Infectious Disease Flashcards
1
Q
Bartonella
A
-B. henselae, B. quintana
-transmitted: fleas +/- ticks or lice
-associated w/ endocarditis, uveitis, stomatitis, lymphadenopathy, neurological, and urinary disorders
-dx: blood culture, PCR, histology of infected tissue
-txt: and x 4-6 wk - doxy (cats), azithromycin, enrofloxacin, rifampin, clavamox
2
Q
Lyme disease
A
- Borrelia burgdorferi
- NE, East, and West coast USA
- transmission: Ixodes ticks (from rodent host), at least 48hr tick attachment
- clinical signs: polyarthritis, fever, anorexia, lethargy, lymphadenopathy, stiff gait, shifting lameness, joint swelling
- Lyme nephropathy: C/S of renal insufficiency and PLN (labs, goldens)
- dx: PCR, IFA, ELISA
- txt: doxy 10mg/kg PO SID x min 4wk
3
Q
Brucellosis
A
- B. canis
- zoonotic
- intracellular, gram-, coccobacillus (rod)
- transmission: ingestion, genital/oronasal/conjunctival mucosa. Postabortion fetus, fluids, placenta, vaginal d/c from infected female
- clinical signs: many asymptomatic, reproductive failure, epididymitis/scrotal edema/orchitis in male dogs
- dx: bacterial isolation (culture), blood (RSAT, then AGID if positive)
- txt: relapse common, tetracyclines + dihydrostreptomycin (or gentamicin), enrofloxacin
4
Q
Ehrlichiosis
A
- E. canis, E. chaffeenis, E. ruminantium, Neorickettsia risticii, E. ewingii (CGE only)
- obligate intracellular gram- coccobacilli
- infects circulating monocytes (CME) and granulocytes (CGE)
- transmission: ticks, blood transfusion
- acute phase: 2-4 wks; febrile, antic +/- nasal d/c, lymphadenomegaly, vasculitis (pethechiae, edema). Thrombocytopenia, mild anemia, leukopenia common.
- subclinical phase: months-years; clinical signs resolved if untreated in acute phase (may still have mild thrombocytopenia)
- chronic phase: lifelong; if immunocompromised or otherwise don’t clear infection in subclinical phase
- clinical signs: CME = nonspecific inflammatory (fever, anorexia, lethargy, lymphadnomegaly) +/- petechia, ecchymosis, neuro abnormalities, PU/PD (2° to renal), infections 2° to BM suppression. CGE = polyarthritis
- dx: serology (IFA, SNAP), PCR
- txt: doxycycline 10mg/kg PO SID x 4wk, if resistant: imidocarb, steroids if 2° ITP suspected
- nutrition: renal
- anesthesia: renal, vasculitis, anemia, clotting abnormalities
5
Q
Leptospirosis
A
- L. interrogans, L. kirschneri
- aerobic gram- spirochetes
- transmission: indirect contact w/ water/food/soil/fomites contaminated w/urine; direct contact w/ infected urine/blood/tissue, bite wound, venereal/placental transfer
- clinical signs: renal, hepatic +/- uveitis, acute lung injury, meningitis, abortion/infertility
- dx: inflammatory leukogram +/- mild thrombocytopenia; azotemia, hyperphosphatemia; elevated ALT/ALP/t.bili. Hypoalbuminemia if hepatic failure or vasculitis; glucosuria/granular casts/isosthenuria/proteinuria 2° to renal injury; bilirubinuria 2° to hepatic injury. SEROLOGY OR PCR confirm diagnosis
- txt: penicillins/aminopenicillins during initial phase, doxycycline 5mg/kg PO BID x 2wk to prevent renal shedding.
- nutrition: renal/hepatic = restricted protein & sodium
- anesthesia: renal, hepatic, vasculitis, clotting abnormalities
6
Q
MRSA
A
- Methicillin-resistant Staphylococcus aureus
- gram+ facultative anaerobe
- skin, MMs, urinary, GI tract in healthy people
- clinical signs: skin/soft tissue lesions, osteomyelitis, endocarditis, sepsis, pneumonia, necrotizing fasciitis
- dx: culture
- txt: topical (mupirocin) if skin lesion, systemic abx based on C&S (NO beta-lactam abx, ALWAYS resistant despite C&S results; rapid resistance to fluoroquinolones); vancomycin reserved only for human use
7
Q
Mycoplasma
A
- hemotropic and nonhemotropic
- gram-, nonacid fast, aerobic, or facultative anaerobic bacteria WITHOUT cell walls
- transmission: cats: fleas, contaminated blood products, dogs: brown dog tick (Rhipicephalus sanguineus), IV or PO infected blood, possibly in utero
- C/S: varying degrees of regenerative anemia (unless coinfected with FeLV), lethargy, weight loss; jaundice inconsistent; fever in acute phase, or normo- to hypothermic; nonhemotropic: resp, joint, genitourinary, GI dz, cat abscesses
- dx: M. haemofelis = coccoid, rod-shaped, or circular organism in an epicellular location on RBC (seen on blood film 50% of the time); PCR of blood (may be normal flora on mucosal surfaces, so BAL, etc not trustworthy); splenomegaly on imaging
- txt: doxycycline 10mg/kg PO SID; prednisolone 1-2mg/kg PO BID + pRBCs PRN for hemotropic mycoplasma
8
Q
Pythiosis
A
- P. insidiosum
- Gluf Coast / SE USA
- GIT and skin
- intense submucosal infiltration of fibrous connective tissue
- purulent, eosinophilic, granulomatous inflammation –> gastris ulceration/erosions –> prevents peristalsis (results in stasis)
- C/S: (typically dogs) vomiting, anorexia, diarrhea, +/- weight loss. If colon: tenesmus, hematochezia
- gastric outow obstruction common
- full-thickness biopsies best for dx, need submucosal layer
9
Q
Histoplasmosis
A
- Histoplasma capsulatum
- systemic, originates in lungs (or GIT), disseminates to lymph, bone marrow, eyes, liver, other organs.
- soil (resp route) in areas following Mississippi, Missouri, and Ohio rivers
- cats > dogs, under 4 yo more frequent
- C/S (cats): (wide variety due to multusystemic nature) weight loss, pale MM, anorexia, depression, fever +/- tachypnea, dyspnea, abnormal lung sounds. Cough uncommon
- C/S (dogs): GI signs more common, LI diarrhea w/ mucus and fresh blood, then voluminous SI diarrhea w/ PLE or malabsorption
- dx: cytology from affected tissue = pyogranulomatous inflammation, intracellular yeast 2-4 um in diameter w/ basophilic center and light halo may be seen
- other dianotics: CBC = normocytic normochromic nonregenerative anemia, +/- neutrophilia and monocytosis. Cats = some will have neutropenia, pancytopenia, or both. Histoplasma occasionally seen withing monocytes or neutrophils. Hypoalbuminemia, elevated LE with liver involvement.
- ALERT LAB IF CULTURE SAMPLES ARE HISTO SUSPECT, risk to personnel if mishandled
- serology POOR - False neg early in disease
- Ab titers POOR assessment tool post treatment
- Ag testing available
- TXR = linear or diffuse interstitial pattern
- txt: pulmonary infection may be self-limiting; amphotericin B/keto/itraconazole recommended due to risk of systemic dissemination. Disseminated disease likely fatal without txt. Dogs w/GI dz should also be fed highly digestible diet.
- txt w/ antifungals 1 month post resolution of C/S, azole therapy requires monthly monitoring (including liver chem)
10
Q
Rocky Mountain Spotted Fever
A
- Rickettsia rickettsii
- transmission by Dermacentor spp. (deer ticks)
- severe vasculitis, associated polyarthritis
- C/S: joint, muscle, and neurological pain; stiff gait cause by general inflammation, lymphadenopathy, fever
- txt: doxycycline 10mg/kg PO SID x 28d
11
Q
Anaplasmosis
A
- A. phagocytophilium = granulocytic ehrlichiosis
- transmitted by ixodid spp. ticks
- coinfections with B. burgdorferi common
- C/S: fever, lethargy, inappetence, lameness, scleral injection
- lab findings: thrombocytopenia +- hypoalbuminemia, mild-mod LE elevation
- dx: morulae within neutrophils highly suggestive, ELISA (SNAP), PCR
- txt: doxycycline 5mg/kg PO BID x 14d
- A. platys = thrombocytic anaplasmosis
- transmission: likely Rhipicephalus sanguineus tick
- thrombocytopenia after 1-2 wk incubation, normalizes in days
- morulae within platelets and megakaryocytes in BM may be seen shortly after infection
- dx: morulae in plt with acute and convalescent serology (serology NOT specific between Anaplasma spp, PCR is available)
- txt: doxycycline 5mg/kg PO BID x 14d
12
Q
Clostridium perfringens
A
- anaerobic
- spore forming
- gram+ bacillus
- C. perfringens enterotoxin (CPE) associated with canine acute hemorrhagic diarrhea syndrome (AHDS) (by ELISA)
- fecal culture of little dx value
- PCR available
- txt: abx if systemically ill (fever, HGE, inflammatory or toxic leukogram). Ampicillin, metronidazole, tylosin recommended.
