1. Impact of Laboratory Reporting of Influenza on Flu Surveillance in Arizona
Laura Erhart, Shoana Anderson, Kelly Scranton
Arizona Department of Health Services
National Immunization Conference
March 9, 2006

2. Arizona influenza surveillance
Traditional components:
Influenza-like illness (ILI) sentinel surveillance
Sub-typing at the State Laboratory
Weekly calls to three clinical laboratories
Reports of flu activity & outbreaks from hospitals, doctors, county health departments

3. Rule changes 2004
Directors of clinical laboratory, or their representatives, must submit reports of positive influenza virus test results to the Arizona Department of Health Services within five working days.
Report should include: name, DOB, collection date, type of test, test result, provider’s name and phone number.
Reporting is from LABS, not PROVIDERS

4. Objective
To describe the impact of mandatory laboratory-reporting of influenza on surveillance and communications during the and influenza seasons.

5. Influenza-like illness

6. State lab data: culture & PCR

7. Laboratory reporting
Note scale for is 10x

8. Geographic representation

9. “Statewide” surveillance: ‘05-’06
Enrolled ILI sites
Regular reporters
season is similar

10. “Statewide” surveillance: ‘04-’05
State lab positives
County
Other lab reports
Apache 21 6
Coconino 61
Gila 5
Graham
156 3
Navajo 11 2
Pima
223
Pinal 16

11. “Statewide” surveillance: ‘05-’06
State lab positives
County
Other lab reports 1
Apache 51 4
Coconino
180
Gila 66
Graham
183
Navajo 45 20
Pima
395
Yuma 35

12. Data concordance

13.
ILI somewhat weak signal

21. Discussion

22. Beginning of season
Rapid tests filled in gaps when otherwise might have gone down to “no activity”
Positive rapid tests reported both seasons before first culture-confirmed
ADHS decision to call beginning of season based on culture-positive case
Rapid tests then “count”

23. Middle of season
Lab reports show similar trends to ILI, state lab, and sentinel lab data
Provide greater confidence for decisions & public health responses
Provide greater geographic representation
Fill in gaps in otherwise-limited data
In past, relied on anecdotal clinical reports for when activity was “bad”; now have more solid, passive data

24. End of season Difficult to determine when season ends
Lab tests trickled in through June 2005, sporadic reports throughout summer
Some state lab cases through May/June
Reporting of “sporadic” activity extended
Are we detecting low levels of cases? or lots of false positive rapid tests?

25. What’s in a number?
Current context of media/public wanting to know how many cases of X we have
ADHS can now provide counts of lab-confirmed flu cases
BUT: Is this the correct message when discussing flu & flu surveillance?
Focus on the numbers rather than that flu surveillance is an indication of what is going on in the community.

26. Resources Data entry! First season manageable Second season difficult
Mild season ( )
Reporting was new – all labs reporting?
Second season difficult
Staff time, data entry sometimes lagged
Data entry temp hired partway through season
Need electronic lab reporting

27. Other topics for consideration
Using collection date (proxy for diagnosis or onset) vs. date reported
Rapid vs. culture tests:
Balance between more comprehensive reporting and chance for false positives
Need to weigh type of test in evaluating activity?
Reports may be from any source: no differentiation of severity

28. More considerations
Do communications that flu has arrived (or is widespread) affect testing and thus what is reported?
Might some providers decide to test more for flu once it’s announced that “flu season has arrived”?
Or decide to start treating without testing midseason?

29. Determining activity levels
CDC activity levels do not account for lab reporting
Definitions focus on institutional outbreaks and ILI activity
Reporting of institutional outbreaks is tepid for AZ
ILI has not proven sensitive in recent years
Increasing usage of patterns indicated through laboratory data

30. Conclusions
Lab-reporting of influenza has led to more comprehensive flu surveillance and better understanding of community activity
Facilitated communications and confidence in timing public health responses
Resource drain is a limitation if electronic lab reporting is not available.