A More Sustainable Lyme Disease Surveillance System

Transcription

1 A More Sustainable Lyme Disease Surveillance System Christopher Steward Wisconsin Division of Public Health

2 Overview Lyme disease, reporting, and surveillance Changes to reporting criteria Case estimations for 2012 Impact on local health department (LHDs) and infection preventionists (IPs)

3 Lyme Disease, Reporting, and Surveillance

4 Reported Lyme Disease Case, Wisconsin, (n=25,919) 4000 Probable Cases 70 Number of Reports Confirmed Cases Incidence per 100, Incidence Source: Wisconsin Division of Public Health Year of Illness Onset * In 2008, the case definition for Lyme disease was changed and expanded to include a probable case definition.

5 Changes to Reporting Criteria

6 What Other States Are Doing? Connecticut Centralized team of epidemiologists Assisted by computer generated follow-up request and automated mailing machine New York State Sentinel surveillance in high incidence areas Follow up on 20% of cases and create estimates Minnesota Centralized team of epidemiologists and students Have laboratory restrictions on follow-up Looking at changing as their system is not sustainable

7 Total Reported Confirmed Lyme Disease and EM rash, Wisconsin, Confirmed Cases EM Cases Percent EM % 90% 80% Number of Reports % 60% 50% 40% 30% 20% 10% 0% Percent Year of Illness Onset Source: Wisconsin Division of Public Health

8 Lyme Disease 3-Year Average All confirmed cases Incidence, EM only Source: Wisconsin Division of Public Health

9 Reporting Requirements For 2012 Required reporting: Health care providers continue to report all cases of erythema migrans (EM 5cm and diagnosed by a physician or medical personnel). Laboratories continue to report all Lyme positive results. Continue to report date of illness onset and patient demographic information (address, birthdate, gender, race, and ethnicity). Optional reporting: Reporting of Lyme disease cases without EM rash is now optional, unless requested by the LHDs (these include non- EM confirmed and probable cases). Reporting of signs and symptoms other than EM rash, exposure, and treatment information is now optional, unless requested by the LHDs.

10 Case Estimation for 2012

11 Lyme Disease Cases, Wisconsin, Number of Cases Estimated Cases Reported Probable Cases Reported Non-EM Confirmed Cases Reported EM Cases Year of Illness Onset * In 2008, the case definition for Lyme disease was changed and expanded to include a probable case definition. In 2012, reporting criteria changed to reduce burden and create a more sustainable system. Source: Wisconsin Division of Public Health

12 Impact on LHDs and IPs

13 Results from LHDs LHDs in Wisconsin: 97 Response to Pre-test: 67 (69.1%) Post-test: 67 (69.1%) 56.7% reported that the change has resulted in a more sustainable reporting system and makes better use of limited resources 6.0% reported that the change has made reporting worse

14 Results from LHDs Average number of reports received per day Average time waited till follow-up was initiated Average number of attempts to perform follow-up Average time spent performing follow-up per case Average time spent performing dataentry per case Pre-Test Post-Test P-value Median N Median N Less than 5 67 Less than Less than a week 67 Less than a week minutes minutes 66 < minutes minutes 66 <0.001

15 Results from IPs Questionnaire sent to 808 IPs in Wisconsin Not all IPs work in hospital or clinic settings, expectation of getting 100 responses Response to: Pre-Test: 70 (70.0%) Post-Test: 50 (50.0%) 30.6% reported that the change has resulted in a more sustainable reporting system and makes better use of limited resources 10.2% reported that the change has made reporting worse

16 Results from IPs Average time spent performing follow-up per case Average number of data systems need to access data How extensive, on average, was follow-up per case Pre-Test Post-Test P-value Median N Median N min min 47 < Moderate 67 Minimal

17 Conclusions Changing the reporting requirements for Lyme disease surveillance has resulted in a more sustainable surveillance system, that still allows for the identification of newly emerging areas and for the targeting of public health interventions.

18 Acknowledgements Richard Heffernan, MPH, Section Chef of the Bureau of Communicable Diseases and Emergency Response, Wisconsin Division of Public Health Preceptor Dr. Suzanne Gibbons-Burgener, DVM, PhD, Section Chef of the Bureau of Communicable Diseases and Emergency Response, Wisconsin Division of Public Health Preceptor Professor Susan Paskewitz, PhD, Department of Entomology, UW-Madison Associate Professor Ronald Gangnon, PhD, Department of Population Health Sciences, UW-Madison Diep Hoang Johnson, Vector-borne Epidemiologist, Wisconsin Division of Public Health Dr. James Kazmierczak, DVM, MS, State Public Health Veterinarian, Wisconsin Division of Public Health Dr. Jeff Davis, MD, Chief Medical Officer and State Epidemiologist, Wisconsin Division of Public Health