SOUTH AUSTRALIAN THERE IS JUST WAY TO PROTECT ARBOVIRUS AND YOURSELF AND MOSQUITO MONITORING YOUR F AND CONTROL ANNUAL REPORT: AVOID 2019-2020 BIT

Health Protection Programs

Health Protection and Licensing Services 1 Contents

List of Tables...... 3 6. Sentinel Chicken Program...... 22 List of Figures...... 4 Flock locations in :...... 22 Acronyms and Abbreviations...... 5 7. Notifications of Arbovirus Infections...... 24 1. Executive Summary...... 6 Ross River virus...... 24 Mosquito and arbovirus surveillance...... 6 Exposure location...... 25 Mosquito control and arbovirus prevention Barmah Forest virus...... 27 campaign...... 6 Exotic mosquito-borne diseases...... 27 2. Introduction...... 7 8. Exotic Mosquito Detections...... 28 3. Meteorological Data...... 8 9. Arbovirus Prevention Campaign Summary of weather (environmental) (Fight the Bite)...... 29 conditions...... 8 Communications tools/tactics...... 29 South Australia in 2019: very dry with 10. Globe Derby Park Mosquito warm days...... 8 Management Program...... 30 Driest year on record...... 8 History...... 30 South Australia in spring/summer 2019-20: Northern Connector...... 30 warm with average to above average rainfall in some areas...... 8 11. Local Council Mosquito Management Subsidy...... 31 4. Mosquito Trapping...... 9 12. South Australian Arbovirus Coordinated Northern mosquito surveillance....9 Control and Operations Plan...... 33 South Australian River Murray mosquito Arbovirus Response Cross Agency Group surveillance...... 12 (ARCAG)...... 33 Overview...... 12 ARCAG Membership...... 33 ...... 14 13. Future directions for mosquito surveillance Berri Council...... 15 and control in South Australia……..……… 35 ...... 16 Acknowledgement…………………………...... 35 District Council of Loxton Waikerie...... 17 ...... 18 Rural City of Murray Bridge...... 19 ...... 20

5. Arbovirus Isolations from Trapped Mosquitoes (whole trap grinds)...... 21

2 List of Tables List of Figures Table 1 Northern Adelaide mosquito Figure 1 Northern Adelaide mosquito surveillance trapping locations...... 9 surveillance trapping locations...... 9

Table 2 South Australian mosquito surveillance Figure 2 Total number of mosquitoes trapped at trap colour key...... 13 northern Adelaide trap sites during the 2019-20 mosquito season...... 10 Table 3 Alexandrina Council mosquito The average total number of surveillance trapping locations...... 14 Figure 3 mosquitoes trapped at northern Adelaide trap Table 4 mosquito sites from the 2016-2017 and 2019-20 mosquito surveillance locations...... 15 seasons...... 10

Table 5 Coorong District Council mosquito Figure 4 Average monthly mosquito surveillance locations...... 16 abundance by trap location - September 2019-April 2020...... 11 Table 6 District Council of Loxton Waikerie Figure 5 Mosquito surveillance trap locations in mosquito surveillance locations...... 17 South Australia during the 2019-20 season...... 12 Table 7 Mid Murray Council mosquito Figure 6 Average monthly trapped mosquito surveillance locations...... 18 abundance by council area - September Table 8 Rural City of Murray Bridge mosquito 2019-April 2020...... 13 surveillance locations...... 19 Figure 7 Alexandrina Council mosquito surveillance trapping locations...... 14 Table 9 Renmark Paringa Council mosquito surveillance locations...... 20 Figure 8 Alexandrina Council mosquito abundance and species by month and Molecular detections of arbovirus in Table 10 trap location...... 14 trapped mosquitoes...... 21 Figure 9 Berri Barmera Council mosquito Table 11 Sentinel chicken flock locations...... 23 surveillance locations...... 15

Table 12 MVEV and KUNV titre results in Figure 10 Berri Barmera Council mosquito Waikerie sentinel chicken flock - abundance and species by month and trap February 2020...... 23 location...... 15

Table 13 RRV infection notifications by Figure 11 Coorong District Council mosquito South Australian River Murray councils and surveillance locations...... 16 notifications per 100,000 population between Figure 12 Coorong District Council mosquito 1 July 2019 and 30 June 2020...... 26 abundance and species by month and trap location...... 16 Table 14 ARCAG Member agencies and organisations...... 35 Figure 13 District Council of Loxton Waikerie mosquito surveillance locations...... 17

Figure 14 District Council of Loxton Waikerie mosquito abundance and species by month and trap location...... 17

Figure 15 Mid Murray Council mosquito surveillance locations...... 18

3 Figure 16 Mid Murray Council mosquito abundance and species by month and trap location...... 18

Figure 17 Rural City of Murray Bridge mosquito surveillance locations...... 19

Figure 18 Rural City of Murray Bridge mosquito abundance and species by month and trap location...... 19

Figure 19 Renmark Paringa Council mosquito surveillance locations...... 20

Figure 20 Renmark Paringa Council mosquito abundance and species by month and trap location...... 20

Figure 21 Sentinel chicken flock locations...... 22 Figure 22 Total number of RRV cases notified in South Australia, per month between 1 July 2018 and 30 June 2020...... 24

Figure 23 Total number of RRV cases notified in South Australia, by age group and sex, between 1 July 2019 and 30 June 2020...... 25

Figure 24 RRV infection notifications by South Australian River Murray council and notifications per 100,000 population between 1 July 2019 and 30 June 2020...... 26

Figure 25 Total number of BFV cases notified in South Australia, per month between 1 July 2018 and 30 June 2020...... 27

Figure 26 The Asian tiger mosquito, Aedes albopictus, is the exotic mosquito of greatest concern in South Australia...... 28

Figure 27 The aerial treatment application area (highlighted in green) adjacent to the new Northern Connector motorway...... 30

Figure 28 Total mosquito subsidy expenditure 2009-2020*...... 32

4 Acronyms and Abbreviations ARCAG Arbovirus Response Cross Agency Group

BFV Barmah Forest virus

CDCB Communicable Disease Control Branch, Department for Health and Wellbeing

DAWR The Commonwealth Department of Agriculture and WaterResources

EVS Encephalitis Vector Survey

HoR Hierarchy of Response

HPO Health Protection Operations, Department for Health and Wellbeing

HPP Health Protection Programs, Department for Health and Wellbeing

ICPMR Institute of Clinical Pathology & Medical Research, Westmead Hospital

KUNV Kunjin virus

MVEV Murray Valley encephalitis virus

OG Original grind

RRV Ross River virus

UniSA Healthy Environments, Healthy People Research Group, University of South Australia

5 1. Executive Summary The South Australian Arbovirus and Mosquito Monitoring and Control Annual Report for the 2019- 20 season summarises mosquito-borne disease notification data from South Australia, as well as the various mosquito surveillance and control activities undertaken by the Department for Health and Wellbeing and local health authorities across the state. The 2019-20 season was the driest year on record with below average rainfall across most of South Australia. This resulted in fewer than average mosquito numbers collected in surveillance traps and fewer than average case notifications of human arbovirus infection.

Mosquito and arbovirus surveillance Health Protection Programs (HPP), Department for Health and Wellbeing continued to support local government through the provision of the South Australian mosquito management subsidy which included training, technical support, and funding to undertake the following activities: → mosquito surveillance activities including adult mosquito trapping and identification → viral analysis of trapped mosquitos → mosquito larval control → local and interstate mosquito management training → Fight the Bite campaign.

Trapped mosquito numbers across northern Adelaide and River Murray regions were low throughout the season. Screening of trapped mosquitoes did not result in arbovirus detections. However, the South Australian sentinel chicken program detected Murray Valley encephalitis virus (MVEV) and Kunjin virus (KUNV) in the River Murray region in February 2020.

Ross River virus (RRV) and Barmah Forest virus (BFV) human case notifications were fewer than the five year average and all notified cases of exotic mosquito-borne diseases were acquired overseas. In addition, no exotic mosquitos have been detected since March 2016 at any South Australian international ports as part of the exotic mosquito detection surveillance and mitigation activities.

The 2019-20 season was the third season the Globe Derby Park mosquito management program employed aerial mosquito larvicide application. Based on northern Adelaide mosquito surveillance trap results there has been a considerable reduction in mosquito activity in the suburb of Globe Derby Park.

Mosquito control and arbovirus prevention campaign For the 2019-20 season, SA Health’s Fight the Bite campaign comprised of the following tools and tactics:

→ An integrated advertising campaign → SA Health’s mosquito-borne disease information website: www.sahealth.sa.gov.au/fightthebite → SA Health’s social media channels including Facebook, Twitter and Instagram → A campaign pack provided to partner agencies.

6 2. Introduction The annual report provides an overview of the wide range of programs, surveillance and other activities undertaken in South Australia during the 2019-20 mosquito season, which collectively aimed to: → Monitor human mosquito-borne disease risk status → Provide an early warning of the presence of the viruses known to cause mosquito-borne disease → Inform activities to reduce mosquito breeding opportunities in high risk locations → Advise the public and visitors to South Australia of the risks and how to protect themselves from mosquito-borne disease → Promote interagency cooperation on matters relating to the monitoring, prevention and control of human mosquito-borne disease.

Mosquito monitoring and arbovirus prevention in South Australia is a multi-agency collaborative effort involving the work of officers from the following agencies and contract service providers:

→ Health Protection Branch, Department for Health and Wellbeing → Communicable Disease Control Branch (CDCB), Department for Health and Wellbeing → Aerotech Australasia → Arbovirus Response Cross Agency Group (ARCAG) → Commonwealth Department of Agriculture and Water Resources (DAWR) → Corporate Communications Branch, Department for Health and Wellbeing → Local councils: - Alexandrina Council - - Berri Barmera Council - City of Port Adelaide Enfield - - City of - Coorong District Council - District Council of Loxton Waikerie - Kingston District Council - Mid Murray Council - Port Pirie Regional Council - Rural City of Murray Bridge - Renmark Paringa Council → NSW Health Pathology, Medical Entomology, ICPMR, Westmead Hospital → One Health SA Working Group (formerly Zoonoses Working Group) → Private pest control service providers → veterinarians → Saltmarsh Environmental Consulting → Sentinel chicken host families.

7 3. Meteorological Data Summary of weather (environmental) conditions Mosquito numbers in inland parts of South Australia are influenced by rainfall and temperature during the peak period for mosquito breeding, which usually spans the months of September through to April. In coastal saltmarsh areas, tidal inundation patterns significantly impact mosquito abundance, particularly during the months of January through to April.

As detailed below, during the 2019-20 season, rainfall was below average across most of South Australia, resulting in fewer than average mosquito numbers collected in surveillance traps, and fewer than average notifications of cases of human arbovirus infection.

South Australian weather in 2019: very dry with warm days Rainfall in 2019 was below average across most of South Australia, including large areas of driest on record in the north and west. Overall, it was the state’s driest year on record, with large areas of the pastoral districts receiving less than 30mm of rainfall. Daytime temperatures were highest on record in many areas of the pastoral districts and warmer than average elsewhere. Night-time temperatures were closer to average, but still warmer than average in most districts. Overall, it was South Australia’s second-warmest year on record.

Driest year on record → Rainfall for South Australia was 65% below average. → Averaged across the state, 80mm of rainfall was recorded during 2019, making it the first year since national rainfall records began in 1900 that South Australia has had less than 100mm of rainfall, with the previous lowest being 111.4mm in 1944.

South Australian weather in spring/summer 2019-20: warm with average to above average rainfall in some areas Rainfall in spring was below average over most of South Australia, making it the state’s third-driest spring on record and lowest spring rainfall total since 1967. Daytime temperatures in spring were warmer than average, particularly in the west, with the state’s mean maximum temperature the sixth-highest on record for spring. Night-time temperatures were generally closer to average, though above average in the west and some areas of below average mean minimum temperatures in the Riverland, Mid North, and South East districts.

Rainfall in summer was generally close to average or above average over many areas of South Australia, though it was a drier than average season in parts of the North East Pastoral district and in the far west. Daytime temperatures were warmer than average across the state, while night- time temperatures were close to average in the south and above average in the northern Pastoral districts.

Acknowledgement Content thanks to Bureau of Meteorology, Australian Government (content has been adapted).

8 4. Mosquito Trapping

Northern Adelaide mosquito surveillance Northern Adelaide mosquito surveillance for the 2019-20 mosquito season commenced on 5 September 2019 and concluded on 17 April 2020. Mosquito surveillance was conducted at six locations over 28 weeks with a total of 168 dry ice baited encephalitis vector survey (EVS) mosquito traps set. Eight of the 168 mosquito traps failed or were not included due to ant attacks.

Trapped mosquitoes were counted and the results were recorded. Identification and viral screening of mosquitoes trapped in northern Adelaide was not undertaken during the 2019-20 mosquito season. This would be considered if there was suspicion of local arbovirus transmission in the area.

The six northern Adelaide mosquito surveillance trapping locations are listed in Table 1 and shown in Figure 1.

Table 1 Northern Adelaide mosquito surveillance trapping locations.

Trap Code Trap Name Location Latitude / Longitude DAW Daniel Avenue Globe Derby Park -34.787358 / 138.586398 Wetland GDR Globe Derby Globe Derby Park -34.794579 / 138.589952 Racetrack ML Mawson Lakes Mawson Lakes -34.799232 / 138.597332 SA Swan Alley Globe Derby Park -34.790797 / 138.580558 TIPS Torrens Island Power Torrens Island -34.805968 / 138.525777 Station TIQ Torrens Island Torrens Island -34.776148 / 138.523854 Quarantine

Figure 1 Northern Adelaide mosquito surveillance trapping locations. 9 Figure 2 shows that the greatest numbers of mosquitoes were trapped at Torrens Island Quarantine Station, followed by the Swan Alley trap site. The site with the smallest total catch was the Globe Derby Racetrack site followed by the Globe Derby Daniel Avenue site. This indicates that larval control activities conducted by the City of Salisbury and SA Health in the area were effective in reducing saltmarsh mosquito activity in the residential areas located adjacent the Globe Derby Park saltmarsh.

This is further demonstrated in Figure 3, showing the average of the total number of mosquitoes trapped at each site across the four previous seasons, from 2016-17 to 2019-20. The total number of trapped mosquitoes across all trap sites for the 2019-20 season was significantly lower than the four year average. This reduction in numbers across all trap sites is also likely a result of environmental conditions with higher temperatures and reduced rainfall across the season. The reduction in the total number of trapped mosquitoes at Swan Alley is likely due to the construction of the Northern Connector (shown in Figure 27).

Total catch for 2019-20 season 3228 Globe Derby Park Racetrack 3748 Daniel Avenue Wetland Swan Alley 1627 Torrens Island Quarantine Station Torrens Island Power Station 2729 Mawson Lakes

22114 6420

Figure 2 Total number of mosquitoes trapped at northern Adelaide trap sites during the 2019-20 mosquito season.

Four year average trap numbers from 2016-17 to 2019-20 13601 7285 Globe Derby Park Racetrack 6391 Daniel Avenue Wetland 10334 Swan Alley Torrens Island Quarantine Station Torrens Island Power Station Mawson Lakes

78393 52625

Figure 3 The average total number of mosquitoes trapped at northern Adelaide trap sites from the 2016-2017 and 2019-20 mosquito seasons.

10 Figure 4 shows a breakdown of average monthly surveillance trap results for each trap site during the 2019-20 season. The average numbers of trapped mosquitoes at Torrens Island Quarantine Station trap site were consistently greater than for other trap sites over the majority of the season. No larval control was undertaken at this remote location which provides an indicator of likely mosquito numbers that would have been caught in the Swan Alley trap site at the same time if comprehensive larval control was not being undertaken routinely in that area.

2500 Globe Derby Park Racetrack 2244 Daniel Avenue Wetland Swan Alley 2000 Torrens Island Quarantine Station Torrens Island Power Station Mawson Lakes 1500 Monthly average e

1196

Abundanc 1017 1000

641 559 460 500 429 421 443 332 303 262 265236 198 154 162 133 130 117 131 111 85 91 81 80 102 75 101 55 61 69 35 40 41 54 45 69 39 52 29 11 11 64 11 19 33 0 September October November December January February March April Month

Figure 4 Average monthly mosquito abundance by trap location - September 2019-April 2020.

11 South Australian River Murray mosquito surveillance Overview The Healthy Environments, Healthy People Research Group at the University of South Australia (UniSA) provided mosquito surveillance and identification services to the seven South Australian local councils along the River Murray from late August 1999 to April 2019. The cost to the councils for this service was 50% subsidised by SA Health.

The SA Health annual mosquito management subsidy budget was reduced in 2018. In order to sustain ongoing local arbovirus surveillance, SA Health developed a proposed alternative adult mosquito surveillance program along the River Murray involving local council officer participation in the setting and collecting of traps. The proposed program required each participating River Murray council to arrange for four mosquito surveillance traps to be set in strategically selected locations monthly from September to April (eight times during the season). All catches were to be sent to NSW Health Pathology, Medical Entomology, ICPMR to be counted, identified to species level and then ground and screened for RRV, BFV, MVEV and KUNV.

The following four River Murray councils decided to conduct their own mosquito surveillance in accordance with the proposed program with SA Health support: Alexandrina Council, Berri Barmera Council, the District Council of Loxton Waikerie, and Renmark Paringa Council. Trap locations were selected to best inform the assessment of public health risk.

The three other River Murray councils; Coorong District Council, Mid Murray Council and the Rural City of Murray Bridge, contracted Saltmarsh Environmental Consulting to undertake a continuation of the UniSA surveillance model in those council areas. SA Health would like to take this opportunity to acknowledge the significant contribution of UniSA and Saltmarsh Environmental Consulting (particularly Dr Craig Williams and Mr Steven Fricker) to arbovirus surveillance in South Australia.

All South Australian mosquito surveillance trap locations in season 2019-20 are shown in figure 5.

Figure 5 Mosquito surveillance trap locations in South Australia during the 2019-20 season.

12 Table 2 South Australian mosquito surveillance trap colour key.

Key Authority Alexandrina Council Berri Barmera Council Coorong District Council District Council of Loxton Waikerie Mid Murray Council Rural City of Murray Bridge Renmark Paringa Council HPP Figure 6 shows a breakdown of average monthly surveillance trap results for each South Australian River Murray council during the 2019-20 season. Mosquito abundance was greatest along the River Murray early in the season in the months of October to December.

Alexandrina Council Berri Barmera Council Coorong District Council District Council of Loxton Waikerie Mid Murray Council Rural City of Murray Bridge Renmark Paringa Council Monthly average of trapped mosquitoes for 2019-20

Figure 6 Average monthly trapped mosquito abundance by council area - September 2019-April 2020.

13 Alexandrina Council Alexandrina Council’s mosquito surveillance activities included trapping once per month between October 2019 and April 2020 at four locations. Trapped mosquitoes were sent to NSW Health Pathology, Medical Entomology, ICPMR for counting, identification and viral screening. The four Alexandrina Council mosquito surveillance trapping locations are listed in Table 3 and shown in Figure 6.

Table 3 Alexandrina Council mosquito surveillance trapping locations.

Trap Code Trap Name Location Latitude / Longitude A1 Island View Clayton Bay -35.49088889 / 138.9221389 A2 Cinema Court Port Elliot -35.53122222 / 138.67175 A3 Bike Track Port Elliot -35.50752778 / 138.67175 A4 Football Club Goolwa -35.50286111 / 138.7806111

Figure 7 Alexandrina Council mosquito surveillance trapping locations.

As shown in Figure 8, the most abundant species in 2019-20 in the Alexandrina Council area were Aedes camptorhynchus, Culex molestus, and Coquillettidia linealis. Large numbers of mosquitoes were caught in the Clayton Bay (A1) trap (mostly Aedes camptorhynchus) in October, November and December. Numbers in the other traps remained comparatively low throughout the season.

Figure 8 Alexandrina Council mosquito abundance and species by month and trap location.

14 Berri Barmera Council Berri Barmera Council’s mosquito surveillance activities included trapping in October 2019, and January, February, and April 2020 at four locations. Trapped mosquitoes were sent to NSW Health Pathology, Medical Entomology, ICPMR for counting, identification and viral screening. The four Berri Barmera Council mosquito surveillance locations are listed in Table 4 and shown in Figure 9.

Table 4 Berri Barmera Council mosquito surveillance locations.

Trap Code Trap Name Location Latitude / Longitude B1 Monash Playground Monash -34.23313889 / 140.5581389 B2 Glossop Glossop -34.26872222 / 140.5268889 B3 Berri Caravan Park Berri -34.28591667 / 140.6126389 B4 Cobdogla -34.24205556 / 140.3969444

Figure 9 Berri Barmera Council mosquito surveillance locations.

As shown in Figure 10, the most abundant species in 2019-20 in the Berri Barmera Council area were Aedes camptorhynchus, Culex molestus, and Culex quinquefasciatus. Numbers of mosquitoes caught in all traps were very low throughout the season other than a relatively small spike in Aedes camptorhynchus at the Berri Caravan Park in April.

Figure 10 Berri Barmera Council mosquito abundance and species by month and trap location. 15 Coorong District Council Coorong District Council’s mosquito surveillance activities included trapping once per month between October 2019 and April 2020 at five locations. Trapped mosquitoes were counted and identified by Saltmarsh Environmental Consulting. The five Coorong District Council mosquito surveillance locations are listed in Table 5 and shown in Figure 10.

Table 5 Coorong District Council mosquito surveillance locations.

Trap Code Trap Name Location Latitude / Longitude C1 Tailem Bend Tailem Bend Golf Course -35.265 / 139.4583333 C2 East Wellington B45, East Wellington -35.32444444 / 139.3922222 C11 Narrung Alexandrina Drive, Narrung -35.51275 / 139.1715278 C12 Meningie Golf Course Princess Hwy, Meningie -35.69461111 / 139.3366389 C5 Meningie School North Terrace, Meningie -35.68472222 / 139.3433333

Figure 11 Coorong District Council mosquito surveillance locations.

As shown in figure 12, the most abundant species in 2019-20 in the Coorong District Council area were Aedes camptorhynchus, Culex molestus, and Culex globocoxitus.

Figure 12 Coorong District Council mosquito abundance and species by month and trap location.

16 District Council of Loxton Waikerie The District Council of Loxton Waikerie’s mosquito surveillance activities included trapping once per month between November 2019 and April 2020 at five locations. Trapped mosquitoes were sent to NSW Health Pathology, Medical Entomology, ICPMR for counting, identification and viral screening. The five District Council of Loxton Waikerie mosquito surveillance locations are listed in Table 6 and shown in Figure 13.

Trap Code Trap Name Location Latitude / Longitude L1 Thieles Floodplain Loxton -34.43386111 / 140.5915556 L2 Boardwalk Loxton -34.45086111 / 140.5589444 L3 Moorook Campground Moorook South -34.28880556 / 140.3682778 L4 Kingston Caravan Park Moorok -34.27125 / 140.3491944 L5 Waikerie Caravan Park Waikerie -34.17536111 / 139.9803889

Table 6 District Council of Loxton Waikerie mosquito surveillance locations.

Figure 13 District Council of Loxton Waikerie mosquito surveillance locations.

As shown in Figure 14, the most abundant species in 2019-20 in the District Council of Loxton Waikerie were Anopheles annulipes, Culex annulirostris, and Culex globocoxitus. Numbers of mosquitoes caught in all traps were very low throughout the season.

Figure 14 District Council of Loxton Waikerie mosquito abundance and species by month and trap location. 17 Mid Murray Council Mid Murray Council’s mosquito surveillance activities included trapping once per month between October 2019 and April 2020 at five locations. Trapped mosquitoes were counted and identified by Saltmarsh Environmental Consulting. The five Mid Murray Council mosquito surveillance locations are listed in Table 7 and shown in Figure 15.

Table 7 Mid Murray Council mosquito surveillance locations.

Trap Code Trap Name Location Latitude / Longitude MM1 Morgan Ferry Morgan-Cadell Rd, -34.03888889 / 139.6772222 North West Bend MM2 Blanchetown Golf Course Skurray, Blanchetown -34.3575 / 139.6161111 MM3 Swan Reach Ferry Angaston – Swan -34.56277778 / 139.5977778 Reach Rd, Swan Reach MM4 Mannum Caravan Park Mannum -34.90944444 / 139.3175 MM5 Pt Mannum Port Mannum -34.93 / 139.3027778

Figure 15 Mid Murray Council mosquito surveillance locations.

As shown in Figure 16, the most abundant species in 2019-20 in the Mid Murray Council area were Aedes camptorhynchus, Culex molestus, and Anopheles annulipes.

Figure 16 Mid Murray Council mosquito abundance and species by month and trap location. 18 Rural City of Murray Bridge The Rural City of Murray Bridge’s surveillance activities included trapping once per month between October 2019 and April 2020 at five locations. Trapped mosquitoes were counted and identified by Saltmarsh Environmental Consulting. The five Rural City of Murray Bridge mosquito surveillance locations are listed in Table 8 and shown in Figure 17.

Table 8 Rural City of Murray Bridge mosquito surveillance locations.

Trap Code Trap Name Location Latitude / Longitude MB1 Mypolonga School Mypolonga -35.04194444 / 139.3580556 MB2 Sturt Reserve Riverfront Rd, Murray -35.12388889 / 139.2877778 Bridge MB3 Murray Bridge Golf Murray Bridge -35.13055556 / 139.27 Course MB4 Jervois Bowling Club Drummond Street, -35.26583333 / 139.4386111 Jervois MB5 Wellington Caravan Park Wellington -35.33 / 139.3822222

Figure 17 Rural City of Murray Bridge mosquito surveillance locations.

As shown in Figure 18, the most abundant species in 2019-20 in the Rural City of Murray Bridge were Aedes camptorhynchus, Culex globocoxitus, and Culex quinquefasciatus.

Figure 18 Rural City of Murray Bridge mosquito abundance and species by month and trap location.

19 Renmark Paringa Council Renmark Paringa Council’s mosquito surveillance activities included trapping in October and December 2019, and February, March and April 2020 at four locations. Trapped mosquitoes were sent to NSW Health Pathology, Medical Entomology, ICPMR for counting, identification and viral screening. The four Renmark Paringa Council mosquito surveillance locations are listed in Table 9 and shown in Figure 19.

Table 9 Renmark Paringa Council mosquito surveillance locations.

Trap Code Trap Name Location Latitude / Longitude R1 Bert Dix Park Lock 5 Rd, Paringa -34.18241667 / 140.7773611 R2 Ski Site Renmark -34.17763889 / 140.76275 R3 Jane Eliza Murtho -34.16327778 / 140.7888889 R4 Bookmark Creek Twentyfirst St, Renmark -34.17394444 / 140.7289167 MB5 Wellington Caravan Park Wellington -35.33 / 139.3822222

Figure 19 Renmark Paringa Council mosquito surveillance locations.

As shown in Figure 20, the most abundant species in 2019-20 in the Renmark Paringa Council area were Culex molestus, Culex quinquefasciatus, and Culex annulirostris. Numbers of mosquitoes caught in all traps were very low throughout the season.

Figure 20 Renmark Paringa Council mosquito abundance and species by month and trap location.

20 5. Arbovirus Isolations from Trapped Mosquitoes (whole trap grinds) All mosquitoes trapped by Alexandrina Council, Berri Barmera Council, the District Council of Loxton Waikerie, and Renmark Paringa Council were sent to NSW Health Pathology, Medical Entomology, ICPMR for molecular viral screening.

As a result of positive detections of MVEV and KUNV in the Waikerie sentinel chicken flock in February 2020, mosquitoes trapped in March 2020 on behalf of Coorong District Council, Mid Murray Council, the Rural City of Murray Bridge, and mosquitoes trapped by Health Protection Operations (HPO) in the far north of South Australia were sent to be screened for arboviruses. Refer to section 6 of this report for more information on the Sentinel Chicken Program.

For viral analysis, all trap catches were sent to NSW Health Pathology, Medical Entomology, ICPMR. Each batch of trapped mosquitoes were processed according to trap location, and were counted, identified to species level and then ground and screened for RRV, BFV, MVEV and KUNV. A total of 5128 mosquitoes were screened, resulting in no virus detections during the 2019-20 season. The results are presented in Table 10.

Table 10 Molecular detections of arbovirus in trapped mosquitoes.

Arbovirus RRV BFV MVEV KUNV Detections 0 0 0 0

21 6. Sentinel Chicken Program The aim of the South Australian Sentinel Surveillance Program is to monitor for MVEV and KUNV in the environment before the presentation of human cases. Although only a few people who become infected with MVEV will develop symptoms, in those people who do, it is fatal in about 20 per cent of cases and for those who survive, about 40 per cent of cases will suffer permanent neurological damage. KUNV encephalitis is similar to MVEV but is usually milder.

Chickens are a good indicator of mosquito-borne disease risk to the community as they readily produce antibodies to arboviruses once infected without developing symptoms. Six sentinel chicken flocks have been established along the River Murray in South Australia. Each flock contains five chickens that were bled by local vets once per month between October 2019 and April 2020. The chicken blood samples were sent to NSW Health Pathology, Medical Entomology, ICPMR and tested for MVEV and KUNV antibodies.

Flock locations in South Australia The location of the six sentinel chicken flocks is shown in Figure 21.

Figure 21 Sentinel chicken flock locations. 22 Table 11 Sentinel chicken flock locations.

Flock name Location Paringa Murtho Loxton Loxton Waikerie Ramco Swan Reach Fisher Murray Bridge Murray Bridge Meningie Waltowa

MVEV and KUNV were detected in blood samples taken from chickens in the Waikerie flock at Ramco on 28 February 2020. This is the first time sentinel chickens in South Australia have tested positive to these viruses since the program’s inception in 2011. These detections were unexpected due to the consistently dry environmental conditions and low numbers of mosquitoes caught during the season.

Due to the death of one chicken in the flock in a heatwave earlier in the season, only four chickens remained in the flock at the time of the positive results. The results are shown in Table 12.

Table 12 MVEV and KUNV titre results in Waikerie sentinel chicken flock - February 2020.

Sentinel chicken Virus Titre identification tag colour Yellow MVEV 80 KUNV 80 Olive MVEV 640 KUNV 320 Orange MVEV 160 KUNV 160 Red MVEV 10 KUNV Negative

A further bleed of this flock was undertaken as soon as results were reported. However, these were negative for MVEV and KUNV indicating that the chickens had likely been infected several weeks before the positive samples were collected.

The positive results triggered a Level 2 response according to the South Australian Arbovirus Coordinated Control and Operations Plan (refer to section 12 of this report). This resulted in the immediate implementation of a range of public health responses, including:

→ Calling an emergency ARCAG meeting (refer to section 12 of this report) → Issuing a SA Health Public Health Alert → The publication of a SA Health Media Release → Targeted Facebook advertising → Undertaking extra mosquito trapping and viral analysis of trapped mosquitoes → Activation of the SA Health ‘Fight the Bite’ standby action plan (refer to section 9 of this report).

23 7. Notifications of Arbovirus Infections All arbovirus infections detected in humans in South Australia are notifiable under the South Australian Public Health Act 2011. The CDCB of SA Health receive laboratory notifications for all positive arbovirus tests and medical notifications from doctors with place of acquisition when known.

The two most common locally-acquired arbovirus infections notified in SA are infections with RRV and BFV.

Ross River virus (RRV) RRV infection is the most commonly notified mosquito-borne disease in South Australia. Patients with RRV infection experience a polyarthritic condition with or without other symptoms such as fever, headaches, lethargy, rash, and sore muscles. Serological testing is the only reliable way to diagnose an active RRV infection.

In the 2019-20 financial year there were 42 cases of RRV infection notified in South Australia. This was fewer than the 44 cases notified in the previous financial year and the monthly 5-year moving average for all months except July to November 2019. The RRV case notifications are shown in Figure 22.

Figure 22 Total number of RRV cases notified in South Australia, per month between 1 July 2018 and 30 June 2020.

24 Cases comprised of 20 females and 22 males with ages ranging between 20 to 75 years. The age and sex of notified RRV cases for the 2019-20 financial year are shown in Figure 23 below.

Figure 23 Total number of RRV cases notified in South Australia between 1 July 2019 and 30 June 2020.

Exposure location The notified case data indicates the place of infection acquisition as follows: → 40% of cases lived in or reported travel to or from the South Australian River Murray Councils (n=17) → 31% of cases lived in or reported travel to or from the Adelaide Metropolitan Councils (n=13) → 24% of cases lived in or reported travel to or from the Regional Councils (n=10) → 5% of cases lived in or reported travel to or from interstate (n=2). The locally acquired arbovirus infections in South Australia are most prevalent along the River Murray Councils; Alexandrina Council, Berri Barmera Council, Coorong District Council, District Council of Loxton Waikerie, Mid Murray Council, Rural City of Murray Bridge, and Renmark Paringa Council.

In the 2019-20 financial year the majority of cases reported their likely location of exposure as the River Murray region (n=17), of which the highest number of notifications were from Renmark Paringa council and Berri and Barmera council (n=6).

Table 13 and Figure 24 show RRV notifications in each of the River Murray councils and notifications per 100,000 population between 1 July 2019 and 30 June 2020.

25 Table 13 RRV infection notifications by South Australian River Murray councils and notifications per 100,000 population rate between 1 July 2019 and 30 June 2020.

River Murray Council FY 2019/20 5 year average Local council FY 2019/20 5 year average number of notifications est. population notifications notifications notifications (FY 2015/16 - (ABS 2016) per 100,000 per 100,000 FY 2019/20) population population* Alexandrina 2 5 25873 8 21 Berri Barmera 6 11 10545 57 102 Coorong 0 6 5380 0 112 Loxton Waikerie 0 12 11487 0 108 Mid Murray 2 11 8642 23 123 Murray Bridge 1 4 20858 5 20 Renmark Paringa 6 11 9475 63 112

Figure 24 RRV infection notification rate per 100,000 population* for South Australian River Murray councils between 1 July 2019 and 30 June 2020.

*Notifications per 100,000 estimated resident population based on ABS population estimates from 2016 census.

26 Barmah Forest virus (BFV) BFV infection is the second most commonly notified mosquito-borne disease in South Australia. The virus is closely related to RRV and the symptoms of infection are similar. Serological testing is used to correctly diagnose the causative virus and differentiate an active infection from RRV infection.

Five BFV cases were notified in South Australia during the 2019-20 financial year. This was more than for the previous year (n=4) and for the 5-year moving average for all months except August, November and December 2019 and March 2020. However, it is important to note that due to the low number of notified cases, these differences are not statistically significant. Figure 25 shows BFV cases notified in South Australia per month between 1 July 2018 and 30 June 2020.

Figure 25 Total number of BFV cases notified in South Australia, per month between 1 July 2018 and 30 June 2020.

In the 2019-20 financial year cases comprised of two females and three males with an age range of 25 to 78 years. All cases resided in regional South Australia with one case residing in the Renmark Paringa council area.

Exotic mosquito-borne diseases Mosquito-borne diseases not locally acquired within South Australia are considered exotic mosquito- borne diseases. These diseases are diagnosed in residents or visitors returning from international travel.

The most common exotic mosquito-borne diseases diagnosed in South Australia are Dengue Virus infection, Chikungunya Virus infection, and Malaria (caused by infection with one of five different species of protozoan parasites). All notified cases of exotic mosquito-borne diseases are followed up to determine whether the disease was acquired overseas. In the 2019-20 financial year, there were five Chikungunya cases, 23 Dengue fever cases, six Malaria cases, and one Japanese Encephalitis Virus case notified in South Australia. All cases were acquired overseas.

27 8. Exotic Mosquito Detections Some species of mosquito, not currently established in Australia, are capable of transmitting diseases that can have severe impacts on the health of people and animals. For this reason, it is vital that processes are in place to ensure these mosquitoes are prevented from entering and becoming established in Australia. Aedes aegypti and Aedes albopictus (shown in Figure 26) are the two exotic mosquito species most frequently detected through inspection and surveillance procedures.

The DAWR conduct exotic mosquito detection surveillance and mitigation activities at international ports. DAWR performs mosquito vector monitoring within a 400 metre perimeter at international air and sea ports and identifies mosquito breeding sites within the port area for remediation. DAWR encourages and promotes source reduction with stakeholders in the port area. Following ground surveys, sites requiring remediation are reported to the port authority and/or land/lease holder for action.

If exotic mosquitoes are detected at an international port, DAWR will notify SA Health. SA health is responsible for coordinating surveillance and control activities in the port area extending beyond the 400m interception perimeter, or beyond the port area, and liaising with Local Government responsible for areas where an incursion has been detected.

There have been no detections of exotic mosquitoes at South Australian international ports since March 2016.

Figure 26 The Asian tiger mosquito, Aedes albopictus, is the exotic mosquito of greatest concern in South Australia.

Image source: Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Aedes-albopictus.jpg

28 9. Arbovirus Prevention Campaign (Fight the Bite) SA Health uses the annual Fight the Bite campaign to advise and inform South Australians about the health risks associated with mosquito bites and how individuals can reduce their risk of acquiring an arbovirus. Fight the Bite was first launched in 2004 and has been run each year since its inception.

The Fight the Bite campaign highlights the adverse effects of mosquito bites on human health and encourages individuals to adopt protective measures to reduce the likelihood of being bitten by mosquitoes and acquiring a mosquito borne disease. In addition to raising awareness about the health issues associated with mosquito bites, the campaign also aims to raise awareness about the importance of eliminating environments where mosquitoes live and breed.

Communications tools/tactics For the 2019-2020 season, to increase awareness about mosquito-borne disease and the importance of protecting against mosquito bites, the following tools and tactics were used to increase awareness of mosquito borne diseases and protection measures:

→ Advertising - An integrated advertising campaign was undertaken to increase awareness of mosquito-borne diseases and protection measures, serving to motivate and remind target audiences to take appropriate action to prevent mosquito bites and the spread of mosquito- borne disease. → Website - SA Health’s online central repository of mosquito-borne disease information is available at www.sahealth.sa.gov.au/fightthebite. The short URL was used in print publications and in SA Health’s social media content. → SA Health proactively promoted Fight the Bite messages through its owned social media channels, Facebook, Twitter and Instagram, for the duration of the campaign period. → Internal communications including an email signature banner, screensavers and TV screens were distributed and displayed. → Campaign pack - SA Health provided a campaign pack to partner agencies with a cover letter outlining activities and encouraging them to share the information in their local communities.

29 10. Globe Derby Park Mosquito Management Program History Globe Derby Park is an outer metropolitan suburb located approximately 15km to the north of the Adelaide CBD. It is located adjacent to highly mosquito-prone saltmarsh and samphire habitats. From approximately September to April the nuisance impacts associated with mosquitoes cause significant community unease.

Despite a longstanding comprehensive ground based mosquito larviciding program coordinated by SA Health in the saltmarsh adjacent Globe Derby Park, community concerns were raised relating to unprecedented levels of mosquito activity over the 2015/16 summer period. In response, SA Health established an interagency working group to investigate the feasibility of aerial larvicide application to replace ground based larviciding in order to provide more comprehensive mosquito control in the area.

The working group endorsed two trials of aerial mosquito larvicide application by fixed wing aircraft which were undertaken in the saltmarsh area adjacent Globe Derby Park in March and April 2017. Rigorous evaluation was conducted to determine efficacy and safety. Assessment was undertaken by an environmental consultant during the first trial to investigate potential off-target effects of the aerial application of Bti and s-methoprene mosquito larvicides.

Following evaluation of the trials, an ongoing program was established to replace the ground based program and a considerable reduction in mosquito activity has been evident in the suburb of Globe Derby Park based on surveillance trap results. In the 2019-20 season, the total cost of the program was $36,152 including GST.

Northern Connector In early 2020, work was completed on the Northern Connector and it was opened to traffic. This six lane raised concrete motorway is located directly between the suburb of Globe Derby Park and the aerial treatment program in the adjacent saltmarsh (shown in Figure 27). It is likely that this new large physical barrier will greatly reduce the number of mosquitoes leaving the saltmarsh and entering the residential suburb beyond the motorway. Comprehensive investigations will be undertaken during the 2020/21 mosquito season, particularly in January-April 2021, with a view to potentially reducing or ceasing larvicide treatment in the area if this is found to no longer be necessary.

Figure 27 The aerial treatment application area (highlighted in green) adjacent to the new Northern Connector motorway. 30 11. Local Council Mosquito Management Subsidy As public health authorities for their areas, local councils are responsible for ensuring appropriate mosquito management on public land (including Crown Land) within their jurisdiction.

In order to achieve the best possible public health outcomes, councils are encouraged to implement integrated programs incorporating a considered balance of surveillance, mosquito control, and health promotion activities. Where mosquito control activities are necessary, these are targeted to those locations which most directly impact on residents and visitors to particular localities.

Local council subsidy funding for mosquito management began in the summer of 2000-2001. The aim of the subsidy is to support mosquito surveillance and control activities undertaken by, or on behalf of, local councils in specific high risk mosquito breeding areas of South Australia where the cost of effective mosquito management exceeds available local council resources.

The subsidy covers up to half of the cost of mosquito control and surveillance undertaken by council on public land, including Crown Land. Funding for local council activities is assessed and allocated on an annual basis and is prioritised on the basis of:

→ Public health risk - High risk areas are defined as mosquito breeding sites in close proximity to population centres where there is risk or evidence of locally acquired cases of human arboviruses transmitted by mosquitoes. → Amenity benefit - Amenity is the perceived pleasantness of and/or intended use of an area/location. Increased amenity can contribute to health in its broader meaning (wellbeing). Councils report on their mosquito management activities monthly during the mosquito season and adult mosquito trap abundance and species data is provided to HPP.

The mosquito control subsidy was reduced from $92,000 to $53,000 prior to the 2019-20 season. River Murray Councils were engaged to identify options for ongoing mosquito management and arbovirus surveillance within their areas.

Four of the seven South Australian River Murray councils elected to participate in a revised mosquito surveillance program involving direct setting and collecting of traps (refer to section 4 of this report). All trap catches from those councils were sent to NSW Health Pathology, Medical Entomology, ICPMR to be counted, identified to species level and then ground and screened for RRV, BFV, MVEV and KUNV. Total subsidy expenditure for the period 2009—2020 is detailed in Figure 28.

31 Figure 28 Total mosquito subsidy expenditure 2009-2020*.

* Note: 2010-11 was a season of very high arbovirus and mosquito activity during which some councils commissioned additional surveillance and contracted treatment of some mosquito breeding sites.

32 12. South Australian Arbovirus Coordinated Control and Operations Plan The South Australian Arbovirus Coordinated Control and Operations Plan (the plan) was prepared for the Chief Executive and approved by the Minister for Health and Wellbeing in 2015. The plan details the strategies to be administered by SA Health for mosquito control and prevention of human cases of MVEV and KUNV.

The plan guides collaboration between relevant state and local government agencies in South Australia in the areas of mosquito surveillance, management and control and provides the framework for the implementation of coordinated mosquito control programs. The plan establishes procedures for SA Health officers to implement coordinated mosquito control programs and outlines the responsibilities, authorities, and the mechanisms to minimise, manage and recover from an outbreak of MVEV or KUNV infection in South Australia.

Arbovirus Response Cross Agency Group (ARCAG) The ARCAG was established pursuant to the South Australian Arbovirus Coordinated Control and Operations Plan. The purpose of the ARCAG is to provide a mechanism for effective communication amongst key stakeholder agencies and organisations on all aspects of the planning and implementation of coordinated mosquito control programs.

The ARCAG assists SA Health to plan and, if necessary, implement a state coordinated response through: → Providing advice (technical, operational and strategic) → Facilitating access to intelligence, information and resources → Facilitating communication and decision making within the representative agencies, where required, to ensure an effective and timely response.

The ARCAG also considers the preparedness of representative agencies, other organisations and the state as a whole to support a state coordinated response should it be necessary, and makes appropriate recommendations to government.

Meeting frequencies are determined by the Hierarchy of Response (HoR) level for each mosquito season. This season was at a HoR Level 1 until the detection of MVEV and KUNV in the Waikerie sentinel chicken flock, when it changed to a Level 2. As a result, HPP called an emergency meeting on 16 March 2020 to discuss response strategies if repeated bleeds detected MVEV and KUNV. Subsequent chicken bleed results triggered a return to a HoR Level 1. Further information regarding the detection of MVEV and KUNV in the Waikerie flock is detailed in section 6.

33 ARCAG Membership Membership of the ARCAG reflects the main purpose of the plan to guide collaboration between relevant state and local government agencies in South Australia in the areas of mosquito surveillance, management and control. Membership of the ARCAG is shown in Table 14.

Table 14 ARCAG Member agencies and organisations.

Coordinator - SA Health, Health Protection Murray and Mallee Zone Emergency Programs Management Committee Alexandrina Council PIRSA – Biosecurity SA Berri Barmera Council Renmark Paringa Coorong District Council Rural City of Murray Bridge Department of Environment and Water SA Health, CDCB District Council of Loxton Waikerie SA Health, HPO Environmental Protection Authority SA Water Mid Murray Council

34 13. Future directions for mosquito surveillance and control in South Australia The 2019-20 mosquito season was a successful trial for four of the seven River Murray councils in conducting their own mosquito surveillance and control programs with the support of SA Health. With the success of this trial season, the remaining three River Murray councils have now decided to conduct mosquito surveillance and control for the upcoming 2020-21 season.

Each River Murray council will trap in four strategically selected locations once per month between September 2020 and April 2021. As was done for this season, each mosquito catch will be sent to NSW Health Pathology, Medical Entomology, ICPMR for counting, identification, and viral screening. Over this coming season SA Health hopes to build council capacity for mosquito surveillance and control across South Australia and will 3D print and supply mosquito surveillance traps at no charge for all South Australian councils wishing to use them.

The South Australian Arbovirus and Mosquito Monitoring and Control Annual Report will be published online at the completion of each subsequent mosquito season. SA Health will build on the data each year to form a comprehensive overview of mosquito activity across South Australia and the associated public health risks.

35 For more information Health Protection Programs Health Protection and Licensing Services Department for Health and Wellbeing Email: [email protected] Telephone: 08 8226 7100 www.sahealth.sa.gov.au

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© Department for Health and Wellbeing, Government of South Australia. All rights reserved. ISBN: 978-1-76083-338-1. FIS: 20163 November 2020.

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