Ticks in Australia
Ticks are obligate haematophagous ectoparasites (blood-feeding parasites, that live on the outside of their host) and are abundant in most continents. They are important vectors for the transfer of microorganisms causing disease in livestock and humans. They can feed on mammals, birds and reptiles. Globally they transmit Borrelia (the bacteria which cause borreliosis - also known as Lyme disease/Lyme-like disease, Lyme borreliosis or relapsing fever), Ehrlichia, Babesia, Rickettsia, Bartonella and other infections.
Ticks are arachnids, a subset of the arthropod family (insects and crustaceans are also arthropods), having a segmented body, jointed limbs and usually a chitinous shell that undergoes molting. They are also capable of inducing allergies, causing toxicoses and paralysis.
They are generally divided into hard and soft ticks. The hard ticks belong to the class Ixodidae and soft ticks to Argasidae. They are listed below.
HARD TICKS (Ixodidae)
- Ixodes holocyclus -paralysis tick (Queensland, New South Wales, Victoria)
- Ixodes australiensis (Western Australia and Tasmania)
- Ixodus cornuatus -southern paralysis tick (South East Coast of New South Wales, Central Victoria and Tasmania)
- Ixodes tasmani -common marsupial tick (Tasmania, Victoria, New South Wales, Queensland, South Australia, Western Australia)
- Ixodes vestitus -numbat tick (Western Australia)
- Haemophysalis bancrofti -wallaby tick (east coast of Australia)
- Haemophysalis longicornis -bush tick (Eastern Australia-Queensland, NSW, some parts of Victoria Western Australia- between Walpole and Denmark
- Rhipicehpalus sanguineus -brown dog tick (Eastern, Northern and Western Australia)
- Rhipicephalus (Boophilus) australis (Australian cattle tick) (Queensland, Northern Territory, Western Australia, Northeastern New South Wales)
- The Amblyomma triguttatum -ornate kangaroo tick (Western Australia, Queensland, Northern New South Wales, Southwestern Western Australia)
- Bothriocroton auruginans -wombat tick (Queensland-NSW border to South Australia-Western Australian border and Tasmania)
- Bothriocroton hydrosauri -south reptile tick (Southern NSW, Victoria, South Eastern South Australia And Tasmania)
SOFT TICKS (Argasidae)
- Argas persicus -poultry tick (mainland Australia)
- Argas robertsi -Roberts bird tick (Northern Territory and Queensland-not well studied)
- Ornithodoros gurneyi -kangaroo soft tick (Central Australia, Queensland, Western Australia, Northern Territory)
- Ornithodoros capensis -seabird soft tick(nests of seabirds on islands and mainland –not well studied, reported along coast from Perth in Western Australia to Sydney, NSW)
The Paralysis Tick
RickettsiaRickettsia honei sub sp marmionii
|Australian Spotted Fever||Haemaphysalis novaeguineae||Eastern QLD
Eastern & Southern NSW
South East SA
|Unsworth et al., 2007|
|Rickettsia typhi||Murine Typhus||Flea-Ctenocephalides felis||Small areas in North East & South East QLD
South East SA
West Cast around Perth and Cape Range National Park
|Graves & Stenos, 2009|
|Orientia tsutsugamushi||Scrub Typhus||Mites-larval “chiggers” Leptotrombidium deliense||Northern Australia||Graves & Stenos, 2009|
|R.australis||Queensland Tick Typhus||Ixodes holocyclus, Ixodes tasmini||East Coast of Australia QLD, NSW, Victoria||Graves & Stenos, 2009|
|Rickettsia honei||Flinders Island Spotted Fever||Bothriocroton hydrosauri||Victoria, Tasmania, SE South Australia, Southern NSW||Graves & Stenos, 2009|
|Rickettsia grevesii||?||Amblyomma triguttatum||Abdad et al., 2014|
|Rickettsia felis||Cat Flea Typhus||Flea-Ctenocephalides felis||Abdad et al., 2011; Williams et al., 2011|
|Coxiella burnetii||Q-fever||Ixodes holocyclus, Amblyomma triguttatum||QLD, WA, NSW, SA||Cooper et al., 2013; Tozer et al., 2014; McDiarmid et al, 2000|
|Bartonella henselae||Bartonellosis, Cat Scratch Disease||Flea-Ctenocephalides felis; ticks?||Arvand et al., 2007|
|Bartonella clarridgeiae||Bartonellosis, Cat Scratch Disease||Flea-Ctenocephalides felis; ticks?||Eastern Australia||Barrs et al., 2010|
|Babesia microti||Babesiosis||?||?||Senanyake et al, 2012|
|?||Lyme-like disease||?||?||Stewart, 1982; McCrossin, 1986; Lawrence et al., 1986;
Wills & Barry, 1991; Hudson et al., 1994; Hudson et al., 1998
How Ticks Spread Infection
Three host ticks have a life cycle consisting of eggs – hatch– larva (6 legs) – feed – nymph (8 legs) – feed – adult (8 legs) – feed – lay thousands of eggs and die (see diagram). The male tick usually feeds on the female while they copulate. Male ticks are less dangerous than females as they are more likely to feed on female ticks than hosts. Nymphs are asexual and smaller in size than adults. There are also one-host ticks that spend all of their life cycle with one animal and two-host ticks which have two animals as hosts.
Tick Bite Meat Allergy
The life cycle of Babesia microti.
This is an excellent video by the Tick Encounter Resource Center (University of Rhode Island) on how infections are transmitted from a tick to its host.
Distribution of Ticks in Australia
The maps below show the main distribution of 3 common ticks in Australia
Growing evidence of an emerging tick-borne disease that causes a Lyme like illness for many Australian patients
On 12 November 2015, the Senate referred the following matter to the Senate Community Affairs References Committee for inquiry and report:
The growing evidence of an emerging tick-borne disease that causes a Lyme‑like illness for many Australian patients.