WEST NILE VIRUS RESPONSE

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1 WEST NILE VIRUS RESPONSE Chesapeake Health Department Chesapeake Mosquito Control Commission

2 Mosquito population and disease surveillance BG Sentinel trap Aedes albopictus Gravid trap Culex pipiens / restuans ULV Action Threshold = 60 gravid females

3 In-house VectorTests Ran 435 for WNV in Positives

4 Prevention Public Notification of increasing WNV activity

5 Larvicide F O C U S Adulticide 2 consecutive treatments - Zenivex

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7 1 st West Nile Virus Case Mosquito Control Notified Heightened Response Neighborhood where 1 st WNV case resides works in Norfolk Existing gravid trap sites Additional special setting sites

8 Altosid WSP - Stormwater Points

9 ATV with DeltaGard

10 Pre & Post adulticide of the area Site 5 exceeded ULV action threshold 8/7 whole area was treated with Truckmounted ULV on 8/8. All sites were treated with Truck-mounted ULV (Aqua-Zenivex) and ATV (DeltaGard) on 8/9 All sites were re-treated with Truckmounted ULV (Aqua-Zenivex) on 8-10

11 Pre & Post Treatment Surveillance Results Increase / Decrease in Cx. pipiens gravid catches from initial setting (Aug 7 or Aug 9) Established Special Settings Sites Mosquito pools tested at state lab (DCLS) 6 pools Cx. pipiens collected pre-treatment all negative for WNV 5 pools Cx. pipiens collected post-treatment all negative for WNV 2 pools Ae. albopictus collected post-treatment both negative for WNV 10/18 Site 3 1 positive Cx. pipiens WNV in-house Vector test

12 2 nd West Nile Virus Case Mosquito Control Notified (late in day)

13 Inspection, surveillance & larviciding (property and neighbors) performed 9-18 Adulticiding performed 9-19

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18 Pre-Treatment Surveillance Traps set 9/18/18 Case 2 (Nuisance species) Trap Type Trap Comments Ae albopictus An quadrimaculatus Cx pipiens Cx salinarius Ps columbiae Total Females Gravid Gravid-A-Chick coop East side Gravid Gravid-B-Chick coop front under willow tree Gravid Gravid-C- under shed by buckets BG Sentinel BG-A- in bush/goldenrod under shed BG Sentinel BG-B- in greenhouse BG Sentinel BG-C-under shed by buckets Total Males 4 pools Cx. pipiens collected pre-treatment all negative for WNV 4 pools Ae. albopictus collected pre-treatment all negative for WNV

19 1. Did gravid catches exceed action threshold during period when patient was likely infected? CASE 1 - YES ALL 3 ROUTINE SITES 2. Did we ULV the area during that period? CASE 1 - YES BEGAN ONE NIGHT & FINISHED THE NEXT 3. Was our action threshold low enough? MAYBE NOT WVN Case 1 Date trapped during incubation period Catch during incubation period Site 1 Site 2 Site 3 7/25 67 Site 4 7/19 95 Site 5 7/17 87 ULV during incubation period 7/19 & 7/20 7/19 & 7/20 7/19 & 7/20

20 Year WNV positives per 1,000 Cx. pipiens pools tested Cx. pipiens / Gravid Trap Night *

21 What we did right: Lessons Learned Our response time was very quick Readiness & flexibility Mapping & surveillance skills already in place Testing agreement with DCLS in place War-room discussion Pesticides on hand and equipment operational Improvements for next time Lower ULV action thresholds for Cx. pipiens / restuans Heavier emphasis on larviciding Try catch basin adulticide treatments (dichlorvos strips) More sensitivity to ALL residents attitudes Give easy to use Bs product to residents

22 Environment Trump administration report: Hampton Roads facing more flooding, economic losses and bad news By Peter Coutu Staff writer Nov 28, 2018 Updated 2 hrs ago The National Climate Assessment, which is mandated by Congress and was released by President Donald Trump's administration Cities face the "greatest threat" from diseases that mosquitos carry, and climate change will only worsen this, the report said. The region will see the biggest increase in West Nile, as well.