Leptospirosis Guidelines Flashcards
How susceptible are cats to Lepto?
very resistant to clinical infection but up to 20% of outdoor cats may be carriers
How does Lepto cause endothelial damage?
lepto organisms corkscrew through the endothelium causing holes and increasing permeability
List organs affected by Lepto and how they are affected
kidneys - glomerulonephritis
liver - cholestatic hepatopathy, disruption of hepatocyte intercellular junctions - bile leakage
brain - aseptic meningitis
pancreas - may develop pancreatitis
GI tract - gastroenteritis
Platelets - leptospires –> direct cytotoxic platelet damage
lung- leptospiral pulmonary hemorrhage, endothelial damage may be contributing
What 2 organs does Lepto persist in after it is cleared from the blood?
eyes
kidneys
In an lepto-unvaccinated dog with acute onset febrile illness, what test should be recommended?
Is empirical treatment recommended in these cases?
NAAT
yes, 7 days of doxy could be considered, but more evidence needed for better antibiotic stewardship
What are the most common CBC findings in dogs with lepto?
neutrophilia with increased bands, lymphopenia, monocytosis
mild to moderate, non-regenerative anemia
thrombocytopenia
What are usual chem/lyte changes in dogs with lepto?
elevated SDMA and creatinine
ALP elevated, to less extend: ALT, AST, also hyperbilirubinemia
depending on extend of kidney disease: hypo/hyperkalemia, hyponatremia, hypochloremia
elevated lipase, amylase
elevated CK
What is the evidence of heart disease in lepto?
elevated troponin-I cc - but has also been reported in non-lepto AKIs so may be indirect complication of AKI rather than lepto
What is the suspected cause for the increse of lipase and amylase in lepto?
decreased renal excretion or other GI disease considered before making conclusion on pancreatitis
What are typical UA findings in lepto?
- proteinuria (usually UPC < 5 through)
- cylinduria
- isosthenuria/hyposthenuria
- glucosuria
What are the 2 types of proteinuria seen in Lepto?
tubular - defective tubular reabsorption of low molecular weight proteins
glomerular - high molecular weight proteins
What are commonly observed Coag profile and teg changes in lepto dogs?
thrombocytopenia
elevated PT and aPTT
hyperfibrinogenemia (more common) and hypofibrinogenemia
low antithrombin %
increased D-dimers
teg: 20% hypocoagulable, 40% hypercoagulable
How does MAT work. What are its limitations and advantages?
MAT: tests serum for antibodies against usually 6-7 serovar of leptospirosis
titer established
ideally 2 titers: acute and convalescent titers (7-14 days apart)
single positive titer lacks specificity - previous vaccine or exposure - vaccine may increase titers for 4 months to a year
What is the method of point-of-care serologic tests?
Which type of antibodies does the WITNESS letpo rapid test detect?
later flow technology
SNAP (IDEXX) or WITNESS (Zoetis)
witness –> IgM
How specific is a positive WITNESS test in an unvaccinated dog with CS consistent with lepto?
> 97%
What type of samples should be obtained when to submit for NAAT? How does the sensitivity and specificity of each of these samples compare? Which of these samples is confirmatory if positive?
blood (without heparin, e.g., EDTA) and urine
blood more specific, urine more sensitive but less specific (positive in up to 20% in apparently healthy dogs)
negative sample with either does not r/o lepto
blood is confirmatory if positive
How do vaccinations affect NAAT testing for lepto?
do not affect them
What are Lepto cultures most important for?
for surveillance - assessing what species are present in a region
What are the requirements to say a case probably has lepto versus confirming it has lepto?
probably: clinical criteria met and at least one supportive diagnostic test
confirmed: clinical criteria met and at least one confirmatory diagnostic test
What are the clinical criteria for lepto?
- acute systemic disease within past 2 weeks (e.g., fever, lethargy, PU/PD, anorexia)
plus at least 2 of the following:
* neutrphilic leukocytosis
* thrombocytopenia
* evidence of AKI
* cholestatic hepatopathy on blood work
* blood work evidence for pancreaitits
* elevated CK
* glucosuria
* active urine sediment
* xray findings consistent with pulmonary hemorrhage syndrome
* US findings including pancreatitis, hyperechoic renal cortices, or perirenal fluid
* cardiac arrhythmias on ECG or elevated troponin
What are the supportive laboratory criteria for Lepto diagnosis?
- single positive titer on MAT
- single positive IGM titer (POC)
- positive on darkfield microscopy
- urine NAAT positive
What are the confirmatory laboriatory criteria for the lepto diagnosis?
- 4 fold increase from acute and convalescent titer
- positive blood NAAT
- positive culture
What is the antibiotic therapy recommendation for leptospirosis?
- doxycycline - if eating, 2 weeks
- if vomiting or other adverse reactions - ampicillin IV, amoxicillin IV, or penicillin G IV
What is the recommended diet for patients suffering from leptospirosis?
normal high quality protein
avoid kidney diet - is high in fat and could worsen pancreatitis, no evidence that protein has to be restricted in acute kidney disease from lepto
What is the recommendation for liver protectants and ursodiol in lepto?
not recommended, lack of evidence
When is referral of Lepto patients to a facility providing extracorporeal therapy recommended?
if AKI IRIS stage 4 or serum creatinine > 5 mg/dL
What are negative prognostic factors for leptospirosis in dogs?
hyperbilirubinemia
hypocoagulability
What is the cutoff score to predict non-survival in the Sege’s model C for dogs with AKI with lepto managed with extracorporeal therapy?
19.9
How soon after infection does leptospiruria commence?
7-10 days
For how long after starting doxycycline treatment should owners wear gloves at home, avoid contact to their dog’s urine, and wear eye protection when cleaning urine?
48 hours
