Transmission Dynamics and Spatiotemporal Evolution of H1N1pdm09 in Anhui
Province, China, 2009--2023
Abstract
Background: No studies have deeply examined the transmission
patterns of H1N1pdm09 in Anhui Province, China. Methods: We
conducted a genome-wide analysis of 162 historical epidemic strains in
Anhui Province, China to understand the transmission patterns, incoming
and outgoing events, and evolutionary dynamics of the strains.
Results: Our study showed that the number of recent infections
was higher in 2018-2023 compared to previous years. Compared to the
global strain sequences, the clade production times were all delayed in
Anhui Province, China, suggesting that Anhui is an introduced region in
the global transmission chain. The NA fragments had higher dN/dS values
than the HA fragments. The circulation pattern of the strain in Anhui
Province, China was mainly from central to northern, followed by
northern to central and central to southern. Central Anhui was the
transmission center of H1N1pdm09 in Anhui Province, China. Calculation
of transmission events for the whole country showed that the main source
of the epidemic strain in Anhui Province was East China, but the
national epidemic of the H1N1pdm09 strain in 2023 appeared to originate
from Anhui Province, China. Conclusion: The above results
emphasize the focus of influenza prevention and control in Anhui
Province, China, as well as the importance of sharing information about
epidemics between different provinces.