Arthropod-bourne infectious disease 1 Flashcards
(59 cards)
1
Q
What tick borne pathogens my be importe in dogs travelling from EU
A
NON ENDEMIC to UK: babesia canis canis, babesia gibsoni, ehrlichia canis
ENDEMIC TO UK: borrelia burgdorferi, anaplasma phagocytophilum
2
Q
Which ticks are present in Europe?
A
- Ixodes ricin us: widespread
- Dermacentor reticularis: more restricted distribution
- Rhipicephalus sanguineus : life cycle requires temp > 18 degrees, not endemic in UK, intro from dogs travelling from EU, establish in houses / kennels here, vector for Mediterranean spotted fever (rickettsia conorii), carries babesia and ehrlichia
3
Q
What are babesia and theileria?
A
Piroplasms
4
Q
Most important agents of canine babesiosis
A
- LARGE BABESIA: b. Canis canis, B canis vogeli and B. Canis Rossi
- SMALL BABESIA: b. Gibsoni
5
Q
How do different babesia spp vary?
A
- size
- vectors
- geo distribution
- Virulence
- prognosis
- response to tx
6
Q
Babesia pathogens sis
A
- within ticks transmitted trans-stadially and trans-ovarially
- sporophytes injected from tick salivary glands
- enter circulation, endocytosed by RBC
- IM component of pathology
- TP common (but usually doesn’t cause bleeding or abnormal coagulation)
7
Q
Which babesia spp are zoonotic?
A
- b.microti - rodent reservoir
- b. Divergent - cattle reservoir
8
Q
CS - babesiosis
A
- those of haemolytic anaemia
- lethargy, depression, inappetance
- icterus
- splenomegaly
- tachycardia and tachypnoea
9
Q
Babesia - diagnosis
A
1 clinical laboratory findings: non-specific, TP common, many dogs are Coombs positive / auto agglutinate
- Microscope identification : low sensitivity so must use another test to verify
- PCR : high sensitivity, broad range babesia PCR, spp id possible using species specific PCR / sequencing
- Serology: usually IFA or ELISA
10
Q
Babesia - tx
A
- antibabesia drug : Imidiocarb dipropronate
- LARGE BABESIA: rapid clinical response
- SMALL FORMS : clinical and parasitological cure uncommon, clinical relapses may occur
11
Q
What type of bacteria are rickettsia?
A
Small obligate intracellular gram negative
12
Q
Which rickettsia infect monocytes?
A
- ehrlichia canis
- ehrlichia Chaffeensis: causes human monocytes ehrlichiosis, transmitted by ambylomma americanum, molecular evidence canine infections
13
Q
Which rickettsial parasite infects thrombocytes?
A
Anaplasma platys
14
Q
Which ricketssia infects granulocytes?
A
- anaplasma phagocytophilum
- ehrlichia erwingii
15
Q
Incubation time - ehrlichia canis
A
1-3 weeks
16
Q
Acute CS - ehrlichia canis
A
- vascular is and immune destruction leading to thrombocytopenia and cpagulopathy
- multi systemic signs
- spleen and LN enlargement
- CNS / ocular signs
17
Q
Chronic - CS - ehrlichia canis
A
- BM destruction leading to pancytopaenia
- signs as for acute
18
Q
Species infected by ehrlichia canis
A
Dogs and wild canids only
19
Q
Diagnosis - ehrlichia canis
A
- modular in blood smears or macrophages from tissue as pirates (spleen, lung, LN)
- thrombocytopenia / pancytopaenia
- IFA/ELISA
20
Q
Tx/ prevention - Ehrlichia canis
A
- tx: TCs for 28d/ chloramphenicol
- no vaccine
- chemo prophylaxis
- tick control
21
Q
Anaplasma phagocytophilum - CS
A
- mild/ moderate TP
- lymphopaenia
- mild anaemia
- naturL chronic infection has not been seen
- impaired PMn function can predispose to secondary infection
22
Q
A. Phagocytophilum in cats?
A
Very rarely
23
Q
A.phagocytophilum - zoonotic?
A
Yes but unclear if infected domestic animals pose zoonotic risk. May have role as sentinels
24
Q
What is Borrelia burgdorferi sensu lato associated with?
A
Lyme borreliosis
25
Hosts - borrelia
Humans, dogs incidental host (sylvatic tick- wildlife cycle)
26
What are the Borrelia pathogenic genospecies?
- b.afzelli (skin complications)
- b. Garinii (Neuro complications)
- b.burgdorferi sensu stricto ( the only pathogenic spp in USA, present in some parts of. Europe and can cause Neuro / arthritic complications)
27
What is the most prevalent tick- transmit infection in temperate areas of Europe, USA and Asia?
Lyme disease in people
28
CS - human Lyme disease
- erythema migrans in 80-90%
| - later involves skin, Neuro and msk systems
29
Overall mean prevalence of b.burgdorferi in ticks in Europe
12%. Central Europe has highest tick infection rates
30
CS - borreliosis in dogs
- co infections common
- lethargy, anorexia and pyrexia
- inflammatory PA
- inflammatory arthritis
- lymphadenopathy
- protein losing glomerulonephropathy
31
Dx - borreliosis in dogs
- no pathognomic test
- a symptomatic seroconversion common
- microscopic / genetic detection often not possible
32
Tx - borreliosis in dogs
Empirical AB tx (doxycycline - amoxicillin)
33
Describe leishmania
- flagellate Protozoa
- phlebotomous vector
- reservoir host
- non- vector routes of transmission: venereal, blood products, direct contact (skin wounds)
34
What is the most important leishmania spp in Europe?
L. Infantum
35
Outline canine Leishmaniosis in Europe
- 2.5 million infected in France, Spain, Italy and Portugal
- infection rates 70-90% in some areas (Spanish Balearics)
- prevalence requires PCR and serology
- in North Europe infection generally restricted to dogs travelling from endemic area ( and high sandfly exposure March to November)
36
UK dog Leishmaniosis situation
Infected dogs are potential reservoir should incursion of a competent vector occur
37
Outline leishmania lifecycle
Promos tigons develop in macrophages - ingested by sandfly rep, infected human/ dog - flagellate amastigote in sandfly - then becomes inoculated into dog/ human
38
Pathogenesis - leishmania
- macrophage is target cell
- systemic infection in haemolymphatic organs
- parasite persistence can cause chronic infection
- protective immunity mediated by TC
- signs may develop months to years after infection > 7 years
39
What determines leishmania clinical outcome?
- host immune response
- also:
- age (2-4 and >7 more susceptible)
- breed
- nutrition
- concurrent dz
- immunosuppression
40
CS - leishmania
Chronic systemic dz
- usually visceral and cutaneous signs
- waxing and waning
41
Dx - canine leishmania
1. Demonstration of parasite: definitive diagnosis, specificity 100%, sensitivity
42
Tx - canine leishmaniasis
- ANTILEISHMANIAL DRUGS: often give clinical remissions persistent parasite ai, meglumine antimoniate ('glucantime') + allopurinol, prolonged tx, not licensed for use in UK
- consider euthanasia d/t zoonotic risk, especially where endemic
43
Prevention - canine Leishmaniosis
- sandfly avoidance
- topical insecticides: imidacloprid/ permethrin spot on 2d before travel, deltamethrin collars 2 wks before travel
- vaccine available
44
Human Leishmaniosis - CS
- cutaneous
- visceral ( can be fatal)
- mucocutaneous
- self- limiting / sub clinical
45
At risk groups for human Leishmaniosis
Young, immunosuppression, poor
46
Primary route of infection - human leishmania
Sandflies from dogs, also possibly direct contact
47
T/f: human and canine Leishamnia correlated at population level
True
48
Dirofilaria immitis - distribution
- endemic in Europe USA, Australia np but not UK
49
Vector - dirofilaria immitis
Mosquito (>70spp can transmit)
50
What does dirofilaria immitis cause?
- heart worm
- occupy RHs heart and PA
- CS: coughing, dyspnoea, decrease exercise tolerance and right sided heart failure
- cats more resistant than dogs but dz can occur
- zoonotic
51
PPP - dirofilaria immitis
6 months
52
Prophylaxis - dirofilaria immitis
- selamectin (stronghold)
- milbemycin (milbemax)
- moxidectin (advocate)
53
Dirofilaria immitis - tx
1. Symtomatic - steroids and tx CHF
2. Adults code - melarsomine
3. Microfilarial - levamisole, ivermectin, milbemycin
54
What type of bacteria is bartonella?
Small gram negative haemotropic bacteria. Different host- adapted spp within bartonella
55
What is commonest bartonella in cats?
Bartonella hensellae (also B. Clarridgeiae)
56
Prevalence of bartonella
Widespread - seroprevalence up to 40%. Feline dz reported but unusual.
57
Main relevance of bartonella
Zoonotic potential - causes cat scratch disease. Causes lymphadenomegaly in immunocompetant hosts. Roughly 125 human cases / year in UK. Serological diagnosis but indirect IFA.
58
Why may diagnosis of arthropod borne diseases be complicated?
Long incubation period and aasymptomatic states.
59
What is the pets travel scheme?
- protect pets and UK disease status
- rabies and tapeworm tx
- no tick tx
