Comparative epidemiology of six respiratory pathogens among children aged 28 days to 14 years with acute respiratory infections in coastal Xiamen and inland Linxia, China: a multicenter retrospective study - Xingxiang Zheng; Hongmei Ma; Jiali Cao; Jumei Liu; Rui Guo; Qunshan Xu; Xiaoli Chen; Shiqiang Han; Huiming Ye (Frontiers in Public Health, 2026)