Australian paralysis ticks

The Australian Paralysis Tick is found in bush areas down the eastern aspect of the continent. It contains a toxin in its saliva that may cause progressive paralysis in humans by interference with presynaptic transmission in motor nerves. It may also cause severe allergy in some individuals. The female must feed on blood during each of the three stages of the reproductive cycle, and humans can become unintentional hosts. The tick usually feeds for a period of 4-5 days, during which time the accumulation of toxic saliva in the host may result in progressive motor paralysis. Deaths due to tick poisoning are rare, but at least twenty have been recorded in New South Wales this century. Tick paralysis may cause significant losses of livestock and farm animals such as dogs.

Another Australian tick, Ixodes cornuatus, may also cause paralysis.

Clinical features of tick envenomation

• Significant illness is more common in children, and may present as difficulty walking or general lethargy, progressing to problems with swallowing and limb or generalised weakness.
• Older children and adults may present with double or blurred vision followed by progressive weakness and paralysis.
• Occasionally, paralysis is localised, e.g., Bell's palsy.

Tick envenomation should be considered in the differential diagnosis of progressive paralysis in all patients who have been in tick-infested areas.

Related Treatments

• Australian paralysis ticks, Treatment for bites

Related Venomous creatures

• Arthropods, Australian

Books

• Stackhouse, J., Australia's Venomous Wildlife, Paul Hamlyn, Sydney, 1970, 144 pp. [ Details... ]

Journal Articles

• Domrow, R. and Derrick, E. H., 'Ixodes holocyclus, the Man-Biting Tick in S. E. Queensland', Aust. J. Sci., vol. 27, no. 8, 1965, pp. 234-236. [ Details... ]
• Ferguson, E. W., 'Deaths from Tick Paralysis in Human Beings', The Medical Journal of Australia, vol. 2, 1924, pp. 346-348. [ Details... ]
• Hamilton, D. G., 'Tick Paralysis: A Dangerous Disease in Children', The Medical Journal of Australia, vol. 1, 1940, pp. 759-765. [ Details... ]
• Roberts, F. H. S., 'A Systematic Study of the Australian Species of the Genus Ixodes (Acarina: Ixodidea)', Australian Journal of Zoology, vol. 8, no. 3, 1960, pp. 392-485. [ Details... ]
• Ross, I. C., 'The Bionomics of Ixodes holocyclus Neumann, with a Redescription of the Adult and Nymphal Stages and a Description of the Larvae', Parasitology, vol. 16, no. 4, 1924, pp. 365-381. [ Details... ]