Ross River Virus In The City of Kalgoorlie - Boulder

Transcription

1 Ross River Virus In The City of Kalgoorlie - Boulder Alex Wiese - Manager Health and Compliance Alain Baldomero Senior Environmental Health Officer Kenan Bender Coordinator Indigenous Environmental Health

2 OVERVIEW City of Kalgoorlie-Boulder Background on Mosquito Environment 2013 Ross River Virus Outbreak Notification Investigation and Trapping/Sampling Vector Control Review of Control Strategies Multi Agency Benefits

3 City of Kalgoorlie-Boulder (CKB)

4 City of Kalgoorlie-Boulder Located approximately 600km east-northeast of Perth Shire s of Boulder & Kalgoorlie established in 1897 Shire s amalgamation in 1989 to form CKB Demographics Current Population 35k Two main streets Hannan & Burt Municipal Area 95,576 km² Main Industries - mining and mining support services The City contains a significant number of old buildings The City employs 300+ staff

5 Background on Mosquito Environment Vector Sources Sewage Overflow Area (Plant - 7 MLts/day) Treated Effluent Holding Dams and Tanks Septic tanks, Containers and Rain Water Tanks Stormwater Retention Basins and Gribble Creek Ephemeral Salt Lakes Average Level of Mosquito Borne Disease Ave of 4 RRV cases per year (excluding the two epidemic years)

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10 Ross River Virus (RRV) Epidemic RRV cases in the WA Goldfields Region 157 RRV cases in the City of Kalgoorlie-Boulder (CKB) postcodes 95,576 km² (WANIDD - WA Modifiable Infectious Disease Database) Associated with well above average rainfall levels during summer

11 Surveillance and Information Gathering Mosquito Surveillance Including Interlinked Work with DoH Mosquito-Borne Disease Control Section and Local DoH Population Health Unit Enhanced Surveillance Follow-up Questionnaires Identify RRV contributing high-priority breeding habitat(s) Inform mosquito management program

12 Surveillance and Information Gathering Mosquito Trapping Locations Source: Janes, R. And Neville, P, 2013

13 Surveillance and Information Gathering Advanced Surveillance Data - Confirmed Cases in Townsite Source: Janes, R. And Neville, P, 2013

14 Surveillance and Information Gathering Larval Sampling Locations Source: Janes, R. And Neville, P, 2013

15 Surveillance and Information Gathering Larval Sampling Locations Source: Janes, R. And Neville, P, 2013

16 Surveillance and Information Gathering DoH Population Health Unit reviewed historical RRV incidence Mapped Current RRV Cases Enhanced Surveillance Follow-up Questionnaires DoH Mosquito-Borne Disease Control Section Adult Mosquito Trapping Larval Sampling Virus Isolation

17 Surveillance Results 1289 mosquitoes trapped over 2 nights Nuisance Species Culex quinquefasciatus (43%) Culex molestus (21%) Species implicated in RRV transmission Aedes notoscriptus Domestic Container Breeding Mosquito (7%) Aedes camptorynchus Southern Saltmarsh Mosquito (7%) Culex annulirostris Common Banded Mosquito (4%)

18 Vector Control Treatment Larvacide Prolink Briquette and ProSand Vectobac G Graybate 50 SG Application Methods Mobile Applicator Hand Dosing Briquettes

19 Vector Control Combination of Treatments Treated Effluent Storage Tanks Animal Recreational Water Bodies & Retention Areas Wastewater Treatment Plant (WWTP) Golf Course Treatment Program Golf Course & WWTP Overflow Area 4 Day Blitz On-going monitoring

20 Vector Control Treatment Difficulties Vast Areas Accessibility Weather Conditions Health & Safety Issues Additional Set-up Requirements WWTP Operational Changes Officer Knowledge Job Satisfaction Hot difficult work

21 Review of Control Strategies Regular Meetings City s EH Team and DOH Local Population Health Unit Incident Rates Current and Predicted Feedback From Advance Surveillance Surveys Media, Education and Health Promotion Understand Gathered Information The Lag Time RRV onset 3 days to 3 weeks, Ave 14 days. Most people sick for 3-7 days, Doctor and a blood test, and bloods 3-5 days. Lag time from being bitten to positive result 4 weeks (9 days min, 6 weeks max)

22 Review of Control Strategies Source and Quality of Information Checking and cross referencing may be required What s the Information Telling You? About Your Current Control Initiatives Level of Mosquito Activity Larvae, Adults, Species Is It What You Expected Lag Time Forecast Breeding Conditions and Budget Resourcing Levels

23 Review of Control Strategies What We Found The Two Breeding Sites with Vector Mosquitoes Were City Controlled No Mosquito Management and No Knowledge Problem areas had been allowed to become permanent Little to No Internal Communication Industrial Area Very High Level of Nuisance Mosquitoes Education and pre-season inspection probably required Mosquitoes Were Present Across Entire City There is a Significant Problem outside of the Townsite

24 Review of Control Strategies Understand the Chemicals and Treatment Options Available Residual effects and resourcing levels The need to monitor to determine effectiveness Are you treating at the right time and using correct dosage rates? Having Good Success in Controlling Mosquitoes can lead to Community Apathy People stop taking personal responsibility for protection

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26 Benefits of Multi Agency Approach Quality and Amount of Information Gathered Technical Expertise Enormous Time Savings New Information Is Collected Know Your Enemy Know The Real Story Opportunity to Learn Shared Worked Load Ability to subdivide tasks and duties Increased Communication Capacity

27 Questions