Mitsuo Uchida

Aim: Endometriosis affects 6%–10% of women of reproductive age and is associated with chronic pelvic pain, infertility, and impaired quality of life. The endometriosis fertility index (EFI) predicts spontaneous pregnancy postoperatively, but requires operative findings, limiting its use in non‐surgical cases. This study evaluated whether magnetic resonance imaging (MRI) could serve as an alternative to EFI. Methods: This retrospective study included 34 women aged 18–43 years who underwent laparoscopic ovarian cystectomy at Gunma University Hospital (2018–2022). Surgical videos were reviewed to calculate EFI. Preoperative MRI findings were assessed using ovarian cyst shape, ovarian position, and follicle location. MRI indicators were compared with EFI surgical factor scores using logistic regression. Results: The mean EFI was 5.7 ± 1.8. Abnormal follicle location on MRI significantly correlated with lower EFI surgical factor scores ( p < 0.05), whereas cyst shape and ovarian position showed no significant associations. Postoperatively, six women conceived spontaneously, and three conceived through assisted reproductive technology (ART). Conclusion: Abnormal follicle location may noninvasively predict surgical factors for EFI. Considering that MRI is routinely performed preoperatively in Japan, MRI‐based EFI prediction can be used as a supporting finding to assist in determining whether to proceed with ART without surgical intervention.

Background & Aims: COVID-19 incidence has persisted since December 2019, with emerging variants affecting infection rates in children. Limited studies exist on the effectiveness of non-pharmaceutical interventions for children. To investigate the relationship between hygiene habits and infection rates among elementary school students during the COVID-19 pandemic.Methods: A prospective observational study was conducted with 498 students in Gunma Prefecture. Hygiene habits were surveyed, and handwashing frequency and daily physical condition were recorded from January to February 2022. Incidence of acute upper respiratory tract infections (AURI) and influenza-like illness (ILI) was calculated based on self-reports, while COVID-19 and influenza cases were confirmed via medical tests.Results: Data was available for 431 students; 35 reported episodes of AURI, ILI, or COVID-19. Handwashing 16 or more times a day significantly reduced infection risk (OR, 0.43; 95% CI, 0.20-0.92). Cloth masks were associated with a higher infection risk compared to non-woven masks (OR, 3.02; 95% CI, 1.05-2.73).Conclusions: Regular handwashing and the use of non-woven masks are effective non-pharmaceutical interventions to prevent infectious diseases, including COVID-19, in elementary school students.

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.

Objectives: Health problems of truck drivers, including cardiovascular and major blood vessel diseases, have long been reported. This study aimed to collect vital signs of truck drivers while working by using commercial wearable devices and to determine the utility of the devices for occupational health. Methods: Wearable devices were attached and obtained data from 130 truck drivers working at a single company in Gunma Prefecture in 2020 for 3 continuous working days. Systolic blood pressure (SBP), heart rate (HR) and respiratory rate (RR) were monitored during working hours. The duration and proportion of time at which these parameters exceeded preset upper limits were calculated, as were the frequency and proportion of 10% and 20% increases from previous measurement points. Results: The average proportions of time during which SBP, HR, and RR exceeded their preset upper limits were 7.17%, 21.22% and 0.36%, respectively. Also, the average proportions of frequency during which SBP, HR and RR were ≥10% increased above previous measurement points were 5.97%, 12.66% and 11.83%, respectively. These results differed slightly from those obtained during regular health checkups. Health guidance should be provided to truck drivers with excess SBP, HR, and RR who were not identified on regular health checkups. Conclusions: Wearable devices may be useful in promoting the health conditions of truck drivers.

The “Go To Travel” campaign in Japan, which encouraged people to travel throughout the country, was started in July 2020 to revitalize economic activity that was sluggish due to COVID-19. Although risks of infection spread have been reported for tourists crossing prefectural borders, the spread of infection among residents living in sightseeing resort areas is unclear. This study evaluated the number of COVID-19 cases in residents of sightseeing resort areas in Gunma Prefecture using the descriptive epidemiological method. Data about infected individuals were obtained from open data on the prefectural official homepage. Evaluation of epidemic curves showed that the number of infected 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 affected cases increased in both resort areas and non-resort areas, with the increase being smaller in resort areas. Thus, the increased occurrence of infection during the campaign suggested a need to take additional preventive measures more so for tourists than for resort area residents.

Significance: Empirical evidence on detailed transmission patterns of influenza among students within and between classes and grades and how they are shaped by school population structure (e.g., class and school sizes) has been limited to date. We analyzed a detailed dataset of seasonal influenza incidence in 29 primary schools in Japan and found that the reproduction number at school did not show any clear association with the size or the number of classes. Our findings suggest that the interventions that only focus on reducing the number of students in class at any moment in time (e.g., reduced class sizes and staggered attendance) may not be as effective as measures that aim to reduce within-class risk (e.g., mask-wearing and vaccines).

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. 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. 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. 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.

Although long work hours have been associated with various physical health problems, studies of their association with mental health have yielded inconsistent results, due to differences in study settings, study outcome and/or unmeasured background factors. In this study, we used a propensity score method to evaluate the association between work hours and depressive state. A total of 467 Japanese white-collar workers were surveyed and divided into long and regular work hour groups according to overtime work records. Propensity score matching was performed based on 32 individual background and workplace factors, yielding 74 pairs of propensity-matched subjects. CES-D score, an indicator of depressive state, did not differ significantly among the two groups (p=0.203). However, work motivation, work control, social support and emotional stability correlated with CES-D score. These findings suggest that work control and social support factors are more associated with depressive state than control of work hours. These results also suggest that it is possible to use propensity score matching to evaluate the association between work hours and mental health in occupational study settings. Further studies, in larger populations, are required to determine the association between work hours and mental health parameters.