lecture 1

Question 1

Pathogenesis

Answer 1

process by which infection leads to disease

Question 2

tissue tropism

Answer 2

viral affinity for specific body tissue

Question 3

incubation period

Answer 3

time between exposure to virus and onset of disease

Question 4

congenital infections

Answer 4

infection of fetus as target organ

Question 5

failed infections

Answer 5

virus can’t find material necessary for life cycle

Question 6

acute infections

Answer 6

rapid onset, short duration (cold virus)

Question 7

persistent or chronic infection

Answer 7

lasts many years and almost always detectable, latent infection (not detectable during dormancy), recurrent infection, transformation infection (virus permanently alters host genetic material-> cancer)

Question 8

viral transmission

Answer 8

to host: shedding, respiratory-> enveloped viruses, saliva, blood, skin lesions, vectors

Question 9

viral transmission

Answer 9

within host: viremia-spread via blood, via neurons

Question 10

viral parthenogenesis

Answer 10

implantation of virus at portal of entry, local replication, spread within host to target organs, spread into the environment

Question 11

laboratory diagnosis of viruses

Answer 11

description of virus-induced cytopathologic effects on cells-> changes in morphology, vacuolation, fusion, inclusion bodies. Electron microscope detection of viral particles

Question 12

laboratory diagnosis of viruses

Answer 12

isolation and growth of virus in: tissue culture, embryonated eggs, expreimental animals, Detection of viral components: proteins, nucleic acid, hemagglutinatinins, evaluation of patients immune response-> serology tests

Question 13

Prions

Answer 13

misfolded proteins with no nucleic acids

Question 14

replication of prions

Answer 14

alteration of normal host protein into beta-sheets,beta-sheets are insoluble and resistance to proteases. resistance also to chemicals, UV radiation, heat up to 80 C.

Question 15

Prions evade immune response how?

Answer 15

evade immune response because they are naturally occurring proteins

Question 16

Prions and TSE’s

Answer 16

Prions cause transmissible spongiform encephalopathies due spongy nature of brain.

Question 17

symptoms of TSE’s

Answer 17

progressive CNS degenerative disease, always fatal, dementia, ataxia, pyramidal signs, characteristic waves

Question 18

Creutzfeld-Jazob disease (CJD)

Answer 18

individuals 50 years and older, rapid mental deterioration, spontaneous, by genetic mutation, contamination during medical procedure.

Question 19

CJD symptoms

Answer 19

no fever or flu-like symptoms, impaired memory, coordination and judgment, insomnia. Late: myoclonus, blindness, comatose, ultimately death

Question 20

Variant Creutzfeldt-Jakob disease (vCJD)

Answer 20

younger patients (28-29 years old). Linked with TSE’s of cattle.

Question 21

Symptoms of vCJD

Answer 21

initially-> psychiatric symptoms (depression, schizophrenia-like psychoses), Late-> difficulty walking, become immobile, mute, ultimately death

Question 22

Kuru

Answer 22

“trembling with fear”, outbreak in New Guinea, get from eating brains of those with Kuru, cannibalistic behaviors

Question 23

Prion pathogenesis

Answer 23

oral ingestion, intestinal absorption, and transported to lymph tissue via blood, replication in lymph tissue, transport to brain via peripheral nerves, direct penetration across blood brain barrier