2.1 Sample collection and processing
A total of 734 samples from various submitted sample types, including
serum, pooled tissue samples, semen, feces, aborted fetuses, and oral
fluids, were obtained from Chulalongkorn
University, Veterinary
Diagnostic Laboratory (CU-VDL) and Diagnostic Laboratory of Large
Animal Hospital and Students Training Center between January 2019 and
December 2020. The samples were collected from 145 swine farms located
in 18 provinces from different geographical regions of Thailand, mainly
in the high pig density areas in the Western, Central, and Eastern parts
(Figure S1). The experimental protocol was approved by the certification
of the institutional biosafety committee of the Faculty of Veterinary
Science, Chulalongkorn University (protocol number 2131007).