Kansas influenza cases jump to 'high' level as respiratory illness season intensifies

TOPEKA — Kansas has seen a sharp increase in influenza activity, jumping from low to high levels in just one week, according to the latest data from state and federal health officials.

The Kansas Department of Health and Environment reported that the state moved from the "low" category for the week ending Dec. 13 to the "high" category for the week ending Dec. 20, 2025, according to the Centers for Disease Control and Prevention's Weekly Influenza Surveillance Report.

Laboratory testing at Kansas Health and Environmental Laboratories showed the increase in late December. Testing detected one influenza A/H3 case for the week ending Dec. 13, which increased to six cases the following week and nine cases for the week ending Dec. 27.

For the 2025-2026 season through Dec. 22, KDHE reported that influenza, pneumonia and COVID-19 combined have been the direct or contributing cause in 401 deaths.

The state launched a wastewater monitoring dashboard this season tracking data from Shawnee, Reno and Johnson counties. The dashboard shows influenza levels are moderate and increasing, while COVID-19 levels remain low but increasing.

Kansas' spike reflects a national trend. The CDC estimates at least 7.5 million illnesses, 81,000 hospitalizations and 3,100 deaths from flu nationwide so far this season as of the week ending Dec. 20.

Influenza A(H3N2) viruses are the most frequently reported this season. During Week 51, of 2,086 influenza viruses reported by public health laboratories nationwide, 2,029 were influenza A and 57 were influenza B. Of influenza A viruses that underwent additional testing, 91.8% were A(H3N2).

Kansas' activity level falls between neighboring states. Colorado and Missouri are in the "very high" category, while Nebraska and Oklahoma are in the "moderate" range.

KDHE issued a Kansas Health Alert Network advisory on Jan. 17, 2025, informing clinicians and laboratories about high levels of seasonal influenza activity. The department reminds clinicians to continue testing for influenza and subtyping influenza A-positive specimens from hospitalized patients.

The CDC recommends that everyone 6 months and older who has not yet been vaccinated this season get an annual influenza vaccine. Approximately 130 million doses of influenza vaccine have been distributed in the United States this season.