × 10⁶ cells (95% CI 1.2 × 10⁵ to 8.9 × 10⁶), respectively. This indicates that the B. pertussis load in NPS is closely correlated with patient age. Our observations suggest that adult pertussis is characterized by a lower bacterial load in the nasopharynx, resulting in milder symptoms and negative cultures.

Complete atrioventricular block as a complication of varicella in children

Although varicella is a benign and self-limited disease in children, serious complications can occur. We herein report a case of a 15-month-old boy who required a permanent pacemaker because of complete atrioventricular block as a complication of varicella. Universal vaccination is warranted to prevent such a potentially fatal complication in Japan where varicella is still endemic.

Risk factors of acute exacerbation of idiopathic pulmonary fibrosis

BACKGROUND

Although acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is a well known clinical condition, predicting risk factors remain unknown. We evaluated the frequency, risk factors and impact on survival of AE-IPF.

METHODS

We retrospectively studied patients diagnosed with IPF based on the criteria of the ATS/ERS consensus statement and followed them for periods of more than 3 years except in dead cases. Initial characteristics including the level of dyspnoea, which was assessed with the modified Medical Research Council (MRC) scale, and decline of forced vital capacity (FVC) defined by at least 10% decline at 6 months, were evaluated as possible risk factors for AE.

RESULTS

Seventy-four patients with IPF were studied. One-year, two-year, and three-year incidence of AE were 8.6%, 12.6%, and 23.9%, respectively. Multivariate analysis revealed that higher body mass index (BMI) [hazard ratio (HR), 1.20; 95% confidence interval (CI), 1.03-1.40], higher modified MRC scale [HR, 2.93; 95% CI, 1.46-5.85], and a decline in FVC at 6 mounths [HR, 0.97-2.60 (per mo); 95% CI, 1.01-7.45] were independent risk factors for AE-IPF. The causes of death were assessed to be AE in 20 of 57 expired patients. A stepwise multivariate Cox regression model evaluating AE-IPF, adjusted for %FVC and decline in FVC, demonstrated a statistically significant impact on overall survival [HR, 2.79; 95% CI, 1.59-4.88; p < 0.001].

CONCLUSION

These data suggest that initial high modified MRC scale, high BMI, and decline in FVC at 6 months were significant independent risk factors for AE-IPF. AE was an independent prognostic factor in IPF.

Measles Outbreak in a Suburb of Tokyo, Japan, in 1998-1999

A 1998-1999 outbreak of measles in Kawasaki City was studied to provide an up-to-date epidemiological understanding of the disease in Japan. 21 of the 69 total patients (30.4%) seen at the hospital were under 1 y of age. None of the 69 patients had received measles vaccine. 43 out of 50 nasopharyngeal swabs subjected to polymerase chain reaction assay (86%) were positive for the hemagglutinin (H) gene. The measles strain isolated from patients was classified as a D3 genotype. Such outbreaks are important epidemiologically, and these findings shed light on vaccination and immunity patterns in this urban population.

[Local reactions after diphtheria-tetanus-acellular pertussis vaccines in mice; changes in histopathology at the injection site]

Diphtheria-tetanus-acellular pertussis vaccine (DTaP) developed in Japan is now widely used worldwide. DTaP is safer than the diphtheria-tetanus-whole-cell pertussis vaccine (DTwP) and has fewer severe side effects, but local reactions such as redness, swelling, and induration are still reported. The pathophysiological mechanism of these reactions is controversial. To clarify the cause of local reactions, we conducted studies using the mouse model. After administering either one or two abdominal subcutaneous DTaP inoculations, we observed changes in histopathology at the injection site at 24h, 48h, and 7 days. The control group, inoculated with physiologic saline, showed no significant changes either pathologically or with the naked eye. All mice after DTaP vaccination showed indurations at the injection site. Pathologically, we watched leukocyte invasion into or around the site, especially neutrophils and eosinophils. After the first vaccination, the extent of the invasion was strong 24h and 7 days later. At 24h following the second vaccination, a dramatic leukocyte invasion seen persisted at 7days. At 7 days after the first vaccination, peripheral fibrosis had begun, and when a second vaccination was administered, it began even earlier at the second site. These histopathological changes show that local reactions are caused by both inflammatory and allergic responses. Because this mouse study resulted in the same pattern of reactions observed in humans, this method will be useful for studies focusing on local reactions.

Cutaneous necrosis after superficial temporal artery-to-middle cerebral artery anastomosis: is it predictable or avoidable?

OBJECTIVE

This study was carried out to determine whether a relationship exists between cutaneous necrosis after superficial temporal artery-to-middle cerebral artery anastomosis and background risk factors or surgical methods, and to determine whether such necrosis is predictable or avoidable.

METHODS

Forty-seven patients (a total of 51 sides) with atherosclerotic lesions of the internal carotid artery or middle cerebral artery who underwent superficial temporal artery-to-middle cerebral artery anastomosis at the National Kyushu Medical Center Hospital between September 1, 1994, and August 31, 1999, were reviewed. Each procedure was analyzed to determine whether cutaneous necrosis was present postoperatively around the donor site, whether preexisting risk factors (hypertension, diabetes mellitus, hyperlipidemia, ischemic heart disease, and arteriosclerosis obliterans) were present, and whether a flap or cutdown method or a single or double anastomosis was performed.

RESULTS

Postoperative necrosis was clearly related to arteriosclerosis obliterans (P < 0.003). The tendency for a relationship between necrosis and smoking was noted. Although statistical analysis failed to demonstrate a significant difference, necrosis was found with the flap method but not with the cutdown method.

CONCLUSION

Further study is needed using greater numbers to clarify the relationship between the surgical method and the presence of necrosis. To prevent cutaneous necrosis, however, it may be preferable to use the cutdown method in patients with the preexisting risk factors of arteriosclerosis obliterans or in smokers.

Hearing restoration from deafness after resection of a large cerebellopontine angle meningioma--case report

A 61-year-old man presented with a large cerebellopontine angle meningioma manifesting as a 1-year history of deafness on the right side, in whom hearing was restored from the deaf state immediately after tumor resection. Neuroimaging demonstrated a large mass in the right cerebellopontine angle, originating at the region adjacent to the jugular foramen. Audiometry showed his hearing was off-scale (> 105 dB) on the right. The tumor was successfully removed through the retrosigmoid approach, and the integrity of the 7th and 8th cranial nerves was maintained. The patient regained hearing on the day after the operation, which continued to improve until near-normal. The 8th cranial nerve function may recover dramatically after removal of non-acoustic tumors, even if preoperative hearing loss is profound. To maximize the opportunity to regain hearing, approaches which devastate cochlear function should be avoided and more meticulous manipulation during tumor removal is needed.

[Extracranial metastasis of glioblastoma to the lung and heart with a histological resemblance to small cell carcinoma of the lung: an autopsy case]

An autopsy case of small cell glioblastoma, showing multiple extracranial metastases, is reported with special reference to histopathological differentiation from metastatic small cell carcinoma. Widely spread lesions in the bilateral lungs were developed after an operation and chemo-radiotherapy for glioblastoma, and the lung lesions led to fatal respiratory failure. Postmortem examination revealed multiple tumors in the lung, lymph nodes, and the heart, as well as local invasion of the primary tumor to the dura, skull, and the scalp. The mechanism of extracranial metastasis of brain tumor is discussed.

[A case of gliomatosis cerebri: remarkable improvement after radiation therapy]

A 30-year-old female case of gliomatosis cerebri, which showed remarkable improvement after radiation therapy is reported. The lesion had spread widely in the frontal and parietal lobes of both sides, causing diffuse swelling of the cerebral hemispheres. A specimen obtained by open biopsy revealed diffuse proliferation of astrocytic (GFAP positive) tumor cells, associated with little tissue destruction. After whole-brain radiation of 60 Gy, the lesion shrunk gradually but markedly. Hemiparesis and mild dementia, which the patient had experienced before treatment, subsided completely within 6 months, until she was able to restart her job as a dentist. Although gliomatosis cerebri is thought to have a poor prognosis, this case demonstrates the potential of radiotherapy for this disease. Factors which may lead to a better outcome are discussed.

Interleukin-8 and SDF1-alpha mRNA expression in colonic biopsies from patients with inflammatory bowel disease

OBJECTIVES

Interleukin-8 (IL-8) as an alpha-chemokine recruits and activates neutrophils, which are abundant in the intestinal lesions of ulcerative colitis (UC) and Crohn's disease (CD). Stromal cell-derived factor 1 (SDF1-alpha) is a new chemokine that is chemotactic to neutrophils. The aims of this study were to assess the relative expression of SDF1-alpha and IL-8 mRNA in different colonic regions and patients with inflammatory bowel disease with varied degrees of inflammation in the colon.

METHODS

Colon biopsy samples were obtained from 19 patients with UC, 12 with CD, and 5 with irritable bowel syndrome (IBS) who underwent colonoscopy. Levels of IL-8 and SDF1-alpha mRNA expression were measured semiquantitatively by reverse-transcription and polymerase chain reaction amplification. The cytokine mRNA levels were corrected for glyceraldelyde-3-phosphate dehydrogenase mRNA expression.

RESULTS

IL-8 mRNA expression was significantly correlated with SDF1-alpha expression in normal biopsies from IBS patients (r = 0.58, p < 0.01). There was no significant difference in cytokine mRNA expression (IL-8 or SDF1-alpha) across different regions of the colon or rectum in uninflamed normal biopsies. The IL-8 mRNA expression ratios in UC (mean +/- SD, 1.03 +/- 0.52) and CD (0.90 +/- 0.38) patients were significantly higher than in IBS (0.52 +/- 0.17) (p < 0.01, p < 0.05, respectively). The SDF1-alpha mRNA expression ratio in UC (0.30 +/- 0.52) was higher than in both CD (0.21 +/- 0.10) and IBS patients (0.22 +/- 0.11) (p < 0.01, <0.05, respectively). A statistically significant correlation was found between the IL-8 mRNA expression and the colonic inflammation in UC patients (r = 0.44, p < 0.05) but not for SDF1-alpha expression in UC patients.

CONCLUSIONS

IL-8 but not SDF1-alpha mRNA expression was associated with inflammation in UC. This suggests that IL-8 may play a more important role in inflammatory bowel disease than does SDF1-alpha.

Proximal gastrectomy and gastric tube reconstruction for early cancer of the gastric cardia

BACKGROUND

Advances in diagnostics and techniques have increased the number of detections of early cancer of the gastric cardia. The aim of this report is to describe a new technique of proximal gastrectomy and gastric tube reconstruction using an autosuture stapler.

METHODS

At operation, the upper part of the stomach was fully mobilized, and the abdominal esophagus was transected. The stomach was cut between the points of the distal three fourths of the lesser curvature and a half of the greater curvature, and a gastric tube measuring 20 cm in length and 4 cm in width was made. A circular stapler was inserted through a stapled line, and direct anastomosis between the esophagus and gastric tube was completed.

RESULTS

When compared with the patients who underwent proximal gastrectomy and jejunal interposition, those who underwent gastric tube reconstruction showed a significantly shorter operation time. All 3 patients who underwent proximal gastrectomy and gastric tube reconstruction recovered uneventfully and took foods satisfactorily. Good passage through the gastric tube was recognized on roentgenography, and reflux esophagitis or stomal ulcer was not found on fiberscopy.

CONCLUSIONS

We believe the procedure is technically simple and safe, and provides good postoperative results in patients with early cancer of the gastric cardia.

Trajectory of the hypoglossal nerve in the hypoglossal canal: significance for the transcondylar approach

A microanatomical study of the hypoglossal canal and its surrounding area was carried out using dry skulls and cadaveric heads to determine the course of the hypoglossal nerve in the hypoglossal canal, especially the significance for the transcondylar approach. The hypoglossal nerve enters the superomedial part of the hypoglossal canal as two bundles, which then change course abruptly to an anterosuperior direction, and unite as one trunk before exiting the canal. The hypoglossal nerve has an oblique course in the canal rather than being located in the center, and exits through the inferolateral part of the canal. A venous plexus surrounds the entire length of the nerve bundles in the canal. The present results suggest that during drilling the occipital condyle toward the hypoglossal canal from behind, the surgeon does not need to be overly concerned even if some bleeding occurs from the posterolateral edge of the hypoglossal canal.