Fleas(2) wild birds(2) assay development(2) China(2) pentaplex real‐time PCR(2) reassortant(2) Yersinia pestis (2) Avian influenza virus(2) Yersinia pseudotuberculosis (2) H3N6(2) DBS(1) PCR(1) real-time PCR.(1) hepatitis B(1) DNA extraction(1)