Haemaphysalis longicornis: the life-cycle on dogs and cattle, with confirmation of its vector status for Theileria orientalis in Australia

Dominique Marendy; Kim Baker; David Emery; Peter Rolls; Ralph Stutchbury

doi:10.1016/j.vpoa.2019.100022

Haemaphysalis longicornis: the life-cycle on dogs and cattle, with confirmation of its vector status for Theileria orientalis in Australia

Vet Parasitol. 2020:277S:100022. doi: 10.1016/j.vpoa.2019.100022. Epub 2019 Dec 27.

Authors

Dominique Marendy¹, Kim Baker¹, David Emery², Peter Rolls³, Ralph Stutchbury⁴

Affiliations

¹ Elanco Animal Health, Yarrandoo Research and Development Centre, New South Wales 2178, Australia.
² Sydney School of Veterinary Science, University of Sydney, New South Wales 2006, Australia. Electronic address: david.emery@sydney.edu.au.
³ Queensland Department of Agriculture and Fisheries, Tick Fever Centre, Wacol, Queensland 4076, Australia.
⁴ Queensland Department of Agriculture and Fisheries, Biosecurity Sciences Laboratory, Coopers Plains, Queensland 4108, Australia.

PMID: 34392949
DOI: 10.1016/j.vpoa.2019.100022

Abstract

The intracellular protozoal parasite Theileria orientalis ikeda has rapidly spread across South-eastern Australia since 2006, causing deaths and production losses in cattle. The 3-host "bush tick" Haemaphysalis longicornis (Neumann) appears the principal biological vector in the endemic regions. To generate sufficient numbers of ticks to produce stabilate for infection to confirm vector competency and for acaricide trials, the optimal conditions and stage-specific intervals for the generational life-cycle of H.longicornis was defined on two dogs and two steers. To determine whether H.longicornis was a definitive host for Theileria orientalis, nymphal stages were fed on a steer infected with T.orientalis and moulted adults were permitted to feed for 3 days on an uninfected calf prior to harvest. Subsequent detection of infection after inoculation of four naïve calves with stabilate produced from ground-up adult ticks or dissected salivary glands confirmed H.longicornis as one final (definitive) host for T.orientalis in Australia.

Keywords: Haemaphysalis; Ikeda; Theileria orientalis; Theileriosis; Ticks; Transmission.