NR i503 i Epidemiology imidterm iExam
1. The ipopulation iof ia icity ion iFebruary i15, i2005, iwas i36,600. iThe icity ihas ia ipassive isurveillance
isystem ithat icollects ihospital iand iprivate iphysician ireports iof iinfluenza icases ievery imonth.
iDuring ithe iperiod ibetween iJanuary i1 iand iApril i1, i2005, i2,200 inew icases iof iinfluenza ioccurred iin
ithe icity. iOf ithese icases, i775 ipersons iwere iill iwith iinfluenza iaccording ito isurveillance ireports ion
iApril i1, i2005. iThe iprevalence irate iof iactive iinfluenza ias iof iApril i1, i2005, iwas:
Correct! i20 iper i1,000 ipopulation
2. The ipopulation iof ia icity ion iFebruary i15, i2005, iwas i36,600. iThe icity ihas ia ipassive isurveillance
isystem ithat icollects ihospital iand iprivate iphysician ireports iof iinfluenza icases ievery imonth.
iDuring ithe iperiod ibetween iJanuary i1 iand iApril i1, i2005, i2,200 inew icases iof iinfluenza ioccurred iin
ithe icity. iOf ithese icases, i775 ipersons iwere iill iwith iinfluenza iaccording ito isurveillance ireports ion
iApril i1, i2005. iThe imonthly iincidence irate iof iactive icases iof iinfluenza ifor ithe i3-month iperiod
iwas:
Correct! i 20 iper i1,000 ipopulation
3. What iwould ibe ithe ieffect ion iage-specific iincidence irates iof iuterine icancer iif iwomen iwith
ihysterectomies iwere iexcluded ifrom ithe idenominator iof iincidence icalculations iassuming ithat
imost iwomen iwho ihave ihad ihysterectomies iare iolder ithan i50 iyears iof iage?
Correct!: iRates iwould iincrease iin iwomen iolder ithan i50 iyears iof iage ibut imay idecrease iin
iyounger iwomen ias ithey iget iolder.
4. The iability iof ia isingle iperson ito iremain ifree iof iclinical iillness ifollowing iexposure ito ian iinfectious
iagent iis iknown ias:
Correct!: i Immunity
5. Which iof ithe ifollowing ireasons ican iexplain iwhy ia iperson iwho idid inot iconsume ithe iinfective
ifood iitem igot isick?
Correct: iAll iof ithe iabove
6. Which iof ithe ifood iitems i(or icombination iof iitems) iis imost ilikely ito ibe ithe iinfective iitem(s)?
Correct!: iIce icream ionly
7. The icase-fatality irate iassociated iwith iplague iis ilowest iin iwhich icommunity?
Correct iAnswer: iCommunity iC
i
8. The iincidence iand iprevalence irates iof ia ichronic ichildhood iillness ifor ia ispecific icommunity iare
igiven ibelow.
Correct iAnswer: iThe iduration iof idisease iis ibecoming ilonger.
, 9. The ifollowing itable igives ithe imean iannual iage-specific imortality irates ifrom imeasles iduring ithe
ifirst i25 iyears iof ilife iin isuccessive i5-year iperiods. iYou imay iassume ithat ithe ipopulation iis iin ia
isteady istate i(i.e., imigrations iout iare iequal ito imigrations iin).
Based ion ithe iinformation iabove, ione imay iconclude:
Correct iAnswer: i Children iages i5 ito i9 ihad ithe ihighest irate iof ideath iin iall iperiods
10. In ia icountry iwith ia ipopulation iof i16 imillion ipeople, i175,000 ideaths ioccurred iduring ithe iyear
iending iDecember i31, i2005. iThese iincluded i45,000 ideaths ifrom ituberculosis i(TB) iin i135,000
ipersons iwho iwere isick iwith iTB. iAssume ithat ithe ipopulation iremained iconstant ithroughout ithe
iyear. iNot iall i135,000 icases iof iTB iwere icontracted iduring i2005. iWhich iof ithe ifollowing
istatements iis itrue?
Correct iAnswer: iNone iof ithe iabove
11. In i2001, ia istate ienacted ia ilaw ithat irequired ithe iuse iof isafety iseats ifor iall ichildren iunder i7 iyearsiof
iage iand imandatory iseatbelt iuse ifor iall ipersons. iThe itable iabove ilists ithe inumber iof ideaths idue ito
imotor ivehicle iaccidents i(MVAs) iand ithe itotal ipopulation iby iage iin i2000 i(before ithe ilaw) iand iin
i2005 i(4 iyears iafter ithe ilaw iwas ienacted).
Correct iAnswer: i Correct, ibecause iboth ithe itotal iand ithe iage-adjusted imortality irates iare ihigheriin
i2005 ithan iin i2000
12. Which iof ithe ifollowing iis ian iadvantage iof iactive isurveillance?
Correct!: i More iaccurate idue ito ireduced ireporting iburden ifor ihealth icare iproviders
13. A idisease ihas ian iincidence iof i10 iper i1,000 ipersons iper iyear, iand i80% iof ithose iaffected iwill idie
iwithin i1 iyear. iPrior ito ithe iyear i2000, ionly i50% iof icases iof ithe idisease iwere idetected iby
iphysician idiagnosis iprior ito ideath. iIn ithe iyear i2000, ia ilab itest iwas ideveloped ithat iidentified i90%iof
icases ian iaverage iof i6 imonths iprior ito isymptom ionset; ihowever, ithe iprognosis idid inot iimprove
iafter idiagnosis. iWhich istatement iis itrue iconcerning ithe iduration iof ithe idisease iafter ithe
idevelopment iof ithe ilab itest?
Correct iAnswer: i Mean iduration iof ia icase iof ithe idisease iis ilonger iin i2000
14. What iis ithe ioverall iattack irate iin ipersons iwho idid inot ieat iice icream?
iCorrect!: i 33%
15. The itable iabove idescribes ithe inumber iof iillnesses iand ideaths icaused iby iplague iin ifour
icommunities. iThe iproportionate imortality iratio iassociated iwith iplague iis ilowest iin iwhich
icommunity?
Correct!: i Community iD
16. Which iof ithe ifollowing iis icharacteristic iof ia isingle-exposure, icommon-vehicle ioutbreak?
1. The ipopulation iof ia icity ion iFebruary i15, i2005, iwas i36,600. iThe icity ihas ia ipassive isurveillance
isystem ithat icollects ihospital iand iprivate iphysician ireports iof iinfluenza icases ievery imonth.
iDuring ithe iperiod ibetween iJanuary i1 iand iApril i1, i2005, i2,200 inew icases iof iinfluenza ioccurred iin
ithe icity. iOf ithese icases, i775 ipersons iwere iill iwith iinfluenza iaccording ito isurveillance ireports ion
iApril i1, i2005. iThe iprevalence irate iof iactive iinfluenza ias iof iApril i1, i2005, iwas:
Correct! i20 iper i1,000 ipopulation
2. The ipopulation iof ia icity ion iFebruary i15, i2005, iwas i36,600. iThe icity ihas ia ipassive isurveillance
isystem ithat icollects ihospital iand iprivate iphysician ireports iof iinfluenza icases ievery imonth.
iDuring ithe iperiod ibetween iJanuary i1 iand iApril i1, i2005, i2,200 inew icases iof iinfluenza ioccurred iin
ithe icity. iOf ithese icases, i775 ipersons iwere iill iwith iinfluenza iaccording ito isurveillance ireports ion
iApril i1, i2005. iThe imonthly iincidence irate iof iactive icases iof iinfluenza ifor ithe i3-month iperiod
iwas:
Correct! i 20 iper i1,000 ipopulation
3. What iwould ibe ithe ieffect ion iage-specific iincidence irates iof iuterine icancer iif iwomen iwith
ihysterectomies iwere iexcluded ifrom ithe idenominator iof iincidence icalculations iassuming ithat
imost iwomen iwho ihave ihad ihysterectomies iare iolder ithan i50 iyears iof iage?
Correct!: iRates iwould iincrease iin iwomen iolder ithan i50 iyears iof iage ibut imay idecrease iin
iyounger iwomen ias ithey iget iolder.
4. The iability iof ia isingle iperson ito iremain ifree iof iclinical iillness ifollowing iexposure ito ian iinfectious
iagent iis iknown ias:
Correct!: i Immunity
5. Which iof ithe ifollowing ireasons ican iexplain iwhy ia iperson iwho idid inot iconsume ithe iinfective
ifood iitem igot isick?
Correct: iAll iof ithe iabove
6. Which iof ithe ifood iitems i(or icombination iof iitems) iis imost ilikely ito ibe ithe iinfective iitem(s)?
Correct!: iIce icream ionly
7. The icase-fatality irate iassociated iwith iplague iis ilowest iin iwhich icommunity?
Correct iAnswer: iCommunity iC
i
8. The iincidence iand iprevalence irates iof ia ichronic ichildhood iillness ifor ia ispecific icommunity iare
igiven ibelow.
Correct iAnswer: iThe iduration iof idisease iis ibecoming ilonger.
, 9. The ifollowing itable igives ithe imean iannual iage-specific imortality irates ifrom imeasles iduring ithe
ifirst i25 iyears iof ilife iin isuccessive i5-year iperiods. iYou imay iassume ithat ithe ipopulation iis iin ia
isteady istate i(i.e., imigrations iout iare iequal ito imigrations iin).
Based ion ithe iinformation iabove, ione imay iconclude:
Correct iAnswer: i Children iages i5 ito i9 ihad ithe ihighest irate iof ideath iin iall iperiods
10. In ia icountry iwith ia ipopulation iof i16 imillion ipeople, i175,000 ideaths ioccurred iduring ithe iyear
iending iDecember i31, i2005. iThese iincluded i45,000 ideaths ifrom ituberculosis i(TB) iin i135,000
ipersons iwho iwere isick iwith iTB. iAssume ithat ithe ipopulation iremained iconstant ithroughout ithe
iyear. iNot iall i135,000 icases iof iTB iwere icontracted iduring i2005. iWhich iof ithe ifollowing
istatements iis itrue?
Correct iAnswer: iNone iof ithe iabove
11. In i2001, ia istate ienacted ia ilaw ithat irequired ithe iuse iof isafety iseats ifor iall ichildren iunder i7 iyearsiof
iage iand imandatory iseatbelt iuse ifor iall ipersons. iThe itable iabove ilists ithe inumber iof ideaths idue ito
imotor ivehicle iaccidents i(MVAs) iand ithe itotal ipopulation iby iage iin i2000 i(before ithe ilaw) iand iin
i2005 i(4 iyears iafter ithe ilaw iwas ienacted).
Correct iAnswer: i Correct, ibecause iboth ithe itotal iand ithe iage-adjusted imortality irates iare ihigheriin
i2005 ithan iin i2000
12. Which iof ithe ifollowing iis ian iadvantage iof iactive isurveillance?
Correct!: i More iaccurate idue ito ireduced ireporting iburden ifor ihealth icare iproviders
13. A idisease ihas ian iincidence iof i10 iper i1,000 ipersons iper iyear, iand i80% iof ithose iaffected iwill idie
iwithin i1 iyear. iPrior ito ithe iyear i2000, ionly i50% iof icases iof ithe idisease iwere idetected iby
iphysician idiagnosis iprior ito ideath. iIn ithe iyear i2000, ia ilab itest iwas ideveloped ithat iidentified i90%iof
icases ian iaverage iof i6 imonths iprior ito isymptom ionset; ihowever, ithe iprognosis idid inot iimprove
iafter idiagnosis. iWhich istatement iis itrue iconcerning ithe iduration iof ithe idisease iafter ithe
idevelopment iof ithe ilab itest?
Correct iAnswer: i Mean iduration iof ia icase iof ithe idisease iis ilonger iin i2000
14. What iis ithe ioverall iattack irate iin ipersons iwho idid inot ieat iice icream?
iCorrect!: i 33%
15. The itable iabove idescribes ithe inumber iof iillnesses iand ideaths icaused iby iplague iin ifour
icommunities. iThe iproportionate imortality iratio iassociated iwith iplague iis ilowest iin iwhich
icommunity?
Correct!: i Community iD
16. Which iof ithe ifollowing iis icharacteristic iof ia isingle-exposure, icommon-vehicle ioutbreak?
