Emerging Disease in CA Flashcards
What % of new or emerging infectious diseases are zoonotic in origin?
75%
Tick borne diseases?
- Ehrlichia
- Borrelia
- Babesia
- Anaplasma
- (Mediterranean spotted fever (MSF))
- (hepatozoonosis)
- (tick-borne encephalitis)
Sand fly borne diseases?
Leishmania
Mosquito transmitted dx?
Dirofilaria
Describe Ehrlichiosis
- Ehrlichia canis
- Infection of monocytes – ‘canine monocytic
ehrlichiosis, CME’ - Vector → Rhipicephalus sanguineus
- Mediterranean countries
what 3 phases of Ehrlichiosis infection?
- Acute phase
- Subclinical persistent infection
- Chronic phase (months to years after infection)
- Not all cases develop chronic CME
CLS of Ehrlithiosis?
Range from non specific (lethargy, lymphadenopathy) to bleeding diathesis or neuro signs
Haematology of Ehrlichiosis?
mild to severe nonregenerative anaemia, thrombocytopenia,
pancytopenia (bone marrow hypoplasia,
poor prognosis).
* Chronic CME profound pancytopaenia
Biochem of Ehrlichia?
polyclonal hypergammaglobulinaemia**, hypoalbuminaemia,
increased liver enzymes
What is seen on urinalysis with Erhlichia?
Renal proteinuria (PLN)
How an we Diagnose Ehrlichiosis?
- Blood smear?
- Serology
- PCR -> highly sensitive
Describe serology testing?
- Qualitative test
- Most seropositive dogs from endemic areas are asymptomatic and seropositive for months to
years - Quantitative test: high titer = active infection more likely
Describe PCR
→ blood, bone marrow
* +ve = active infection, highly sensitive
* Test quality is lab-dependent
Tx for Ehrlichiosis
Doxycycline
Acute phase: curative
Chronic: variable resp
What is Lyme dx name?
Borreliosis
describe Borreliosis broadly
- Caused by bacteria (spirochaete) sp of Borrielia burgdoferi sensu lato complex
Is Borreliosis zoonotic?
yes
CLS of Borriela?
non-specific..! lethargy, lymphadenopathy, pyrexia, lameness/IMPA
w-What are the two syndromes of Borriela seen in dogs?
Lyme arthropathy
Lyme nephropathy
(Lyme nephritis cases tend to be markedly proteinuric)
Is Borriella commmon in cats?
not really
Diagnosis of Borreliosis?
- Exposure to Borrelia burgdorferi
- Positive serology: >95% asymptomatic
- C6 peptide antibodies: only during infection, but ≠ proof of cause of clinical signs
Resp to therapy? Exclude other
Tx for Borreliosis?
Doxycycline 10mg/kg PO SID 4 weeks + management of PLN
What causes Anaplasmosis?
Anaplasma phagocytophiylum bacteria
Describe Anaplasmosis generally
- ENDEMIC in Europe
- Vector → Ixodes ticks
- Reservoir hosts → mice, deer
PathoG or AnaP?
Infection of grnaulocytes (mostly neutrohils); cells found in circulating blood + spleen/liver/BM
Incubation AnaP?
1 -2 weeks
CLs of AnaP?
Mostly Asymptomatic, non specific
- Acute: lethargy, anorexia, pyrexia, lameness (IMPA), uveitis,
epistaxis, petechiae - Chronic forms
Diagnosis of Anaplasmosis?
- Anaemia common
- Thrombocytopenia very common (90%)
- Blood smear: +ve in 60%
- Serology → two samples, looking for seroconversion
- 4-fold increase/decrease in Ab titre within 1 month
- PCR
Tx for Anaplasma?
Doxycycline 2-4 weeks PO BID
Describe Babesiosis
- Protozoal dx , diff sp
- ‘Piroplasmosis’
- Diff species with diff tick vectors -> B. Canis, gibsoni, rossi
- Intra-erythrocytic parasitaemia
Where do we see babesiosi?
- Emerging in mainland Europe - UK-> some endmic foci but mainly travel import
CLS of Babesiosis?
- Clinical signs → vary in severity depending on species…
lethargy, anorexia, pyrexia - Signs of haemolysis
- Subclinical → life threatening illness
- Multiple organ involvement
Diagnosis of Babesiosis?
A combination of clinical presentation, haematology,
biochemistry, urinalysis
What would we see on blood smear with babesiosi
Piriform bodies in large type
Se in acute infections
PCR for babesiosis?
MOST SENSITIVE test & species differentiation
Tx for babesia?
- Large Babesia species → imidocarb dipropionate
- B. gibsoni → atovaquone + azithromycin
- pRBC transfusion
- Supportive therapy (complicated cases mainly)
Name of Leishmania? Transmission & prevalence?
- Leishmania infantum – protozoal disease
- Transmitted by phlebotomine sand flies
- Mediterranean countries
CLS of LEishmania?
*skin lesions (dermatitis +/- alopecia) most common;
vague, non-specific systemic signs, peripheral lymphadenopathy
- Renal disease (mild renal proteinuria → end-stage CKD)
- Other: uveitis, epistaxis, lameness (IMPA)
Diagnosis of Leishmania?
Often based on CLS
What would u see Haem/ Biochem with Leishmania?
- Haematology → mild-moderate non-regenerative anaemia, thrombocytopenia OR thrombocytopathy, leuks up/down
- Biochemistry → hyperproteinaemia (polyclonal hyper-gammaglobulinaemia,
hypoalbuminaemia), renal azotaemia, increased liver enzymes
Urinalysis Leishmania?
Proteinuria
Cytology on Leighmania lymph node /skin?
Pyogranulomatous inflammation
Amastigotes (in macrophage)
Serology of Leishmaniosis?
- Serology titer (ELISA or IFAT)
- Test of choice sensitive + specific but …
seroconversion only months after infection - median : after 5 months
Clinical leishmaniosis=
compatible CLS + high titer (>3/4 x cutoff)
What if we see mild inc titer?
diseased or infected but healthy
Describe PCR for Leishmania ?
- Sensitive & specific diagnosis of ‘infection’
not disease - Lymph node, skin, other
- Only if other tests are inconclusive
Tx in which dogs for Leishmania?
- Aimed at clinically healthy seropositive dogs
- Clinically healthy seronegative but PCR-positive dogs → DO NOT treat, but follow-up q3-6-12
months
Does Tx of LEishmania eliminate infection?
NO -> clinical cure only ; risk of relapse lifelong
Tx of Leishmania?
- Allopurinol alone or allopurinol + meglumine antimoniate or allopurinol + miltefosine
- Allopurinol: 10 mg/kg PO BID, at least 6-12 months → lifelong
- Meglumine antimoniate or miltefosine: 4 weeks
Describe Dirofilariosis
- ‘Heartworm disease’, caused by nematode Dirofilaria
immitis - Vector → mosquito
- Mediterranean countries
- Adult worms in pulmonary vasculature
CLS of Dirofilaria?
Asymptomatic cough, exercise intolerance, dyspnoea, ascites?
Progression to Right sided heart failure
Diagnosis fo Dirofilaria?
- Chest Xray/ Echo
- Antigen test (detects adult females)
- Microfilaria testing
Describe Antigen test
Very specific
Sensitive but:
* Negative first 5-6 months of infection
* Negative with low female burden or male only infection
* Negative due to presence of immune complexes
If antigen test +VE …
confirm with +ve microfilaria or another type of antigen test
Tx protocol Dirofilaria?
- Monthly macrocyclic lactone & doxycycline 4 weeks
- Adulticide : melarsomine (3 doses)
What diseases notifiable?
- Mycobacterium bovis
- Rabies
- Echinococcus multilocularis
What diseases reportable?
- Brucella canis
- Salmonella in dogs
What is Feline Mycobacterial dx?
- Slow growing highly resistant, bacilliform bacteria
- Cats can become infected with a range of different mycobacteria → variable clinical presentation
- Reported in dogs but less common
Infection routes for feline mycobacterial dx?
- Direct contact with wild rodents or bovine
- Environmental contamination.
- Outdoor lifestyle and hunting behaviour risk factors **
Most common species?
: Mycobacterium microti, M. BOVIS ,M. avium, and non-M. avium nontuberculous mycobacteria
What three lassifications of mycobact dx?
- TB complex M Bvosi , M microti
- Feline leprosy
- Non tuberculous mycobact
CLS of Feline mycobact dx?
- Cutaneous lesions most common (single or multiple nodules) and often on the head and extremities
- Ulceration, discharging, local or generalized lymphadenopathy (SMLN)
- Pulmonary lesions → pneumonia, hilar lymphadenopathy, diffuse interstitial/nodular bronchial lesions
- Systemic signs → hepatomegaly, splenomegaly, effusions, pyrexia) – less common
- Systemic, digestive, and respiratory forms: more common in the TB complex and MAC species.
Dx of Fleine mycobact dx?
- Difficult to culture
- suggestive cytology/histo pyogrnaulomatous inflammation
- Interferon gammma test
- PCR or culture
Describe cytology results for feline mycobact dx?
Detection of morphologically typical acid-fast bacteria (Ziehl-Neelsen
(ZN)-staining) (false negatives possible)
Tx for feline mycobacterial dx?
- Prolonged course of antibiotics (often combo or triple), depending on
species, for multiple months
Signs of M bovis in people?
weight loss, fever, persistent cough
BARRIER NURSING
What species are zoonotic?
- M.tuberculosis ->euthanasia
- M.bovis -> risk to humans low but poss
- M.microti and MAC -> low risk to humans but poss
- YOPI - discourage tx and encourage euthanasia
Rabies Transmission?
via the saliva of an infected
animal (bites/licking wound) and travels via
the nervous system to the brain (CNS)
* Replicates and moves to salivary glands
* Incubation 10d-4 months, depending on bite
site and viral load
Do Lyssaviruses persist in environment?
not well no
CLS of Rabies?
- Two forms classically in the literature
- Excitatory (‘Furious’) vs Paralytic (‘Dumb’) forms?
Describe stages / phases of Rabies signs
- Prodromal → behavioural change, movement
- Excitatory → erratic, aggression
- Paralytic → wound limb first
Non specific signs?
- Inappetence
- Sudden weight loss
- Pyrexia
- Intermittent lameness
Neuro signs Rabies?
- Drooping jaw (drooling saliva)
- Inability to swallow and hydrophobia
- Change in voice/bark
- Ataxia and paresis/paralysis
- Aggression - will bite/chew on inanimate objects
tx for Rabies?
Euthanasia
NOTIFIABLE
One Health context of rabies?
- The main components of human rabies elimination program are control, prevention, and eventual elimination of rabies in
dogs by mass immunization. - Must reach at least 70% of the dog population,
- Has been proven to lead to progressive disease control and ultimately elimination in both dogs and humans
- Focus: especially in free-roaming community dogs
- One health approach
What is Echinococcus Multilocularis?
- Tapeworm, infecting foxes (definitive hosts) but also
other canids - Widespread in central and eastern Europe
- No known domestically acquired cases in the UK
- Definitive hosts release worm eggs in their faeces,
both are often asymptomatic
What effect does echinococcus have on adult host?
- Usually adults in SI do not cause significant dz
- Could lead to multilocular hydatid cysts with organ
failure
Echinococcus in humans?
- Serious disease in humans (zoonosis)
- Causes alveolar hydatid disease (cystic liver disease
→ liver failure)
Diagnosis of Echinococcus
- Adults too small to see grossly
- Eggs look like Taenia spp!
- Coproantigen ELISA or PCR for differentiation of species
Tx of Echinococcus?
PRAZIQUANTEL
- Compulsory to give 1-5 days before re-entry in UK
- Advise repeat one month after return
- Give monthly when abroad
