Division of Disease Control and Health Protection

COUNTY INFLUENZA ACTIVITY LEVEL DEFINITIONS

These definitions and guidelines are to be used by each County Influenza Coordinator to assess current influenza activity within their county on a weekly basis. Data is reported to the Bureau of Epidemiology weekly through EpiGateway and is published in the weekly influenza report.

0 = No Activity:

                    Overall clinical activity remains low with no laboratory confirmed cases¹ in the county.

1 = Sporadic:

And/or	a. Isolated cases of laboratory confirmed influenza1 in the county.
	b. An ILI2 outbreak in a single setting4 in the county. (No detection of decreased ILI2 activity by surveillance systems3)

2 = Localized:

And/or	a. ILI2 activity detected by a single surveillance system3 within the county.
	b. Two or more outbreaks (ILI2 or laboratory confirmed1) detected in single setting3 in the county.
	AND
	c. Recent (within the past three weeks) laboratory evidence1 of influenza activity in the county.

3 = Widespread:

And/or	a An increase in ILI2 activity detected in >2 surveillance systems in the county.
	b. Two or more outbreaks (ILI2 or laboratory confirmed1) detected in multiple settings3 in the county.
	AND
	c. Recent (within the past three weeks) laboratory evidence1 of influenza activity in the county.

No Report: (No report was received from the county at the time of publication)

 ¹Laboratory confirmed case = case confirmed by rapid diagnostic test, antigen detection, culture, or PCR.
²ILI = Influenza-like illness, fever >100 degrees F AND sore throat and/or cough in the absence of another known cause.
³ILI surveillance system activity can be assessed using a variety of surveillance systems including sentinel providers, school/workplace absenteeism, long-term care facility (LTCF) surveillance, correctional institution surveillance, hospital emergency department surveillance and laboratory surveillance.
⁴Settings include institutional settings (LTCFs, hospitals, prisons, schools, companies) & the community.