retro 2 Flashcards
What is the etiology of avian leukosis? how are the viruses classified?
-alpharetrovirus-10 subgroups, based on antigenic differences in viral envelope antigens-subgroup a & b; most field outbreaks of leukosis-subgroups c & d; infrequent-subgroup e; endogenous, non-oncogenic-subgroup j; myeloid leukosis
If avian leukosis virus is transmitted congenitally via the _____ or within the ______ days of life, the chicken develops a _____ because of the induction of immunological tolerance.
egg; first few; persistent viremia
t/f - birds that become PI with avian leukosis may grow normally but subsequently develop viremia
true
t/f - birds that are PI with avian leukosis are not a threat to healthy birds.
false; major source of virus that spreads to other birds by contact
describe avian leukosis transmission/outcomes
-if infected horizontally when more than 5 or 6 days of age, they are unlikely to get leukemia. instead they develop transient viremia, and produce a neutralizing antibody-vertical transmission trhough provirus integrated into host germ cells; usually latent, no viremia, no leukemia.
primary target of avian leukosis?
lymphocytes, with b-lymphocyte markers in bursa
what is the difference between exogenous replication competent/defective viruses?
-competent: proviral DNA is integrated into many different kinds of cells—sometimes, by chance, in a location where the activity of a c-onc gene is disturbed-defective: viruses acquire an oncogene (v-onc) from a cellular onc (conc) gene and then can induce malignant tumors rapidly
what are the three major clinical features of exogenous replication competent avian leukosis viruses?
-lymphoid leukosis (visceral lymphomatosis; big liver dz)-osteopetrosis (thick leg); proliferation of periosteal osteoblasts of long bones-renal tumors
what are the three clinical features of exogenous replication defective avian leukosis viruses?
-myelocytomatosis-myeloblastosis-erythroblastosisoutcome of above: anemia, leukemia
what is the etiology of FIV? what is the grouping?
-feline lentivirus-5 subtypes (a-e); variations of env gene
which subtypes of feline lentivirus dominate north america?
a & b
t/f- FIV does not infect wild felids
false; it can infect some wild felids
FIV is mainly shed in ______
saliva
FIV infection lasts _____
whole life
principal mode of FIV transmission is ______
cat bites
the hallmark of FIV is disruption of _______; this is due to progressive loss of ________
immune function; CD4 t-helpers in early stages, as well as CD8’s in later
what are the four causes of CD4 loss in FIV cats?
1- decreased production due to bone marrow or thymic infection2- cytopathic effect of fiv3- CTL mediated cytoloysis of cells4- death by apoptosis
what are the three phases of FIV?
acutelatentterminal
what is characteristic of the acute phase of FIV?
-asymptomatic; or transient fever, malaise, lymphadenopathy, and diarrhea-antibodies against virus, but ineffective at eliminating
what is characteristic of the latent phase of FIV?
-follows acute phase-variable duration; may persist for years before signs of immunodeficiency occur-persistent lymphadenopathy
what is characteristic of the terminal phase of fiv?
-immunodeficiency syndrome-predisposed to chronic recurrent, opportunistic infections cause by bact and fung… i.e. chronic stomatitis, gingivits, chronic respiratory dz, chronic diarrhea/wasting, dermatitis, neuro signs, etc
what is the major tool for diagnosis of FIV? what protein is involved?
detection of p24 core protein by snap test
t/f - FIV can infect humans
false; no evidence of this. highly species-specific virus. felines only
what is the etiology of equine infectious anemia? what else is it called?
equine lentivirusAKA Swamp Fever
