1. Mosquito-borne Arbovirus Surveillance in West Virginia Rachel Radcliffe, DVM, MPH CDC Career Epidemiology Field Officer Division of Infectious Disease Epidemiology 1

2. Objectives Describe arbovirus surveillance in WV –Historical methods –Plans for 2011 Describe 2010 arbovirus surveillance data 2

3. Components of Mosquito-borne Arbovirus Surveillance Species –Humans –Mosquitoes –Dead birds –Horses Viruses –WNV –LAC –EEE –SLE 3

4. Human Surveillance Local health departments receive reports from laboratories and healthcare providers –Conduct follow up to determine patient case status –Environmental investigation to provide education on mosquito-borne disease prevention 4

5. Arbovirus Case Definition — Clinical Criteria Neuroinvasive disease –Fever (≥100.4°F or 38°C) AND –Meningitis, encephalitis, acute flaccid paralysis, or other acute signs of central or peripheral neurologic dysfunction, as documented by a physician, AND –Absence of a more likely clinical explanation. Non-neuroinvasive disease –Fever (≥100.4°F or 38°C) AND –Absence of neuroinvasive disease AND –Absence of a more likely clinical explanation 5

6. Arbovirus Case Definition — Laboratory Criteria Confirmatory Laboratory Criteria 1.Isolation of virus or demonstration of specific viral antigen or nucleic acid from tissue, blood, CSF, or other body fluid 2.Four-fold or greater change in virus-specific quantitative antibody titers in paired sera 3.Virus-specific IgM antibodies in serum with confirmatory virus-specific neutralizing antibodies in the same or a later specimen 4.Virus-specific IgM antibodies in CSF and a negative result for other IgM antibodies in CSF for arboviruses endemic to the region where exposure occurred Probable Laboratory Criteria 1.Virus-specific IgM antibodies in CSF or serum 6

7. Arbovirus Case Classification — Confirmed Neuroinvasive disease –Meets clinical criteria for neuroinvasive disease –One or more of the 4 confirmatory laboratory criteria Non-neuroinvasive disease –Meets clinical criteria for non- neuroinvasive disease –One or more of the 4 confirmatory laboratory criteria 7

8. Arbovirus Case Classification — Probable Neuroinvasive disease –Meets clinical criteria for neuroinvasive disease –Only has virus specific IgM antibodies in CSF or serum with no other testing Non-neuroinvasive disease –Meets clinical criteria for non- neuroinvasive disease –Only has virus-specific IgM antibodies in CSF or serum with no other testing 8

9. 2010 Human Surveillance Data 8 cases of LAC reported from 5 counties –4 confirmed and 4 probable –All neuroinvasive –Illness onsets occurred June–October –Median age of cases=7.5 years –50% were female No cases of WNV, SLE, or EEE reported 9

10. Travel-Associated Cases Dengue –2 cases –Travel included Honduras and Phillipines –Both hospitalized Malaria –3 cases –Travel included Nigeria and India –One hospitalization 10

11. Mosquito Surveillance Routine mosquito trapping began in 2007 Trapping occurred May–October in most years Trapping historically focused in Jackson and Kanawha counties –Cabell and Ohio counties have also participated Mosquitoes tested for arboviruses depending on species –Culex spp. tested for WNV and SLE –Non-Culex spp. tested for WNV, LAC, SLE, and EEE 11

12. 2010 Mosquito Surveillance Data Trapping only occurred May–August in 3 counties 36,731 mosquitoes from 459 pools collected 26 (5.7%) of 459 pools tested positive for WNV –Positive pools found in all 3 counties where trapping conducted No pools positive for SLE, LAC, or EEE 12

13. 13

14. 2011 Plans for Mosquito Surveillance New entomologist in DIDE Regular mosquito trapping postponed –Assessing previous trapping methods and locations –May do larval studies in a portion of the state Would like to see surveillance expanded to more parts of state 14

15. Dead Bird Surveillance Collection kits sent to local health departments each spring Freshly dead birds suitable specimens Swab oral cavity of bird and send swab to OLS –ID numbers obtained from DIDE prior to OLS submission Specimens tested for WNV, SLE, and EEE 15

16. 2010 Dead Bird Surveillance Data 9 dead bird samples tested 0 were positive for WNV, SLE, and EEE Specimens submitted from 8 counties 16

17. 17

18. 2011 Dead Bird Surveillance Dead bird testing will continue Specimen collection and suitable specimens are the same Specimens should be sent to OLS OLS will send to Southeastern Cooperative Wildlife Disease Study for testing 18

19. Horse Surveillance Veterinarians submitted horse serum samples to OLS OLS sends specimens to National Veterinary Services Laboratory for WNV and EEE testing Free testing service 19

20. 2010 Horse Surveillance Data 3 horse specimens submitted and tested 0 were positive for WNV and EEE Specimens received from 2 counties 20

21. 21

22. 2011 Horse Surveillance Testing service will continue Specimen collection and submission to OLS will remain the same Advertising testing services through WV Veterinary Medical Association 22

23. Enhanced Passive Surveillance HAN sent at beginning of season to healthcare providers Letter sent to hospital laboratories Communication with local health departments More outreach to veterinarians in 2011 23

24. 2011 Surveillance Activities May 2 — Email memo May 9 — Hospital laboratory letter May 16 — HAN to healthcare providers 24

25. Arbovirus Surveillance Summary LAC continues to be the major arbovirus affecting humans in WV WNV continues to be detected in mosquitoes –Previous surveillance methods being reviewed –Want to expand surveillance No arboviral cases detected in dead birds or horses –Submission numbers of both are declining –Assistance needed to increase submission numbers 25