Beijing, Dec 19: China’s A(H3N2) flu subtype has dominated since late March, driving 87.1% of 6,499 influenza outbreaks recorded from March 31 to December 14—a staggering 1,675% surge from 366 cases in 2024, per Chinese CDC data.
The wave peaked late November with 1,541 outbreaks, H3N2 claiming 75.7% of tested clusters; by mid-December, outbreaks halved but the strain’s share exceeded 80%.
From a quiet mid-September baseline of just seven outbreaks, H3N2 fueled a rapid escalation, doubling weekly cases by month’s end and dominating 75% of clusters amid climbs across northern and southern provinces.
