Changes in frequency of benign convulsions with mild gastroenteritis and their viral causes before and during the COVID-19 pandemic: a single-center study.

Background: Benign convulsions with mild gastroenteritis (CwG) are prevalent in young children during the winter. Early in the coronavirus disease 2019 (COVID-19) pandemic, viral gastroenteritis occurrence decreased and seasonal variation was lost, which can change CwG.

Purpose: Here we investigated changes in frequency, seasonal variation, and causative viruses of CwG during the COVID-19 pandemic.

Methods: We screened 1134 patients (3-36 months) with "other and unspecified convulsions" treated at Chonnam National University Hospital between March 2017 and February 2023; of them, we enrolled 41 (3.6%) with CwG. We compared their medical records from period I (March 2017 to February 2020) to those from period II (March 2020 to February 2023). Publicly available viral gastroenteritis surveillance data from the Korea Disease Control and Prevention Agency (KDCA) were reviewed as reference.

Results: Of the 41 patients with CwG, 18 (2.9% of 613) were affected in period I versus 23 (4.4% of 512) in period II (P=0.184). In period I, CwG mainly occurred in winter and spring (55.6% and 22.2%, respectively). In period II, there were fewer CwG cases (39.1%) in winter and more cases in summer and autumn (26.1% and 17.4%, respectively): the cases of norovirus genogroup II (GII)-associated CwG increased significantly in the summer (38.5% vs. 0%, P= 0.046). Norovirus GII was the most common virus (56.1% of isolates). Enteric adenovirus was the second most common (19.5%), with one case in period I and 7 cases in period II (P=0.059). The clinical characteristics of enteric adenovirus-associated CwG were similar to those of norovirus. Seasonal changes in and viral causes of CwG were consistent with those observed in the KDCA stool surveillance data.

Conclusion: During the COVID-19 pandemic, CwG frequency did not change, seasonal variation was unapparent, and enteric adenovirus-associated CwG frequency increased.