Emerging Vector borne diseases Flashcards
What are tick borne diseases?
*Lyme disease
*Tick-borne rickettsias
*African swine fever
What are mosquito borne diseases?
*Dengue / chikungunya / Zika
-spread by Aedes
*West nile / Usutu
-spread by Culex
What are midge borne disease?
*Bluetongue
*African horse sickness
What are vector borne disease?
A disease caused by a pathogen spread by an arthropod host
(insect, tick, crustacean)
What are examples of hard ticks?
*Ixodes
*Rhipicephalus
*Hyalomma
What is an example of a soft tick?
*Ornithodorus
What is lyme disease?
Borrelia burgdorferi
What does lyme cause in humans?
*rash
*flu
*fatigue
*joint pain
*neuroborreliosis
What does lyme cause in dogs?
*fever
*lameness
*joint swelling (Lyme arthropathy, polyarthritis)
*swollen lymph nodes
*lethargy
*inappetance
Why is there a larger Ixodes problem in the UK?
Deer tick - highest population of deer in UK since Roman times
What are vectors of babesiosis, ehrlichiosis, anaplasmosis?
*Ixodes ricinus
*Dermacentor reticulatus - ornate cow tick
*Rhipicephalus sanguineus - brown dog tick
What are the reasons for increased emergence of tick borne diseases?
*Spread of ticks – related to climate
*Increased numbers and spread of hosts - deer
*Increased movements of animals (eg, dogs)
*Spread of viruses or ticks by migratory birds
*Changes in international regulations – stopping of tick treatments for imported dogs
how is African swine fever transmitted?
Soft tick - ornithodorus
Feed
Aerosol
What type of virus is African swine fever?
Only DNA arbovirus
What does african swine fever cause?
Fatal haemorrhagic disease of pigs
What is the significance of it being a DNA virus?
Highly stable
-survive 15 weeks in chilled meats
-6-9 months in cured meats
-15years in frozen meats
What is the Asian Tiger mosquito?
Aedes albopictus
Where do Aedes lay their eggs?
In water
What can Aedes spread?
*dengue
*Chikungunya
*Zika
*Dirofilaria
What are the drivers of spread of Aedes?
Global trade (in tyres, plants)
Road transport
Facilitated by climate change
What is West nile virus spread by?
Culex mosquitos
What are the natural hosts of west nile?
Birds
What does west nile cause in horses + humans?
Horses = severe disease + death
Humans = Fatal neurological disease
What is the relevance of Culex pipiens molestus?
It likes to feed on mammals
Found in the UK
May cause West Nile in UK soon
What is Usutu?
Mosquito borne disease found in UK
*doesn’t cause disease in humans though
What does bluetongue cause?
How is it transmitted?
Transmitted by culicoides
Causes severe disease in sheep + mild in cattle
How is African horse sickness transmitted? What does it cause?
Transmitted by culicoides
Causes severe disease in horses + Mild in mules/donkeys
What are the drivers of emergence of Bluetongue?
Climate change
-Causing midges to spread
-Increasing their vector competence
Global movements of animals/goods - bringing the viruses into Europe
