Background The coronavirus disease 2019 (COVID-19) pandemic is having a profound impact on the health and development of children worldwide. There is limited evidence on the impact of COVID-19 and its related school closures and disease-containment measures on the psychosocial wellbeing of children; little research has been done on the characteristics of vulnerable groups and factors that promote resilience. Methods We conducted a large-scale cross-sectional population study of Hong Kong families with children aged 2–12 years. Parents completed an online survey on family demographics, child psychosocial wellbeing, functioning and lifestyle habits, parent–child interactions, and parental stress during school closures due to COVID-19. We used simple and multiple linear regression analyses to explore factors associated with child psychosocial problems and parental stress during the pandemic. Results The study included 29,202 individual families; of which 12,163 had children aged 2–5 years and 17,029 had children aged 6–12 years. The risk of child psychosocial problems was higher in children with special educational needs, and/or acute or chronic disease, mothers with mental illness, single-parent families, and low-income families. Delayed bedtime and/or inadequate sleep or exercise duration, extended use of electronic devices were associated with significantly higher parental stress and more psychosocial problems among pre-schoolers. Conclusions This study identifies vulnerable groups of children and highlights the importance of strengthening family coherence, adequate sleep and exercise, and responsible use of electronic devices in promoting psychosocial wellbeing during the COVID-19 pandemic. Electronic supplementary material The online version of this article (10.1007/s00787-020-01680-8) contains supplementary material, which is available to authorized users.

The COVID-19 pandemic has had significant health, social, and economic consequences internationally. While the pandemic has direct implications on infected patients and families, there is a need to examine the pandemic's effect on patients with non-COVID-19-related diseases. This study examines the impact of the COVID-19 pandemic on 272 rare disease patients with 89 distinct rare diseases in Hong Kong using a cross-sectional online survey between April 10 and April 29, 2020 from the patient and caregiver perspective. The pandemic has impacted patient's health status in 46%, service use patterns in 71%, mental health in 79%, daily living in 82%, social life in 92%, and financial status in 81% of patients. Patient's health status, medical and rehabilitation, and mental health were more impacted by the COVID-19 pandemic in the group of patients with any level of dependency according to the Barthel Index for Activities of Daily Living compared with that in the group of patients who are fully independent (p < 0.0001; p < 0.0001; p = 0.0420). This study is the first study to examine the impact of COVID-19 pandemic on the rare disease population in Hong Kong, and demonstrates the pandemic's effect on service and resource utilization, and patient's physical and mental well-being.

This cross-sectional study investigates the clinical characteristics and sources of infection of COVID-19 among children and youths in Hong Kong.

Loss of WM anisotropy is significantly affected by age at CSI, and there is a trend toward increasing anisotropy loss with larger CSI dose. Both age at CSI and CSI dose are known risk factors of neurotoxicity.