Cross-sectional surveillance study of long COVID in Toyonaka city, Osaka prefecture, Japan.

BACKGROUND: As the COVID-19 epidemic continues, concerns about long-term health impacts, specifically long COVID, persist. While the prevalence and symptomatology of long COVID have been explored in various global contexts, large-scale cohort studies in Japan remain limited, especially after the advent of the Omicron variant. METHODS: In this observational study, 4,047 residents with a history of COVID-19 living in Toyonaka City, Osaka Prefecture, were assessed for long COVID symptoms using the VOICE mobile application and a paper survey. Respondents provided demographic and health information, as well as information regarding COVID-19 infection and subsequent symptoms. A Cox proportional hazard regression model was used to estimate the multivariable-adjusted hazard ratios and 95 % confidence intervals for overall morbidity of long COVID symptoms. RESULTS: The survey found that 5.2 % of participants reported the persistence of one or more symptoms at 30 days post-onset. Fatigue was the most commonly reported symptom (1.75 %), followed by hair loss (1.41 %), and cough (1.28 %). Factors associated with an increased risk of experiencing long COVID symptoms included BMI, severe illness during the acute phase, and infection with certain COVID-19 variant strains, including Alpha, Delta, and Omicron. However, the incidence rate of long COVID appears to be decreasing with the dominance of the Omicron variant. CONCLUSIONS: This large-scale study from Toyonaka City suggests a 5.2 % prevalence rate for persistent COVID-19 symptoms 4 weeks post-infection, potentially indicating a lower prevalence of long COVID in Japanese populations after the rise of the Omicron variant.

The number of erupted teeth as a risk factor for dental caries in eighteen-month-old children: a cross­sectional study.

BACKGROUND: Dental caries is one of the most common chronic diseases worldwide, affecting lifelong as well as children. Therefore, it is important to clarify factors related to early childhood caries (ECC) in a younger population in terms of caries prevention. However, the prevalence of ECC is low in developed countries in the twenty-first century and a large-scale survey is needed to clarify the risk factors. Furthermore, earlier tooth eruption is not taken into consideration in most studies of ECC, even though it may be a factor of ECC. The present study investigated the prevalence and risk factors of dental caries in children aged 18 months in a core city of Japan. METHODS: Findings from a total of 7351 children aged 18 months were analyzed. Anthropometric measurements of height and weight, as well as an oral examination and a microbiological caries-risk test, were performed. Additionally, a structured interview sheet was provided to the parents or guardians. Findings of dental caries at 18 months of age were evaluated using a logistic regression model. RESULTS: Of the enrolled children, 1.2% had experienced dental caries. Multivariable logistic regression analysis results indicated a significant association with dental caries at 18 months of age for the following factors: second child (OR = 1.78; 95% CI:1.08-2.93, P < 0.05), third and later child (OR = 2.08; 95% CI:1.12-3.89, P < 0.05), 12 or fewer erupted teeth (OR = 0.47; 95% CI:0.24-0.96, P < 0.05), 17 or more erupted teeth (OR = 4.37; 95% CI:1.63-11.7, P < 0.01), Cariostat score (+ + +) (OR = 3.99; 95% CI:1.29-12.31, P < 0.05), daily eating before bed (OR = 2.62; 95% CI: 1.55-4.45, P < 0.001), three or more snacks per day (OR = 2.03; 95% CI:1.15-3.58, P < 0.05), and breastfeeding (OR = 3.30; 95% CI:2.00-5.44, P < 0.001). CONCLUSIONS: These results suggest that the number of erupted teeth, as well as birth order, eating habits, and breastfeeding, are significant factors in dental caries occurrence at 18 months of age.

Intrauterine Ureaplasma is associated with small airway obstruction in extremely preterm infants.

BACKGROUND: The long-term follow-up of lung function (LF) in extremely preterm (EP) infants with bronchopulmonary dysplasia (BPD) has shown a worldwide increase in small airway obstructions (SAO). OBJECTIVES: We investigated the relationships between intrauterine Ureplasma infection in EP infants and bubbly/cystic lung, BPD, and SAO at school age. METHODS: Placental pathology, placental Ureaplasma DNA (pU-DNA), and cord blood immunoglobulin M (IgM) (C-IgM) were investigated in 360 EP infants born from 1981 to 2004. Maternal amniotic inflammatory response (M-AIR) scores and hemosiderin deposition (HD) were estimated in the chorioamnion. The study subjects were divided into groups based on their M-AIR scores. Their LF at school age was compared with those of 33 healthy siblings. FINDINGS: pU-DNA and C-IgM were significantly related to SAO at school age (p < 0.012). M-AIR score 3 and pU-DNA >1000 units had an odds ratio (OR) of 35 (95% confidence interval: 10-172) and 18 (5.6-67) for bubbly/cystic lung, and 11 (3.1 - 43) and 31 (4.5-349) for severe BPD, and 5.3 (2.1-11) and 12 (2.4-74) for SAO, respectively. The ORs of surfactant treatment, BPD grade III, O2 at 40 weeks, HD, and C-IgM >30 mg/dl for SAO were 0.21 (0.075-0.58), 5.3 (2.1-15), 2.5 (1.4-4.6), 3.6 (1.5-9.1) and 2.5 (1.0-5.2). 84% (90/107) SAO infants showed no or mild BPD in infancy, and 61% of infants had no severe CAM. CONCLUSION: Our long-term cohort study of LF in EP infants revealed that intrauterine Ureaplasma was associated with bubbly/cystic lung, severe BPD, and SAO at school age.

Challenge to improve Japan's deplorable HPV vaccination rate by local government actions.

AIM: In Japan, in 2013, following reports of several alleged adverse reactions in young girls following vaccination, the previously successful national human papillomavirus infection (HPV) vaccination program collapsed rapidly. In the 8 years since vaccination rates have hovered near zero. In October of 2020, in an attempt to mitigate this lingering disaster, the Japanese Ministry of Health, Labor, and Welfare (MHLW) agency finally revised its HPV vaccination informational leaflet that was designed to be distributed by local governments nationwide. Prior to this revision, Toyonaka City, in Japan's Osaka province, had already begun sending out their own unique leaflet to girls in the targeted 6th-10th grades. As a preview of how MHLW's revised leaflet might eventually succeed, we have studied the HPV vaccination results from Toyonaka City's experiment. METHOD: This study was a population-based analysis that compared the monthly rates of new vaccinations in girls of a targeted grade school age group. We looked at rates before and after the leaflets were sent by Toyonaka City's Division of Health Promotion and Senior Services. RESULTS: The vaccination rates between April 2020 and March 2021 were improved across all grades; 1.2% in 6th grade (p = 0.000185), 2.5% in 7th grade (p < 0.0001), 3.5% in 8th grade (p < 0.0001), 6.8% in 9th grade (p < 0.0001), and a remarkable 16.5% in 10th grade (p < 0.0001). CONCLUSION: When a local government sends an HPV informational leaflet targeted at young girls, it can significantly improve their HPV vaccination rates.

Perinatal factors associated with long-term respiratory sequelae in extremely low birthweight infants.

OBJECTIVE: To assess lung function at 8 years old in extremely low birthweight (ELBW) survivors and to identify perinatal determinants associated with impaired lung function. DESIGN: Retrospective cohort study. SETTING: Level III neonatal intensive care unit. PATIENTS: ELBW survivors born in 1990-2004 with available spirometry at 8 years old were studied. Children were excluded if they had a Wechsler Intelligence Scale for Children Third Edition full IQ <70. MAIN OUTCOME MEASURES: Multivariate logistic regression analysis was used to identify perinatal determinants associated with airway obstruction (forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <80%) at school age and the predictive power of potential determinants. Potential risk factors and predictors assessed in this study were gestational age, birth weight, small for gestational age, sex, chorioamnionitis, premature rupture of membranes, antenatal steroids, surfactant administration, respiratory distress syndrome, postnatal steroids, severe bronchopulmonary dysplasia and bubbly/cystic appearances of the lungs by X-ray during the neonatal period. RESULTS: Of 656 ELBW survivors, 301 (45.9%) had attended a school-age follow-up at 8 years old. A total of 201 eligible children completed the lung function test. Bubbly/cystic appearance of the lungs (OR 4.84, 95% CI 1.26 to 18.70) was associated with a low FEV1/FVC ratio. Children with bubbly/cystic appearance had characteristics of immaturity and intrauterine inflammation. CONCLUSIONS: Within a cohort of ELBW infants, a bubbly/cystic appearance of the lungs in the neonatal period was the strongest determinant of a low FEV1/FVC ratio at school age.

Trends in morbidity and mortality among very-low-birth-weight infants from 2003 to 2008 in Japan.

BACKGROUND: Although medical care for very-low-birth-weight (VLBW) infants has improved over time, it is unclear how this has affected mortality and morbidity. To characterize these trends, a network database was analyzed. METHODS: This is a cohort study of VLBW infants born from 2003 through 2008. RESULTS: Over the 6-y period, 19,344 infants were registered and analyzed. Crude mortality rates among the infants at discharge decreased significantly (from 10.8 to 8.7%) during the study period. The greatest improvement in mortality was observed among infants with birth weights between 501 and 750 g (25.6-17.7 %). The odds ratio (OR) of mortality over year adjusted for potential confounders by a logistic regression model was 0.94 (95% confidence interval 0.92-0.97). Significant increases were observed in some morbidities, including symptomatic patent ductus arteriosus with an OR of 1.11 (1.09-1.13); late-onset adrenal insufficiency, 1.21 (1.17-1.26); and necrotizing enterocolitis/intestinal perforation, 1.10 (1.01-1.12). However, the severe form of intraventricular hemorrhage, with an OR of 0.98 (0.92-0.99), decreased significantly. Risk-adjusted trends in other morbidities showed no significant change. CONCLUSION: Mortality of VLBW infants decreased significantly over the 6-y study period. Decreasing morbidity is essential for further improvement in the outcomes in VLBW infants.

Birth length is a predictor of adiponectin levels in Japanese young children.

BACKGROUND: Adiponectin has been shown to be inversely related to birth weight in schoolchildren and adolescents. However, the available information regarding a relation between birth size and adiponectin in infants and preschoolers is limited. METHODS: A longitudinal study was conducted among healthy Japanese children, and serum adiponectin levels were measured at consecutive visits. The effect of sex, gestational age, birth length, birth weight, or placental weight on adiponectin was analyzed by using a linear mixed model for repeated measures. RESULTS: Eighty-three children were evaluated. The age range at the first visit was 0.07-5.3 years. A total number of 227 measurements were made, 1-12 per subject (median, 3) and the duration of follow-up ranged from 1 day to 2.3 years (median, 1.0 years). The subjects were divided into four groups according to the age at the first visit: (1) 0-2 months (n = 29), (2) 3 months to 1 year (n = 17), (3) 2-3 years (n = 19) and (4) 4-5 years (n = 18). In the multivariate model, birth length (coefficient = 3.94, 95% CI, 0.23-7.65) was an independent predictor of serum adiponectin levels in subjects aged 0-2 months. Gestational age (3.53, 1.14-5.92), birth length (-2.71, -4.90 to -0.53) and placental weight (2.58, 0.86-4.29) were independent predictors of serum adiponectin levels in subjects aged 4-5 years. CONCLUSION: Birth length, not birth weight, is an independent predictor of serum adiponectin levels in Japanese young children.

Anti-annexin A2 IgM antibody in preterm infants: its association with chorioamnionitis.

Intrauterine infection is associated with chorioamnionitis (CAM), which can lead to preterm delivery. We previously reported that the levels of IgM and the incidence of CAM were elevated in preterm infants with neonatal pulmonary emphysema. The pathogen and target of this IgM remain unclear. By using Western blot and amino acid sequences, we have determined one of the target proteins: annexin A2. Immunohistochemical analysis showed that annexin A2 was expressed at fetal chorion and amnion membranes. Among very low birth weight (VLBW) infants with hyper-IgM (> or = 30 mg/dL), 58.8% showed a high titer against annexin A2 (more than x 16), which accounted for about 20%-40% of the total IgM. Anti-annexin A2 IgM antibody inhibited plasmin generation. Furthermore, the median of anti-annexin A2 IgM titer from preterm infants who were delivered with high-grade (grade III) CAM was significantly higher than those from preterm infants without CAM (p = 0.011) and with low-grade CAM (grade I and II) (p = 0.010). Here, we indicate the fetal autoimmunoreactivity against the fetomaternal interface in preterm infants.

Morbidity and mortality of infants with very low birth weight in Japan: center variation.

OBJECTIVES: The objectives of this study were to describe the characteristics and morbidity of very low birth weight infants, to identify the medical intervention for these infants, and to evaluate the factors affecting the mortality of these infants among the participating hospitals. METHODS: A large multicenter neonatal research network that included level III NICUs from throughout Japan was established. A standardized mortality rate was formulated by giving a ratio of the observed deaths and the predicted deaths based on a 100-g birth weight interval mortality. A regression model was used to predict the factors that affect neonatal mortality. RESULTS: The network included 37 centers and 2145 infants weighing < or = 1500 g, born or admitted to the centers in 2003. Gestational age and birth weight of studied infants were 28.6 +/- 3.6 gestational weeks (mean +/- SD) and 1025 +/- 302 g, respectively. Overall, 11% of the infants died before being discharged from hospitals (range: 0%-21%). The standardized mortality rate varied among the facilities (range: 0%-30%). No association between the annual number of patients admitted and standardized mortality rate was found. Among all of the very low birth weight infants, 14% were outborn infants, 72% were delivered by cesarean sections, 27% had patent ductus arteriosus, 3% had gastrointestinal perforation, 8% had bacterial sepsis, and 13% had intraventricular hemorrhage. Medical interventions involved were: 41% antenatal corticosteroids, 54% surfactant therapy, 18% postnatal steroids for chronic lung disease, and 29% high-frequency oscillatory ventilation. We found variations in the medical interventions and the clinical outcomes among the centers. CONCLUSIONS: The overall survival rate for very low birth weight infants among neonatal centers in Japan was approximately 90%. However, differences in the morbidity and mortality were observed among these centers.