feline leukemia virus
DESCRIPTION
Feline Leukemia Virus . Zarah Hedge, DVM Chelsea Reinhard, DVM . FeLV Overview. Retrovirus Oncornavirus subfamily First discovered in the 1960s Enveloped ssRNA with protein core Transmission Typically oro -nasal route Close contact social behaviors Saliva* - PowerPoint PPT PresentationTRANSCRIPT
FELINE LEUKEMIA VIRUS Zarah Hedge, DVMChelsea Reinhard, DVM
FELV OVERVIEW Retrovirus Oncornavirus subfamily First discovered in the 1960s Enveloped ssRNA with protein core Transmission
Typically oro-nasal route Close contact social behaviors
Saliva* Other secretions (feces, urine) – less common “Friendly cat” transmission
Transplacental &/or via milk, close contact
FELV OVERVIEW Young kittens most susceptible 1-8% prevalence worldwide
Declined over past 25 years Median survival time: 2.4 years
FELV CLINICAL PICTURE Tumors Immunosuppression
Concurrent disease Hematologic (blood) disorders Immune-mediated disease Many more...
INFECTION Progressive = Lifelong
FeLV is not contained early in infection Virus replication in lymphoid tissue (lymph
nodes), bone marrow, other tissues Cats with progressive disease succumb to FeLV-
associated illness within a few years Regressive
Immune response that contains virus before/at the time of bone marrow infection
Transient Low risk of developing FeLV-associated illness
PATHOGENESISExposure
Regressor cat
Transient viremia
viremia
days
Latent infection
lifelong
3-13 wk
3 wk
Stress or immunosuppression
FELV DIAGNOSTICS Screening test
ELISA Confirmatory tests
IFA PCR
Detects free FeLV p27 (core protein) Ag in plasma or serum
*recommended screening test*Most cats will test positive within 30 days of exposure
False +• Whole blood (hemolyzed)
False –• rare
IFADetects p27 Ag
• More prone to false negative results than ELISA
PATHOGENESISExposure
Regressor cat
Transient viremia
viremia
days
Latent infection
lifelong
3-13 wk
3 wk
Stress or immunosuppression
ELISA +
ELISA +
IFA +
PCR
FELV DIAGNOSTIC TESTING PCR (?)
Supposed to detect viral DNA in the cat’s genome
Testing protocols not standardized or validated
CONFUSION! Detection = CONFUSING Discordant test results may be due to the
stage of infection Reasons can include cats that resist bone
marrow infection and cats that have regressive infections
Repeat both tests (ELISA and IFA) in 30 days
QUESTIONS?