Within and between classroom transmission patterns of seasonal influenza among primary school students in Matsumoto city, Japan.

Schools play a central role in the transmission of many respiratory infections. Heterogeneous social contact patterns associated with the social structures of schools (i.e., classes/grades) are likely to influence the within-school transmission dynamics, but data-driven evidence on fine-scale transmission patterns between students has been limited. Using a mathematical model, we analyzed a large-scale dataset of seasonal influenza outbreaks in Matsumoto city, Japan, to infer social interactions within and between classes/grades from observed transmission patterns. While the relative contribution of within-class and within-grade transmissions to the reproduction number varied with the number of classes per grade, the overall within-school reproduction number, which determines the initial growth of cases and the risk of sustained transmission, was only minimally associated with class sizes and the number of classes per grade. This finding suggests that interventions that change the size and number of classes, e.g., splitting classes and staggered attendance, may have a limited effect on the control of school outbreaks. We also found that vaccination and mask-wearing of students were associated with reduced susceptibility (vaccination and mask-wearing) and infectiousness (mask-wearing), and hand washing was associated with increased susceptibility. Our results show how analysis of fine-grained transmission patterns between students can improve understanding of within-school disease dynamics and provide insights into the relative impact of different approaches to outbreak control.

Determinant factors behind changes in health-seeking behaviour before and after implementation of universal health coverage in Indonesia.

BACKGROUND: The health insurance system in Indonesia was transformed in 2014 to achieve universal health coverage (UHC). The effective implementation of essential primary health services through UHC has resulted in efficient healthcare utilisation, which is reflected in the health-seeking behaviour of the community. Our study aimed to examine the changes in health-seeking behaviour before and after the implementation of UHC in Indonesia and to identify what factors determine these changes. METHODS: We conducted a retrospective cohort study using the recall method and data collected through questionnaire-based interviews in Bandung, Indonesia. We used a two-step sampling technique-randomised sampling and purposive sampling, and a total of 579 respondents with acute or chronic episodes were recruited. [Formula: see text] tests were used to identify the association between factors. Difference in difference model and a logistic regression model for binary outcomes were used to estimate the effect of the implementation of UHC on the health-seeking behaviour. RESULTS: Utilisation of public health facilities increased significantly after implementation of UHC, from 34.9% to 65.4% among the respondents with acute episodes and 33.7% to 65.8% among those with chronic episodes. The odds of respondents going to health facilities when they developed an acute episode increased after the implementation of UHC (OR = 1.22, p = 0.05; AOR = 1.42, p < 0.001). For respondents experiencing chronic episodes, the implementation of UHC increased the odds ratio (OR = 1.74, p < 0.001; AOR = 1.64, p < 0.001) that they would use health facilities. Five years after the implementation of UHC, we still found respondents who did not have health insurance (26 and 19 respondents among those with acute episode and chronic episode, respectively). CONCLUSIONS: The effect of the implementation of UHC seemed greater for those experiencing chronic episodes than for those with an acute episode. Although the implementation of UHC has improved utilisation of public health facilities, the presence of people who are not covered by health insurance is a potential problem that could threaten future improvements in healthcare access and utilisation.

Childhood Tuberculosis in Mongolia: Trends and Estimates, 2010-2030.

Mongolia was listed among the 30 countries with a high tuberculosis burden in 2021. Approximately 10-11% of the tuberculosis cases are of children, which is higher than the global average (6.0%). As children are a vulnerable population, it is important to understand the current situation and prioritize the development of tuberculosis prevention strategies. However, only few studies have addressed childhood tuberculosis in Mongolia. Therefore, we aimed to describe the characteristics of childhood tuberculosis and to show its trends and estimates in Mongolia. We performed descriptive and trend analyses on secondary data from the National Center for Communicable Diseases from 2010 to 2020. A total of 4,242 childhood tuberculosis cases, compiled from nine districts of the capital city and 21 provinces, were analyzed. We found that tuberculosis occurred more frequently in school-age children, and 71.8% of the all cases were an extrapulmonary tuberculosis. Trend analysis revealed that childhood tuberculosis continuously increased with fluctuations from 2018 onwards. The central region, including the capital city of Ulaanbaatar, is the most tuberculosis-burdened. Childhood tuberculosis is estimated to increase in the central region and decrease in the others from 2021 to 2030. Our findings showed that the national childhood tuberculosis trend is increasing, although there are differences in the pattern between regions. Further studies are needed to identify the determinant factors of regional differences, and age-specific public health interventions, such as scale-up screening and preventive treatment, are in demand in high-prevalence areas.

Fine-scale family structure shapes influenza transmission risk in households: Insights from primary schools in Matsumoto city, 2014/15.

Households are important settings for the transmission of seasonal influenza. Previous studies found that the per-person risk of within-household transmission decreases with household size. However, more detailed heterogeneities driven by household composition and contact patterns have not been studied. We employed a mathematical model that accounts for infections both from outside and within the household. The model was applied to citywide primary school seasonal influenza surveillance and household surveys from 10,486 students during the 2014/15 season in Matsumoto city, Japan. We compared a range of models to estimate the structure of household transmission and found that familial relationship and household composition strongly influenced the transmission patterns of seasonal influenza in households. Children had a substantially high risk of infection from outside the household (up to 20%) compared with adults (1-3%). Intense transmission was observed within-generation (between children/parents/grandparents) and also between mother and child, with transmission risks typically ranging from 5-20% depending on the transmission route and household composition. Children were identified as the largest source of secondary transmission, with family structure influencing infection risk.

High vaccination coverage is associated with low epidemic level of seasonal influenza in elementary schools: an observational study in Matsumoto City, Japan.

BACKGROUND: Influenza virus transmission may be prevented by infection control measures, including vaccination, wearing a mask, gargling with water, and hand washing. It is unclear, however, whether these measures affect influenza epidemics in school settings. METHODS: A prospective epidemiological survey in all public elementary schools in Matsumoto City, Japan, during the 2014/2015 season evaluated the number of diagnosed patients in each school and calculated the reproduction number of schoolchildren. At the end of the prospective survey, a cross-sectional survey evaluated the implementation of infection control measures in these schools. Both results were combined and associations among infection control measures including vaccination, mask wearing, hand washing, water gargling, and epidemic level were evaluated. RESULTS: Of the 13,217 schoolchildren in 29 schools, 2548 were diagnosed with seasonal influenza. A significant negative association was observed between vaccination coverage and reproduction number at each school, but not between other infection control measures and the reproduction number. A regression curve with exponential function was most predictive. At 0% vaccination, the reproduction number was estimated to be 1.39. CONCLUSION: These findings provide evidence that high vaccination coverage was associated with reduced epidemic levels in schools and suggest the need for increased vaccination of schoolchildren.

Individual background factors associated with vaccination for seasonal influenza in Japanese schoolchildren.

There is little evidence about how individual background factors affect seasonal influenza vaccination of children. At the end of the 2014/2015 influenza season, a cross-sectional questionnaire survey of all elementary schoolchildren in 29 schools in Matsumoto City, Japan, was conducted to obtain information about vaccine uptake activity and individual background factors. Of the 10,524 subjects who responded, 5063 (48.1%) had been vaccinated. Grade in school, underlying disease, number of siblings, and diagnosis with and vaccination for influenza during the previous influenza season differed significantly in vaccinated and unvaccinated groups. Multivariate logistic regression showed that underlying disease and vaccination during the previous influenza season was associated with a higher rate of vaccination, whereas higher grade in school and having ≥3 siblings was associated with a lower rate of vaccination. The findings may be useful to promote a vaccination policy recommending financial support to households with many children or to encourage higher uptake of vaccination in higher grade children.

Candida concentrations determined following concentrated oral rinse culture reflect clinical oral signs.

BACKGROUND: Oral candidiasis is an infection caused by a yeast-like fungus called Candida. Various methods can be used to isolate Candida from the oral cavity. However, it is difficult to correctly and satisfactorily diagnose oral candidiasis because currently no microbiological or laboratory standards based on samples from the oral cavity are available. The aim of this study is to establish a reliable laboratory test for diagnosing oral candidiasis. METHODS: Oral swab, rinse and concentrated rinse samples were obtained from 200 consecutive outpatients (103 male patients and 97 female patients; mean age, 47.2 years; age range, 9-89 years). Candida colonies from cultured samples were enumerated to compare the sensitivities and specificities of the above sampling methods, and the associations between Candida detection or concentration and the clinical oral signs were examined. RESULTS: The mean colony numbers were 263 ± 590 CFU/swab for the swab method, 2894 ± 6705 CFU/100 µL for the rinse method, and 9245 ± 19,030 CFU/100 µL for the concentrated rinse method. The median numbers were 23 CFU/swab for the swab method, 56 CFU/100 µL for the rinse method, and 485 CFU/100 µL for the concentrated rinse method. Candida was detected in the oral cavity of 33.5 % and 52.0 % of the outpatients by the swab method and concentrated rinse, respectively. Candida concentrations determined by the concentrated rinse were closely related to the severity of the clinical oral signs. The positive predictive values of residual root, redness of the oral mucosa, denture, glossalgia, dry mouth, and taste disorder were useful predictors of oral candidiasis. CONCLUSIONS: Concentrated rinse sampling is suitable for evaluating oral candidiasis, and Candida concentrations examined using this method strongly associated with the oral signs associated with Candida infection.

Role of household factors in parental attitudes to pandemic influenza-related school closure in Japan: a cross-sectional study.

BACKGROUND: To investigate how household background factors affect parental behavior during pandemic influenza-related school closures, we determined associations between such factors and three parental attitudes: "caring for the child", "taking leave from work", and "permitting out-of-home activities". METHODS: A hypothetical pandemic influenza situation was presented and a questionnaire survey among households of 2146 schoolchildren from 6 schools was conducted. Odds ratios of background factors were estimated using univariate and multivariate logistic regression models. RESULTS: Responses pertaining to 1510 children indicated that junior high school (OR = 0.11), both parents working (OR = 0.03), and family including grandparent(s) or other relatives (OR = 7.50) were factors associated with "caring for the child", and elementary school (OR = 2.28), special education school (OR = 3.18), and both parents working (OR = 5.74) were associated with "taking leave from work". Having an older sibling (OR = 0.74) and awareness of the technical term for school closure (OR = 0.73) were factors associated with "permitting out-of-home activities". CONCLUSION: Not only work status but also other household factors may be associated with parental behaviors during pandemic influenza-related school closures.

Evaluation of the spread of pandemic influenza A/H1N1 2009 among Japanese university students.

The pandemic influenza A/H1N1 2009 virus is commonly known to affect younger individuals. Several epidemiological studies have clarified the epidemic features of university students in Japan. In this study, we reviewed these studies in Japan in comparison with reports from other countries. The average cumulative incidence rate among university students was 9.6 %, with the major symptoms being cough, sore throat, and rhinorrhea. These epidemiological features were similar between Japan and other countries. Attitudes and behaviors toward pandemic influenza control measures were different before and improved during and after the epidemic. These features were also similar to those in other countries. On the other hand, the epidemic spread through club activities or social events, and transmission was attenuated after temporary closure of such groups in Japan. This transmission pattern was inconsistent among countries, which may have been due to differences in lifestyle and cultural habits. Based on these results, infection control measures of pandemic influenza for university organizations in Japan should be considered.

Prevalence and risk factors for medication-refractory reflux esophagitis in patients with systemic sclerosis in Japan.

BACKGROUNDS: Patients with systemic sclerosis (SSc) often have esophageal motility abnormalities and weak esophago-gastric junction (EGJ) barrier function, which causes proton pump inhibitor (PPI)-refractory reflux esophagitis (RE). The aims of this study were to clarify the current management of RE and prevalence and risk factors of medication-refractory RE in patients with SSc in Japan. METHODS: A total of 188 consecutive patients with SSc who underwent both esophageal high-resolution manometry (HRM) and esophagogastroduodenoscopy (EGD) were reviewed. The presence of RE and grades of the gastroesophageal flap valve (GEFV) were assessed. Esophageal motility was assessed retrospectively according to the Chicago classification v3.0. When RE was seen on a standard dose of PPI or any dose of vonoprazan (VPZ), it was defined as medication-refractory RE. RESULTS: Approximately 80% of patients received maintenance therapy with acid secretion inhibitors regardless of esophageal motility abnormalities. Approximately 50% of patients received maintenance therapy with PPI, and approximately 30% of patients received VPZ. Medication-refractory RE was observed in 30 patients (16.0%). In multivariable analyses, the number of EGD and absent contractility were significant risk factors for medication-refractory RE. Furthermore, combined absent contractility and GEFV grade III or IV had higher odds ratios than did absent contractility alone. CONCLUSIONS: Patients with persistent reflux symptoms and those with absent contractility and GEFV grade III or IV should receive maintenance therapy with strong acid inhibition to prevent medication-refractory RE.

Evaluation of factors affecting variations in influenza A/H1N1 history in university students, Japan.

Although the natural history of H1N1 has been found to vary among patients, little is known about the factors that affect these variations. Infected patients with an extended infection history may shed virus longer and spread infection. To further clarify these variations, we evaluated the natural history of H1N1 infection in 324 university students using a descriptive epidemiological method and analyzed factors affecting the natural history of infection. The median times from infection to fever development and from fever development to cure were 2 days (range 0-8 days) and 5 days (range 1-12 days), respectively, and the median time not attending classes was 5 days (range, 1-13 days). Variations in H1N1 natural history were associated with both environmental and individual factors, including route of infection, grade, gender, epidemic period, respiratory and gastrointestinal symptoms and headache. Steps affecting these factors may help control variations in H1N1 natural history and may enhance infection control measures.

Does change of residence affect pollinosis? A study of Japanese university students.

The effects of change of residence on pollinosis symptoms remain unclear. We investigated the effects of geographical change of residence on pollinosis symptoms among university freshmen. All freshmen (n = 2142) entering Shinshu University in 2011 completed self-administered questionnaires. Associations between history of pollinosis and environmental factors were assessed. Subjects were classified into three groups according to pollen count at previous residences (stationary, low pollen, and high pollen). Pollinosis both before and after relocation were compared among and within the groups. Of the 1558 subjects, 540 (34.7%) developed pollinosis before and 483 (31.0%) after entering university. The rates of pre- and post-university entrance pollinosis were 40.0 and 32.5% in the high pollen group (P < 0.001) but were similar in the other two groups. Pollinosis symptoms decreased among students that moved from high to low pollen areas, indicating that pollinosis was affected by geographic environmental factors.

Rate of diagnosed seasonal influenza in children with influenza-like illness: A cross-sectional study.

INTRODUCTION: Although influenza surveillance systems have been used to monitor influenza epidemics, these systems generally evaluate diagnostic information obtained from medical institutions and they do not include patients who have not been examined. In contrast, community based epidemiological studies target people with influenza-like illness (ILI) that self-reported influenza-like symptoms whether they have medical examinations or not. Because the criteria for influenza surveillance systems and ILI differ, there is a gap between them. The purpose of this study was to clarify this gap using school-based survey data. METHODS: Questionnaires about both ILI and the influenza diagnosis history during the 2018/19 season were administered to the guardians of 11,684 elementary schoolchildren in a single city in Japan. Based on their responses, a Bayesian model was constructed to estimate the probability of infection, ILI onset, and diagnosis at medical institutions. RESULTS: Responses were obtained from guardians of 10,309 children (88.2%). Of these, 3,380 children (32.8%) had experienced ILI, with 2,380 (23.1%) diagnosed as influenza at a medical institution. Bayesian estimation showed that the probability of influenza cases being diagnosed among ILI symptomatic children was 70% (95% credible interval, 69-71%). Of the infected children, 5% were without ILI symptoms, with 11% of these patients diagnosed with influenza. CONCLUSIONS: This epidemiological study clarified the proportion gap between ILI and influenza diagnosis among schoolchildren. These results may help to establish epidemic control measures and secure sufficient medical resources.

The association between the dynamics of COVID-19, related measures, and daytime population in Tokyo.

In Japan, a novel coronavirus has been prevalent since January 2020. The Japanese and local governments have implemented various measures, including declaring a state of emergency, according to the epidemic situation in each region. This study estimated the effective reproduction number (Rt) using the number of confirmed positive cases and positivity rates in Tokyo and examined the association between Rt and the rate of increase/decrease in the number of people across 12 sites. In Tokyo, there were five waves in which Rt was persistently estimated as approximately 1.0. The fourth and fifth waves started under the declaration of the state of emergency and coincided with an increase in the number of people. However, the contribution of the number of people to Rt was inconsistent, even when the number of people was of the same magnitude. A possible reason for this is difference in the countermeasures content, as the impact of vaccination was considered to be minor at the time. Where vaccination is insufficient, the wave is terminated by controlling the number of people leaving their homes. It is suggested that infection could be controlled more efficiently, depending on the content of the countermeasures.

Current Issues in Social Medicine and Public Health from the Viewpoint of Early-career Researchers: Summary of Opinions at the Social Medicine Young Retreat.

The coronavirus disease 2019 (COVID-19) pandemic highlighted the importance of research, practice, social contribution, and education in social medicine and public health, which relate to the core mission of universities. Early-career researchers and professionals play an important role in these domains, but little is known about the challenges and issues they encountered or recognized during this pandemic. Therefore, we summarized the opinions of 37 participants (30 early-career researchers and seven senior researchers) on this issue from discussions at the Social Medicine Young Retreat, 2019, of the Japanese Medical Science Federation. The retreat was initially planned to be held during March 5-6, 2020 in Yamanashi but was changed to be held virtually on March 5, 2021. Early-career researchers participated in group discussions on how social medicine should transform itself to serve the public during the COVID-19 pandemic. Afterward, each group provided opinions on challenges and issues in social medicine. For example, participants perceived difficulties in implementing research in a timely way and the lack of multidisciplinary collaboration. They recognized challenges in continuing practice because of the limited evidence on COVID-19. On social contribution, they described difficulties in communicating risk as professionals. They also noted issues arising from online teaching and learning. One group suggested that the essence of social medicine did not need to be changed, but methodologies should be updated to tackle multiple existing challenges. These opinions may not cover all issues but could help establish a better relationship between medicine and society in a bottom-up manner. The continuous promotion of interdisciplinary collaboration in social medicine (and basic and clinical medicine) would provide ideas to solve these issues at scale. Organizational support is warranted to ensure sustainability and scalability of these actions.

Swine-origin influenza a outbreak 2009 at Shinshu University, Japan.

BACKGROUND: A worldwide outbreak of swine flu H1N1 pandemic influenza occurred in April 2009. To determine the mechanism underlying the spread of infection, we prospectively evaluated a survey implemented at a local university. METHODS: Between August 2009 and March 2010, we surveyed 3 groups of subjects: 2318 children in six schools attached to the Faculty of Education, 11424 university students, and 3344 staff members. Subjects with influenza-like symptoms who were diagnosed with swine flu at hospitals or clinics were defined as swine flu patients and asked to make a report using a standardized form. RESULTS: After the start of the pandemic, a total of 2002 patients (11.7%) were registered in the survey. These patients included 928 schoolchildren (40.0%), 1016 university students (8.9%), and 58 staff members (1.7%). The incidence in schoolchildren was significantly higher than in the other 2 groups (P < 0.0001) but there were no within group differences in incidence rate between males and females. During the period of the survey, three peaks of patient numbers were observed, in November 2009, December 2009, and January 2010. The first peak consisted mainly of schoolchildren, whereas the second and third peaks included many university students. Staff members did not contribute to peak formation. Among the university students, the most common suspected route of transmission was club activity. Interventions, such as closing classes, schools, and clubs, are likely to affect the epidemic curves. CONCLUSION: Schoolchildren and university students are vulnerable to swine flu, suggesting that avoidance of close contact, especially among these young people, may be effective way in controlling future severe influenza pandemics, especially at educational institutions.

Changes in Numbers of COVID-19 Cases among Residents of Tourist Resort Areas before and during the "Go To Travel" Campaign: Descriptive Epidemiology in Gunma Prefecture.

The "Go To Travel" campaign in Japan, which encouraged people to travel throughout the country, was implemented in July 2020 to revitalize economic activity that was sluggish due to COVID-19. Although the risk of the spread of infection has been reported for tourists crossing prefectural borders, the spread of infection among residents living in tourist areas is unclear. The present study evaluated the number of COVID-19 cases among residents of tourist resort areas in Gunma Prefecture using a descriptive epidemiological method. Data regarding infected individuals were obtained from public data available on the prefecture's official homepage. Evaluation of epidemic curves showed that the number of cases increased slightly after the start of the campaign, with numbers affected by the occurrence of clusters. Toward the end of 2020, the number of cases increased in both resort and non-resort areas, although the increase was smaller in resort areas. Thus, the increased transmission of cases during the campaign suggested a need to take additional preventive measures, more-so for tourists than for resort area residents.

Effects of influenza vaccination on seasonal influenza symptoms: A prospective observational study in elementary schoolchildren in Japan.

Although influenza vaccine has been shown to prevent influenza symptom onset, its further beneficial effects after vaccinated individuals become symptomatic remain undetermined. This epidemiological survey compared influenza symptoms in subjects diagnosed with influenza who were and were not vaccinated. A prospective survey was performed among the 13,217 schoolchildren who attended all 29 public elementary schools in Matsumoto City, Nagano Prefecture, Japan, during the 2014/2015 influenza season. Information about symptoms and background demographic and clinical factors were obtained from a questionnaire. Of these schoolchildren, 2,548 were diagnosed with influenza and 1,122 were previously vaccinated and 1,426 were unvaccinated. Fever duration and frequency of symptoms and hospitalization were compared in vaccinated and unvaccinated children. The hospitalization rate was lower in vaccinated children, whereas symptom frequency and fever duration were similar in the two groups. This study showed that hospitalization was less in vaccinated children. Vaccination may attenuate symptom intensity after symptom onset.

Prevalence and clinical characteristics of earlobe crease in systemic sclerosis: Possible association with vascular dysfunction.

Patients with systemic sclerosis (SSc) develop various vasculopathy-induced vascular disorders such as Raynaud's phenomenon, abnormal nail-fold capillaries, persistent digital ischemia, digital ulcers (DU), and sometimes develop renal crisis and pulmonary artery hypertension (PAH), affecting prognosis. Earlobe crease (ELC), also known as Frank's sign, is a wrinkle extending from the tragus to the outer border of the earlobe and is generally recognized as the sign of cardiovascular events. However, no previous study analyzed the association between ELC and SSc. In this study, we examined the prevalence and clinical characteristics of ELC in SSc patients. We analyzed 145 Japanese SSc patients and found that the prevalence of ELC in SSc patients was 23.4% (43/145), similar to that previously reported in the general population without SSc. Using univariate analysis, we found that SSc patients with ELC were characterized by old age, high incidence of DU, ILD and PAH, and high complication of coronary artery diseases (CAD) compared with SSc patients without ELC. In multivariate analysis, ELC was significantly associated with old age and incidence of DU. PAH tended to correlate with ELC without statistical significance. These results suggest that ELC may be associated with vascular disorders in SSc patients. This is the first report concerning the prevalence and clinical characteristics of ELC in patients with SSc. ELC is very easy to detect in clinical practice and helps physicians to identify SSc patients at risk of developing vascular disorders such as DU and PAH.

Expression profile of liver genes in response to hepatotoxicants identified using a SAGE-based customized DNA microarray system.

Gene expression analysis using customized or focused DNA microarrays is favorable because of a reduction in the cost and time needed for the analysis. To examine the effect of chemicals on the liver, we developed an in-house cDNA microarray system, mouse Liver Stress Array ver. 1.0, containing 355 unique genes involved in drug metabolism, inflammation and liver-related proteins. These genes were selected for sensing the homeostasis of the liver and based on the information of liver transcriptome revealed by serial analysis of gene expression. By using this customized microarray, we analyzed gene expression changes in the mouse liver treated by 11 known hepatotoxicants. Gene expression measurements corresponding to the in vivo response to known hepatotoxicants revealed that profiles of chemicals with similar mechanisms clustered together. For each of the chemicals tested, several genes that were induced or repressed were common in each chemical exposure, whereas other genes were unique for the specific class compound. Ingenuity pathways analysis revealed that significant alterations in gene expression occurred in a number of biological networks by these treatments. Although the genes spotted on our array was limited to a highly focused set for toxicity classification, this work provides proof of concept that patterns of gene regulation assessed by a focused array system are useful to classify unknown chemicals.