Introduction The epidemic of coronavirus disease 2019 (COVID-19) rapidly spread worldwide, and the various infection control measures have a significant influence on the spread of many infectious diseases. However, there have been no multicenter studies on how the number of hospitalized children with various infectious diseases changed before and after the outbreak of COVID-19 in Japan. Methods We conducted a multicenter, prospective survey for hospitalized pediatric patients in 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to February 2021. We defined July 2019 to February 2020 as pre-COVID-19, and July 2020 to February 2021 as post-COVID-19. We surveyed various infectious diseases by sex and age. Results In total, 5,300 patients were hospitalized during the study period. The number of patients decreased from 4,266 in the pre-COVID-19 period to 701 (16.4%) post-COVID-19. Patients with influenza and RSV decreased from 308 and 795 pre-COVID-19 to zero and three (0.4%) post-COVID-19. However, patients with adenovirus (respiratory infection) only decreased to 60.9% (46 to 28) of pre-COVID levels. Patients with rotavirus, norovirus, and adenovirus gastroenteritis decreased markedly post-COVID-19 to 2.6% (38 to 1), 27.8% (97 to 27) and 13.5% (37 to 5). The number of patients with UTIs was similar across the two periods (109 and 90). KD patients decreased to 31.7% (161 to 51) post-COVID-19. Conclusions We suggest that current infection control measures for COVID-19 such as wearing masks, washing hands, and disinfecting hands with alcohol are effective against various infectious diseases. However, these effects vary by disease.

Background: Many reports have reported a reduction in respiratory infectious diseases and infectious gastroenteritis immediately after the coronavirus disease 2019 (COVID-19) pandemic, but data continuing into 2022 are very limited. We sought to understand the current situation of various infectious diseases among children in Japan as of July 2022 to improve public health in the post-COVID-19 era. Methods: We collected data on children hospitalized with infectious diseases in 18 hospitals in Japan from July 2019 to June 2022. Results: In total, 3417 patients were hospitalized during the study period. Respiratory syncytial virus decreased drastically after COVID-19 spread in early 2020, and few patients were hospitalized for it from April 2020 to March 2021. However, an unexpected out-of-season re-emergence of respiratory syncytial virus was observed in August 2021 (50 patients per week), particularly prominent among older children 3–6 years old. A large epidemic of delayed norovirus gastroenteritis was observed in April 2021, suggesting that the nonpharmaceutical interventions for COVID-19 are less effective against norovirus. However, influenza, human metapneumovirus, Mycoplasma pneumoniae, and rotavirus gastroenteritis were rarely seen for more than 2 years. Conclusions: The incidence patterns of various infectious diseases in Japan have changed markedly since the beginning of the COVID-19 pandemic to the present. The epidemic pattern in the post-COVID-19 era is unpredictable and will require continued careful surveillance.

The PP amplification is observed even in children. The degree of the PP amplification increases with age during childhood contrary to the relationship in adults.

The ascending aortic PP was augmented in the patients after the aortic arch repair. It could be one of the causes of future cardiovascular disease.

We read with great interest the article by Egbe and colleagues, 1 which reported a new operation with the homograft conduit from the right ventricle (RV) to the right pulmonary artery (PA) for the patient with occlusion of the right PA. The operation is excellent; however, the description of the RV deserves comment.The outlet belongs to the ventricle. Anatomically, the RV can be divided into inlet, trabecular, and outlet regions.2 Therefore, the double-outlet ventricle has 2 outlet portions, usually to the systemic and the pulmonary circulation. In the case of Egbe and colleagues, the RV has only 1 outlet portion and 2 routes (to the right and the left PA) that originate from the 1 outlet portion. The operation resembles RV-PA conduit repair (Sano operation) 3 for patients with hypoplastic left heart syndrome. In the operation, the outlet portion of the RV has 2 exits, to the systemic circulation (via pulmonary valve) and the pulmonary circulation (via conduit). However, because the RV has only 1 outlet, the Sano operation is not described as a "surgically constructed double-outlet ventricle." Therefore, in our opinion, the operation in the article by Egbe and colleagues is not a "construction of double-outlet ventricle" but rather an right RV PA conduit repair or Egbe operation.