Survey of cases of tick‐paralysis and the presence of the eastern paralysis tick, Ixodes holocyclus, and the southern paralysis tick, Ixodes cornuatus, in the Greater Melbourne Area

Abstract

Objective The objective of this study was to test the hypothesis that the paralysis ticks, Ixodes holocyclus and Ixodes cornuatus, are epizootic and/or enzootic in the Greater Melbourne Area (GMA). Methods We examined the ticks in the museum collections of Australia, wrote to, phoned and visited veterinarians and other colleagues in the GMA to gather information about the cases of tick paralysis and to request the ticks for identification. Results We present evidence of I. holocyclus at 24 postcodes and I. cornuatus at 28 postcodes in the GMA. Conclusions We found evidence that I. holocyclus is epizootic at four postcodes in the GMA: at East Melbourne, Williamstown, Moonee Ponds and Hoppers Crossing. We did not find evidence that I. holocyclus is enzootic in the GMA. I. cornuatus is apparently enzootic in the GMA at Bullengarook, Kinglake, Chum Creek and Healesville. Our hypothesis is that I. cornuatus is also enzootic at Mt Macedon, Gisborne and at other bushy postcodes in the GMA. Since this tick is apparently enzootic in the GMA, it may also be epizootic at postcodes adjacent to busy postcodes such as Bullengarook, Kinglake, Chum Creek and Healesville. The concept of hitch‐hiker larvae, nymphs and adult female ticks may explain many of the cases of tick paralysis due to I. holocyclus in the GMA. The accurate assessment of the risk of tick paralysis in dogs and cats in the GMA requires a more detailed map of the distribution of I. holocyclus and I. cornuatus in Victoria.

Tick paralysis in Australian birds caused by Ixodes holocyclus

“…The presence of ticks on Australian birds may contribute to movement of I. holocyclus outside of tick enzootic areas, supporting the 'hitch-hiker hypothesis' of Barker and Barker. 29 These findings are consistent with reports of Ixodes sp transportation on migratory passerines overseas but rely on the assumption of a prolonged delay in the development of clinical signs following I. holocyclus attachment. 7,30 Once envenomation occurs, the impact on wild birds would be significant on an individual level as even mild weakness or altered vision has an impact on hunting success and predator avoidance.…”

Immunomic Investigation of Holocyclotoxins to Produce the First Protective Anti-Venom Vaccine Against the Australian Paralysis Tick, Ixodes holocyclus

“…Despite evidence from scientific studies (transcriptomic, sentinel studies and antibody screens) failing to show that the causative agent of Lyme disease Borrelia burgdorferi sensu lato is present in Australia ( 10 , 12 ), a similar multisystem disorder has been identified with similar symptoms in humans ( 13 ). Currently, in Australia, there is no formal reporting system of paralysis tick cases with incidence data only available from focused geographical or specific annual survey reports ( 14 , 15 ).…”

Efficacy of combination products containing sarolaner, moxidectin and pyrantel (Simparica Trio™) or afoxolaner and milbemycin (NexGard Spectra®) against induced infestations of Ixodes holocyclus in dogs

“…Ixodes holocyclus , also known as the Australian paralysis tick, is the major cause of tick paralysis in dogs in Australia. It is widely distributed along the eastern coastal regions of Australia from North Queensland to Lakes Entrance of Victoria [ 26 – 29 ]. Another ixodid tick, Ixodes cornuatus , is also reported to cause clinically significant paralysis in some parts of south-eastern Australia [ 29 , 30 ].…”

“…It is widely distributed along the eastern coastal regions of Australia from North Queensland to Lakes Entrance of Victoria [ 26 – 29 ]. Another ixodid tick, Ixodes cornuatus , is also reported to cause clinically significant paralysis in some parts of south-eastern Australia [ 29 , 30 ]. Clinical manifestations of tick paralysis caused by I. holocyclus in dogs have been well documented [ 31 , 32 ].…”