National Arbovirus Monitoring Program NAMP Coordination Committee

The Australian National Arbovirus Monitoring Program (NAMP) is an integrated national program that is jointly Highlights funded by industry and governments. The program monitors the distribution of economically important This NAMP report covers the first half of 2012. insect-borne viruses (e.g. bluetongue, Akabane and During this period, rainfall in many states and bovine ephemeral fever viruses) and their vectors through the monitoring of strategically placed sentinel cattle territories was above average, with flooding herds, cross-sectional serosurveillance of cattle and the in several areas of New South Wales. placement of vector traps. This report covers the first half of 2012, when arboviral activity in northern Australia June. Eight sentinel herds (Bamaga, Chinchilla, Normanton, is expected. Tara, Maryborough, Townsville, Alpha and Tambo) and No vector activity or seroconversions to bluetongue, three serosurvey herds (Mt Isa, Kynuna and Blackall) Akabane or bovine ephemeral fever were recorded in the showed evidence of BTV. southern states of Tasmania, Victoria or South Australia. In New South Wales, BTV seroconversions were detected in herds in the North West Slopes from April and at the Climate end-of-season sampling in June. All animals in the sentinel herds at Coolatai, Warialda and Moree seroconverted, but Most of Queensland had a wet summer with above- the incidence was low at the other sites. This has resulted average rainfall, while rainfall from March to May was in the expansion of the zone of possible bluetongue average to above average. In New South Wales, above- transmission to the south and west in north-eastern New average to highest-on-record rainfall was recorded across South Wales and into southern Queensland. BTV-21 was the state during the first quarter of the year, with flooding detected and there was no evidence of clinical disease. A occurring on the mid and far North Coast in late January, single seroconversion was detected on the far North Coast in the North West Slopes during February and in southern at Casino in June. inland regions during March. Associated with the wet conditions, maximum temperatures were generally 1–3 °C below average except on the far North Coast. During the Akabane virus second quarter, rainfall was generally average to below In Western Australia, Akabane activity was detected in one average across the state. In the Northern Territory, the wet sentinel herd and three serosurvey herds in the Kimberley. season was slightly wetter than average, characterised by long, dry periods interspersed by short but very wet Akabane activity was found in all of the northerly bursts. Central Australia experienced average rainfall sentinel herds of the Northern Territory. Activity began and temperatures. in December 2011 and continued through January and February. Activity occurred in the Katherine district Bluetongue virus through to April. In Western Australia, bluetongue virus (BTV) activity was Akabane activity was detected throughout Queensland, detected in one sentinel herd and two serosurvey herds in as far west as Quilpie (serosurvey), Kynuna (serosurvey), the northern Kimberley. Tambo (sentinel herd) and Winton (sentinel herd).

BTV activity was widespread in the Northern Territory, with In New South Wales, Akabane activity was initially activity detected in all northern sentinel herds between detected on the far North Coast from December 2011, to February and May. BTV-1 and BTV-20 were identified by the south at Singleton by March and in Camden (south- isolation at Beatrice Hill, and BTV-1 by virus neutralisation west of Sydney) by June. Activity was also detected in the testing serology at other sentinel and serosurvey sites. North West Slopes from January through to the end-of- season collection in June. In Queensland, four sentinel herds at Weipa, Tambo, Bamaga and Townsville showed evidence of BTV seroconversions during January to March 2012. One Bovine ephemeral fever virus serosurvey herd at Quilpie showed serological evidence In Western Australia, bovine ephemeral fever (BEF) (1/31) for presence of bluetongue, later confirmed to activity was detected in one sentinel herd in the be serotype BTV-21. Seven bluetongue isolates from northern Kimberley. Weipa were confirmed to be BTV-1 serotype, Malaysian A genotype. Bluetongue activity was extensive from April to

4 Animal Health Surveillance — Volume 17 Issue 2 In the Northern Territory, virus activity was very was detected at Moree, Inverell and Wallangra. The Moree widespread, with activity in the northern herds from detection was the first and most westerly detection since January to May and extending through the Barkly trapping began. C. wadai was not detected this season. Tableland and into the Alice Springs district up until May. The port sites of Newcastle, Port Kembla and Eden remained vector free. BEF activity was widespread in Queensland — detected from coastal sites such as Townsville and Maryborough In Queensland, C. brevitarsis was collected throughout the to the west at sites such as St George, Quilpie, Mt Isa period at inland sites such as Alpha and Tara, reflecting the and Blackall. favourable conditions throughout western Queensland produced by the above-average rainfall. C. wadai and In New South Wales, BEF seroconversions were detected C. actoni, however, were collected only on the coast and in the North West Slopes and west to Bourke from April to not at inland sites. No vectors were collected at the port June. Cases were also confirmed in the North West Slopes of Brisbane. from early March. A single seroconversion was detected in the sentinel herd at Dubbo, although no cases were In Western Australia, vectors were only collected at two reported. On the North Coast, activity was detected in the sites in the north-east Kimberley. However, this includes sentinel herds from Casino south to Paterson from March the suspected first Australian detection ofC. nudipalpis to June, with cases also reported during April. (pending DNA confirmation), with a single specimen collected at Kalumburu in March. No further specimens were found in subsequent collections. This species Insect trapping is a suspected competent vector and has a tropical distribution across South-East Asia. Various Culicoides species were detected in South Australia, but none are considered significant to NAMP. C. actoni, C. brevitarsis, C. fulvus and C. wadai were collected at Kalumburu, and C. actoni, C. brevitarsis and C. wadai were On the New South Wales coastal strip, C. brevitarsis also collected at Carlton Hill Station, near Kununurra. was detected at all sites and as far south as Cattai, near Windsor. In the Hunter Valley, C. brevitarsis was active In the Northern Territory, C. brevitarsis was widespread in until April. On the Great Dividing Range, detections were the Top End and Victoria River district. In three northerly made at all sites, except Armidale. Inland, C. brevitarsis sites, C. actoni, C. fulvus and C. wadai were detected.

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