title: Investigation into High Barmah Forest Virus Disease Case Numbers Reported in the Northern Territory, Australia in 2012-2013.
abstract: Between October 2012 and October 2013, unprecedented high numbers of Barmah Forest virus (BFV) disease cases were reported in the Northern Territory (NT). An investigation was launched by the NT Department of Health in cooperation with the Department of Primary Industry and Fisheries and the Department of Land Resource Management to investigate possible causes for this phenomenon. The investigation included virus isolations from mosquitoes collected in Darwin urban areas, BFV antibody testing in peri-urban small mammals and a human BFV disease case series investigation of recent cases. No BFV was isolated from the 4641 mosquitoes tested, none of the mammals tested positive for BFV antibodies, and the high BFV disease case numbers did not correlate with the relatively low mosquito vector numbers trapped in 2012-2013. It was estimated that up to 89% of the 79 human cases investigated did not have an acute arboviral illness and therefore had tested falsely positive. An Alere PanBio BFV immunoglobulin M enzyme-linked immunosorbent assay test kit is generally used to test for BFV, with the BFV disease case definition based on immunoglobulin M positives only. Other jurisdictions in Australia also reported high numbers of BFV disease cases, with the majority of the cases suspected to be false positives. Therefore, current testing methods need to be revised to reflect the true numbers of BFV disease cases occurring in Australia and to provide correct diagnoses for patients.
authors.affiliation: 1 Medical Entomology, Centre for Disease Control, Northern Territory Department of Health , Darwin, Northern Territory, Australia .
authors.forename: Nina
authors.initials: N
authors.lastname: Kurucz
authors.affiliation: 2 Disease Surveillance, Centre for Disease Control, Northern Territory Department of Health , Darwin, Northern Territory, Australia .
authors.forename: Peter
authors.initials: P
authors.lastname: Markey
authors.affiliation: 2 Disease Surveillance, Centre for Disease Control, Northern Territory Department of Health , Darwin, Northern Territory, Australia .|3 National Centre for Epidemiology and Population Health, Australian National University , Australia .
authors.forename: Anthony
authors.initials: A
authors.lastname: Draper
authors.affiliation: 4 Berrimah Veterinary Laboratories , Department of Primary Industry and Fisheries, Darwin, Northern Territory, Australia .
authors.forename: Lorna
authors.initials: L
authors.lastname: Melville
authors.affiliation: 4 Berrimah Veterinary Laboratories , Department of Primary Industry and Fisheries, Darwin, Northern Territory, Australia .
authors.forename: Richard
authors.initials: R
authors.lastname: Weir
authors.affiliation: 4 Berrimah Veterinary Laboratories , Department of Primary Industry and Fisheries, Darwin, Northern Territory, Australia .
authors.forename: Steven
authors.initials: S
authors.lastname: Davis
authors.affiliation: 1 Medical Entomology, Centre for Disease Control, Northern Territory Department of Health , Darwin, Northern Territory, Australia .
authors.forename: Allan
authors.initials: A
authors.lastname: Warchot
authors.affiliation: 2 Disease Surveillance, Centre for Disease Control, Northern Territory Department of Health , Darwin, Northern Territory, Australia .
authors.forename: Rowena
authors.initials: R
authors.lastname: Boyd
authors.affiliation: 5 Flora and Fauna Division , Department of Land Resource Management, Palmerston, Northern Territory, Australia .
authors.forename: Danielle
authors.initials: D
authors.lastname: Stokeld
mesh_terms: D000524:Alphavirus / Q000302:isolation & purification*; D018354:Alphavirus Infections / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D009033:Culicidae / Q000821:virology; D005189:False Positive Reactions; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007303:Insect Vectors / Q000821:virology; D015876:Northern Territory / Q000453:epidemiology; D011634:Public Health
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M
keywords: Antibodies; Arboviruses; Diagnosis; Mosquitoes; Virology