2.1. Clinical Samples

Nasopharyngeal Swabs (NPS) from patients with suspected influenza infections were collected in viral transport media (Copan UTM 321c, USA) as part of the routine ongoing influenza diagnosis/surveillance program. These samples were initially screened for influenza A(H1N1)pdm09, influenza A/non-H1N1, and influenza B using Xpert Flu kits (Cepheid, USA) at the molecular virology laboratory in KAMC as per the manufacturer’s instructions. All patients with laboratory-confirmed samples during the study period from 2015 to 2019 were included. Samples were stored at −80°C for further nucleic acid extraction.