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Aim: To investigate possible differences in neurodevelopment between lockdown-exposed and non-exposed 18-month-old toddlers in Sweden.

Methods: Data were extracted from the prospective NorthPop Birth Cohort Study in Sweden. Neurodevelopment was assessed using the Ages and Stages Questionnaire Third Edition (ASQ-3) and a clinical routine evaluation at the child health care centre for additional validation. Statistical analyses were performed using IBM SPSS Statistics.

Results: More lockdown-exposed toddlers fell below the cut-off score on the ASQ-3 “Gross motor function” assessment at 18 months, compared to the pre-lockdown category (5.1% vs. 3.6%, adjusted p = 0.002). Conversely, fewer lockdown-exposed toddlers failed the fine motor task “Can draw scribble” versus the pre-lockdown category (1.4% vs. 2.4% adjusted p = 0.014).

Conclusions: Toddlers who were lockdown-exposed had lower gross motor function but were more successful in the fine motor task at 18 months.

Introduction: The immunogenicity and safety of MenACYW-TT (MenQuadfi^®) were compared to another quadrivalent meningococcal conjugate vaccine, MCV4-TT (Nimenrix^®), when administered in infants alongside routine childhood vaccines in Europe.

Methods: One set of healthy infants was randomized 1:1 to receive MenACYW-TT (group 1; n = 714) or MCV4-TT (group 2; n = 726) at age 2, 4, and 12-18 months (2 + 1 regimen) concomitantly with routine vaccines (including 10-valent pneumococcal conjugate vaccine). Another set was randomized 1:1 to receive MenACYW-TT in a 2 + 1 regimen (group 3; n = 112) or a 3 + 1 regimen at age 2, 4, 6, and 12-18 months (group 4; n = 108) concomitantly with routine vaccines (including 13-valent pneumococcal conjugate vaccine). Immune responses against meningococcal serogroups A, C, W, and Y were measured by serum bactericidal assay using human complement (hSBA). Non-inferiority of MenACYW-TT versus MCV4-TT was based on hSBA geometric mean titers (GMTs) 30 days post-booster (dose 3; primary endpoint) and rates of seroprotection 30 days post-dose 2 (secondary endpoint) against all vaccine meningococcal serogroups. Immune responses to co-administered vaccines and safety were also assessed. Post hoc, non-inferiority of MenACYW-TT was also assessed based on seroresponse rates 30 days post-booster.

Results: Non-inferiority of MenACYW-TT versus MCV4-TT, based on GMTs post-booster, was demonstrated for serogroups C, W, and Y but not for A. GMTs against serogroups C, W, and Y were 1.5- to 4.5-fold higher with MenACYW-TT than MCV4-TT; those against serogroup A were marginally lower. Antibody responses in groups 3 and 4 against all serogroups were similar to group 1. Non-inferiority of MenACYW-TT based on seroresponse rates post-booster against all serogroups was demonstrated post hoc. No interference with concomitant routine vaccines nor safety concerns were identified.

Conclusions: Consideration of all immunogenicity and safety data generated in this study supports the incorporation of MenACYW-TT into the routine childhood vaccination schedule as a 2 + 1 regimen starting at age 6 weeks.

ClinicalTrials.gov identifier: NCT03547271.

Aim: The burden of respiratory disease is great among children. This study aimed to examine the temporal relationship between hospitalisation for respiratory syncytial virus (RSV) and bacterial pneumonia.

Methods: A Swedish population-based cohort was created by combining data from the Swedish Medical Birth Register, the National Inpatient Register, the Cause of Death Register, the Total Population Register, and the Longitudinal Integration Database for Health Insurance and Labour Market Studies. Children born between 1998 and 2015 were included and followed for 2 years. We examined the temporal relationship between RSV hospitalisation and bacterial pneumonia using piecewise exponential models.

Results: The final cohort comprised 1 641 747 children, 48.5% were females. There were 23 632 RSV and 4722 bacterial pneumonia hospitalisations, with mean age of 137.8 and 424.2 days, respectively. RSV hospitalisation was associated with bacterial pneumonia with an adjusted incidence rate ratio (aIRR) of 3.18. The risk was highest in the first month after RSV hospitalisation, aIRR 11.19. The risk of bacterial pneumonia was elevated for 4 months after RSV hospitalisation and before RSV hospitalisation.

Conclusion: We found an increased risk for bacterial pneumonia hospitalisation in children hospitalised for RSV both before and after RSV hospitalisation, indicating a bidirectional relationship.

Background: Non-communicable diseases (NCDs) are a global health issue, posing a substantial burden on the individual, community, and public health. The risk of developing NCDs is influenced by a complex interplay between genetic, epigenetic, and environmental factors.

Methods: The NorthPop Birth Cohort Study (NorthPop) constitutes an infrastructure enabling cutting-edge research on the foundational pathways to NCDs in childhood, including allergic diseases and asthma, overweight/obesity, cognitive and neurodevelopmental dysfunction, gastrointestinal disorders, and caries. NorthPop aims at recruiting 10,000 families. Pregnant women and their partners residing in Västerbotten County, Sweden are eligible. Recruitment started in 2016 and is anticipated to end in 2025. Extensive data on parental, fetal and child health outcomes, lifestyle, diet, and environmental exposures are prospectively collected using web-based questionnaires in pregnancy and childhood until the children turn 7 years old. Urine samples are collected from the pregnant woman at gestational age 14–24 weeks. Blood samples are collected at gestational age 28 weeks. Placenta and cord blood are collected at birth. A breast milk sample is collected 1 month postpartum. Blood samples from the children are collected at 18 months and 7 years of age. Oral swabs and fecal samples are collected from the children within 48 h of birth, at 1, 9 and 18 months, 3 and 7 years of age. At age 7 years, children are invited to a follow-up visit, including measurements of weight, height, blood pressure, pulse, hand grip strength, working memory, skin prick test and saliva sampling. Additional measurements, such as sleep–wake and light exposure, and additional biological samples are collected in sub-cohorts. Permission for linkage to medical records and national registers e.g., the Swedish Pregnancy Register, the National Patient Register, the Longitudinal Integration Database for Health insurance and Labor market studies and the Swedish Prescribed Drug Register has been granted.

Discussion: Our multidisciplinary approach allows us to study how early life exposures, as well as parental health and lifestyle, influence future health in the offspring. Our results are anticipated to contribute to the understanding of disease risk and may inform future strategies aimed at risk reduction, highly significant for public health.

Trial registration: Retrospectively registered at Researchweb 11 November 2024 (project number 279272).

Background: Respiratory infections in early life are an identified risk factor for asthma. We hypothesized that infection-prevention measures during the coronavirus disease 2019 (COVID-19) pandemic influenced the risk of respiratory morbidity and aeroallergen sensitization in early childhood. Objective: We compared respiratory morbidity and aeroallergen sensitization in children born before and during the pandemic. Methods: We compared a COVID-19 category (exposed children; n = 1661) to a pre–COVID-19 category (nonexposed children; n = 1676) by using data from the prospective population-based NorthPop Birth Cohort study in Sweden. Data on respiratory morbidity and concomitant medication were retrieved from national registers. Prospectively collected data on respiratory morbidity using web-based questionnaires at 9 and 18 months of age were applied. At age 18 months, serum IgE levels to aeroallergens were determined (n = 1702). Results: The risk of developing any respiratory tract infection (adjusted odds ratio [aOR] = 0.33 [95% CI, 0.26-0.42]), bronchitis (aOR = 0.50 [95% CI, 0.27-0.95]) and croup (aOR = 0.59 [95% CI, 0.37-0.94]) were decreased in the COVID-19 category. The risk of wheeze in the first 9 months was lower in the COVID-19 category (aOR = 0.70 [95% CI, 0.55-0.89]). There were also fewer prescriptions of antibiotics in the COVID-19 category. The prevalence of aeroallergen sensitization was similar between categories. Conclusion: Children born during the COVID-19 pandemic demonstrated significantly decreased risks of respiratory infections and prescribed antibiotics until 18 months of age compared to children born before the COVID-19 pandemic. Whether this will affect the risk of developing asthma in childhood is being followed.

Aim: To study the development of overweight, obesity and underweight among 4-year-olds from 2007 to 2022, covering the COVID-19 pandemic period.

Methods: This repeated cross-sectional analysis was conducted in Västerbotten County, northern Sweden. It used data on weight, height, age and sex, which were collected when children attended their 4-year check-ups at any of the 38 Child Health Centres.

Results: The data comprised 42 614 4-year-old children (52% boys). From 2007 to 2022, the prevalence of overweight decreased from 13.4% to 9.5% in the boys and from 14.9% to 12.0% in the girls. The prevalence of obesity decreased from 3.7% to 1.8% in the boys and from 2.4% to 2.0% in the girls. During the first year of the COVID-19 pandemic, overweight and obesity temporarily increased for both the boys and girls, but the levels had returned to pre-pandemic levels by 2022. The prevalence of underweight increased among both boys and girls.

Conclusion: Our study documents a decline in the prevalence of overweight and obesity among Swedish 4-year-olds over more than a decade, except for a surge during the early COVID-19 pandemic. Additionally, we observed an unexpected increase in the prevalence of underweight during the same period.

Importance: A diagnosis of bacterial meningitis in childhood can lead to permanent neurological disabilities. Few studies have examined long-term consequences for work ability in adulthood.

Objective: To compare earnings, work loss, and educational attainment between adults diagnosed with bacterial meningitis in childhood and population comparators.

Design, Setting, and Participants: This nationwide registry-based matched cohort study included individuals in Sweden diagnosed with bacterial meningitis in childhood (aged <18 years) from January 1, 1987, to December 31, 2019, and general population comparators matched 1:9 on age, sex, and place of residence. Follow-up was completed December 31, 2020. Data were analyzed from February 7 to September 12, 2023.

Exposure: A diagnosis of bacterial meningitis in childhood recorded in the National Patient Register.

Main Outcomes and Measures: Annual taxable earnings (in 2020 US dollars), work loss (sum of sick leave and disability insurance), and educational attainment.

Results: The cohort included 2534 individuals diagnosed with bacterial meningitis in childhood (mean [SD] age at diagnosis, 4.7 [5.3] years) and 22 806 comparators (13 510 [53.3%] male). Among those with childhood bacterial meningitis, 812 (32.0%) were diagnosed at younger than 1 year and 1351 (53.3%) were male. From 18 to 34 years of age, those with childhood meningitis had lower adjusted earnings relative to comparators and higher adjusted work loss. When pooling observations for individuals 28 years or older, the annual mean reduction in earnings was -$1295 (95% CI, -$2587 to -$4), representing a 4.0% (95% CI, 0%-8.0%) reduction relative to comparators, and the annual increase in work loss was 13.5 (95% CI, 8.6-18.5) days. There was a larger reduction in earnings for those with childhood meningitis relative to comparators with pneumococcal (Streptococcus pneumoniae) vs meningococcal (Neisseria meningitidis) meningitis. For work loss, there was a difference among all 3 major causes of meningitis, with the largest increase for pneumococcal meningitis. Individuals diagnosed at a younger age (below the median) had lower earnings relative to comparators and higher work loss than individuals diagnosed at an older age (above the median). Fewer individuals with childhood meningitis relative to comparators had obtained a high school degree at age 30 years (adjusted odds ratio, 0.68 [95% CI, 0.56-0.81]).

Conclusions and Relevance: In this cohort study of adults diagnosed with bacterial meningitis in childhood, findings suggest that work ability decreases relative to population comparators, with lower earnings and higher work loss, especially among adults diagnosed with pneumococcal meningitis or diagnosed at a young age, with long-lasting costs for the individual patient and society at large.

IMPORTANCE: Few studies have examined the incidence of long-term disabilities due to bacterial meningitis in childhood with extended follow-up time and a nationwide cohort.

OBJECTIVE: To describe the long-term risks of disabilities following a childhood diagnosis of bacterial meningitis in Sweden.

DESIGN, SETTING, AND PARTICIPANTS: This nationwide retrospective registry-based cohort study included individuals diagnosed with bacterial meningitis (younger than 18 years) and general population controls matched (1:9) by age, sex, and place of residence. Data were retrieved from the Swedish National Patient Register from January 1, 1987, to December 31, 2021. Data were analyzed from July 13, 2022, to November 30, 2023.

EXPOSURE: A diagnosis of bacterial meningitis in childhood recorded in the National Patient Register between 1987 and 2021.

MAIN OUTCOMES AND MEASURES: Cumulative incidence of 7 disabilities (cognitive disabilities, seizures, hearing loss, motor function disorders, visual disturbances, behavioral and emotional disorders, and intracranial structural injuries) after bacterial meningitis in childhood.

RESULTS: The cohort included 3623 individuals diagnosed with bacterial meningitis during childhood and 32 607 controls from the general population (median age at diagnosis, 1.5 [IQR, 0.4-6.2] years; 44.2% female and 55.8% male, median follow-up time, 23.7 [IQR, 12.2-30.4] years). Individuals diagnosed with bacterial meningitis had higher cumulative incidence of all 7 disabilities, and 1052 (29.0%) had at least 1 disability. The highest absolute risk of disabilities was found for behavioral and emotional disorders, hearing loss, and visual disturbances. The estimated adjusted hazard ratios (HRs) showed a significant increased relative risk for cases compared with controls for all 7 disabilities, with the largest adjusted HRs for intracranial structural injuries (26.04 [95% CI, 15.50-43.74]), hearing loss (7.90 [95% CI, 6.68-9.33]), and motor function disorders (4.65 [95% CI, 3.72-5.80]). The adjusted HRs for cognitive disabilities, seizures, hearing loss, and motor function disorders were significantly higher for Streptococcus pneumoniae infection (eg, 7.89 [95% CI, 5.18-12.02] for seizure) compared with Haemophilus influenzae infection (2.46 [95% CI, 1.63-3.70]) or Neisseria meningitidis infection (1.38 [95% CI, 0.65-2.93]). The adjusted HRs for cognitive disabilities, seizures, behavioral and emotional disorders, and intracranial structural injuries were significantly higher for children diagnosed with bacterial meningitis at an age below the median.

CONCLUSIONS AND RELEVANCE: The findings of this cohort study of individuals diagnosed with bacterial meningitis during childhood suggest that exposed individuals may have had an increased risk for long-term disabilities (particularly when diagnosed with pneumococcal meningitis or when diagnosed at a young age), highlighting the need to detect disabilities among surviving children.

Background: Social-emotional difficulties in early childhood are associated with a range of outcomes across the life course and are related to socioeconomic factors. The aim of this study was to examine intersectional inequalities in social-emotional problems in preschool children relating to their parents’ income, education and country of birth in addition to investigating the public health implications.

Methods: This population-based study with a repeated cross-sectional design in the Västerbotten County of Sweden used the Ages and Stages Questionnaires: Social-Emotional (ASQ:SE) for children aged 3 in child health care services over the years of 2014-2018 and socio-economic information from national population registers. The effective sample of 8,823 individuals was analyzed using additive binomial regression in combination with an analysis of individual heterogeneity and discriminatory accuracy (AIHDA) approach to estimate risk differences for social-emotional problems across 27 intersectional groups and discriminatory accuracy.

Results: Average risk differences generally increased in the groups where multiple dimensions of social inequality intersected, with risk differences as high as 18% (95% CI 8 to 28%) and 25% (95% CI 14 to 37%) compared to the most advantaged category. The discriminatory accuracy of all three included regression models was estimated as moderate, but improved in a slight but statistically significant way with the addition of social inequalities.

Conclusions: This study increases our understanding of intersectional and social inequalities in social-emotional problems in preschool children. It supports the need for universal public health policies in addition to policies targeting more vulnerable groups when addressing this issue, consistent with the concept of proportionate universalism. An intersectional research perspective including discriminatory accuracy could increase our knowledge of health inequities and improve public health effectiveness.