Deployable Molecular Detection of Arboviruses in the Australian Outback

The most common causes of human infection from the arboviruses that are endemic in Australia are the arthritogenic alphaviruses: Ross River virus (RRV) and Barmah Forest virus (BFV). The most serious infections are caused by the neurotropic flaviviruses, Murray Valley encephalitis virus (MVEV) and the Kunjin subtype of West Nile virus. The greatest individual risk of arbovirus infection occurs in tropical/subtropical northern Australia because of the warm, wet summer conditions from December to June, where conventional arbovirus surveillance is difficult due to a combination of low population density, large distances between population centers, poor roads, and seasonal flooding. Furthermore, virus detection requires samples to be sent to Perth up to 2,000 km away for definitive analysis, causing delays of days to weeks before test results are available and public health interventions can be started. We deployed a portable molecular biology laboratory for remote field detection of endemic arboviruses in northern Queensland, then in tropical Western Australia and detected BFV, MVEV, and RRV RNA by polymerase chain reaction (PCR) assays of extracts from mosquitoes trapped in Queensland. We then used a field-portable compact real-time thermocycler for the samples collected in the Kimberley region of Western Australia. Real-time field PCR assays enabled concurrent endemic arbovirus distribution mapping in outback Queensland and Western Australia. Our deployable laboratory method provides a concept of operations for future remote area arbovirus surveillance.