Enteroviruses Flashcards Preview

Medical Microbiology > Enteroviruses > Flashcards

Flashcards in Enteroviruses Deck (23):
1

Picornaviruses

Pico(Small) RNA viruses, enterovirus, rhinovirus, hepatitis A

2

How many serotypes of enteroviruses are there?

71, polioviruses 1-3, coxsackie viruses, echoviruses, numbered enteroviruses

3

Enterovirus seasonality

Temperate climates: summer and fall, Tropics: year round.

4

Who does enterovirus affect most?

Children

5

What type of symptoms do most enteroviruses cause?

Most are asymptomatic or result in non-febrile illness with mild respiratory symptoms

6

Enterovirus viral characteristics

+ sense, single stranded RNA viruses, icosahedral capsid, NO envelope but resistant to harsh environmental conditions like sewage, broad pH range, GI tract, detergents

7

VP1

Contains receptor binding site that is buried within a canyon to hide it from antibodies

8

Enterovirus replication cycle

Reception, internalization, replication in cytoplasm, inhibition of host cell RNA synthesis, cytolytic

9

Pathogenesis of poliovirus

Enters the nasopharynx, replicates in oropharynx, primary virema, travels via nerves from muscle to motor neurons in anterior horn and brainstem, shedding in stool

10

Where can viruses be shed for weeks?

Nasal secretions and stool (longer in stool)

11

Mechanism of injury for enteroviruses

Cytolysis (for all but Hep A), immune mediated (for Hep A).

12

What prevents establishment of initial infection

Sec IgA

13

What prevents/controls viremia?

Serum IgG

14

What type of clinical syndromes does poliovirus cause?

Asymptomatic in 90%, Minor febrile illness in 5%, non paralytic aseptic meningitis in 1-2 percent, Paralytic in 2% or less.

15

Two polio vaccines

Inactivated: Salk (IM)
Live: Sabin (oral)

16

3 countries that still have polio

Afghanistan, Nigeria, Pakistan

17

Other enteroviruses cause

Exanthems, febrile illness, URI, acute hemorrhagic conjunctivitis

18

Which virus causes Hand foot and mouth disease

Coxsackie A

19

Which virus causes overwhelming neonatal disease?

Coxsackie B

20

How to distinguish viral meningitis from bacterial?

Elevated WBC in CSF, but markedly less than bacteria. Lymphocytic predominance, normal glucose and protein.

21

Prion diseases

Long incubation period, Slow but progressive neurologic deterioration, uniformly fatal over a period of months

22

Common pathologic findings in prion diseases

Minimal inflammatory response, neuronal degeneration, astrocyte proliferation, vacuoles within cells,

23

PrP

Prion protein, conformation isomer of a normal host protein, accumulates in the brain of affected individuals very resistant to chemical or physical inactivation, transmitted by infected brain tissue, transmission can be iatrogenic, can be genetic