title: A retrospective study of Babesia macropus associated with morbidity and mortality in eastern grey kangaroos (Macropus giganteus) and agile wallabies (Macropus agilis).
abstract: This is a retrospective study of 38 cases of infection by Babesia macropus, associated with a syndrome of anaemia and debility in hand-reared or free-ranging juvenile eastern grey kangaroos (Macropus giganteus) from coastal New South Wales and south-eastern Queensland between 1995 and 2013. Infection with B. macropus is recorded for the first time in agile wallabies (Macropus agilis) from far north Queensland. Animals in which B. macropus infection was considered to be the primary cause of morbidity had marked anaemia, lethargy and neurological signs, and often died. In these cases, parasitised erythrocytes were few or undetectable in peripheral blood samples but were sequestered in large numbers within small vessels of visceral organs, particularly in the kidney and brain, associated with distinctive clusters of extraerythrocytic organisms. Initial identification of this piroplasm in peripheral blood smears and in tissue impression smears and histological sections was confirmed using transmission electron microscopy and molecular analysis. Samples of kidney, brain or blood were tested using PCR and DNA sequencing of the 18S ribosomal RNA and heat shock protein 70 gene using primers specific for piroplasms. The piroplasm detected in these samples had 100% sequence identity in the 18S rRNA region with the recently described Babesia macropus in two eastern grey kangaroos from New South Wales and Queensland, and a high degree of similarity to an unnamed Babesia sp. recently detected in three woylies (Bettongia penicillata ogilbyi) in Western Australia.
authors.affiliation: Taronga Conservation Society Australia, Mosman, New South Wales 2088, Australia ; Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Donahoe
authors.affiliation: School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Western Australia 6009, Australia ; Telethon Kids Institute, Subiaco, Western Australia 6008, Australia.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Peacock
authors.affiliation: School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Western Australia 6009, Australia.
authors.forename: Ace Y L
authors.initials: AY
authors.lastname: Choo
authors.affiliation: Regional Veterinary Laboratory, NSW Department of Primary Industries, Wollongbar, New South Wales 2477, Australia.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Cook
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: O'Donoghue
authors.affiliation: Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation, Geelong, Victoria 3219, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Crameri
authors.affiliation: Taronga Conservation Society Australia, Mosman, New South Wales 2088, Australia.
authors.forename: Larry
authors.initials: L
authors.lastname: Vogelnest
authors.affiliation: Biosecurity Sciences Laboratory, Department of Agriculture, Fisheries and Forestry, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia.
authors.forename: Anita N
authors.initials: AN
authors.lastname: Gordon
authors.affiliation: School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Jenni L
authors.initials: JL
authors.lastname: Scott
authors.affiliation: Taronga Conservation Society Australia, Mosman, New South Wales 2088, Australia ; School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Karrie
authors.initials: K
authors.lastname: Rose
keywords: Anaemia; Babesia; Kangaroo; Piroplasm; Wallaby