10/18/23,n11:06nPM NRn503nWeekn8nFinalnExamnStudentnConsultnQuestionsnwithnRationale-
nL…
NR 503 Final exam Question And Answers
n n n n n n
(Completen solutionsn andn resourcesn forn then coursen exam)
Chaptersn2-4
1. Whichnofnthenfollowingnisnanconditionnwhichnmaynoccurnduringnthenincuba
tionnperiod?
a. Onsetnofnclinicalnillness
b. Receiptnofninfection
c. Signsn&nsymptomsnofndisease
d. Transmissionnofninfection
e. Isolationn ofn diseasen carriern throughn quarantine
Rationale:n Thenincubationnperiodnisndefinednasnthenintervalnfromnreceiptnofnin
fectionntonthentimenofnonsetnofnclinicalnillness.nAccordingly,nindividualsnmayntr
ansmitninfectiousnagentsnduringnthenincubationnperiodnasntheynshownnonsignsn
ofndiseasenthatnwouldnenablenthenisolationnofnsicknindividualsnbynquarantine.
2. Chickennpoxnisnanhighlyncommunicablendisease.nItnmaynbentransmittednbyndi
rectncontactnwithnanpersonninfectednwithnthenvaricella-
zosternvirusn(VZV). nThentypicalnincubationntimenisnbetweenn10nton20ndays.n
Anboynstartednschooln2nweeksnafternshowingnsymptomsnofnchickennpoxninclu
dingnmildnfever,nskinnrash,n&nfluid-
fillednblisters.nOnenmonthnafternthenboynreturnedntonschool,nnonenofnhisnclass
matesnhadnbeenninfectednbynVZV.nThenmainnreasonnwas:
a. Herdnimmunity
b. Allnhadnbeennimmunizednpriorntonthenschoolnyear
c. Contactnwasnafterninfectiousnperiod
d. Subclinicalninfectionsnwerennotnyetndetected
e. Diseasenwasnendemicninnthenclass
Rationale:nThendiseasenisnspreadnbyncontactnwithnanninfectednindividualnwhonc
anntransmitnthenagentn(VZV)ntonimmunologicallynnaivenpersonsnduringntheninc
ubationnperiodn&nfornseveralndaysnafternonsetnofnclinicalnillness.nSincenthenbo
ynstartednschooln14ndaysnafternshowingnsignsnconsistentnwithnchickennpox,nitn
isnmostnlikelynthatnhenwasnnonlongerninfectious.
3. Whichnofnthenfollowingnisncharacteristicnofnansingle-exposure,ncommon-
vehiclenoutbreak?
a. Longnlatencynperiodnbeforenmanynillnessesndevelop
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nL…
b. Therenisnannexponentialnincreaseninnsecondaryncasesnfollowingninitialnexposures
c. Casesnincludenonlynthosenwhonhavenbeennexposedntonsicknpersons
d. Thenepidemicncurvenhasnannormalndistributionnwhennplottednagainstnthenlogarith
mnofn time
e. Widenrangeninnincubationntimesnfornsicknindividuals
Rationale:nSingle-exposure,ncommon-
vehiclenoutbreaksninvolvenansudden,nrapidnincreaseninncasesnofndiseasenthatna
renlimitedntonpersonsnwhonsharenancommonnexposure.nAdditionally,nfewnsecon
daryncasesndevelopnamongnpersonsnexposedntonprimaryncases.nAnhistogramnof
nthenoutbreakncannplotnthennumbernofncasesnbyntimenofndiseasenonset.nInnsin
gle-exposure,ncommon-
vehiclenoutbreaks,nanlogntransformationnofnthentimenofndiseasenonsetnwillnofte
nntakenonnthencharacteristicnshape nofnannormalndistributionn(i.e.,nanbellncurve
)nwithnthenmediannincubationntimenfoundnatnthenpeaknofnthencurve.
4. Whatnisnthendiarrheanattacknrateninnpersonsnwhonatenbothnicencreamn&npizza?
a. 39/52
b. 21/70
c. 39/67
d. 51/67
e. Nonenofn then above
Rationale:
Thenattacknrateninnthisnexamplenisndefinednasnthennumbernofnpersonsnwhonde
velopndiarrheandividednbynthentotalnnumbernofnpeoplenatnrisk.nInnthisnexample,
nthenat-
riskngroupnisnthosenwhonhaveneatennbothnicencreamn&npizza.nOfnthesen52nper
sons,n39ndevelopedndiarrhea.
5. Whatnisnthenoverallnattacknrateninnpersonsnwhondidnnotneatnicencream?
a. 30%
b. 33%
c. 35%
d. 44%
e. 58%
Rationale:
Thenattacknratenisnthennumbernofnpersonsnwithndiarrhean(14n+n9)ndividednbynt
hentotalnnumbernofnpersonsnwhondidnnotneatnicencreamn(40n+n30).
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6. Whichnofnthenfoodnitemsn(orncombinationnofnitems)nisnmostnlikelyntonb
entheninfectivenitem(s)?
a. Pizzan only
b. Icencreamnonly
c. Neithern pizzan orn icen cream
d. Bothn pizzan &n icecream
e. Cannotn ben assumedn fromn then datan shown
Amongnpersonsneatingnicencream,novern70%ndevelopedndiarrheanregardlessnof
ntheirnpizzanconsumptionn(39/52n&n11/15).nAmongnbothngroupsnofnpersons nwho
ndidnnotneatnicencream,neachnattacknratenwasnequalntonornlessnthann35%n(14/
40n&n9/30).
7. Whichnofnthenfollowingnreasonsncannexplainnwhynanpersonnwhondidnnotncons
umentheninfectivenfoodnitemngotnsick?
a. Theynwerendirectlynexposedntonpersonsnwhondidneatntheninfectivenfoodnitem
b. Diarrheanisnangeneralnsymptomnconsistentnwithnannumbernofnillnesses
c. Therenmaynhavenbeennanninaccuratenrecallnofnwhichnfoodsnwereneaten
d. Allnofnthenabove
e. Nonenofnthenabove
Rationale:nWithoutnknowledgenasntonthenspecificnagentninnthisninstance,nitnisna
lsonlikelynthatnitncannbenspreadnby ndirectncontactnwithninfectednpersons.nSince
ndiarrheanisnangeneral ndiseasensymptom,nitnisnpossiblenthatnseveralninfectious
nagentsnmaynbenpresentnatnthisnmealnornothersneatennduringnthensamentimen
period.nFurther,ninformationnregardingnfoodnconsumptionnmaynhavenbeenncoll
ectednlongnafternthendiseasenepisode.nThisnmaynhavenlednpersonsntonincorrect
lynremembernthenfoodsnthatntheynconsumed.
Annoutbreaknofngastroenteritis noccurrednatnanboardingnschoolnwithnanstudentnenroll
mentnofn846.nFifty-
sevennstudentsnreportednsymptomsnincludingnvomiting,ndiarrhea,nnausea,n&nlow-
gradenfevernbetweenn10np.m.nonnSeptembern24n&n8np.m.nonnSeptembern25.nThenil
lnstudentsnlivedninndormitories nthatnhousedn723nofnthenstudents.nThentablenbelownpr
ovidesninformationnonnthennumbernofnstudentsnperntypenofnresidencen&nthennumbe
rnreportingnillnessesnconsistentnwithnthendescribednsymptomsn&nonsetntime.nCalcula
tenthenattacknratenamongnallnstudentsnatnthenboardingnschool.
1.n Calculatenthenattacknratenamongnallnstudentsnatnthenboardingnschool.
57/846n=nThenanswernisnfoundnbyndividingnthentotalnnumbernofncasesn(57)nbynth
entotalnnumbernofnstudentsn(846).nThisnequalsn6.7%.
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nL…
NR 503 Final exam Question And Answers
n n n n n n
(Completen solutionsn andn resourcesn forn then coursen exam)
Chaptersn2-4
1. Whichnofnthenfollowingnisnanconditionnwhichnmaynoccurnduringnthenincuba
tionnperiod?
a. Onsetnofnclinicalnillness
b. Receiptnofninfection
c. Signsn&nsymptomsnofndisease
d. Transmissionnofninfection
e. Isolationn ofn diseasen carriern throughn quarantine
Rationale:n Thenincubationnperiodnisndefinednasnthenintervalnfromnreceiptnofnin
fectionntonthentimenofnonsetnofnclinicalnillness.nAccordingly,nindividualsnmayntr
ansmitninfectiousnagentsnduringnthenincubationnperiodnasntheynshownnonsignsn
ofndiseasenthatnwouldnenablenthenisolationnofnsicknindividualsnbynquarantine.
2. Chickennpoxnisnanhighlyncommunicablendisease.nItnmaynbentransmittednbyndi
rectncontactnwithnanpersonninfectednwithnthenvaricella-
zosternvirusn(VZV). nThentypicalnincubationntimenisnbetweenn10nton20ndays.n
Anboynstartednschooln2nweeksnafternshowingnsymptomsnofnchickennpoxninclu
dingnmildnfever,nskinnrash,n&nfluid-
fillednblisters.nOnenmonthnafternthenboynreturnedntonschool,nnonenofnhisnclass
matesnhadnbeenninfectednbynVZV.nThenmainnreasonnwas:
a. Herdnimmunity
b. Allnhadnbeennimmunizednpriorntonthenschoolnyear
c. Contactnwasnafterninfectiousnperiod
d. Subclinicalninfectionsnwerennotnyetndetected
e. Diseasenwasnendemicninnthenclass
Rationale:nThendiseasenisnspreadnbyncontactnwithnanninfectednindividualnwhonc
anntransmitnthenagentn(VZV)ntonimmunologicallynnaivenpersonsnduringntheninc
ubationnperiodn&nfornseveralndaysnafternonsetnofnclinicalnillness.nSincenthenbo
ynstartednschooln14ndaysnafternshowingnsignsnconsistentnwithnchickennpox,nitn
isnmostnlikelynthatnhenwasnnonlongerninfectious.
3. Whichnofnthenfollowingnisncharacteristicnofnansingle-exposure,ncommon-
vehiclenoutbreak?
a. Longnlatencynperiodnbeforenmanynillnessesndevelop
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,10/18/23,n11:06nPM NRn503nWeekn8nFinalnExamnStudentnConsultnQuestionsnwithnRationale-
nL…
b. Therenisnannexponentialnincreaseninnsecondaryncasesnfollowingninitialnexposures
c. Casesnincludenonlynthosenwhonhavenbeennexposedntonsicknpersons
d. Thenepidemicncurvenhasnannormalndistributionnwhennplottednagainstnthenlogarith
mnofn time
e. Widenrangeninnincubationntimesnfornsicknindividuals
Rationale:nSingle-exposure,ncommon-
vehiclenoutbreaksninvolvenansudden,nrapidnincreaseninncasesnofndiseasenthatna
renlimitedntonpersonsnwhonsharenancommonnexposure.nAdditionally,nfewnsecon
daryncasesndevelopnamongnpersonsnexposedntonprimaryncases.nAnhistogramnof
nthenoutbreakncannplotnthennumbernofncasesnbyntimenofndiseasenonset.nInnsin
gle-exposure,ncommon-
vehiclenoutbreaks,nanlogntransformationnofnthentimenofndiseasenonsetnwillnofte
nntakenonnthencharacteristicnshape nofnannormalndistributionn(i.e.,nanbellncurve
)nwithnthenmediannincubationntimenfoundnatnthenpeaknofnthencurve.
4. Whatnisnthendiarrheanattacknrateninnpersonsnwhonatenbothnicencreamn&npizza?
a. 39/52
b. 21/70
c. 39/67
d. 51/67
e. Nonenofn then above
Rationale:
Thenattacknrateninnthisnexamplenisndefinednasnthennumbernofnpersonsnwhonde
velopndiarrheandividednbynthentotalnnumbernofnpeoplenatnrisk.nInnthisnexample,
nthenat-
riskngroupnisnthosenwhonhaveneatennbothnicencreamn&npizza.nOfnthesen52nper
sons,n39ndevelopedndiarrhea.
5. Whatnisnthenoverallnattacknrateninnpersonsnwhondidnnotneatnicencream?
a. 30%
b. 33%
c. 35%
d. 44%
e. 58%
Rationale:
Thenattacknratenisnthennumbernofnpersonsnwithndiarrhean(14n+n9)ndividednbynt
hentotalnnumbernofnpersonsnwhondidnnotneatnicencreamn(40n+n30).
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nL…
6. Whichnofnthenfoodnitemsn(orncombinationnofnitems)nisnmostnlikelyntonb
entheninfectivenitem(s)?
a. Pizzan only
b. Icencreamnonly
c. Neithern pizzan orn icen cream
d. Bothn pizzan &n icecream
e. Cannotn ben assumedn fromn then datan shown
Amongnpersonsneatingnicencream,novern70%ndevelopedndiarrheanregardlessnof
ntheirnpizzanconsumptionn(39/52n&n11/15).nAmongnbothngroupsnofnpersons nwho
ndidnnotneatnicencream,neachnattacknratenwasnequalntonornlessnthann35%n(14/
40n&n9/30).
7. Whichnofnthenfollowingnreasonsncannexplainnwhynanpersonnwhondidnnotncons
umentheninfectivenfoodnitemngotnsick?
a. Theynwerendirectlynexposedntonpersonsnwhondidneatntheninfectivenfoodnitem
b. Diarrheanisnangeneralnsymptomnconsistentnwithnannumbernofnillnesses
c. Therenmaynhavenbeennanninaccuratenrecallnofnwhichnfoodsnwereneaten
d. Allnofnthenabove
e. Nonenofnthenabove
Rationale:nWithoutnknowledgenasntonthenspecificnagentninnthisninstance,nitnisna
lsonlikelynthatnitncannbenspreadnby ndirectncontactnwithninfectednpersons.nSince
ndiarrheanisnangeneral ndiseasensymptom,nitnisnpossiblenthatnseveralninfectious
nagentsnmaynbenpresentnatnthisnmealnornothersneatennduringnthensamentimen
period.nFurther,ninformationnregardingnfoodnconsumptionnmaynhavenbeenncoll
ectednlongnafternthendiseasenepisode.nThisnmaynhavenlednpersonsntonincorrect
lynremembernthenfoodsnthatntheynconsumed.
Annoutbreaknofngastroenteritis noccurrednatnanboardingnschoolnwithnanstudentnenroll
mentnofn846.nFifty-
sevennstudentsnreportednsymptomsnincludingnvomiting,ndiarrhea,nnausea,n&nlow-
gradenfevernbetweenn10np.m.nonnSeptembern24n&n8np.m.nonnSeptembern25.nThenil
lnstudentsnlivedninndormitories nthatnhousedn723nofnthenstudents.nThentablenbelownpr
ovidesninformationnonnthennumbernofnstudentsnperntypenofnresidencen&nthennumbe
rnreportingnillnessesnconsistentnwithnthendescribednsymptomsn&nonsetntime.nCalcula
tenthenattacknratenamongnallnstudentsnatnthenboardingnschool.
1.n Calculatenthenattacknratenamongnallnstudentsnatnthenboardingnschool.
57/846n=nThenanswernisnfoundnbyndividingnthentotalnnumbernofncasesn(57)nbynth
entotalnnumbernofnstudentsn(846).nThisnequalsn6.7%.
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