Serological studies of influenza infection among population in southern region of Kazakhstan during the 2018-2021 epidemic season.

Objective: To conduct serological studies of influenza infection rate during an epidemic.

Methods: The retrospective study was conducted at the Research and Production Centre for Microbiology and Virology, Almaty, Kazakhstan, and comprised data, including blood samples, from patients with symptoms of acute respiratory viral infection, bronchitis and pneumonia during 2018-21 from various healthcare institutions in the Almaty region. Serological tests on blood serums were carried out sing haem agglutination inhibition assay and enzyme-linked immunosorbent assay.