Global trends in adult viral gastroenteritis: A comprehensive analysis of epidemiology, diagnosis, treatment, complications, and mortality in the Pre-COVID and Post-COVID Era

Acute gastroenteritis (AGE) represents a significant global health burden, particularly affecting adults in healthcare settings and long-term care facilities. The COVID-19 pandemic dramatically altered the epidemiological landscape of enteric infections through non-pharmaceutical interventions. The post-pandemic era has witnessed an unprecedented resurgence of viral gastroenteritis pathogens, necessitating a comprehensive analysis of temporal trends and clinical outcomes. This systematic review and meta-analysis assessed global trends in adult VGE epidemiology, diagnostics, treatment, complications, and mortality by comparing pre-COVID (2015-2019) and post-COVID (2022-2024) periods. PubMed/MEDLINE, Embase, Cochrane Library, Web of Science, Scopus, and regional databases were searched from January 2015 to December 2024. Observational studies reporting on adults (≥18 years) with confirmed or suspected VGE were included. Risk of bias was assessed using the Newcastle-Ottawa Scale and JBI Critical Appraisal Checklist. Random-effects meta-analysis was conducted using the DerSimonian-Laird method. A total of 127 studies encompassing 2.847,392 adult patients from 42 countries were included. Norovirus outbreak incidence increased by 96% in the 2024-2025 season compared to pre-pandemic levels (2.407 vs. 1.230 outbreaks; p