In summary, total 281 research articles were identified which reported several influenza viruses in swine populations globally. The highest number of studies were reported from Asia (n = 107), followed by North America (n = 76), Europe (n = 55), South America (n = 21), Africa (n = 18) and Australia (n = 4). The highest number of reports per country were documented in United States (n = 40) followed by China (n = 39) and Canada (n = 24). Until February 2020, influenza viruses have been reported from 53 countries worldwide. Four subtypes of IAV including H1N1, H1N2, H3N2, and A(H1N1)pdm09 viruses were most frequently detected in swine populations (Table 1).