Louisville, Kentucky, November 25, 2025

In Louisville, Kentucky, health officials are closely observing the emergence of a new flu variant, Subclade K, as cases of influenza spike in the area. The positivity rate for flu tests has surpassed 5%, prompting the implementation of additional precautions. Health authorities express concern over the potential severity of illness from this variant, particularly among unvaccinated individuals, and continue to promote vaccination and hygiene practices as preventive measures.

Louisville, KY: Health Officials Monitor New Flu Variant Amid Rising Cases

Louisville, Kentucky – Health authorities in Louisville are closely monitoring a new flu variant, Subclade K, as influenza cases rise in the area. This variant, which has been affecting countries like Japan and the United Kingdom, has recently been detected in Louisville, raising concerns about its potential impact on the local flu season.

Current Flu Situation in Louisville

As of November 24, 2025, Louisville has surpassed a 5% positivity rate for flu tests, prompting health officials to implement additional precautions to prevent further spread. Emergency departments are reporting an increase in patients presenting with severe flu symptoms, including high fevers unresponsive to over-the-counter medications, severe chills, muscle aches, and, in some cases, shortness of breath and chest pain. Unvaccinated individuals, particularly young children, older adults, and those with compromised immune systems, are experiencing more severe illness.

Subclade K Variant Concerns

The Subclade K variant has been identified in other countries, and its presence in Louisville is being closely monitored. While it is too early to determine its full impact in the United States, health experts are concerned that this variant could lead to an increase in flu cases and potentially more severe illnesses. The variant emerged after the flu vaccine was formulated, leading to a mismatch between the circulating strain and the vaccine. Despite this, health officials emphasize that the flu vaccine remains the best defense against severe complications, hospitalization, and death.

Preventive Measures and Recommendations

Health officials continue to recommend the following preventive measures to reduce the risk of flu transmission:

• Vaccination: The flu vaccine is recommended for everyone six months and older. It remains effective in reducing the severity of illness, even if there is a mismatch between the circulating strain and the vaccine.
• Hygiene Practices: Wash hands frequently with soap and water, cover coughs and sneezes, and avoid close contact with sick individuals.
• Stay Home When Sick: Individuals exhibiting flu symptoms should stay home to prevent spreading the virus to others.

Health officials also advise residents to stay informed about the flu situation and adhere to public health guidelines to protect themselves and the community during this flu season.

Background on Flu Surveillance in Kentucky

The Kentucky Department for Public Health (KDPH) relies on a network of doctors’ offices, hospitals, and health departments, known as influenza sentinel surveillance sites, to track the level of influenza activity in the state and identify which strains are circulating. These sites collect data and report influenza-like illness cases weekly, providing valuable information to guide public health responses.

Weather Advisory

Residents should also be aware of the current weather conditions, as wet weather can make for slow holiday travel. Light rain is expected today, with temperatures reaching a high of 61°F (16°C) and a low of 42°F (6°C). Tomorrow, expect breezy and cooler conditions with sunshine and some clouds, with a high of 46°F (8°C) and a low of 30°F (-1°C).

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Author: HERE LOUISVILLE