Infectious Disease Flashcards
1
Q
Transmission of infectious disease
A
- infectious agents can live on/in animals and humans
- infectious agents can be in food, water, waste, faeces and enviro
- vehicles and equipment can bring in and spread infectious agents
- ticks, fleas and mosquitos can transmit infectious agents through bite or ingestion of insect
2
Q
Routes of Transmission
A
- direct contact
- airborne
- fomite = inanimate objects that can spread disease
- oral- vector-borne
3
Q
Factors that determine outcome of infectious disease exposure (wether animal develop disease)
A
- pathogen involved (highly pathogenic)
- contact time with pathogen
- the amount of pathogen that animal comes into contact with
- route of transmission
- animals immune status (age, concurrent disease, stress = increase cortisol which supresses immune funtion)
4
Q
Control of infectious disease
A
- minimise contact between animals
- ensuring contagious animals dont enter group setting = isolation, quarantine
- avoid contact with enviro and objects that might be contaminated
- control disease vectors - insects, wildlife
- hand hygiene
- effective cleaning/disinfection
- managing stress
- vaccination and parasite control measures
- early identification/isolation of potentially infectious animal from other animals in group
5
Q
Vaccination - abour
A
- key metho of control of infectious disease
- uses principles of immune reposnse
- antigens in a base which allows controlled access of antigen to the bodies immune system
- antigen= either part of organism to be protected against or the whole organism or closely related but relatively harmless organism
- vaccines can be made with living or killed organisms
6
Q
Vaccination - response to infectious agent
A
- first exposure to infection/vac, animal recognises antigen as foreign and antibodies are produced
- primary response takes time to build ~ abs not identified for two-three weeks, white blood cells develop and fight disease
- if stimulus actual infection = response may be too slow and animal succumb to infection and show clinical signs
- if animal survives and is challenged again or given second vaccine = rapid response occurs due to memory induced by first exposure
- high levels ab produced within next 5-7 days
- in absence of further exposure = ab levels decrease over months = booster vaccines given at intervls
- individuals differ in responses to vaccination (some very high/low or intermediate)
- a few animals dont respond to vaccination = non-responder (enough animals in local are vaccinated/ decent protection, most wont contract disease and pass on to non-responder = herd immunity)
7
Q
How does age of animal impact vaccination
A
- younger = less able to respond
- less mature/competent (immune defence require time to respond fully
- response to vac may be interfered with by the presence of maternally derived antibodies (abs passed on by mother while young animals developing own defences)
8
Q
other factors that affect response to vaccination
- general heath/nutrition
- adjuvants
A
- healthy/well fed = respond better than ill/malnourished as immune system runs optimally with less wbc compromised along with other organs and systems
- e.g. aluminium hydroxide
- substances provide for a slow release of antigen from vaccination site
- producing constant triggering of antibody forming mechanisms
- a number of secondary responses of increased magnitude
9
Q
Living vaccines - adv and dis
Killed vac - adv
A
- organism may multiply in body = greater stimulus produced and longer lasting immunity can result even from single vaccine
- introduction of potentially dangerous virulent pathogen into body is not appropriate
(living vaccines normally produced from organisms modified in some way e.g. grown on abnormal media at abnormal temperature or are an avirulent strain)
- organism may revert to their original virulent form and produce disease = safety for killed vac (inability to produce infection)
10
Q
Dog routine vaccinations
A
- canine distemper virus
- canine adenovirus type 2 (hepatitis
- canine parvovirus
- canine parainfluenza (part of KC syndrome
- Leptospirosis - Leptospira canicola, icterohaemorrhagiae, Grippotyphosa and Australis = Nobivac®
11
Q
Distemper
A
- virus
- multiplies in variety of cell types and organs
- fever followed by catarrhal discharge from eyes and nose
broncho-pneumonia may develop and fits may occur - hardpad paws due to presence of virus in skin = hyperkeratosis of footpads
12
Q
Canine adenovirus (CAV), Infectious canine hepatitis (ICH)
A
- virus initially invades the tonsils and cervical lymphnodes
- viraemia
- possible involvement of liver
- Signs: fever, vomiting, diarrhoea followed by jaundice
- 2 antigenetically closly related but distinct types = CAV 1 and CAV 2
- vaccination utilises CAV 2
- CAV 1 = responsible for genralised disease
- CAV 2 = implicated in some cases of respiratory disease but not with systemic infection (affetcs entire body)
13
Q
Canine parvovirus
A
- first identified 1978
- hypothesised origin by natural genetic mutations of feline panleukopenia virus
- CPV and FPLV = 98% simmilar in nucleotide and amino acid sequence
- causes severe gasteroenteritis
- in very young pups = can casue sudden death as heat muscle affecting = myocarditis
14
Q
Parainfluenza (Pi)/CAV-2
what do they cause
A
- viruses two of the causes of kennel cough = upper respiratory disease
- harsh cough that spreads easily among animals in close confinement
- pure infection with Pi are rare and mild
- Bordetells bronchiseptica = bacterium may be involved in this disease
15
Q
Bacterial vaccines - Leptospirosis (serogroups protect against)
A
- current vaccine is tetravalent preparation that protects against the following serogroups ~ Leptospira canicola ~ Leptospira icterohaemorrhagiae ~ Leptospira Grippotyphosa ~ Leptospira Australis
