Microevolution and phylogenomic characterization of Respiratory Syncytial Virus Type A: An outlook of 2022-2023 outbreak

A communal respiratory syncytial virus (RSV) causes mild to severe illness, predominantly in older adults, or people with certain chronic medical conditions, and in children. Symptoms may include runny nose, cough, fever, and difficulty breathing. In most cases, the infection is mild and resolves on its own, but in some cases, it can lead to more serious illness such as bronchiolitis or pneumonia. The RSV genome codes for ten proteins, NS1, NS2, N, P, M, SH, G, F, M2 and L. We aimed to identify the RSV geographical distribution and transmission pattern using site parsimonious frequencies, and investigate hotspot regions across the complete RSV genomes. These results indicated that RSV strains circulating in South and North America are not mixed to the European samples, however, genomes reported from Australia are the direct decedents of European samples. Samples reported from the United Kingdom were found diverse. Further, this report provides a comprehensive mutational analysis of all the individual RSV genes and in particular the 32 hotspot substituting regions circulating across the globe in RSV type A samples. This is the first comprehensive analysis of RSV type A that features mutational frequencies across the whole genome providing more clues for epidemiological control and drug development.