Genomic regions insertion and deletion in Monkeypox virus causing multi-country outbreak-2022

The genetic diversity and evolutionary origin of the Monkeypox virus (MPXV) that is currently creating a multi-country outbreak-2022 is not fully understood. Here we report that the MPXVs that cause outbreak-2022 (MPXVs-2022) have deletion/insertion of [~]500 to 2000bp nucleotide in multiple genomic regions. Our analyses revealed that MPXVs-2022 are very close to the West African Clade of MPXVs (WA-MPXVs) that caused the Outbreak in Nigeria in 2017-2018. Furthermore, we classified the WA-MPXVs detected before 2017 that could not be transmitted from human-to-human as WA-MPXVs-I and WA-MPXVs detected after 2017 that could be transmitted from human-to-human as WA-MPXVs-II (including MPXVs-2022), and human-to-human transmissible Central African MPXVs (CA-MPXV) remained as a separate clade. Overall our results suggest that although WA-MPXVs-II are almost identical to WA-MPXVs-I throughout the genome and two large genomic insertions ([~]500, 2000bp size insertion), they differ from WA-MPXVs-I in 5-inverted terminal repeat (5-ITR) (deletion of the last-2000bp-5-ITR) and 13 proteins that of CA-MPXVs, and the presence of seven unique proteins in WA-MPXVs-II is likely to be a significant cause of outbreak-2022. This study shed light on the genetic diversity and evolutionary origin of MPXVs causing outbreak-2022.