ticks in Australia

see also:

• insect bites and stings
• toxinology

• ticks are blood sucking, external parasites which belong to the order Acarina (which also contains mites) and are related to spiders and scorpions
• globally, only mosquitoes spread more human and animal diseases than ticks
• Australia has ~75 species of ticks which are divided into 2 families - soft ticks (family Argasidae of which there are only a few species), and hard ticks (family Ixodidae)
  • 16 species will attach and feed on humans
• the main tick of medical concern is the Paralysis Tick (Ixodes holocyclus)
  • in Victoria, the other ticks of concern are:
    • Tasmanian paralysis tick (Ixodes cornuatus) also is in central Victoria and hard to distinguish from Ixodes holocyclus - can attach to humans and cats
    • the bush tick (Haemaphysalis longicornis)) host is mammals, esp. livestock (which can die from Theileria orientalis ikeda infections), and birds and are found from Otways to Brisbane along the coastal and for ~200km inland
    • the common marsupial tick (Ixodes tasmani) host is mainly marsupials and rodents but can attach to humans and pets and prefers to live in tree hollows, in dense vegetation and burrows or dens.
    • the brown dog tick (Rhipicephalus sanguineus) - mainly an issue for dogs - found along the western, northern, and eastern coasts of Australia
    • the southern reptile tick - host is reptiles but can attach to humans
• tick bites may cause:
  • hypersensitivity reactions
  • tick-induced mammalian meat allergy
  • less commonly, mammalian milk allergies
  • and rarely, anaphylaxis
• other diseases potentially spread by ticks in Australia include ¹⁾:
  • Tick scrub typhus is an infection with a rickettsia transmitted from native animals by ixodid ticks and is confined to the eastern coast line of Australia and Bass Strait Islands. Clinical symptoms include headaches, multiple rashes, swollen glands, fever and flu like symptoms. The disease is rarely fatal and is commonly treated with antibiotics.
  • Flinders Island spotted fever due to Rickettsia australis carried by the southern reptile tick (Bothriocroton hydrosauri)
  • Q fever carried by the ornate kangaroo tick (Amblyomma triguttatum which is assumed to be endemic to south-western Western Australia (including Barrow Island), Queensland (excluding Cape York Peninsula), and New South Wales, south to Dubbo and Barham) and by Ixodes holocyclus

• If a tick is detected that is attached, never attempt to place any chemical such as methylated spirits onto the tick, nor should it be touched or disturbed, as the tick will inject saliva into the skin, which could make the situation worse.
• a tick’s mouthpiece is barbed, not spiraled, so twisting the tick to pull it out doesn’t help.
• to minimise an allergic reaction from saliva, the tick should be sprayed with a instant freeze agent such as one containing ether such as Medi Freeze Tick Off Spray, Wart-Off Freeze or Elastoplast Cold Spray (spray 5x within 1cm of the tick, if legs still move after 10 minutes, repeat once again) if this is not available, an insecticide for use on skin preferably containing pyrethrin or a pyrethroid (consider Lyclear, a scabies cream containing permethrin will work fine).
• The combination of hydrocarbons and the pyrethrin acts as a narcotic and a toxicant, and prevents the tick from injecting its saliva. The tick should be sprayed again one minute later (or dabbed with the Lyclear) and left.
• After 24 hours it should drop off naturally or be gently removed with fine-tipped forceps placed as close to the skin as possible.
• http://www.lowchensaustralia.com/bites.htm
• It is normal for a tick bite to remain slightly itchy for several weeks.
• For larval and nymph stage which are only 1-2mm in size, use a permethrin cream such as Lyclear

• if walking in tick infested areas:
  • wear long trousers and tuck into socks, and tuck shirts into pants
  • wear light coloured clothing so you can see ticks on clothing easier
  • An insect repellent containing DEET or Picaridin should be applied, with a cream repellent applied to the skin and a spray repellent to footwear and clothing
  • reapply repellant every few hours
  • on returning home, remove all clothing and place in hot dryer for 20 minutes which will kill all remaining ticks
  • examine children and pets for ticks on returning from bushland areas.

• Ixodes holocyclus - see wikipedia
• http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-tick-bite-prevention.htm

• main host is the bandicoot, but also echidnas and possums
• mainly confined to a 20km wide area along the eastern coast of Australia from Lakes entrance in east Gippsland up to almost the northern tip of Queensland, and are especially common in wet sclerophyll forests and temperate rainforests, and their survival relies upon humid conditions at temperatures between 7-32degC and thus numbers tend to peak in spring to mid-summer along the NSW coast, but adults can be found even in winter, although they are rare in the very hot summer months.
• since 2010, it seems they have been causing issues in Melbourne
• the almost invisible 0.5mm 6-legged larval tick sits at tips of vegetation awaiting a host to brush past then they attach to the host feed on blood for 4-6 days resulting in itching, then drop off so they can moult to the 8 legged nymphal stage.
• the 1.2mm barely visible nymphs (mainly driest, coolest months) require a further blood meal for 4-8 days before moulting to the adult stage.
• the 4mm 8 legged adult female Paralysis tick will feed for up to around 10 days, drop off the host and lay eggs over several weeks.
• adults are more abundant in the spring and the early summer months, larvae in mid to late-summer, and nymphs during winter.
• ticks may wander on the body for 2 hours or so before attaching, and often prefer to migrate to behind the ears or the scalp.
• very susceptible to dry conditions as eggs need to be deposited in moist leaf litter hence mainly found in wet sclerophyll forests and temperate rainforests

• relatively easy to distinguish from non-paralysis inducing species as they have:
  • different coloured legs with the front and back pairs being darker than the middle 2 pairs
  • legs are close to their mouth parts and form a V shape line from the snout
  • pear shaped body that is yellow-grey to light grey in colour with black bands on the side

• mainly pets and children affected by paralysis (ticks take a high toll on pets every summer)
• no children in Australia have died since 1945 from ticks, although anaphylaxis is also possible
• initial symptoms of tick paralysis may include unsteady gait, increased weakness of the limbs, multiple rashes, headache, fever, flu like symptoms, tenderness of lymph nodes, and partial facial paralysis. Tick paralysis develops slowly as the tick engorges, which will take several days.
• Despite the removal of the tick, the patient's condition typically will continue to deteriorate for a time and recovery is often slow.
• Undetected ticks are another possible reason for any prolonged debilitation.
• antitoxin is available from CSL.
• a single adult female may engorge for a period of 6 to 21 days (average around 10 days), signs of paralysis take a minimum of 4 days to appear and may take as long as 3 weeks, and a single female has enough toxin to paralyse a young calf, a dog or a child

• Recently a new syndrome known as “tick-induced mammalian meat allergy” has been described, whereby people bitten by the Paralysis Tick can subsequently develop an anaphylactic reaction to consuming meats and animal by-products such as gelatine.
• This syndrome has also been described overseas.
• see tick-induced mammalian meat allergy

• found in southern parts of Australia and usually bite lizards, snakes and terrestrial turtles but can attach to and feed on humans (and cattle and horses) and can potentially transmit Rickettsia honei. R. honei causing Flinders Island spotted fever (FISF) which was first identified on Flinders Island in 1991
• humans are most likely to be bitten if camping, hiking, gardening, or hunting in scrub or woodland areas where the tick is present, especially during the spring and summer months
• people will not usually detect a tick until it has engorged by feeding - in addition to the bite being painless, often the person will not sense a tick moving on their skin - they will generally move to an area that has soft skin (eg. around the buttocks) or hairy areas such as the scalp
• the tick bite usually looks like a small dark freckle with a scab, or mole, on the skin - a magnifying glass may be needed to confirm a tick is present

• risk areas:
  • Flinders Island
  • Tasmania, reported cases include Great Oyster Bay, the east coast, including Schouten Island, south of Freycinet Peninsula
  • south-eastern coastal regions of South Australia near Adelaide
  • possibly also in south-eastern Australia (ie. all of Victoria), south-western coastal areas of Western Australia on Salisbury Island and in Walpole
• incubation period one to two weeks after being bitten by an infected tick
• abrupt onset of symptoms include:
  • fever, headache, myalgia, transient arthralgias
  • a maculopapular rash
  • some people have a cough
• without antibiotic Rx, symptoms last 19 days - 6 weeks
• early Rx with antibiotics reduces severity
• most will develop long lasting immunity

• see https://www.health.gov.au/sites/default/files/documents/2021/07/debilitating-symptom-complexes-attributed-to-ticks-dscatt-clinical-pathway.pdf

• see also: https://www.hopkinslymetracker.org/geography-ticks-and-you/
• Lyme disease - there are no confirmed cases in Australia since the 1980's.
  • much debate rages still ²⁾
  • there are almost half a million cases each year in the US according to CDC
  • a Swedish study suggests ~2% of people bitten by a Borrelia-carrying tick fall ill
  • Borrelia bacteria typically take a day to be transmitted from the tick so early removal of the tick even with fingernails is important (whereas viruses can be transmitted in minutes)
• Rocky Mountain spotted fever - Rickettsia rickettsii spread to humans by Dermacentor ticks. Widespread throughout most of USA and including southern Canada, Central America and parts of South America.
• Colorado Tick Fever - viral infection usually in March-September with peak in June. Mainly found in the high regions of western USA and Canada.
• Babesiosis - Babesia microti is endemic in the Northeast of USA.
• Ehrlichiosis - Ehrlichia chaffeensis is a gram negative coccobacillus causing an illness like Rocky Mounted spotted fever but without the rash. Most commonly foud in the south central states of Missouri, Oklahoma, Tennessee and Arkansas.
• Anaplasmosis - Anaplasma phagocytophilum is a gram negative coccobacillus and the cause of human granulocytotropic anaplasmosis, formerly known as human granulocytic ehrlichiosis. Human infection first described in the late 1990's. Most commonly transmitted in May-June by the deer tick and other ixodes species.
• Crimean-Congo haemorrhagic fever virus (CCHF)
  • up to 40% mortality untreated, but rare
• severe fever with thrombocytopenia syndromevirus (SFTS)
  • discovered in 2009; mainly in Asia, esp. Japan
  • 57 deaths 2013-2017
• Powassan virus
  • fever, headache, vomiting, and fatigue, and can cause encephalitis and myelitis
• tick-borne relapsing fever (TBRF)
  • most TBRF infections are caused by different bacteria to Borrelia and are spread by “soft ticks”
  • some are spread by “hard ticks” and these tend to be caused by Borrelia sp. such as Borrelia miyamotoi and newly detected cause, B. lonestari
• southern tick-associated rash illness (STARI)
  • pathogen remains unclear
• tick-borne encephalitis (TBE)
  • viral infection mainly in Europe and across to Siberia
  • eastern and western versions of this virus
• see also: https://en.wikipedia.org/wiki/Tick-borne_disease