Medical Entomology Quarterly Report

Medical Entomology Quarterly Report South Metropolitan Health Region: Oct – Dec 2021

2 Ross River virus disease case data summary Western Australia: 2021/22 Data reflected in this summary of mosquito-borne disease is taken from the Western Australia Notifiable Infectious Disease Database (WANIDD) and includes enhanced surveillance data collected by Population Health Units and local governments (only locations with notified cases of disease are shown in tables and figures). Ross River virus (RRV) Western Australia A total of 129 cases of RRV were notified between 1 October 2021 and 31 December 2021 in Western Australia. Of these 97 cases were notified by Doctor and follow-up data is available for 63 cases. The number of cases was significantly below the long term mean for October and November, and below the long term mean for December 2021. Long term cases of Ross River Virus in WA health.wa.gov.au Please contact Medical Entomology if more information is required (08) 9285 5500 Email: medical.entomology@health.wa.gov.au 2

Ross River virus disease case data summary South Metropolitan Health Region: Oct – Dec 2021 Data reflected in this summary of mosquito-borne disease is taken from the Western Australia Notifiable Infectious Disease Database (WANIDD) and includes enhanced surveillance data collected by Population Health Units and local governments (only locations with notified cases of disease are shown in tables and figures). RRV 2021 Oct Nov Dec Total 2 4 4 10 2 1 2 5 BEELIAR 1 1 COOGEE 1 1 Metro Cockburn (C) COOLBELLUP ROTTNEST ISLAND Ross River virus (RRV) South Metropolitan Health Region 1 Fremantle (C) 2 1 NORTH FREMANTLE Melville (C) 1 ATTADALE WINTHROP MANNING DAWESVILLE BARRAGUP BALDIVIS 5 7 17 1 2 4 7 1 1 1 1 1 1 1 2 1 2 1 1 1 1 1 1 2 1 3 2 1 1 1 4 1 COOLOONGUP 1 1 4 11 1 2 1 GARDEN ISLAND 1 1 1 HILLMAN 1 1 KARNUP 1 1 PORT KENNEDY 1 1 ROCKINGHAM 1 SECRET HARBOUR 1 1 1 SINGLETON 1 1 WARNBRO 1 1 1 3 Waroona (S) LAKE CLIFTON 2 2 2 PRESTON BEACH Total health.wa.gov.au 1 5 PINJARRA Rockingham (C) 1 33 WANNANUP The number of cases was close to the long term mean for October and below the long term mean for November and December 2021. 1 13 MEADOW SPRINGS Murray (S) 1 1 9 MADORA BAY MANDURAH 1 1 11 GREENFIELDS HALLS HEAD 1 1 DUDLEY PARK FALCON 2 1 1 LEDA Mandurah (C) 1 1 1 South Perth (C) SW - Peel 1 1 Kwinana (C) 43 RRV cases were notified for the South Metropolitan Health Region including 34 cases notified by Doctor. Follow-up data is available for 15 cases. 1 2 13 13 1 1 17 43 Please contact Medical Entomology if more information is required (08) 9285 5500 Email: medical.entomology@health.wa.gov.au 3

Barmah Forest virus disease case data summary South Metropolitan Region and State summary: Oct – Dec 2021 Data reflected in this summary of mosquito-borne disease is taken from the Western Australia Notifiable Infectious Disease Database (WANIDD) and includes enhanced surveillance data collected by Population Health Units and local governments (only locations with notified cases of disease are shown in tables and figures). Barmah Forest virus (BFV) Western Australia A total of 10 cases of BFV have been reported between 1 October 2021 and 31 December 2021 in Western Australia. 4 were notified by Doctor and follow-up data is available for 3 cases. The number of cases was above the long term mean for November and December. Long term cases of Barmah Forest Virus in WA Barmah Forest virus (BFV) South Metropolitan Health Region One BFV case was notified by doctor between October to December 2021. Follow-up data is available for this case. The long term monthly mean is less than one case per month for this region. BFV 2021 SW - Peel Murray (S) BIRCHMONT Total health.wa.gov.au Oct Nov Dec 1 1 1 1 Total 1 1 1 1 Please contact Medical Entomology if more information is required (08) 9285 5500 Email: medical.entomology@health.wa.gov.au 4

Climate outlook for Western Australia International Research Institute for Climate and Society (IRI ENSO) Forecast & BOM Australian BOM Temperature Outlook Issued 17 February 2022 Issued 18 February 2022 Mar - May 2022 Predicted impact of climatic conditions on mosquito breeding La Niña remains active and is at or past its peak and should return to neutral in coming months during autumn. The IOD is neutral levels, and has little influence on Australian climate at this time of year. Impact on mosquito breeding: Warmer days and nights across much of the state are conducive to mosquito breeding and possible mosquito-borne virus activity where water remains stagnant. No MVE or Kunjin virus activity has been detected in sentinel chicken flocks in the Pilbara and Kimberley since September 2021. ENSO Alert Status: La Niña at or past its peak, but its influence will persist until mid-autumn. Australian BOM Rainfall Outlook Issued 17 February 2022 Daytime temperatures are likely to be above median the coastal areas and tropical north, with average temperatures in other areas. El Niño–Southern Oscillation (ENSO) A weather forecast based on interaction between the atmosphere and tropical Pacific Ocean. Conditions can be El Niño, La Niña or neutral: El Niño: Associated with drier conditions, decreased rainfall and tidal activity. Warmer days in south. Late start to northern wet season with less cyclones and less flooding. La Niña: Associated with wetter, cooler days and warmer nights (due to increased cloud cover). Earlier start to the northern wet season with more tropical cyclones. More conducive to mosquito breeding and possible mosquito-borne virus activity. Indian Ocean Dipole (IOD) Positive IOD: Brings below average winter-spring rainfall, warmer days in the west, warmer nights in the south west, and cooler nights in the north. Negative IOD: Brings above average winter-spring rainfall, cooler days in the south, and warmer nights in the north with increased chances of flooding. health.wa.gov.au Rainfall is likely to be above median for large parts of the state, with average rainfall expected for other parts. Night-time temperatures are very likely to be warmer than median across the whole state. Please contact Medical Entomology if more information is required (08) 9285 5500 Email: medical.entomology@health.wa.gov.au 5

GARDEN ISLAND 1 HILLMAN 1 1 . SECRET HARBOUR 1 1 SINGLETON 1 1 WARNBRO 1 1 Waroona (S) 2 1 3 LAKE CLIFTON 2 2 PRESTON BEACH 1 1 Total 13 13 17 43. health.wa.gov.au Please contact Medical Entomology if more information is required (08) 9285 5500 Email: medical.entomology@health.wa.gov.au 44