Infectious Diseases Flashcards
Histoplasma capsulatum; Area, transmission, species, organs, diagnosis
Area
• MS. OH. MO river valleys & mid-south US
Transmission
• inhalation
Species
• cats > dogs
Organs
• immune organs, bones, eyes w/ multi-organ (cats), CNS, GI (in dogs)
Diagnosis
• organisms in aspirate or biopsy
• serum or urine Ag test
Blastomyces dermatitidis; Area, transmission, species, organs, diagnosis
Area
• MS. OH. MO river valleys
• mid-atlantic
• S Canada
Transmission
• inhalation
• rare direct innoculation
Species
• dogs>cats
Organs
• lungs, bones, lymph, skin, eyes, CNS, testes
Diagnosis
• organisms in aspirate or biopsy
• serum or urine Ag test
Coccidoides immitis; Area, transmission, species, organs, diagnosis
Area
• SW US, CA, Mexico, S America
Transmission
• Inhalation
Species
• dogs>cats
Organs
• lungs, bones, lymph, skin, eyes, pericardium, CNS
Diagnosis
• organisms in aspirate or biopsy
• serum or urine Ab test (also shows exposure only)
Cryptococcus neoformans; Area, transmission, species, organs, diagnosis
Area
• worldwide
Transmission
• inhalation
Species
• cats>dogs
Organs
• respiratory, skin, eyes, CNS, most common is nasal
Diagnosis
• organisms in aspirate or biopsy
• serum, CSF, or aqueous humor Ag
Most common symptom of fungal infection & other symptoms
- Antibiotic unresponsive fever
- Draining or granulomatous skin lesions
- Chorioretinitis, blindness, anterior uveitis
- Neurologic deficits
- Icterus, hepatomegaly
- Lameness
- Lymphadenomegaly-
- Diarrhea, vomiting, weight loss
- Cough, tachypnea, hyperpnea
- Nasal discharge
Common Clin Path in Fungal Infections
- HIGHLY variable
- Neutrophilic leukocytosis
- Hyperglobulinemia polyclonal gammopathy)
- hypercalcemia
- increased liver enzyme (if liver is involved)
- hypoalbuminemia (GI or renal losses)
- proteinuria.
Diagnostic Techniques for Fungal Infections
Thoracic rads
• highly variable
Serology for Ag
• serum
• urine (more sensitive)
Serology for Ab
• can’t distinguish exposure from infection
• used for C. immitis
organism in cytological or histological preparations
• definitive
Treatment of Fungal Infections
Treat for 60 days or 1mo post clincal signs
relapse common
Ketaconazole
• heptotoxic
Itraconazole
• less hepatotoxic
Fluconazole
• less hepatotoxic
Amphotericin B
• nephrotoxic
FIP Transmission & Epi
Transmission
• fecal-oral
• in utero from asymptomatic queen
• intermittent or continuous shedding
Epi
• Multicat households
• catteries
• single cats (group housing prior)
FIP Pathogenesis
- mutants of FeCoV replicate in macrophages ->
- macrophages disseminate to lymph nodes, brain, spinal cord, liver, kidney, uvea, pleura and peritoneum ->
- macrophages deposited in endothelial lining of small venules
Strong Immune Response
• eliminate the virus OR
• latently infected
Partial Response
• granulomas/pyogranulomas -> dry form
No effective cell-mediated response
• pyogranulomatous or granulomatous inflammation in vessel walls ->
• type III hypersensitivity reaction -> complement-mediated vasculitis ->
• protein and fibrin-rich fluid escapes from vessels -> wet form
FIP Clinical Signs
• anorexia, fever, weightloss
Effusive (wet) • abdominal distention • respiratory distress (restrictive) • scrotal swelling intact males • vomiting and diarrhea • icterus • pancreatic issues
Non-Effusive (Dry) • renal & hepatic insufficiency • pancreatic disease • ocular disease • neurologic disease • mesenteric lymph node enlargement • cough • respiratory distress (non-restrictive)
Diagnosis of FIP
- clinical Signs
- normocytic, normochromic non-regenerative anemia
- azotemia,
- hyperbilirubinemia,
- increased ALT and SAP
- hyperglobulinemia
- proteinuria
- low specific gravity
- fluid w/ high protein, neutrophils, monocytes/macrophages, fibrin clots
- serology but cross-reacts with FeCoV
- histopathology
Differential Diagnosis, Prognosis, Prevention for FIP
- toxoplasmosis
- FeLV/ FIV
- neoplasia (especially lymphosarcoma)
- systemic fungal infections
- hepatic disease (cholangiohepatitis, hepatic lipidosis)
- renal disease
- IBD
Prognosis
• 95% mortality
• cats w/ dry live longer than cats w/ wet
Prevention
• 1 litter box per every 2 cats
• daily clean litterbox
FIV Transmission & Epi
• bite and fight wounds with blood or saliva containing infectious virus
Epi
• male > female
• outdoor > indoor
• adult > adolescent
Diagnosis of FIV
- all cats at risk routinely ANTIBODY tested
- (+) Ab test considered infected unless kitten <6mo
false (+)
• due to use of whole blood, other infectious agents, previous vx;
• confirm w/ western blot or PCR
False (-)
• acute or terminal stage of infection
• can take up to 8wks for seroconversion
FIV; Prognosis & Treatment
- can live normally w/ proper care
* treat symptomatically
FeLV Transmission
- contact w/ infectious saliva and/or nasal secretions of cats with persistent, active FeLV infection
- easily transmitted in social cat situations
FeLV Pathogenesis
Always ANTIGEN tested
Abortive
• replication terminated by humoral & cell response
• viremia doesn’t occur
• cat tests (-) on Ag test
Regressive
• (+) on tests detecting “free” Ag
• immune response contains and eliminates virus after wks to mos
• if persists longer -> spreads to bone marrow
• do not shed FeLV after suppression
• can be reactivated
Progressive • persistent viremia • infect other cats • die w/in a few years • always Ag (+)
Focal
• rare
FIV Clinical Signs
- leukopenia
- non-regenerative anemia
- thrombocytopenia
- erythroleukemia, granulocytic leukemia, or monocytic leukemia
- lymphosarcoma
- immunosuppressive dz
FIV Diagnosis & Prognosis
Ag ELISA
• serum, blood, tears, saliva
• early detection
IFA of Ag in cytoplasm of infected cells
• (+) test indicates bone marrow involvement
• false (-) occurs w/ leukopenia
Prognosis
• 80% progressive infection die in 3yrs
Ehrlichiosis & Anaplasmosis Acute & Chronic Clinical Signs
Acute • anorexia • fever • lymphadomegaly • splenomegaly • petechia • epistaxis • neuro signs
Chronic • acute signs + • pale MMs • peripheral edema • secondary infections • polyarthropathy • ocular lesions
Ehrlichiosis & Anaplasmosis Diagnosis & Tests
- clinical signs
- thrombocytopenia
- neutropenia
- anemia
- hypoalbuminemia
- hyperglobulinemia
- increased BUN & creatinine
- proteinuria
- increased ALT / ALP
- froom endemic area OR at some point may have been (travels well)
Test
• IFA titer greater than 1:20 or 1:40
• cross reactivity w/ other Ehrlichia
Ehrlichiosis & Anaplasmosis Differential Diagnosis
DfDx • sepsis • rocky Mt spotted fever • multiple myeloma • lymphocytic leukemia • immune-mediated thrombocytopenia / anemia • immune-mediated polyarthropy • lupus erythematous
Ehrlichiosis & Anaplasmosis Treatment
- Doxy for 3-4 wks (best)
- 1-2 wks glucocorticoids
- symptomatically
