(Answered)-Are pieces of information missing that leave the investigation - (2025 Updated Original AI-Free Solution

Question

??????????? Are pieces of information missing that leave the investigation incomplete? What are the missing pieces of information or gaps in the investigation?

E8Z
'(7961 :duedruo3 pue {rrat\ :{1q'Lulrqeg
,u Mo{Jag) uaSoqred ?Ileuoules Ploqd& Oq1 Jo sa]Jnos
'pa ID?I .ptlualN ryJatrN aqJ.Pa
.pooc .slse] la^II pue .s1ods asot .sa:n11nl
.lale^\
^{oJIeuI
uoululo) ale PooJ?as p.,n '11,*
slsal 'sJalrJef Jo loJluol pue 'uor1:a1ord
sE 'sornllnl Iools pue poolq opnllul
euoq se
IIa.\\
;ra1em
Sur4utrP Jo uoll?luilnd '(q sI uollual
pooJ pue uollellues ',ffr* l" t'ou"""-"rtnd
.sdorr ur slods pa;oiol-asor
.tsaqr
uo oSraura
P-ue uauoPqe
-aJd .SInfJo l.pSauroualds pue
oseaslP oql sV 'uorltdrlsuor pue 'aln1r:;adua1
Papunor elajfslP 'ntp'n''Lpn'q ""t"8o'd
pale^elo/Ja^aJ.saqfeel]snul.?IxaJouP.eq]?peaq.asIeIPLu.sIIII'{f.}asuo^\olseaPnifulsulo}

-du.{5.(s,{ep 97.ot?.)urua{?}surslue8-ro;oslaqulnuaq}o}salElerpoFadLlol}eqnlulaql
aql s;alua utstueSro
pt'n
'ruals,(s qdurdl pue ulearls pooiq eql sape^ul

""'lzuIlsrlulorlscs
oq^\ s}uet}ed III Jo aulrn lo loo}s eql
alilf? ur: eleq
or{J 'afJnos e osle sI eseaslp aq} Jo aser
qrpaq rqqnd or patrodar aq ]snul ltel
'poo;8ur1pueq urorJ parrqiqord are pue sluaulredap
.rrrrrrn, rruorqf auJoleq sluollud;o oTog s} oTol lnoQV'sJaIlJef lilPulol
dq s.raure: ]uolsrsrad

.sornPold

a]Jnos OqI
-dudse ;o saca; aql dlensn sI uol}feJui Jo
:,uasoqted sauroroq Pue suollraJul eilauourlesJo 'pttllqttot
sass?l)

1t

sutxolopua aq} Jo esne]aq

tqrl:^'r".::ii'rltJll#tr,
",

ur lq8ne1 uaeq seq 'uo1ey1
lelros pue -Aolslq

'fue1n1

'd'ro1srq3o sa8ed

Palelar-salpnls
.rarrref ploqd& fruorqt e se,{\ aqs l?ql Pa.4\oqs srreJ leq Jo
eql ur {retu laq apelu e.rr,on11
lt'r*tpra"proqd'fi aqlJo e)rnos aql se paulluapr '{ipug uaq11
uorleuiurexa lnrtaolorrJonq
proqd'b leralas pu? sqleep ^{ueu pasner 'le)irom
'sgg61 dpea eq] ur
'\\eN uI s>learq}no

arr^Ias pooJ e

{ro1
'"qrrlt';;;;'"l''n1'n'Ploqddr dQ'snotueJraP;#r:il"fi3rlrt?,ugru r.,t

-uostodpooJJosasnerBuilnqtrluolro(euroreuotle;edo'rdpoo;ulsaJnseaur'fuelruespoo8

d'relruus
'pooJ btt'lpttnq aio;aq Surqse'\\ pueq sP sarnseaul
pue uoltlalora pool 1o 4'nl aql
.u-ra}s,(s
a,rr1sa81p eql Jo suol})aJul
eJe SaseaslP qx5
q]ns Jo I]3I e Jo ,,,',,,q pn,,d. uauo
proqddl
orin '"tolttoLules pue '{Elaloql 'ra'ta;
ale ,sas'asrp aSreqtsrp auI I? SE o] poJIaJaJ
Luaprdl

L f iSolor
'ou rpleula8 ue5',{lrstanr u 1 a}e}S e uloJl le ) .'
-866
ut sarpnlS
aslnol 'NB ullB pue 'y ieLqv-I1 Aq "lsopnuaprdE
y :'(pe1:auaq'5 u' p'oqtl'tl" Luort paldepe pue patdrarxl
I

snqe11L5
1o saldr:u116 "ro1

asrJ ,,'Iealqlno auloqpool

[pottauaLps u! ra^al Ploqd{1
)nuaq I dg s sa ulll
: u o!ru&Usa
^uI
auroq-poot a q3nor141 &ur4'tolw

II
ACNIS

'CSV3

284

CASE STUDY

ll /

Working through a Food-borne lllness Epidemic lnvestigation

CASE OF TYPHOID FEVER
In

IN SCHENECTADY, NEW YORK

1939, Schenectady was a city of approximately 90,000 people. On June 20th of this same

year, the Public Health Department's Health Officer received reports of five cases of typhoid fever within the city. The Health Officer also received a report of one case of typhoid
fever in a person who lived about 100 miles away in Massachusetts. The person had visited
Schenectady in recent weeks preceding. No cases of tlphoid had been reported for the past
year up to that date in the city. In the preceding 5 years, the average annual prevalence of
typhoid had been two cases per year.
Schenectady's water supply was obtained from surface water. A stream with drainage
from relatively uninhabited areas was the main water source. About 8 years before the typhoid outbreak, a modern rapid sand filtration water treatment plant was installed and
competently operated by a sanitary engineer. The water supply for the city was chlorinated.
Daily bacteriological analyses of water from six points in the water distribution system were
conducted and reported to the Health Officer. Schenectady had a modern sewer system.
Within the city, 95o/o to 980/o of the houses were connected to the sewer system, which was
a good record for 1939.
City ordinances prohibited the sale of unpasteurized milk or the sale of milk other than
by certified dairies. Approximately 75o/o of the city's milk was supplied by two large dairies.
One other dairy distributed about 300 quarts of pasteurized milk daily. Consumers, using
their own containers, purchased a small but unknown amount of unpasteurized milk from
nearby farmers. About 950lo of all ice cream was supplied by two large manufacturers. They
also supplied ice cream to nearby cities. All shellfish dealers were required to be licensed by
the local health department. Shellfish dealers were also required to keep records of the receipt and distribution of all shellfish stock handled.
Typhoid carriers were required to be registered with the public health department.
Twenty-one carriers were known and tracked by the health department. A survey of the
city's hospitals and all physicians showed a total of 13 known or suspected cases of qphoid,
which included the one reported from Massachusetts. From interviewing each case in their
homes, epidemiologic data were collected. With the use of a spot map, it was observed that
there was no geographical clustering ofcases.
From the interviews and epidemiologic investigations with the 13 cases, a table of the
information was compiled and tabulated and is presented in Table II.1. The epidemiologic
interview gathered usual information from each case as found in almost any survey: name'
age, sex, and occupation. For this particular epidemic, as in most food-borne outbreaks, certain specific data must be gathered, and this outbreak included date of onset, sewage, water
supply, dairy products eaten, uncooked foods eaten, trips, and foods taken away from home.
After studying Table II.1, answer the following questions.

Case Study Questions
What key activities and important facts tie each of the individual cases together?
Prepare a bar graph chart showing the dates and numbers ofcases per day ofthe outbreak
by date of onset for each tlphoid case. Is this an epidemic curve? Why? Defend your answer.
3.

and epidemiologic data, can you estimate possible date of common exposure
(present evidence and facts other than just the date)?

From the

case

S {=?

J

?4

o

r

d

u

?F
E
+#
E
i%?
d
s
e
3
E
A5
+
E:48
s
d
r-5
":doiaiot:it^:oodi

8g;'Yp
=;;tsi
6s
-

o
5-

-=

=.

=

F

aL

l

il g
i
0r Q

=
[
+
0

(J

w

o

=

;

a
o

(t)

c

o

=

6-

AUTSA
L!OA

NJ

Qr

A

Lrr

gl

U]

=

oa

|!

o

T<-nT<

U
o

=..:a={o
=:cj??:A9inoooc

i ? f ???

t

?E? eg
ajo-o-+"6'd'd'o-'

n
o

q

0J

=

o

o
OJ

o
o

AJ5
Fq
,e
6
(a

-l

-o
o

qo

g<
s< ?-5?oto

a c
u?;?!!
;-6 =: < < =!a? ? ?
-o)
Z-o

11
c!'r*
q^
or 11
: F
o o
A'o io QF
ey !.3

uF
rg

@F UO
o t=
p.a

A -

X

a
Ee
o
e o *e a AtgE
: ;e?;o,
= ^
=:_iEi3
tF
oJ o.i

O-

ii

--

--

-f J-

;.;3J;?"i -ui

O

-

T j

;id

O -

?

=
9-

?

(a
AJ

-71

t!

o

@U

+v
;t
;-< $*'

4 a

O

b

P

9#19I
63866
o-f
o
6

zz* oxoxqR-fo:<<o
I-adgdPdEd:P a;dqd<
g,;
u 9 ri c-:
==6- @
o
6E-i
6
@
r
-*:g;:

T-g
o.x
>ii
Nr

= 6 6
6

ZZo
o
f
:5
-a

6

Z
o
-

d

Z
o
-

d

bj
o-^

<Kr
;fn

;;;?FF+{

o+=
=.dO
gr
6
-<
a
o i'

o
o o a - ==
i6
=.=.=.;=.=.y=
qn ur Lrr an
!" !n 5 5
D.D
o o o 9;>0+
o f=1

E.H;
-'o 6'+g e
6 6 - !EE.3e=id

gBZ )ro1

-

a't q
tA.tA.tS;lEea.3_; ; ix8
X:

ZZZ
o o
o
f
J

)
tJ1

c)

o
=
o
o
o_

g>
.-0J

tu

>g
--7el| u

; l-{
Y<.
u=
s!
_(i

f,

u1
+

a
-a

Z
o

;

Lr

;o

oS
ur o
;f
-i

,l,raN ',(pepauaqc5 ur ra^al proqd,(1 Jo asel

:.
A
q
;-

:.:=
6'+-

ur

*.

.

Fi

i?fi;e{
i Fd i i9=l;,5
!a ==
ro =
b
e o o\n ; e3
r.r.r
l.
o'

F

o
a.

S

f

o

{K
$+
\O;

o

AJ

qq-o

zAazz

o-

ibs
o'.t+

ur er

;o _o
;; o

o

E_

=h>

S3
dQ

oo
FJ

x-

286

Il

CASE STUDY

/

Working through a Food-borne lllness Epidemic lnvestigation

4.

Several unrelated cases appeared in the investigation. Explain the exposure to typhoid and
implications of the unrelated cases of tlphoid and give several examples or possibilities.

5.

Briefly outline additional steps that are needed

in order to

complete this particular

investigation.

The Schenectady Methodist Episcopal Church held a Memorial Day celebration at the
church, which included a buffet picnic supper. On the afternoon of May 30th, the annual
Memorial Service was held at the Methodist cemetery in Schenectady and was followed by
a late afternoon picnic supper. A potluck approach was used to furnish the food and was
provided by a number of the participants. Supper was served to 33 of the persons who attended the service.

An epidemiologic investigation was held at the Schenectady Methodist Episcopal church. In
the investigation, inquiries were made of persons attending the picnic. All persons who attended the supper were interviewed. Interviewers recorded as accurately as possible all the
foods consumed by each individual. Information about any previous history of typhoid or
anypossible symptoms was recorded, as well as information concerning the preparation and
serving of foods. Food samples were not available as all food had either been eaten or discarded. An attempt was made to obtain fecal specimens from all individuals who were at the
picnic. A series of three specimens was acquired from all persons who prepared and provided food for the picnic.

No previous history of any typhoid illness was confirmed in any

case. Laboratory studies,
mostly consisting of stool cultures that came out positive, confirmed the clinical diagnosis
of qphoid fever in all 13 cases. Additionally, the following laboratory data were obtained for
persons who attended the picnic but showed no evidence of the tlphoid disease.

.

Irene Picket = positive stools on |uly 4, fuly 5, and |uly 6 and negative stools onluly 23
and August 2.

.
.

Margaret Bennett = 1l consecutive positive stools, fuly 2 through October 4'
Kenneth Rineheardt = positive stools fuly 4 and ]uly 3 and negative stools at

a

later date.

6.

Of the three persons-Pickett, Bennett, and Rineheardt-who was most likely to have been
infected during the church picnic outbreak? Who was most likely to have been infected before the picnic?

7.

Which laboratory tests might be administered nowadays that were not generally available
in medical diagnostic books might be needed to answer this
question.) How would these tests help the church picnic investigation?

in

1939? (Some outside research

Table II.2, which is a checklist of the foods eaten at the Methodist church picnic. Included in the table are the names of the 35 persons/cases involved in the outbreak. The table
provides information on whether a person was a case or not a case, and the different foods
each consumed, with a key at the bottom about each person's eating of different foodstuffs
and the ability to recall the foods each had eaten. See Table II.2 and use the worksheet for
food-specific attack rates, Table II.3.
See

8.

Compute the attack rates for those eating and for those not eating each food and the unknowns. Calculate a relative risk for each food. Include data for all 35 individuals (include
the use offood-specific attack rates).

Name
S. Christian
S. Blair
M, Dencher
F. Howard
T. Jones
E. Ostrander
W Thurber
R. Kmiecziak
D. Wagner
G. Wagoner
R. Wagoner
A. Woods
E. Vogel
G. Harmon
J. Stoddard
J. Pickett
J. Bennett
C. Carrol
G. Anderson
N. Brothers
E. Conrad
E. Gray
G. Harrington
S. McAuliffe
E. Pickett
J. Salisburgh
L. Smith
M. Bennett
E. Thurber
K. Rhinehardt
A. Wagoner
H. Wagoner
B. Alexander
C. Scofield
M. Harrison

Case Potato Salad Macaroni Salad Cabbage Salad Summer Sausage Spiced Ham Baked Beans Rolls
Cakes Coffee Pickles
Y
1
1
2
2
2
2
1
2
1
1
Y
3
3
2
2
2
2
1
2
1
1
Y
1
2
2
2
1
2,4
1,4
1
2
2
Y
1
1
2
2
2
2
2,4
1,4
2
2
Y
1
3
2
1
2
1
1
1
2
2,4
Y
2
1
2
2
2
2
1
2
1
2
Y
1
2
2
2
2
2
2
2
2
2
Y
1
1
2
1
2
1
1
1
1
1
Y
1
1
1
2
1
2
1
1
1
2
Y
3
1
3
1
1
2
1
1,4
1
2
Y
1
1
1
2
1
1
1
1
1
1
Y
1
1
2
1,6
2,6
2,6
1,4
1
1
3
Y
1
1
3
1
1
1
1
1
1
2
N
1
2
2
2
2
1
1
2
1
2
N
1
1
1
2
8
8
8
8
1
1
N
1
1
1
2
2
1
1
1
1
1
N
1
1
1
1
2
1
1
1
1
1
N
1
2
1
1
2
1
1
2
1
1
N
1
2
2
2
2
2
2
2
2
2
N
1
2
2
2
1
2
1
1
1
2
N
1
2
1
2
1
2
1
1
1
2
N
1
2
2
2
2
1
1
2
1
2
N
2
2
2
2
2
1
1
2
1
2
N
1
2
2
2
2
2
2
2
1
2
N
1,4
2
2
1
2
2
1
1,4
1
1
N
2
2
2
2
2
1
1
1
1
2
N
1
3
3,4
2
2
1
1
2
1
1
N
1,4
2,4
2
2
2
2
2
1
2
2
N
2,4
2
2
2
2
2
1
2
2
2
N
1
1
1
2
2
1
1
2
1
2
N
1
1
1
2
1
1
1
1
2
2
N
1
1
2
1
2
1
1
1
1
2
N
Unavail.
Unavail.
Unavail.
Unavail.
Unavail.
Unavail. Unavail. Unavail. Unavail. Unavail.
N
Unavail.
Unavail.
Unavail.
Unavail.
Unavail.
Unavail. Unavail. Unavail. Unavail. Unavail.
N
1
3
2
2
2
1
1
1
1
2

1.Recalled Having Eaten Food 2.Recalled having NOT eaten food 3. Could not remember 4. Brought or prepared food indicated

5. Ate food brought home by Mrs. Thurber 6. Foods store bought 7. Not located 8. Gave contradictory responses regarding the food

'vr

;uor1r:8rlse,r.ur eql ur sdrS:o uorluurlo;rrrJo sorard Surssrru
aq] are 1eq7q ;alalduotur uotlt8tlsa^ul aq] e^eel leq] Suissrur uorleurJoJur 3o satord a-ry

'9I

;.ruo srq] slr rifns
(tsr8olorLuepida ur sv
slruaprde ra^al proqd-{} arntnJ lo"r}uol pup }ue^ard no,'( plno^\
^\og
'uosrad pue ,aleld ,aLuil epnpur :slo]tpJ Surlroddns Jeqio pue sJJnts
-pooJ aql pue suos:ad ipnpr^rpur rqt inoqp :goads og ;:ruraprda srlll roJ uorlruuldxa a1q
-eqord pue L1a>il1 lsow aq] sr lpr{^\'aruopr^e pue ,uorli:ru.roJr.rr .rlpp erllJo ilp Surreprsuo3

;,{;essa:eu a.re sBuipug IertpaLuor(l/ll+rtuans

pue:rSolonuaprda 1eq.'lr'uoissltusuerl eseasrpJo Jrrnos

e se pooJ

relntrl;ud

e

eleuiuutur

oJ_

'9r

'?I

jspooJ relnlrlrud 3urlra

lott suos:ad Suorur: {slr a^IlPIJt pup

sa}pJ

lrel}p }noqe per.rJatlrof lstSolorureprda

ue sr,(qr14

,ZT

2UalPJ O-rJ]\\

stuJlr PooJ eql lou to JJrllrrl^\ lnoqe sasuodsa,r.fuolrrpe-rluor a,re8 oLI^\ lo rrJlea pooJ p
-er louuel lenpilrpur ue qJrql\ ur seluelsLunfrr) qlri\ leap lsr8oloruraprda ur plnoqs

IIrl

.I

^\oH

I

'tradsns aq o1 ,(1ay1 lou erc .(e ql .,(q.u uirldxg .eseasrp
eql 8ul]lltusuertJo alqeqord Suiaq tou roJ srseq lurluor)s aqlJo asnpreq pooqilolrl unur
-rurLu elpri tnq oseasrp Jo uorss(usuerl alil ur Isrr q31q
1o aq o1 .readde ]erlt spo(u Jo ]srJ .

.

eql

.

I

'pooJ JrllJo uorlpurlueluof ssEru-Jo espa aq

Isrr e^rlPler

'pooJ arlr urlea o^eq pporls sestl
Jo l1r-roleru

y

.

:sldaruor tiSolorruaprda 3ur,r,ro11o; aq] uo uorleurrriral
-ap rnoL asEg '{Earq}no proqd,(1 aql ur pa^lo^ur aq o1 .,(1aII1 isollr spooJ ro poq eq} oururol
-ap 'paredard no.{ leql srler lre}}e rgDads-poog papnllur teq} toillqro,\\ arilJo tlnser p sV

'0I

{

'l

;uoIssruISLIe.I]

proqd.fi roJ serrnos sp sarlrlrclrssod q8lq uraql 8ur{uLu snq} ,a3ero}s puu ,3ur,uas .uor1
-B;edard Sur.rnp uorlEurueluol roJ slsu q8rq le are spooj qrlqM 'prralreq roJ Lunipaur
qulor8 poo8 e apr.,r,ord lpq] suoilrpuol pue spooJ asoq] {1tuap1 'uorJeururu}Lror sseur ol
alqrldarsns ]sotu eq plno^\ lurqt no,( qrrq^\ esoq] 1sr1 'papr,r.ord )^pooJJo.,{er;e eql uro-r,1

68Z

)ro1 ,tnaN

ut

la^al

"(peltauar-1r5

a^!lt
'6

proqd,{1 Jo asel

Food
Potato
Salad
Macaroni
Salad
Cabbage
Salad
Summer
Sausage
Spiced
Ham
Baked
Beans
Rolls
Cakes
Coffee
Pickles

Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating
Eating
Not Eating

27
4

Person ConPersons Not
Total
Attack
Relative
tracting Typhoid Contracting Typhoid Persons
Rate
Risk
10
17
10/27=.370
27
.37/.25=1.48
1
3
1/4=.250