Measles and Mumps

Question 1

describe the measles and mumps in terms of the structure of the virus and their nucleic acid content

Answer 1

paramyxoviruses

RNA
single stranded
negative sense
enveloped
helical

Question 2

do paramyxoviruses have to carry RNA polymerase?

Answer 2

yes

Question 3

are measles and mumps capable of radical antigenic shifts?

Answer 3

no- paramyxoviruses only contain one strand of RNA

Question 4

how does the type of infection dictate the incubation period and subsequent immunity for measles and mumps?

Answer 4

they travel through the blood as viremia and cause systemic infections. thus:

1 incubation time is longer

2 IgG provides life long immunity

Question 5

how many serotypes of mumps are there?

Answer 5

1

Question 6

how many other animals act as resevoirs for mumps?

Answer 6

just humans

Question 7

what is the normal incubation period for mumps?

Answer 7

3 weeks

Question 8

what are the symptoms of mumps?

Answer 8

after 3 weeks, prodromal symptoms will develop

fever, malaise, anorexia

followed shortly by asymmetrical parotiditis and potentially orchitis post puberty. parotiditis is the presenting symptom.

aspetic meningitis is also common

Question 9

describe transmission of mumps

Answer 9

occurs usually via respiratory exposure to saliva droplets containing virion

viremia spread from the parotids to the salivary glands, where virions produced there enter the mouth and spread via coughs and sneezes

Question 10

describe antiviral therapy for mumps

Answer 10

none

Question 11

describe the vaccine used for mumps

Answer 11

live-attenuated

parted of the MMR vaccine given twice

Question 12

explain the occurrence of 3 year cycles of epidemics for measles

Answer 12

measles is the most contagious disease known. an outbreak would result in herd immunity, but as years go by and new people are born, the proportion of immune people decreases to a critical point where herd immunity is no longer effective, causing a new epidemic

Question 13

describe measles transmissoin

Answer 13

transmitted through respiratory droplets (coughs/sneezes) and infects respiratory tract.

it multiplies in the lymph and respiratory epithelium

Question 14

describe measles symptoms

Answer 14

prodromal symptoms occur first:

fever, cold-like symptoms, runny nose, red eyes, coughing, sneezing, photophobia

followed by Koplik spots (bright red lesions w white central spot inside mouth)- predicts measles rash

rash begins after 14 days. maculopapular erythematous rash generated at least partially by immune system

Question 15

describe measles virus excretion

Answer 15

excreted from respiratory tract and in tears and urine in the days before and after rash

Question 16

measles incubation period

Answer 16

14 days

Question 17

measles complications

Answer 17

1. pneumonia
2. otitis media
3. acute encephalitis

death in 1/1000

complications more common in kids under 5, people over 20, and immunocompromised

giant cell pneumonia- sometimes pneumonia results w/o measles rash d/t suppression of cell mediated immunity

Question 18

measles treatment

Answer 18

none

treatment with vitamin A in developing countries has helped reduce mortality- death often occurs w/ measles and malnutrition

Question 19

does mumps or measles cause syncitia

Answer 19

measles

Question 20

describe what measles does to cell mediated immunity

Answer 20

suppresses it, causes anergy

Question 21

how many serotypes of measles are there?

Answer 21

1

Question 22

how many animals act as a resevoir for measles?

Answer 22

just humans

Question 23

describe measles immunization

Answer 23

live attenuated

given twice in MMR

life long protection

Question 24

“slow viruses”

Answer 24

1. long incubation period (years)
2. relentless course leading to death
3. genetic predisposition
4. re-emerge from latency b/c of immune suppression

examples: HIV, JC, BK neuropathy

Question 25

JC virus

Answer 25

papovavirus

causes progressive multifocal leukoencephalopathy (PML)

PML is a progressive demyelinating disease of the brain (affects oligodendroglia) w/o inflammation

occurs w/ immunosuppression

progression includes blindness, dementia, and death

Question 26

SSPE

Answer 26

subacute sclerosing panencephalitis

onset of intellectual deterioration, psychological disturbance, blindness and terminal paralysis

associated w/ measles-

• high Ab to measles
• CNS contains measle antigen

distinct inclusion bodies. relation to measles unclear. does occur after vaccination (one in a million)

Question 27

prion characteristics

Answer 27

1 long incubation period
2. slow relentless course to death
3 confined to CNS
4 produce spongiform encephalopathy
5.  genetic predisposition

Question 28

what are prions?

Answer 28

theorized to be infectious proteins w/o nucleic acid

Question 29

what are the 5 spongiform encephalopathies caused by prions?

Answer 29

KURU
CDJ Cretzfeld-Jacob disease
variant CDJ mad cow
GSS- gerstmann straussler scheinker syndrome
fatal familial insomnia

Question 30

scarpie

Answer 30

chronic progressive CNS disorder in adult sheep

genetic predisposition indicated

incubation period of less than a year

prion disease- no nucleic acids

Question 31

KURU

Answer 31

progressive degenerative disorder of the CNS, especially the cerebellum

limited to small tribe in new guniea

no environmental factors- partially genetic

could be transmitted to apes by eating the human brains

Question 32

CDJ

Answer 32

most common human prion

most are the result of a mutation, w/ obvious cause. risk increases w/ age

some reported cases were iatrogenic- caused by physicians using contaminated surgical equipment

some variants are linked to families fCDJ
some are sporadic sCDJ

Question 33

mad cow

Answer 33

variant CDJ

caused an epidemic in great britain as a result of using brains/bone marrow of cows to feed other cows, which became infected, and when consumed, infected other people