Recent (within the past 3 weeks) lab
evidence of influenza in region with increased ILI* OR Recent (within
the past 3 weeks) lab evidence of influenza in region with the outbreaks; virus
activity is no greater than sporadic in other regions**
CLOSE WINDOW TO RETURN
| * ILI activity can be assessed using a
variety of data sources including sentinel providers, school/workplace
absenteeism, and other syndromic surveillance systems that monitor
influenza-like illness. |
| † Lab confirmed case - case
confirmed by rapid diagnostic test, antigen detection, culture, or PCR. Care
should be given when relying on results of point of care rapid diagnostic test
kits during times when influenza is not circulating widely. The sensitivity and
specificity of these tests vary and the predicative value positive may be low
outside the time of peak influenza activity. Therefore, a state may wish to
obtain laboratory confirmation of influenza by testing methods other than point
of care rapid tests for reporting the first laboratory confirmed case of
influenza of the season. |
| ‡ Institution includes nursing
home, hospital, prison, school, etc. |
| ** Region: population under
surveillance in a defined geographical subdivision of a state. A region could
be comprised of 1 or more counties and would be based on each state's specific
circumstances. Depending on the size of the state, the number of regions could
range from 2 to approximately 12. The definition of regions would be left to
the state but existing state health districts could be used in many states.
Allowing states to define regions would avoid somewhat arbitrary county lines
and allow states to make divisions that make sense based on geographic
population clusters. Focusing on regions larger than counties would also
improve the likelihood that data needed for estimating activity would be
available. |
|