2.1 Patients and sample collection
During 2018-2020 (a two-year period), 302 stool samples were collected from children aged under 5 years with acute gastroenteritis admitted to Chiangrai Prachanukroh Hospital in Chiang Rai, Thailand. Acute gastroenteritis was basically defined as the occurrence of watery or loose stools in a period of 24 hours before the visit. Samples were stored at -20°C until further investigation. The study protocol was approved by the Ethics Committee of Chiangrai Prachanukroh Hospital (CR0032.102/8115 and CR0032.102/Research/EC518).