Surveillance of Vector-Borne Diseases in California: Reasons, Resources, and Refinement

1. Surveillance of Vector-Borne Diseases in California: Reasons, Resources, and Refinement Anne Kjemtrup, D.V.M., M.P.V.M., Ph.D Research Scientist III California Department of Public Health Vector-Borne Disease Section

2. Assigned Objectives • What level of public health resource the area needs and why • What vector-borne diseases merit surveillance and investigation and why? • What information do we collect and why • Demonstrate or illustrate how public health surveillance and/or investigation and/or prevention impacts health of population (now and in the future) • What changes to current public health practice might be warranted – why and how would we implement them • How might we measure what we do and what impact we have with our efforts • What can we not do (What should we do to maximize resources? )

3. Level of public health resource area needs

4. Vector-Borne Diseases in CaliforniaPrimary Program Areas • Mosquito • Flea • Tick • Rodent

5. Public Health Surveillance The ongoing systematic collection, analysis, interpretation, and dissemination of health data • Public Health Action • Planning, implementing and evaluating disease: • investigation • control • prevention • Assess public health status • Define public health priorities • Evaluate programs • Stimulate research Surveillance Collection Analysis Interpretation Dissemination

6. Some vector-borne diseases require complex surveillance efforts to monitor, intervene, anticipate, detect, and study their epidemiology (just a few of surveillance functions) West Nile virus transmission cycles in California Urban cycle Rural cycles Rural cycles ?? ?? ?? ?? Culex Culex Culex Culex Bird/Mosquito Bird/Mosquito Aedes, Culiseta Aedes, Culiseta pipiens pipiens pipiens pipiens Movement? Movement? Aedes, Culiseta stigmat stigmat . . stigmat stigmat . . ? ? erythro erythro . . ? ? erythro erythro . . Culex tarsalis Culex tarsalis Culex tarsalis Culex tarsalis ?? ?? Dead end hosts Dead end hosts

7. Context* of Vector-Borne Diseases in CA * Adapted from Braks et al, Parasites and Vectors 2011, 4: 192 ** Endemic infections with human cases *** Not specifically reportable in CA

8. Reportable Vector-Borne Diseases in CA(Context shown in parentheses) * May also have non-vector source, e.g. animal, environment

9. Intervention/Response Surveillance (Improved) diagnosis, treatment(s) recommendations hospital Notifiable/reportable Health care provider Public education Disease burden General pop.:Symptomatic Sero-surveillance, surveys General pop.: (A)symptomatic infected General population: exposure Vaccination, prophylaxis Vector-surveillance Vector control Risk Vector: presence/absence/abundance/distribution pathogen-surveillance pathogen control Reservoir hosts: presence/absence/abundance/distribution Adapted from Braks et al, Parasites and Vectors 2011, 4: 192

10. Current Prioritization of VBD* Various Tick-Borne Diseases (1) Rickettsia spp., Anaplasma, Babesia, etc Associate with Lyme surv.infrast. Imported mosquito-borne diseases Dengue, malaria, chickungunya (3,5) Associate with WNV surv. Infrast. * Subject to change with unexpected increase in disease burden, exotic vector introduction

11. What information do we collect and why

12. Notifiable Disease Surveillance Case definitions are established by the Council of State and Territorial Epidemiologists (nationally notifiable) or California Conference of Local Health Officers (state reportable) to standardize reporting across the country and state. • Need to be able to compare “apples to apples” • Comparable cases over time and space • Some “true” cases may not fit definition, while some non-cases may fit definition • Case definitions are NOT diagnostic definitions!

13. Information Captured for VBD • Demographics • Laboratory • Some quite specialized for case definition purposes, e.g. Lyme disease, Dengue • Exposure • Vector • Exposure • Potential for on-going transmission • Environment • Elevation • Camping • Reservoir

14. Demonstrate or illustrate how public health surveillance and/or investigation and/or prevention impacts health of population (now and in the future)

15. Surveillance for West Nile Virus (context 1)

16. Surveillance translated into action

17. Assessment Table Environmental conditions Mosquito species, abundance, infection prevalence Seroconversions of sentinel chickens Dead bird infection prevalence # of human cases

18. Response Temperature Runoff Human Cases Rainfall Environmental Conditions Dead Bird Infections Adult Mosquito Vector Abundance Average Virus Isolation Chicken Seroconversions Overall Risk Level (Level 1=Normal; Level 2= Emergency Planning; Level 3=Epidemic Conditions)

19. Seasonality • Mosquito • Human

21. Lyme Disease(context 1) • Human, vector, reservoir surveillance in CA • Surveillance information used at national level; defines local risk as well • Risk communication: • Provides prior probability information useful for diagnosis • Specific populations at risk identified and targeted for information • Continued surveillance still turns up surprises

24. Predictive Value of Laboratory Serology Predictive value positive Prior probabiity

25. (n=806)

27. Targeted Public Health Education Kids Occupational Health Public Medical community

28. Surveillance work by VBDS and others identified new places of tick-encounter risk Nymphal ticks: • In leaf litter and on trees and logs in hardwood forests • Be aware that nymphal ticks can be acquired from wood products such as logs, tree trunks, and wooden picnic tables VBDS-CDPH Courtesy Dr. Robert Lane, UCB Courtesy Dr. Robert Lane, UC Berkeley

29. Dengue (context 3)Current Concerns for California • Mosquito vector (Aedesalbopictus) recently detected in southern California • Capable of transmitting dengue, yellow fever, chikungunya, and several other encephalitis viruses  • Vicious day-biting mosquito; prefers mammals • Recent indigenous transmission of dengue virus in south Florida, Texas, and Hawaii • Dengue incidence increasing world-wide • Only a plane ride away? • Collecting information on imported cases, exposure, outcome

30. Aedes albopictus • native distribution (blue) • established introductions (green) Detected September 2, 2011 El Monte trailer park, LA County 30

31. Oct. 27,2011: known infestation = 8 sq miles Oct. 20: 18 / 66 larval samples positive adults found in 15 / 155 back yards inspected

32. Percent Foreign-Born By MATTHEW BLOCH, SHAN CARTER and ALAN McLEAN | Source: 2005-9 American Community Survey, Census Bureau; socialexplorer.com

34. DengueNeed for Vigilance

35. Typhus(Context 1 or 2) • Flea-borne typhus or “endemic” or “murine” typhus • Rickettsia typhi known agent • Urban wildlife (Opossum principally, rats historically) serve as reservoir • “Cat flea” (Ctenocephalidesfelis) vector • Historically known pockets in Los Angeles, Long Beach • Past few years detection expanded into Orange County • Public education primary response available

36. Typhus(Context 1 or 2) • New technologies, expanded surveillance identify new challenges • Diagnostic/Surveillance • Serology nonspecific, requires convalescent for confirmation • Case definition – varies between states where reportable • Ecology/Epidemiology • Role of Rickettsia felis? • Role of cats, particularly feral cats? • Can expanded surveillance better inform our response?

37. Typhus: public concern

38. What changes to current public health practice might be warranted – why and how would we implement them?

39. Healthy People 2020 goal: “to strengthen policies and improve practices that are driven by the best available evidence and knowledge” From: Jacobs et al, 2012. Prev Chronic Dis

40. Challenges/Opportunities • Technology transitions (e.g. CalREDIE) • Impact workload • Eventual ability to better access data • Changing disease landscapes can impact priorities (but sometimes brings resources) • Global level (H1N1) • National, state level (WNV) • Local level (typhus) • Resources, resources, resources

41. Changes or Back to Basics? • Training/information opportunities • CDC grand rounds • Lyme disease (http://www.cdc.gov/about/grand-rounds/archives/2011/May2011.htm) • CalREDIE trainings • Monthly Vector-Borne Disease PIO call provides general updates throughout state.

42. Changes or Back to Basics? • Partnering with other agencies/organizations may improve information gathering or identify resources

43. Changes or Back to Basics? • Establish standard criteria prioritization system diseases under surveillance? • Proposal from Europe: (Balabnova, et al., 2011: PloS ONE 6(10) 1-7.)

44. Partnering with other agencies for VBD Surveillance: WNV example California Department of Public Health Mosquito and Vector Control Assoc. of California Center for Vectorborne Diseases, UC Davis CA Animal Health and Food Safety Lab CA Dept Food and Ag

45. Partnering with other agencies for VBD Surveillance: WNV example Field data retrieved and laboratory test results entered Local agencies enter field data Central server Results automatically sent to CDC Interactive maps automatically updated Historical database updated Results reported to client automatically after entry Arbovirus bulletins http://gateway.calsurv.org

46. Does Spot get Spots? Veterinary Survey for Canine Cases of Rocky Mountain Spotted Fever in California.

47. How might we measure what we do and what impact we have with our efforts

48. Standard Surveillance Evaluation • Importance • Usefulness • Cost • Quality • Simplicity • Flexibility • Acceptablity • Sensitivity • Predictive value positive • Representativeness • Timeliness

49. Quick Ways to Assess Impact • Website metrics • If put out press release- hits to website or specific provided links • Many other assessible metrics (where are people coming from to get to your website? Geographic location ? Etc) • Effort in completing report forms • % of forms that have complete info/not returned for more info? • Are there sections often not completed? Why?

50. Quick Ways to Assess Impact http://www.cdph.ca.gov/programs/vbds/Pages/VBDSAnnualReports.aspx