Ticks Flashcards
Broadly speaking, what things can ticks cause?
Mainly production losses Anaemia Secondary infections Disease transmission Tick paralysis
What are the general features of a hard tick?
Scutum
Ornamanetation
Festoons
How can one tell the difference between male and female hard ticks?
Males scutum covers the whole of their dorsal surface.
What are the features of tick mouthparts?
Palps - sensory organs (temperature and CO2)
Chelicerae - scissor like
Hypostome - like a straw, has backwards pointing teeth and dorsal groove.
Other than backwards pointing teeth, how else is the hypostome kept in place?
The saliva of the tick also contains a cement-like substance.
What are some of the things that may be present in tick saliva?
Anti-histamines Anticoagulants cytolysins vasoactive mediators and, paralytic toxins (not really known why)
What are seed ticks?
Tick larvae
How is the hard tick life-cycle classified and how is this different to soft tick life cycles?
Hard - classified depending on the number of hosts that it infects during its life cycle (however this does not relate to the number of species that the tick can infect)
Soft ticks can have one or many hosts and tend to just feed little and often when there are hosts present.
What is the most important tick species in the UK?
Ixodes ricinus
What diseases can it transmit?
Lyme disease Louping Ill Tick-bourne fever Tick pyraemia red-water fever
Briefly describe its life cycle and how this relates to epidemiology.
It is a three host tick and spends several days each year at each life cycle stage on each host. Most of the time is spent on the ground as it likes R.H. of >90%. Therefore it is mainly associated with matted vegetation, hedgerows etc. The life-cycle takes about 3 years to complete. In some parts of the UK there may be two periods of tick activity throughout the year due to higher temperatures.
What are the soft ticks of importance?
Argas spp. - mainly parasitises birds. Important to note that it comes out at night to feed.
Ornithodoros spp.
Otobius spp. - found in the ears of cattle and dogs in warmer countries.
What might the epidemiology be like in ticks in warmer countries?
a) all year round in areas with all year round rainfall
b) variable periods of activity dependent on seasonal rainfall and transpiration from vegetation
both due to HUMIDITY
What are the priniciples of tick control?
INTEGRATED PARASITE CONTROL (IPS)
- Kill ticks on ground
- microclimate - pasture improvement
- starving (removing livestock from pasture)
- burning - Seperate host from infection
- stock management (remove from pasture when ticks are active)
- fencing (fence off infected areas) - Kill the tick on the host
- ACARICIDES - Enhance host resistance
- stock hybridisation
- vaccination (against hidden antigens)
