Ticks As Parasites Flashcards
Hard ticks
Have a chitinous scutum
Larvae 6 legs
Adults 8 legs
Hard tick species
Ixodes Haemaphysalis Dermacentor Amblyomma Boophilus Hyalomma Rhipicephalus
Soft tick species
Argas
Otobius
Ornithodoros
Soft ticks
Ticks without a chitinous scutum
Ornate ticks
Coloured enamel like patterns on their scutum
Inornate ticks
Ticks with ni patterns on their scutum
Festoons
Notches on the posterior part of the body
Eyes found
If present on the margin of the scutum
Ixodes ricinus
VECTOR!!!
Inornate No eyes or festoons Cause anaemia Infected lesions caused by toothed mouthparts Hide/pelt dam Transmit dis
I canisuga
British dog tick
Cause pruritus hair losss and anaemia in heavy infestations
Survive in crevices in kennels
I hexagonous
Hedgehod tick
I holocyclus
Aussie paralysis tick
I rubicundus
S africa paralysis tick
Toxin causes ascending motor paralysis in man and aninals
I scapularis
N american shoulder tick
Haemaphysalis - 3 host ticks
Inirtnate
No eyes
Have festoons
H punctata
VECTOR!!!
Transmit babesia major and motasi and non pathogenic theileria in cattle and theileria ovis in sheep
In other countries transmit babesia bigemina (cow) anaplasma marginale (sheep) anaplasma centrale (cow)
H leachi
Yellow dog tick in africa and asia
VECTOR!!!
Transmit babesia canis
H longicornis
Cattle tick
Australasia
Dermacentor ticks
Mostly 3 host ticks
1/2 yr pop cycle
Ornate
Have eyes and festoons
D reticulatus
VECTOR!!!
Transmit babesiosis in horses and dogs
D andersoni
N america
D variabilis
VECTOR!!
N america
Transmit anaplasma marginale in cattle and rocky mountain spotted fever to man
Cause tick paralysis
D nitens
VECTOR!!!
One host tick
Transmit equine babesiosis
Amblyomma tocks
3 host ticks Large ornate Have eyes and festoons Legs have bands of colour Long mouthparts
A variagatum
Bont tick africa Large tick Long mouthparts Deep painful bite can become 2o infected Red weight gain in cattle Tick paralysis Transmission of heartwater nairobi sheep dis and Q fever
A hebraeum
VECTOR!!!
Bont tick africa
Transmit heartwater in cattle
A americanun
VECTOR!!!
Lone star tick N america
Transmit Q fever tularaemia and rocky mountain spotted fever
A maculatum
Gulf coast tick
N america
Damage to ears of cattle
Predisposing to screw worm myiasis
A cajennense
S america
Painful bites by long mouthparts
Boophilus ticks
Have eyes
No festoons
One host tick
B microplus
Worldwide except eu
B annulatus
America and africa
B decoloratus
VECTOR!!!
Africa
Babesia vector
Anaplasma marginale vector
Hyalomma ticks
2&3 host ticks Inornate Have eyes Sometimes have festoons Banded legs Long mouthparts
Hy marginatum and dendriticum
S eu and africa
Hu truncatum
Africa
Vector of babesia, theileria and rickettsia
Tick toxicosis
Rhipicephalus ticks
Inornate
Have eyes and festoons
R appendiculatus
Brown ear tick
VECTOR!!!
Africa
Vector of east coast fever and babesia bigemina and nairobi sheep disease
3 host tick
R evertsi
Res legged tick
VECTOR!!!
2 host
Transmit babesia bigemina and equi
R sanguineus
Brown dog tick
Transmit babesia canis and ehrlichia canis
Cause tick paralysis in dogs
Transmit other protozoal viral and reickettsial infections
3 host
Tick enviro
Humidity of micro enviro off host is key
Most active during warm season
Conditions in micro habitat of free living governed by rainfall mainly but also affected by plant transpiration herbage density and type
Housing give unique microhabitats for tocks eg in bedding or crevices
3 host tick lifecycle
Detach after feeding and drop from host moult and then wait for new host so spend most of cycle in enviro
2 hist tick lifecycle
Remain on hist and moult to become nymphs and feed on same host then drop into enviro and moult to adults then find a new host
1 host tick lifecycle
Ramain on same hist
Engirged female drop to ground and seek suitable egg laying enviro
Adult males remain on host for longer before dying
Tick treatment options
Organophosphates
Pyrethroids
Macrocyclic lactone endectocide injection
Acaricides applied to particular parts of animals (but many ticks and larvae are in innaccesable part of body where acaticide wont gey to them)
Repeated acaticide treatment is required and periods of tick activity arent clearly enough defined to allow strategic treatment, also toxic leaving residues in milk and meat and causing enviro pollution. Expensive in deving countries
Res is emerging
Argas ticks
Fowl tocks
VECTOR!!!
One larval and 2 numph stages involved live in cracks in poultry hius suck blood from poultry at night about once a month live several yrs
A persicus
Domestic poultry cause irritation anaemia loss of prod
Transmit borelia anseeria and rickettsia
A reflexus
Pigeons
Otobius ticks
O megnini
Spine nose ear tick america india asia africa
Mainly ibfect dogs ears but can other hosts
Eggs in crevices and around feed troughs
Only larvae and nymphs parasitic remain on same host for months at a time
Ornithodoros
Sand tampans
Live under sand in primitive housing or in shaded areas around trees
Only nymphs and adults parasitic
Feed for short time periods
Cause irritation and anaemia
O moubata africa
Reservoir for african swine fever and relapsing fever in man
O savignyi africa
O turicata america
Vector of Q fever and cause tock paralysis
Soft tock feeding
Freq feed on diff hosts
Feeding via hypostome
Scissor action of digits on chelicerae lacerates skin
Thrust hypostome through
Lock curved teeth of hypostom onto tissues
Hypostome forms a groove through which saliva cont proteases anticoags imm suppressants anaesthetic amd toxins also pathogens and lipopro glue pass and blood meal pass back up the groove
Bio transmission
Pathogen survives and or dev within parasite and moves from gut to mouthparts for transmission
Tran stadial transmission
Pathogen gets from one host to another by entering feeding tick larvae or nymph and surviving to adult or nymph that will feed on another host
Trans ovarial transmission
Pathogen passes from infected female to her eggs then larvae
Esp important in one host ticks
Infection reservoirs
Afapted for long survival periods between feeds and tick borne pathogens survive these periods from one transmission opportunity to the next
Vertebrate hosts act as carriers infecting more ticks
Ticks in UK livestock dis spread
12 spp in uk
Heavy burdens cause irritation and anaemia
Ixodes ricinus most important vector
D reticulatus and haem punctata in s england and wales
Tick feeding activity optimums
Over 85% humidity and over 7 degrees c
Most tick birne dis see in western upland uk
Problems in forested areas of s england
Suitable microhabitat around ditches and conservation areas on lowground farms
Influences of climate change, red sheep no, enviro scheme
I ricinus behaviour
Feed for 28d in 3 yr life Non feeding stages req high humidity eg dense veg mat and mod-high rainfall Quest meal above 10 degrees c Die after no feed for 4-6 wk 1 yr interval between feeds Spring/summer and summer/autumn pops
Tick attachment sites
Head
Neck
Groin
Axillae
Speing feeding i ricinus
Most quest in spring
Eggs hatch in autumn and larvae and nymphs moult at same time
Over winter in unengorged state
Quest when mean day night temp is over 10degrees c
Autumn feeding i ricinus
Incr common in uk
Eggs hatch in summer and larvae and nymphs moult at same time
Overwinter in engorged condition
Questing ends when mean daynight temp over 10 degrees c
Questing during summer
Not usually as temp is high and humidity os low
Why tick infestation of uk livestock is a current concern
Geographical distrib is changing due to climate change
Sheep farming economics and enviro and biodiversity management policies relating to habitat
Risk of importation of hitherto exotic ticks and vector borne dis or endemic ticks carrying exotic dis risk incr as more freedom of international movement
Due to public access of countryside increased and more people doing rural leisure activities the risk of zoonotic trans due to ticks not being host spec is incr
Control of tick habitats
Now uneconomic
List of acaricides available is dwindling
Also res is developing
Rosk of exotic ticks and vector borne dis importation due to
Tock treatment no longer req by PETS
Lead to r sanguineus rep in UK eg household dogs brought home from holiday in france can bring back large infestations of dogs and other visiting dogs
Transmit babesia canis and ehrlichia canis
