Open Access Research article

Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia

Debbie Eagles12*, Lorna Melville3, Richard Weir3, Steven Davis3, Glenn Bellis4, Myron P Zalucki2, Peter J Walker1 and Peter A Durr1

Author Affiliations

1 CSIRO Animal, Food and Health Sciences, 5 Portarlington Rd, 3220 Geelong, Victoria, Australia

2 School of Biological Sciences, The University of Queensland, 4072 Brisbane, Queensland, Australia

3 Department of Primary Industry and Fisheries, Berrimah Veterinary Laboratories, GPO Box 3000, 0801 Darwin, Northern Territory, Australia

4 Department of Agriculture, Northern Australia Quarantine Strategy, PO Box 37846, 0821 Winnellie, Northern Territory, Australia

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BMC Veterinary Research 2014, 10:135  doi:10.1186/1746-6148-10-135

Published: 19 June 2014

Abstract

Background

Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region.

Results

A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days – three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea.

Conclusions

Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial.

Keywords:
Culicoides; Bluetongue; Atmospheric dispersal modelling; Surveillance