What's going around in China?

CNIC's sentinel network, hundreds of hospitals and laboratories across northern and southern China, produces weekly indicators for influenza and RSV. Weekly ILI percentages are reported through WHO FluNet, including via the LAB_RESULT_COMMENT field, with northern and southern China tracked as separate signals. The result is a view of pressure at sentinel sites rather than a raw nationwide count of ill people.

WHO FluNet, which aggregates CNIC's sentinel data, covers influenza and RSV only. SARS-CoV-2 has its own dedicated Chinese surveillance streams, including hospital networks and genomic programmes. Data pages built on FluNet therefore focus on flu and RSV; COVID-19 monitoring in China continues through those separate channels.

Climate and contact patterns differ substantially between the two regions. Northern China follows a temperate winter-peak pattern; southern China shows prolonged autumn-through-winter activity and occasional summer peaks. Reporting a single national average would hide genuine signal. CNIC and WHO FluNet preserve the north–south distinction, which produces noticeably more honest trend visibility than a merged curve would.

Northern China resembles other temperate Northern-Hemisphere countries, with January–February peaks. Southern China resembles subtropical Western Pacific regions with more prolonged and sometimes bimodal activity. Because CNIC reports both regions separately into WHO FluNet, cross-country comparison is straightforward within the Western Pacific regional framework.

CNIC uses qualitative tiers anchored to historical ILI-percentage thresholds, reported separately for the north and south. The ILI% values themselves are published through FluNet's LAB_RESULT_COMMENT field, which makes the classification basis unusually transparent. These tiers describe whether current sentinel pressure is ordinary, elevated, or unusually intense for the region and time of year, not an absolute case count.