Lit Infectious Flashcards
a) What are the most common causal species of Bartonellosis in dogs in the USA, and the associated vector?
b) What are the clinical manifestations associated with canine bartonellosis?
c) What was the reported Bartonella spp. seroreactivity for dogs in the USA, and associated risk factors?
Lashnits JVIM 2021
a) Bartonella vinsonii subsp. berkhoffii (Bvb), Bartonella henselae (Bh), Bartonella koehlerae (Bk). NB all spp are pathogenic. No definitive vector identified yet, potentially arthropods (fleas & ticks).
b) Hemotropic & endotheliotropic G- bacteria. Vasoproliferative diseases – e.g. vasculitis, myocarditis, endocarditis, polyarthritis, granulomatous disease (lymphadenitis, rhinitis, hepatitis), epistaxis, neuro signs
c) 6.1%. Risk factors – mixed breeds (vs toy breeds), dogs 1-5.5yo (vs <1yo), dogs in West South Central & South Atlantic.
(2 papers)
What was the seroprevalence of L. infantum in dogs residing in the US and Canada, and the major risk factor for seropositivity?
What about seroprevalence in the US military dog population?
Gin JVIM 2021
6.4% seropositivity – of which 8% foxhounds, 92% non-foxhound breeds.
Risk factor – travel to LI-endemic countries (87% seropositive dogs had travel). *NB zoonotic.
Seal JAVMA 2021
14.3% military dogs seropositive, of which 37.5% were privately owned & 5.6% government dogs. 81% of positive dogs had hx of travel to endemic areas. 6.5% of asymptomatic dogs were seropositive.
What was the utility of serum cardiac troponin-I (cTnI) concentration to differentiate dogs with infective endocarditis (IE) from non-IE dogs? Answer should include test cut-off with relevant specificity & sensitivity.
Kilkenny JVIM 2021
Serum cTnI is higher in IE dogs vs dogs with preclinical MMVD or IMD (immune mediated dz). Cut-off of >0.625 ng/mL had 100% spec, 52% sens so positive cTnI supports IE. Also neg correlated with survival time in IE dogs.
a) What were the most common clin path findings in canine schistomoniasis?
b) What are the treatment(s) for schistomoniasis & reported outcome?
Graham JVIM 2021
a) Hyperglob, high eosinophil count (>500/uL), increased liver enzymes (NB hyperCa uncommon). US evidence of visceral mineralization (intestines, liver, mesenteric LN).
b) Combo tx with praziquantel & fenbendazole. Variably effective, 73.5% survived to 6mths post diagnosis, HA-associated death in 17.6% of treated dogs.
1) What cytologic finding is diagnostic for acute cytauxzoonosis?
2) Which sample had the highest detection rate of this cytologic finding?
3) Which sample had the highest cytologic agreement for diagnosis of acute CTX between novices & experts?
Sleznikow JVIM 2021
1) ID of schizont-laden macrophages.
2) Spleen FNA (77%) > LN FNA (56%) > blood film (33%).
3) Splenic FNA (sens 77.1%, spec 94.4%). VS LN FNA (sens 52.8%, spec 96.4%), blood film (sens 41.7%, spec 96.9%).
a) In cats inoculated with C felis oocysts, what timeframe post inoculation (PI) did oocyst shedding occur?
b) What was the diagnostic utility of faecal flotation compared to PCR?
c) What clinical manifestations were observed?
Scorza JVIM 2021
a) Oocyst shedding occurred by D10 PI, not detected by D15 PI.
b) Faecal float had some false negatives cf ITS1 PCR.
c) No clinical signs observed in this study.
a) What is the gold standard test for diagnosis of coccidioidomycosis in dogs?
b) What was the % agreement between the point-of-care (POC) lateral flow assay (LFA) and this test?
Reagan JVIM 2021
a) Agar gel immunodiffusion [AGID] antibody assay
b) LFA assay demonstrated agreement with AGID in 32/36 (88%) Ab+ samples & 100% (12/12) Ab- samples.
–> LFA provides excellent predictive value for +ve results - but lower +ve agreement when low AGID titers - recommend confirmatory testing if LFA neg but high index of suspicion exists.
a) Which clinicopathologic findings were negative prognostic factors in dogs with blastomycosis?
b) What was the overall survival rate to discharge and at 6 months post-diagnosis in dogs with blasto?
Motschenbacher JVIM 2021
a) BACU (Blastomyces Ag concentration in urine) >5ng/mL and/or severe RLS (radiographic lung severity scores; 3-4) had poorer survival (FU to 1 year).
b) Survival to discharge 87%; survival to 6 months 69%. (1 week, 85%; 2 months, 74%)
What was the utility of anti-inflammatories in dogs with pulmonary blastomycosis?
Walton JVECC 2017
Use of anti‐inflammatories (NSAIDs and/or steroids) did not impact 30‐day survival.
BUT need for O2 supplementation was associated with significantly lower survival.
Which markers of endothelial activation were useful in a) discriminating leptospirosis as a cause of AKI in dogs; predicting b) prognosis of lepto dogs, and c) development of pulmonary hemorrhagic syndrome (LPHS)?
Sonderegger JVIM 2021
a) Soluble intercellular adhesion molecule (sICAM-1), VEGF, and Ang-2 concentrations DID NOT discriminate lepto from non-lepto AKI.
b) In lepto dogs, VEGF and sICAM-1 were higher in non-survivors vs survivors – therefore predict outcome.
c) sICAM-1 predicted the development of LPHS.
Intracranial coccidioidomycosis in dogs
* Most common clinical presentation
* 2 main MRI lesions
* Prognosis
Kelley JVIM 2021
Generalized tonic-clonic seizures were the most common CSx (55.6%).
2 MRI lesion categories: 1) granulomatous form with >/= 1 distinct, intra-axial, contrast-enhancing foci (37/45), 2) diffuse, bilateral, symmetrical lesions of caudate nuclei & frontal lobes (8/45).
Serum IgG titers ranged from 1:1 to ≥1:256.
All tx dogs with FU serology (34/45) had a reduction in titer. (82%) were alive ≥1yr after diagnosis; 13 of these dogs had FU times ≥2yrs.
Reported prognosis for intracranial Coccidioides infection is generally more favorable with medical tx cf earlier reports.
- Which 2 biochemical parameters were significantly different in dogs with Neospora meningoencephalitis compared to non-infectious aetiologies?
- For each biochemical parameter stated above, what were the cut-offs established to differentiate between the above 2 populations, and the respective test sensitivity, specificity, and negative predictive value?
Jones JVIM 2021
1. CK & AST - significantly increased in Neospora dogs.
2. CK cut-off of 485U/L = 95.24% sens, 96.61% spec, NPV >99%.
AST cut-off of 57U/L = 94.44% sens, 85.71% spec, NPV 99%.
In dogs with leptospirosis, ….. was common despite treatment with recommended antimicrobials, and may lead to …… following AKI. …..% dogs had a positive lepto urine PCR beyond the first 7-10 days.
Hetrick JVIM 2021
Persistent leptospiuria, chronic kidney disease, ~50-53% (17/32 dogs)
When low dose praziquantel & fenbendazole was used to treat asymptomatic schistosomiasis in a population of dogs:
a) Which 2 diagnostic tests were used to evaluate for organism shedding?
b) What % of dogs achieved a negative result by D60 using each test?
Cridge JVIM 2021
a) Faecal saline sedimentation & faecal PCR
b) 100% dogs FSS neg; 66% FPCR neg
1) Define caval syndrome.
2) Risk factors for retrograde migration of HW into RA?
3) In the study, high worm burden occurred in ….% dogs; however prevalence of dogs with intracardiac HW & caval syndrome was only…..%.
Majority of dogs with IC HW were ……… (…%) and had a high likelihood of ……. (…%).
Common clinical findings included …. and ……
Common clin path findings in dogs with high worm burden included ……(list 3)
Romano JVIM 2020
1) Caval syndrome (CS) = dirofilarial hemoglobinuria. HW within the RA obstruct blood flow & result in RBC lysis –> hemoglobinuria. Can also be caused by intracardiac HW.
2) High PA pressures, reduced CO, large HW burden, simultaneous or delayed maturation of worms, administration of preventative or adulticide therapy.
3) 81%; 25%
Small breeds, 75% (esp Chihuahuas), pulmonary hypertension (93%).
Lethargy, pigmenturia (43%).
Anemia (36%), pigmenturia (52%), bilirubinuria (78%).
(2 papers)
Feline mycobacteriosis:
- Most common CT findings?
- 2 most common isolates in cats with non-tuberculous mycobacteriosis (NTM) in Northern California?
- Distinguishing features between M. avium & rapid growing mycobacteria (RGM) infections in cats?
Major JFMS 2016
M. microti & M. bovis most common isolates in this study.
CT findings widely variable. Most commonly thoracic pathology - usually a mix of >1: bronchial, alveolar, ground glass or structured interstitial lung patterns (usually mixed). Tracheobronchial, sternal and cranial mediastinal lymphadenomegaly common (80%).
*Others - abdominal or peripheral lymphadenomegaly, hepatosplenomegaly, mixed osteolytic/osteoproliferative skeletal lesions, cutaneous/SQ masses/nodules.
*
Munro JVIM 2020
M smegmatis & M fortuitum
M. avium infections - more likely than RGM infections to be disseminated.
RGM cats - disease of the skin/subcutis (100%) & outdoor access (93%) = primary features
Abx profile – resistance to FQs & aminoglycosides common among M avium isolates; high prevalence of resistance to 3rd & 4th gen cephalosporins noted in RGM spp.
Death/euthanasia noted in M avium cats (not RGM). ~30% RGM cats went into remission.
Pneumocystis facts (select one per statement for a-c):
a) Intra/extracellular
b) Bacteria/fungal/ protozoal/viral
c) Commensals/pathogens
d) Location?
e) Causes in dogs?
f) Predisposed breeds & associated gene mutation?
Merill JVIM 2020
a) Extracellular
b) Fungal (yeast-like)
c) Commensals (low #s)
d) In pulmonary alveoli
e) Inherited immunodeficiencies, distemper, TKI administration, CD40L gene mutation (case report in Shih Tzu).
f) CKCS, Mini Dachshunds.
CD40L deficiency –> impairs T-cell costimulation, leads to combined cellular (T-cell) & humoral (B-cell) immunodeficiency.
What is the treatment for feline cytauxzoonosis?
What genetic mutations were documented in a cat with C. felis infection resistant to the treatment(s) listed above?
Hartley JVIM 2020
Atovaquone & azithromycin
M128 cytochrome b mutations (isoleucine = M128I & valine = M128V) NB same mutation as B. gibsoni in dogs
Resistance occurs even with higher atovaquone dosing.
Bartonella:
- Gram positive or negative?
- Which vectors?
- Predilection sites (name 2)
Baronella rochalimae
- Reported clinical manifestations?
Ernst JVIM 2020
G-
C. felis (fleas)
RBCs (intraerythrocytic), endothelium
Infective endocarditis (most often)
Seizures
Abx-responsive arthropathy
What was the main limitation affecting diagnostic performance of the in-house Histoplasma antigen enzyme immunoassay (IM EIA) compared to the MiraVista enzyme immunoassay (MV EIA) to diagnose histoplasmosis in dogs?
(Note similar paper in cats - Rothenburg JVIM 2018)
Clark JVIM 2020
IM EIA has modest (poorer) diagnostic sensitivity of 70% - false negatives for dogs with histoplasmosis localized to the GIT). MV EIA has much higher sensitivity of 95% (tested positive in the false negs on IM EIA).
(2 papers)
What is GS-441524 and its reported efficacy?
Key treatment considerations with neuro/ocular FIP compared to non-neuro FIP?
Dickinson JVIM 2020
Adenosine nucleoside analogue; halts viral replication.
May require higher doses for CNS/ocular involvement (>/= 10mg/kg).
Pederson JFMS 2019 (did not include neuro & ocular FIP)
Overall safe & effective tx. After a 12-week course, 18/26 cats healthy after 1 round of treatment. 8/26 cats relapsed with 3-84d (2 with neuro signs); of which 5 had success after 2nd tx at higher dose.
Optimum dose reported = 4mg/kg SQ q24hr for min12wks
What was the efficacy of GC376 (3C-like protease inhibitor) in treating FIP? What adverse effects were noted?
Pedersen JFMS 2018
Required min 12 weeks treament. 13/19 cats had relapse of which 8 cats had severe neuro signs & 5 cats abdominal lesions.
SE: transient stinging upon injection, occasional foci of SQ fibrosis & hair loss. Retarded development & abnormal eruption of permanent teeth in cats treated <16–18 wks old.
Describe the following for pythiosis insidosum infections in dogs in the US:
1. Geographical distribution
2. Any temporal/seasonal association
3. Which diagnostic tests?
4. Clinical presentation?
Nguyen JAVMA 2021
1. Most confirmed cases in SE USA (few in the West coast).
2. Mostly Sept-Feb (Autumn & Winter)
3. Serology (IgG) + 1 of the following: positive C&S (2% Sabrouraud dextrose agar), histo, PCR, or wet mount cytology (with KOH).
4. Granulomatous lesions, non-healing skin lesions/draining tracts
Ocular lesions are observed in …..% of cats with blastomycosis, with ….% cats presenting with unilateral involvement.
Ocular lesions present as …… and/or …….. For each presentation, the most common findings included……
Morris JAVMA 2021
60%, 21% unilateral
Neuro-ophthalmic abnormalities (47%) - negative menace or tracking response, negative PLR.
Inflammatory lesions (53%) - anterior uveitis, active chorioretinitis, retinal detachment.
What infectious disease should be screened for in cats prior to receiving a renal transplant? How does seropositive status of this infection affect post-transplant outcome?
Ludwig JAVMA 2021
Toxoplasma gondii serology.
Cats are maintained on lifelong immunosuppressive tx with cyclosporine + prednisolone.
Lack of prophylactic tx in seropositive cats resulted in morbidity & death due to immunosuppression & recrudescence of infection.
Seropositive cats can be acceptable candidates for renal transplantation if lifelong prophylactic tx for toxo is provided (clindamycin or TMPS).
- What is the causal organism for tularemia in dogs?
- Risk factors?
- Common clinical signs?
- What is the main test used to diagnose infection in most dogs? Limitations of this test?
- Survival outcome in hospitalised dogs?
- Treatment?
Kwit JAVMA 2020
1. Francisella tularensis (G- coccobacillus).
2. Wild rodent/rabbit exposure.
3. Non-specific - lethargy, pyrexia, anorexia, lymphadenopathy.
4. Paired serologic titres.
Impt not to rely on a single titre as 1) acute serologic test results was negative in 95% cases, and 2) single high titre does not indicate active disease for dogs repeatedly exposed to bacteria in endemic areas.
Diagnosis based on >=4-fold increase in convalescent vs acute titres.
5. 100% survived to discharge.
6. Abx (gentamicin, doxy, enro, chloramphenicol), supportive care. Infection can be self-limiting.
What were key differences that may help distinguish between dogs with OSA vs Coccidioides osteomyelitis (C-OM) in terms of:
1. Signalment
2. Clinical presentation (lesion location)
3. Imaging findings
- Prognosis for dogs with C-OM?
Shaver JAVMA 2020
1. C-OM dogs - younger, smaller
2. C-OM - axial lesions & non-adjacent polyostoci disease more common.
3. Radiographic findings significantly overlap!
4. Px fair to good - typically rapid clinical improvement after fluconazole tx started, but require long-term antifungal tx.
What were the health benefits when UV germicidal irradiation of the air was applied in a multi-kitten environment?
Jaynes JAVMA 2020
Significantly reduced incidence of URT infections in kittens (by 87.1%) - likely role in preventing airborne transmission of feline resp pathogens.
Potentially useful as adjunct to standard infection prevention & control protocols.
What was a distinct syndrome identified in the renal biopsies of PLN dogs that were Borrelia C6 antigen positive vs seronegative?
Borys JVIM 2019
Rapidly progressive membranoproliferative glomerulonephritis.
What breed was most commonly identified in Borrelia C6+ve PLN dogs?
What were common bloodwork & urine abnormalities in these dogs?
Borys JVIM 2019
Retrievers/retriever mixes.
- Thrombocytopenia, anemia, neutrophilia
- Azotemia & hyperphosphatemia.
- Hematuria, glucosuria & pyuria despite negative urine culture.
No difference in polyarthritis (vs non-Lyme PLN dogs).
NB: Lyme arthritis responds rapidly to doxycycline but NOT lyme nephritis - doxycycline for 2-3 months has no guaranteed improvement; require immunosuppressive tx.
What was the prevalence of MDR organism carriage in patients at a veterinary hospital in Switzerland at admission, discharge & acquisition in hospital?
What were the 2 most common hospital acquired isolates from oronasal/rectal swabs in these patients?
Dazio JVIM 2021
MDR @ admission 15.5%, acquired 28%, 32% @ discharge.
Extended spectrum β-lactamase-producing E. coli (ESBL-E coli; 17.3%), β-lactamase-producing Klebsiella pneumoniae (13.7%).
Is minocycline a comparable alternative to doxycycline for E. canis infection?
Jenkins JVIM 2018
Assessed in NON-ACUTE infections in dogs.
100% minocycline treated dogs achieved negative PCR after 28 days of therapy (doxy in this study cleared by 21 days).
100% dogs PCR negative 7 days after completing tx, however long term FU not performed so cannot confirm if suppression or true clearance from blood.
Occult infection of which pathogen was identified after experimental Rickettsial rickettsii infection in healthy dogs?
Lashnits JVIM 2020
Bartonella spp. (vinsonii subsp. berkhoffii & henselae).
All affected dogs seroconverted to 1-3 Bartonella spp. between 7-18 days after Rr inoculation (ear tip vasculitis with intralesional Bb in 1 dog).
What serological test is used to diagnose Bartonellosis in dogs What is the reported Sn & Sp?
Does testing for more strains improve these?
Neupane JVIM 2018
Immunofluorescent antibody (IFA) testing.
Low Sn 62%, Sp 85%.
Lack of agreement with PCR (lots of positive PCR dogs were false neg on IFA).
No. IFA is technically time-consuming, increases diagnostic costs & does not substantially enhance overall diagnostic sensitivity in this study.
What is the geographical & seasonal distribution for Bartonellosis in North American dogs?
What are the risk factors for seropositivity to multiple Bartonella species?
Lashnits JVIM 2018
No specific distribution; Bartonella spp exposure present throughout NA & across the year.
Risk factors - male intact dogs, mixed breeds, exposure to other vector-borne diseases (common; top 4 overall - Rickettsia > Babesia canis > HW > E canis
Was neurobartonellosis documented based on CSF testing in dogs with inflammatory CNS disease?
Diagnostic test(s) with highest sensitivity to detect Bartonella spp?
Bartner JVIM 2018
Not in this study (1 dog was positive for B. henselae on PCR of blood).
Possible reasons: bartonella not involved in inflammatory CNS disease, organism present in CNS tissues but not CSF, or present at undetectable levels using PCR.
PCR + culture.
What disease has been reported in a dog infected with Bartonella
henselae San Antonio 2?
Donovan JVIM 2017
Pyogranulomatous pancarditis (intramyocardial Bh identified).
What % of IVCs removed due to clinical complications had positive bacterial cultures, and what was the most common isolate?
What factors are associated with IVC complications?
Guzmán Ramos JVIM 2018
39.6%
Acinetobacter spp. (21%)
Association with junior staff performing IVCs & use of steroid anti-inflammatories.
What coagulation disorders are documented in dogs with leptospirosis?
What is the prognostic significance?
Barthélemy JVIM 2017
Anaemia, thrombocytopenia, hyperfibrinogenaemia.
TEM profiles can be normal, hyper or hypo-coagulable.
Hypocoagulable > likely associated with bleeding diathesis, & worse prognosis (mortality 57% vs 21% for hypercoagulable)
DIC NOT prognostic.
What were the findings regarding 3 serological methods (POC & MAT) for leptospirosis testing in experimentally infected dogs? Which POC test was the most reliable?
Lizer JVIM 2018
IgM-specific WITNESS (Zoetis) detected seroconversion in 100% dogs by D10, earlier than MAT (gold standard) that detected seroconversion in 94% dogs by D14.
SNAP (Idexx) was inconsistent & performed poorly (only detected seroconversion in 9% dogs by D14). (SNAP does not detect IgM-specific antibodies)
WITNESS Lepto = POC test of choice for rapid & reliable screening.
Leptospiral-infected dogs may present with what disease without renal involvement?
What diagnostic tests were used to confirm infection?
Was treatment effective at clearance of organisms from liver tissues?
McCallum JVIM 2019
Chronic granulomatous hepatitis.
100% dogs had increased liver enzymes.
FISH + PCR speciation - isolated L. interrogans/kirschneri.
No; 75% (3/4) dogs had remained positive on post-tx biopsies (after doxycycline tx).
Which was the most common leptospiral serovar in USA dogs?
How is PCR used to identify leptospirosis serovar?
Why does MAT perform poorly in identifying casual serovar in infected dogs?
Harkin JAVMA 2016
L. kirschneri serovar Grippotyphosa (80%)
Variable number tandem repeat (VNTR) analysis is applied on urine samples with lepto DNA confirmed by PCR.
MAT has excellent Sp (100%) but poor Sn (max 41%) in speciation.
Which regions of the USA were significant space-time clusters for Lepto PCR positive dogs?
Smith JVIM 2021
Total 7 clusters from 2009-2016. 1 each located within the states of Arizona, California, Florida, S Carolina, South-central region, midwest & northeast region.
What seasonal factor impacted prevalence of leptospirosis in a dog population in Oregon? What other condition did these infected dogs present with?
Grayzel JAVMA 2016
Rainfall - exposure to water envrionment & contact with wildlife.
Dermatitis or otitis
What type of organism is Rhodococcus equi? (aerobic/anaerobic, intra/extracellular, G+/G-, morphology)
What are clinical manifestations reported in cats?
- Body systems affected
- Bloodwork abnormalities
- Imaging abnormalities
Treatment?
Prognosis?
Aslam JFMS 2019
Aerobic, intracellular, G+ coccobacillus.
Pulmonary disease predominantly (90%). Cutaneous lesions only (10%).
- 87.5% presented with dyspnea.
- Alveolar-interstitial lung changes (75%), pleural effusion, hepatomegaly, thoracic lymphadenomegaly, atelectasis of lung lobe (non-specific), pneumothorax.
- Inflammatory leukogram, thrombocytopenia. Hypoalb & hyperglob with low A:G ratio.
- Pyogranulomatous lesions - organism identified in 86% cases.
Azithromycin, erythromycin, gentamicin, FQs usually effective
Poor; 67% mortality overall.
What was the Brucella canis seropositivity rate among purebred dogs
owned by non-commercial breeders in Michigan?
Clinical manifestations in affected dogs?
Johnson JAVMA 2018
0.4%. But endemic in commercial facilities producing dogs for household pets.
Diskospondylitis, uveitis, reproductive problems (abortion, infertility in males).
Based on a systemic review, was there a clinical benefit of vaccinating dogs against Lyme borreliosis?
Vogt JVIM 2018
Vaccinated dogs had reduced odds of developing clinical signs (lameness, depression, pyrexia, anorexia) cf unvaccinated dogs (OR 0.15-0.23). But quality & design of studies may be a limiting factor.
What type of pathogen is Listeria?
Describe a clinical syndrome reported in cats.
Fluen JVIM 2019
Facultative anaerobe, G+. Non spore forming rod. Saprophytic.
Rare cause of mesenteric lymphadenitis in cats (generally young-middle aged). Possible association with raw meat.
A meta-analysis in 2017 found Mycoplasma felis was associated with URT or LRT disease in cats? What was this dependent on?
Le Boedec JAVMA 2017
URT disease.
Significant association with disease only based on positive PCR of conjunctival/pharyngeal samples from non-shelter cats (asymptomatic carriage in shelter cats)
Which mycoplasma spp. was found to be associated with LRT disease in dogs? Which were commensals?
Jambhekar JVIM 2019
M. cynos = pathogen (consider spp-specific PCR in clinical cases)
M. canis & M. edwardii = commensal
Which Mycoplasma spp. may be transmitted transplacentally or during the peri-natal period in dogs?
Lashnits JVIM 2019
M. haemocanis
