Microorganisms (Jul 2024)

Characterising Eastern Grey Kangaroos (<i>Macropus giganteus</i>) as Hosts of <i>Coxiella burnetii</i>

  • Anita Tolpinrud,
  • Elizabeth Dobson,
  • Catherine A. Herbert,
  • Rachael Gray,
  • John Stenos,
  • Anne-Lise Chaber,
  • Joanne M. Devlin,
  • Mark A. Stevenson

DOI
https://doi.org/10.3390/microorganisms12071477
Journal volume & issue
Vol. 12, no. 7
p. 1477

Abstract

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Macropods are often implicated as the main native Australian reservoir hosts of Coxiella burnetii (Q fever); however, the maintenance and transmission capacity of these species are poorly understood. The objective of this cross-sectional study was to describe the epidemiology of C. burnetii in a high-density population of eastern grey kangaroos (Macropus giganteus) in a peri-urban coastal nature reserve in New South Wales, Australia. Blood, faeces and swabs were collected from forty kangaroos as part of a population health assessment. Frozen and formalin-fixed tissues were also collected from 12 kangaroos euthanised on welfare grounds. Specimens were tested for C. burnetii using PCR, serology, histopathology and immunohistochemistry. A total of 33/40 kangaroos were seropositive by immunofluorescence assay (estimated true seroprevalence 84%, 95% confidence interval [CI] 69% to 93%), with evidence of rising titres in two animals that had been tested four years earlier. The PCR prevalence was 65% (95% CI 48% to 79%), with positive detection in most sample types. There was no evidence of pathology consistent with C. burnetii, and immunohistochemistry of PCR-positive tissues was negative. These findings indicate that kangaroos are competent maintenance hosts of C. burnetii, likely forming a significant part of its animal reservoir at the study site.

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