T
ab l
e of C
o nt
e nt
sL i
st
of T
ab l
e si i i
L i
st
of
F i g
u r e si
vA b
st
r a ct
vA
ck
n ow l
ed g m
e nt
s vi
C
h
ap t
e rI
:I
nt
r od
u ct i
o n1
N
o rw
al k V i
r u s2
H
ep
at i t i
sA V
i
r u s2
V i b
ri
o sp.3
P
ub l i
cH
e alt h Im p
a ct
4
I
nd i
c at
o rB
a ct
e ri
a7
S
h
el lf i
sh M i
c r ob i
al
S
t
a nd
a rd
a nd
A
n al
y
t
i
c al
M
et h
od
s8
D
ep
u r at i
o n9
S
t
ud y
O
b
j
e ct i
v e s1 1
C
h
ap t
e rI I
;R
e s e a r ch D
e si
g
n a nd M
eth
od
s1 2
O
v e r vi
ew
1
2
S
ub
j
e ct
S
el
e cti
o n13
S t
ud y
D
e si g
n1 3
S
ub
j
e ct E
xp
o s u r eM
et h
od
s14
N
a r r ag
a n s ett
B
ay
1
5
G
r ow i
ng
W
at
e rS
am
p
l i
ng ; N
a r r ag
a n s et t B
ay
S
h
el lf i
sh
C
ol l
e ct i
o nS
i t
e1
6
D
ep
u r at i
o n of
S
t
ud y
C
l
am
s1 8
W
at
e rM i
c r ob i
ol
og i
cP
r o c ed
u r e s1 9
C
l
am H
a r v e st
S
t
o r ag
e a nd T
r a n sp
o rt P
r o c ed
u r e s1 9
S
h
el lf i
sh M i
c r ob i
ol
og i
cM
eth
od
s2 0
C
h
ap
t
e rI II
:R
e s ult
s2 3
C
l
am M i
c r ob i
ol
og y
2
3
V
ol
u nt
e e rC
h
a r a ct
e ri
sti
c s2 6
R
at
e s of Il l
n e s s2 9
R
el
at i
o n sh
i p
B
etw
e e nIl l
n e s sR
at
e s a nd M i
c r ob
i
al Q
u al
i
ty
of
C
l
am
s32
g
^
C
h
ap t
e rIV
:D i
s c u s si
o n3 7
C
h
ap t
e rV
:C
o n cl
u si
o n s4 1
I l l
L i
st
of T
ab l
e sT
ab l
eP
ag
e1
S
h
el lf i
sh
-b
o r n eI ll
n e s s ,1 9 7 8
-1 9 8 7
5
-6
2
C l
am
S
am p l i
ng
a nd M
o nt h ly F
e ed i
ng D
at
e s of
S
t
ud y
2 0
3
M i
c r ob i
ol
og i
cA
n al y
si
s of
S
h
ellf i
sh
2 3
-2 5
4
E
x cl
u si
o n s2 7
5
I
nit i
al
C
h
a r a ct
e ri
st i
c s of
S
ub
j
e ct
si
nC
l
am
S
t
ud y
28
6
Il l
n e s sR
at
e sF
ol l
ow i
ng S
h
el lf i
sh I
ng
e st i
o n3 0
-3 1
7
C
l
am
Q
u al it y
a s aP
r ed i
ct
o r of D i
a r rh
e a(
0
-7 d
ay
s)
i
nV
ol
u nt
e e r s,R l
S
it
e3 3
8
C
l
am
Q
u al ity
a s aP
r ed i
cto r of D i
a r rh
e a(
0
-7 d
ay
s)
i
nV
ol
u nt
e e r s ,N
C S
it
e3 4
-3 5
L i
st
of F i g
u r e sF i
g
u r eP
ag
e1
N
a r r ag
a n s ett B
ay
1 7
2
S
ch
em
at i
c of D
a vi
s vi ll
e,R l D
ep
u r at i
o nT
a nk
1 8
•
A b
st
r a ct
E l i
z ab
et h D
H i l b
o r n .R i
sk
of
G
a st
r oi
nt
e st i
n al I l l
n e s sf
r om C
o n s um p t i
o n of R
aw C l
am
s :R
e s ul t
s of
aC
l i
ni
c al
T
ri
al
(
U
nd
e rt h
eD i
r e cti
o n of D
r.M
a rk D
.S
ob
s ey
)
A r a ndom iz ed cl inic al tria l wa s pe rfo rmed to in v est igate t he ass ociat io n bet w e e n c on sum p
t io n of r aw
cla ms a nd de v elo p me nt of ga str o inte st in al d is e a se a nd infect ious hepat it is in he alt h y volunte ers 9 3 8 volunte e r s were r a ndom ized into 3g
r o u ps. T he f ir st(
c o ntr ol)
g
roup
con sum
ed
n o she llf ish Th
e s e c o ndg
r o up co n s um
ed shellf ish har ve ste d fr om
Nat io nalS
hel
lf i
shS
a nitati
o n Pr og
r am
' ap p
r oved
'g
r ow
ing w
ate rsi
nN
a n' ag
a n s et t Bay .T
he th
ird
gr oup
c o n s um
ed sh
el lf ish fr om
t he s ameg
r ow
ing
wate r s th
atw
e r e th
e n dep
u r ated f
o r 30 d
ays tof
urth
e r r educ ep
ote nt ialp
at hog
e ns.S
ubj
e cts \ «^
r e fed
sh
ellf
ish o n 1 of
7f
eed ing
date s t he nf
oll
owed
by
telep
ho n e a nd
w
rit tenq
ue st io n n air e fo r6 0
days to a s s e s s r ate s of g
astrointe st in al il ln e s s a nd
j
au ndi
c e fo llow
ing
e xp
o s u r e I ll
n e s s r ate si
n v ol
u nte e r s ub
j
e ctsw
e r e a s s e s s ed at1
,2
,4
, a nd 8 w
e ek
s af
te r exp
o sur e T he shellf ish fr om t he2
s o u r c e sw
e r e a n a lyz ed fo rp
r e s e n c e of sta n da rd a ndp
r op
o s edm
ic r ob ial ind ic ato r s of fe c al c o ntam in at io nW
he nm
e a s ured at tt i e ha rve st site, dep
ur ated clams had sig
nif
ic a nt ly(
p
<0
0 5)
few
e r totalc ol ifo rm
s,E
nte r o c o c ci a ndC p
e rf ri ng
e n s th
a n d am
s di
r e ctl
y ha rve ste d fr om
Na r r ag
a n s et tB
ay(W
iic o x o n r a nk
s um te st,2
-tai
led
)
.R
ate s of d i
a r rh
e a r ep
o rted
fo rw
e ek 1 w
e r e sig
nifi
c a ntly
(
p
<0 0 5
)
h ig h
e ri
n th
eg
r oup
e xp
o s ed
to cl
amsd
e ri
v ed d i
r e ctl
yf
r om th
eB
ay
c om p
a r ed
tod i
a r rh
e a r ate si
n s ub
j
e ctsw h
o ated
ep
u r ated
clams(
M
a ntel-H
a e n s z el X
^ te st)
o r to d ia r rh
e a r ate s in c o ntr ol
s(
F i
sh
e r's e x a ct te st2
-tai l
ed)
Relat ive ri
sk of d ia r rhea in t he f ir stw
e ek af te r Ing
e st io n of
d ir e ct ly ha rvested
r aw cla ms,w
a s2
.8 6
(
9 5% C
.I : 1 0 0 -8 1 4)
c om p
a r ed to c o ntr ol
s a nd 2 2 1(
1.0
9 -4 4 6)
c omp
a red
to th
o s e w ho ated
ep
u r ated cl
a ms. No s ub
j
e cts r ep
o rtedj
a u nd i
c ed
u ring
t he foll
ow - up p
eri
od
W
h
e n il ln e s s r ate s of
subj
e cts we r e a n al yzedw i
t h le vel
s of
mi
c r ob i
al i
nd ic ato r si
n clam m
e at me a s u r ed inR
.I
,E
nte r o c o c ci e nu me r ated b y t he BE
AA
meth
od w
e r e sig
nif
ic a ntl
y a s s o ciate d w it h sub
s eq
ue nt de v elop m
e nt of
d ia r rhe al Illn e s s duri ng
t hef
ir stw
e ek o f follow -up
(
Ma ntel
-Ha e n s z elX
^ te st,p
<0 0 5
) W
h
e nE
. c oli
, e n um
e r ate d by
t heM F
meth
od at t hef
e ed ing
si
te inN
.C
,w
a s c ateg
ori
z ed i
nto3
level
s,X
^ a n al y
si
sf
o r tr e nd i
nd i
c ated
th
at th
e r ew
a s a sig
nifi
c a nt a s s o ci
at io n(
p
<0 05
)
bet we e nE
.c olia ndd i
a nti e al illn e s s .A
ck
n ow
l
ed g
m
e nt
sI
w
o ul d l i k
et
ot h
a nk D
r s.C
h
ri
sti
n eM
o e ,M
a rk S
ob
s ey
a nd D
a vid
W
eb
e rf
o rt h
ei
r s up p
o rt
a nd g
uid
a n c et h
r o ug
h
o ut t h i
sp
r oj
e ct
.I
n ad d it i
o nI w
o ul d l i k
et
ot
h
a nk D
r sC
a rl
S
h y
a nd
G
r eg
S
am
s af
o rt h
ei
rp
o si t i
v e c rit i
ci
sm
a nd
a s si
st
a n c ed
u ri
ng t h
ed
at
a a n al y
si
s a nd d
r af t i
ng
of t h i
s r ep
o rt
.I
np
a rt i
c ul
a r,I w
o ul d l i k
et
ot h
a nk H
ow
a rd
a nd
S
a r ah f
o rth
ei
rl
o v e a nd
s up
p
o rt
w
h i
ch
m
ad
eit
p
o s si b l
ef
o rm
et
op
u r s u em
y
ed
u c at i
o n al
g
o al
s .C H A P
T
E R I
I N T R
O
D U C T I
O
N
B i
v al
v em
ol l
u s c a n sh
el lf i
sh
s u ch
a sE
a st
e r n oy
st
e r s{
C
r a s s o st
r e a vi
rg
i
ni
c a)
,m
u s s el
s{
M
y ti l
u s ed
ul i
s)
a nd h
a rd
cl
am
s{
M
e r c e n a ri
am
e r c e n a ri
a)
a r ef
i lt
e rf
e ed
e r s,d
e ri
vi
ng
n ut
ri
e nt
sf
r om p
a rti
cul
a te si
n th
ew
ate r of
th
ei
rh
ab i
ta tI
nth
e c o u r s e of f
e ed i
ng
, th
ey m
ay
c o n c e nt
r at
ep
ath
og
e n s a nd
ot h
e r c o nt
am i
n a nt
si
nt h
ei
rd ig
e sti
v e sy
st
em
s a nd i
n ot h
e rt i
s s u e s at l
e v el
s1 0 t
o1 0 0 t im
e sg
r e at
e rt h
a ni
nt h
e s u r r o u nd i
ng w
at
e r(
4
)
.E
xt
e n si
v e c o ok i
ng w
i ll d
e st
r oy
p
at h
og
e n s,b
ut m
a ny
p
e r s o n s e nj
oy
e at i
ng th
ew
h
ol
e a ni m
al
r aw
o rp
a rt i
al ly
c o ok
ed
,t h
e r eb y
e xp
o si
ng
th
em
s el
v e st
op
ot
e nt i
al i
nf
e ct i
o n.E
a rl y i
nt h
etw
e nt i
eth
c e nt
u ry
, c o n s um p t i
o n of
c o nt
am i
n at
ed m
ol l
u s c a n sh
el lf i
sh
r e s ult
ed i
nl
a rg
et y p h
oi d f
e v e r o ut b
r e ak
s al
o ng th
e e a st
e r n s e ab
o a rd
of th
eU
nit
ed
S
t
at
e sI
n1 9 2 5
,i
n r e sp
o n s et
oth i
st h
r e at t
ot h
ep
ub l i
ch
e alt h
, r eg
ul
at i
o n sw
e r ep
r op
o s ed t
ol im i t
h
a r v e st i
ng
of m
ol l
u s c a n sh
el lf i
sh t
o a r e a sf
r e e of
c o nt
am i
n at i
o nb y
s ew
ag
e o ut fl
ow
(
8
)
.G
e n e r al
ad h
e r e n c et
o sh
ell
f
i
sh
g
r ow
i
ng w
at
e r(
c o a st
al
w
at
e r sw
h
e r e sh
el lf i
sh
a r ep
r od
u c ed
)
a nd
sh
el lf
ish m i
c r ob i
ol
og i
c al
st
a nd
a rd
s ad
op t
ed b y
st
at
e st h
r o ug
h t h
eN
at i
o n al
S
h
el lf i
sh
S
a nit
at i
o nP
r og
r am
(
N
S S P
)
h
a s st
op
p
ed t
h
el
a rg
ety
p
h
oi d
ep id
em i
c s,b
ut
oth
e rp
at
h
og
e n sh
a v e em
e rg
ed
a sp
ub
l i
ch
e alt h
c o n c e r n s .A
v a ri
ety
of f
o od
-b
o r n ep
at h
og
e n s a r ek
n ow
nt
ob
e a s s o ci
at
ed
w
it h
c o n s um
p
t i
o n of
r aw m
ol l
u s c a n sh
el lfi
sh
a nd m
a ny
of t h
e s e c om
ef
r om f
e c al
c o nt
am i
n at i
o n of
sh
el lf i
sh
g
r ow i
ng
w
at
e r sT
h
eh
um
a n ent
e ri
c vi
r u s e s,i
n cl
ud i
ng
N
o rw
al
k
a nd N
o n w alk
-l
i k
e vi
r u s es a nd h
ep
at it i
sA
vi
r u s a r et h
em
o st i m
p
o rt
a nt
vi
r al
p
ath
og
e n si m
p
l i
c at
ed i
n sh
ellf
i
sh
-b
o r n e o ut
b
r e ak
s(
8
,4 5
,3 3
)
E
nt
e ri
c vi
r u s e sm
ay b
ei
nf
e ct i
v ei
n v e ry l
ow
n um b
e r s(
3 2
,3 0
)
, a nd
ag
e nt
s s u ch
a sN
o rw
al k
vi
r u s a r ed if fi
c ult t
od
ete ct i
n sh
el lf i
sh
a nd
e n vi
r o nm
e nt
al
s am p l
e s.I
n ad d it i
o n , s om
e sp
e ci
e s of
b
a ct
e ri
a, s u ch
a sV i b
ri
o sp
a r e ap
ub l i
ch
e alt
h
t h
r e at
, e sp
e ci
al l
y
t
ot h
o s ew
i th
l
i
v e rd y
sf
u n ct i
o n o ri m m
u nos up p
r e s si
o n.N
o rw
aN
o rw
alk V i
r u s(
N V
)
a nd
r el
at
ed
S
m
all R
o u nd
S
tr u ct
u r ed V i
r u s e s(
S
R
S
V
)
m
ay b
et h
em
o st
c om m
o n vi
r al
ag
e nt
s of
sh
el lf i
sh
-a s s o ci
at
ed i l l
n e s sN V
a nd
r el
at
ed
sm
al l
r o u nd
vi
r u s e s a r em
em b
e r s of t h
eC
al i
ci
vi
ri d
a ef
am i l y
(
1 3
)
.A l l
vi
ri
o n s a r e ab
o ut 3 0
-3 5
nm i
nd i
am
et
e r, c o nt
ai
n si
ng l
e st
r a nd
ed
, + -s e n s eR N A
of
ab
o ut 7
.6 K
n u cl
e ot id
e si
nl
e ng t h
, a nd
h
a v e a ni
c o s ah
ed
r al
c ap
si d
c o nt
ai
ni
ng
a si
ng l
et y p
e of p
oly p
ep t i d
e of
ab
o ut 6 0
k i l
od
alt
o n s(
4 4
)
T
r a n sm i
s si
o ni
st y p i
c al ly b y th
ef
e c al
-o r al
r o ut
e , alt h
o ug h
th
e r ei
s a r ep
o rt
of
s u sp
e ct
ed
a e r o s ol i
z at i
o n of
vi
r al p
a rt i
cl
e s o c c u r ri
ng
,w
h i
ch l
ed t
ow i d
e sp
r e ad
i
nf
e ct i
o n.(
4 2
)
O
utb
r e ak
sh
a v eb
e e n a s s o ci
at
ed w it h i
ng
e st i
o n of
sh
ellf i
sh
(
1 9
,4 5
,2 9
,5
)
, sw i m m i
ng i
n c o nt
am i
n at
ed w
at
e r, c o n s um p t i
o n of
c o nt
am i
n at
ed w
el l w
at
e r(
2 5
)
,p
e r s o nt
op
e r s o n c o nt
a ct
a nd i
ng
e st i
o n of
c om m
e r ci
al ly p
r od
u c ed i
c e(
3
)
.N
o rw
al k
a nd N
o rw
al k
-l i k
e vi
r al i
nf
e ct i
o n s a r e ch
a r a ct
e ri
z ed b y
a c ut
eg
a st
r o e nt
e rit i
sw
it h i
n2 4
-4 8 h
o u r s of
e xp
o s u r eI ll
n e s si
sg
e n e r al ly
s elf
-l i m it i
ng i
nh
e alt h y i
nd i
vi d
u al
s, r a ng i
ng i
n s e v e ri ty f
r om m i ld
ab
d
om i
n al d i
s c om f
o rt t
o s e v e r ed i
a r rh
e a a nd /
o r v om it i
ng
of 1 2
-6 0 h
o u r sd
u r at i
o n(
2 2
)
H
um
a n s e r op
r e v al
e n c et
oN
o rw
alk
vi
r u si
sw
i d
e sp
r e ad
, e v e n s e em i
ng l y
,i
ni
nf
a nt
sG
r ay
s u r v ey
ed 3
,2 5 0
s e r um
s am p l
e s c ol l
e ct
ed i
nE
ng l
a nd f
r om 1 9 9 1
-1 9 9 2
a nd f
o u nd
s e r op
r e v al
e n c e r a ng
i
ng f
r om 2 4 6
%
i
n6
-1 1 m
o nt h
old i
nf
a nt
s,t
o8 9 7
%
i
np
e r s o n s o v e r6 0 y
e a r s of
ag
e(
1 2
)
L
ef k
ow
i t
z r ep
o rt
ed
n o si g
nif i
c a nt d if f
e r e n c ei
n s e r op
r e v al
e n c eb
etw
e e n3 g
r o up
s of
s ub
j
e ct
s ch
o s e nf
o rh ig h
,m
od
e r at
e a nd
n o sh
el lf i
sh
c o n s um p t i
o nA l l g
r o up
sw
e r e ap p
r o xi m
at
ely 7 0
%
s e r op
o sit i
v et
oN
o rw
al k
vi
r u s, st
r e ng th
e ni
ng t h
e a rg
um
e nt t h
at
c o nt
am i
n at
ed w
at
e r,t h
e e n vi
r o nm
e nt
a nd
p
e r s o nt
op
e r s o n c o nt
a ct m
ay b
et h
ep
ri m
a ry
r o ut
e s of t
r a n sm i
s si
o n(
2 6
)
P
r e s e n c e of
a nt ib
od y t
oN V i
s n ot
u nif
o rm ly
a s s o ci
at
ed w it h
ad
e c r e a s ed
ri
sk
of i l l
n e s s up
o n s ub
s eq
u e nt
e xp
o s u r et
o vi
r u s(
2 1
)
.S
om
e st
ud i
e sh
a v e s ug
g
e st
ed t h
at
p
e r s o n sw
it h
p
r e e xi
st i
ng
a nt ib
od y t i t
e r st
oN V m
ay
a ct
u al l y b
em
o r el i k
el y t
od
e v el
op
cl i
ni
c al i l l
n e s s af t
e r e xp
o s u r et
ot h
e vi
r u s(
2
,1 1
)
H
e pat it i
sA
vi
r u sH
ep
at it i
sA
vi
r u s(
H A V
)
i
s a2 7
-nm
n o n e n v el
op
ed R N A
vi
r u si
nt h
ef
am i l y
P i
c o r n a vi
ri d
a eT h
ep
rim
a ry
r o ut
e of t
r a n sm i
s si
o ni
st h
ef
e c al
-o r al
r o ut
eV i
r u si
s sh
ed
3
p
ri m
a ri l y t h
r oug h t h
ef
e c e s a nd m
ay
r em
ai
ni
nf
e cti
v ef
o r up
to2
w
e ek
s inf
e c alm
ate ria lT h
e vi
r u si
s v e ry p
e r si
ste nt i
n sh
el lf i
sh
a nd i
n e n vi
r o nm
e nt
al m
ed i
a ,i
n cl
ud i
ng
s e aw
at
e r,w
a st
ew
at
e r a nd
s ed i m
e nt
s.H
AV
i
nf
e ct
s o nl y h
um
a n a nd
n o nh
um
a np
ri m
at
e s ,h
e n c e z o o n ot i
ct
r a n sm i
s si
o ni
s n eg l i g i
b
l
ei
nt h
eU S
(
1
5
)
.M
ol l
u s c a n sh
el lf i
sh m
ay
s e r v e a s v eh i
cl
e sw h
e nt h
ey b
e c om
e c o nt
am i
n at
ed
af t
e rh
a r v e st b y i
nf
e ct
ed f
o od h
a nd l
e r s(
3 0
)
, o rw
h
e nth
ey b i
o c o n c e nt
r at
eH A V f
r om f
e c al l y
c o nt
am i
n at
ed w
at
e rd
u ri
ng
a ct i
v ef i lt
e rf
e ed i
ng
.W
h
e ni
nf
e ct i
v e vi
r u sp
a rt i
cl
e si
nt h
e sh
el lf i
sh
a r ei
ng
e st
ed b y
ah
um
a nh
o st
,H
A
V i
nf
e ct i
o nm
ay
o c c u rH
A
V i
nf
e ct i
o n r e s ult
si
n a ni
nf
e ct i
o u sh
ep
at it i
s ch
a r a ct
e ri
z ed b y p
e ri
p
o rt
al
n e c r o si
s a c c om p
a ni
ed b y
a ni
nf i lt
r ati
o n of m
o n o n u cl
e a r c el
l
s(
15
)
.T h
ed i
s e a s eh
a s am
e a ni
n c ub
ati
o np
e ri
od
of 4
w
e ek
s a r a ng
e of
3
-6
w
e ek
s .C
l i
ni
c al i l l
n e s si
n ad
ult
si
s ch
a r a ct
e ri
z ed
b y
f
e v e r, n a u s e a , v om
i
t
i
ng
a nd
j
a u nd i
c eD
u r at i
o n of i l l
n e s si
sg
e n e r al ly 1
-2 w
e ek
s a nd
s e v e rity
of i
l
l
n e s si
n c r e a s e sw
it h
ag
e(
1 5
)
.D
u r at i
o n of
cl i
ni
c al h
ep
at i t i
sm
ay
al
s ob
ep
r ol
o ng
ed i
ni m m
u n o c om p
r om i
s ed
i
nd i
vid
u al
sH A V h
a s a si
ng l
e s e r oty p
e a nd
s e r op
r e v al
e n c ei
n c r e a s e sw
ith
ag
e .A
g
e ad
j
u st
ed
s e r op
r e v al
e n c e of
a nt i
-H A V i
nt h
eU S
p
op
ul
at i
o ni
n1 9 8 0
w
a s4 0 4
%
f
o rm
al
e s a nd 4
2
.4
%
f
o rf
em
al
e s(
4
3
)
P
r e s e n c e of
a nt i
-H A V
c o nf
e r s a ct
i
v ei
m m
u ni
t
y f
o rl
o ng p
e ri
od
s of
t
i
m
e , s om
et i m
e sf
o rl if
e(
1
5
)
.A p
p
r o xi m
at
ely 2 5
,0
0
0
c a s e s of H
ep
at it i
sA
a r e r ep
o rt
ed
a n n u al ly
i
nt h
eU S
(
3 0
)
R i
sk f
a ct
o r s a s s o ci
at
ed
w
it h i l l
n e s sl
i
st
ed i
nd
e s c e nd i
ng
o rd
e r of
i m p
o rt
a n c e a r e :d
ay
-c a r e -c e nt
e r c o nt
a ct
,p
e r s o n al
c o nt
a ct w it h
aH A V i
nf
e ct
ed i
nd
i
vid
u al
, c o n s um p t i
o n of
c o nt
am i
n at
ed f
o od
o rw
at
e r,i
nt
e r n at i
o n al t
r a v el
a nd
p
a r e nt
e r al d
r ug
ab
u s e .A
p p
r o xim
at
ely 4 2
%
of
c a s e sh
ad
n oi d
e nt if i
ab l
e s o u r c e of i l l
n e s s(
4 3
)
.If
s e st i m
at
ed th
at 1 9
-2 5
%
of
al l H
ep
at it i
sA i l l
n e s s e sm
ay b
e c o nt
r a ct
ed
af t
e r c o n s um p t i
o n of
c o nt
am i
n at
ed
r aw
sh
el lf i
sh
(
3 8
)
.V
i
b
ri
o sp.V i
b
ri
o sp
e ci
e s of
b
a ct
e ri
ai
nt h
ef
am i l y V i b
r o n a c e a e, a r eim p
o rt
a nt
s o u r c e s of
sh
el lf i
sh
-b
o r n ed i
s e a s e .Vi
b
ri
o s a r eh
al
op
h i l i
c ,g
r am
n eg
at i
v e , c u r v ed
o r r od
-sh
ap
ed
b
a ct
e ri
at h
at
th
ri
v ei
nw
a rm
, c o a st
al
a nd
e st
u a ri
n ew
at
e r s.Vi b
ii
o sp
e ci
e st h
at h
a v eb
e e n a s s o ci
at
ed
w
it h i l l
n e s sf
r om
sh
ellf i
sh
c o n s um p ti
o ni
n cl
ud
e :Vi b
ri
oty p
e0
1
ch
ol
e r a e,V
. n o n -0
1
ch
ol
e r a e,V p
a r al
i a em
ol y ti
c u s a nd V
. v ul
ni l
i c u sC
o n sum p t i
o n of
r aw
oy
st
e r sh
a sb
e e nl i
nk
ed w it h
outb
r e ak
s of g
a str o e nt
e ri
ti
sd
u e toN
o n-0
g
r o up 1 V ib
ri
o cl
i ol
e r a e(
3 0
,5 0
)
.I
n1 9 8 6
(
2 4
)
a nd 1 9 9 1
,th
e r ew
e r e c a s e s of
ch
ol
e r a(
d
u et
oty
p
e0
1 Vi
b
ri
o ch
ol
e r a e)
as s o ci
at
ed
w
it h
c o n s um
p
t i
o n of
r aw
oy
st
e r sh
a r v e st
ed f
r om t h
eG
ulf
of M
e xi
c o a nd E
c u ad
o r.V
.p
a r al
i a em
ol y ti
c u si
s a c om m
o n c a u s e of
s e af
o od
-b
o r n eg
a st
r o e nt
e ri t i
si
nh
e alt h y p
e r s o n s(
2 0
)
.V
.p
a r ah
a em
oly ti
c u si
nf
e ct i
o nm
ay b
e ch
a r a ct
e ri
z ed b y d i
a r rh
e a, n a u s e a, v om it i
ng
a nd
ab d
om i
n al p
ai
nT h
ei
n c ub
at i
o np
e ri
od i
s ab
o ut 4
-9 6 h
o u r sw
it h d
u r at i
o n of i l l
n e s s of
ap p
r o xi m
at
el y 7 2 h
o u r s(
3 6
)
G
e n e r all y V
.p
a r ah
a em
oly ti
c u sg
a st
r o e nt
e ri t i
si
s s elf
-l i m it i
ng i
nh
e alt h y i
nd i
vid
u al
sVib
ri
o v ul
nifi
c u s,i
s a ni m p
o rt
a nt p
at h
og
e np
ri m
a ri ly i
nt h
o s ew
h
o a r ei m m
u n o s up p
r e s s ed
o rh
a v e ch
r o ni
cl i
v e rd i
s e a s e .V
. v ul
ni fi
c u sm
ay
c a u s ef
at
al
sy
st
em i
ci
nf
e ct i
o n s(
Vi b
ri
o s ep t i
c em i
a)
w i th
am
o rt
al it y
r at
e of
g
r e at
e rt h
a n5 0
%
(
2
3
,3 0
,4 6
)
.Vi b
ri
o n o n-0
1
ch
ol
e r a e a nd V
.p
a r ah
a em
ol y ti
c u si
nf
e ct i
o nm
ay
al
s o o c c a si
o n al ly p
r od
u c e af
at
al
o ut
c om
ei
ni m m
u n o c om
p
r om i
s ed i
nd i
vid
u al
s(
2
3
)
.A l l
of t h
eVi
b
ri
o sp
e ci
e s a s s o ci
at
ed w i th
sh
el lf i
sh
-b
o r n eil l
n e s s a r e nat
u r al ly
o c c u r ri
ng
i
nt h
em
a ri
n e e n vi
r o nm
e nt
Vi b
ri
o sg
e n e r al l y f
a v o rw
a rm
c o a st
al
a nd
e st
u a ri
n ew
at
e r s.I
n ad d it i
o n, of th
e s eV ib
ri
o sp
e ci
e s,V
.p
a r ah
em
ol y ti
c u si
sm
o st
c om m
o nl y i
s ol
at
ed f
r om
f
e c e s a nd m
ay b
et
r a n sm it t
ed b y f
e c al
c o nt
am i
n at i
o n of
sh
el lf i
sh b
ot h b
ef
o r e a nd
af t
e rh
a r v e st
(
3 0
)
.P
ub l i
ch
e alt
h
i m
p a ct
T h
eC
e nt
e r sf
o rD
i
s e a s eC
o nt
r ol
a nd
P
r e v e nt i
o n(
C
D
C
)
r ep
o rt
ed
12
8
o ut b
r e ak
s a nd
3 7 4 7
c a s e s of
sh
el lf i
sh
-b
o r n eil l
n e s si
nt h
e1 0 y
e a rp
e ri
od f
r om 1 9 7 8
-1 9 8 7
T h i
s c o n st it
ut
e s3 1
%
of
al l
s e af
o od
a s s o ci
at
ed
o utb
r e ak
s a nd 6 6
%
of
al l
s e af
o od
-b
o r n e c a s e s r ep
o rt
ed t
ot h
eC
D
C
d
u ri
ng
t h i
sti m
ep
e ri
od
(
3 0
)
.C
D
C
' sd
at
aw
a sd
e ri
v ed f
r om f
o od
-b
o r n ed i
s e a s e o ut b
r e ak
r ep
o rt
sf
r om
st
at
eh
e alt h
d
ep
a rt m
e nt
sR i p p
ey
a nd V
e rb
e r r ep
o rt
3 6 1
o ut b
r e ak
s a nd m
o r eth
a n5
7
9 7
c a s e s of
sh
el lf i
sh
a s s o ci
at
ed
g
a st
r o e nt
e rit i
s a nd
h
ep
at it i
si
nt
h
eU S
f
r om 1 9 7 9
-1 9 8 8
(
3 5
)
.R ip
p
ey
a nd V
e rb
e r ' sd
at
a a r ed
e ri
v ed f
r om
a v a ri
et
y
of
s o u r c e s : st
at
e a nd l
o c al h
e alt h d
ep
a rt m
e nt f i l
e s,b
o ok
s, n ew
s a c c o u nt
s ,C
D
C
rep
o rt
s,P
ub l
i
cH
e alt h
S
e r vi
c ef il
es, c a s eh
i
st
o ri
e s a nd
a r ch i
val
r ep
o rt
s(
3
0
)
.(
T
ab
l
e1
)
T
ab l
e1
:S
h
el if
i sh
-b
om
eIl l
n e s s ,(
1 9 7 8
-1 9 8 7
)
C
D
C
*N
at
u r al l
yO
c c u r ri
n gA
q u at i
cA
g e nt
sV
i b
ri
op
a r ah
em
ol y
t
i
c u sVi b
ri
o ch
ol
e r a e0
1
Vi b
ri
o ch
ol
e r a e n o n-0
1
V ib
ri
o v ul
ni fi
c u sVi b
ri
om
i
m
i
c u sV
i
b
ri
oh
oll
i
s a eVib
ri
ofl
u vi
al i
sP l
e si
om
o n a sA
e r om
o n a sO
ut b
r e ak
sC
a s e s1 5
2
2
1 7 6
1 4
1 1
N
E
T
S U
* *C
a s e s5 2
1 3
1 2 0
1 0 0
5
5
5
1 8
7
I
nf
e ct i
o u sA
g e nt
sA
s s o ci
at
ed
w
i th F
e c al P
ol
l
uti
o n of
W
at
e rH
ep
at it i
s, u n sp
e ci f i
ed
H
ep
at it i
sA
S
al
m
o n ell
a(
n o nt y
p
h
oi d
al
)
S
h i
g
ell
aC
am
p y l
ob
a ct
e rN
o rw
al k
a nd N
o rw
alk
-l i k
e vi
r u s e sN
o n-A
, n o n -B h
ep
at it i
s7
3
4
3 3
80
7 7
4
2
1
.6 4 5
4
5
8 4
1 6
8 2
1
I
nf
e cti
o u sA
ge nt
sA
s s o ci
at
ed
w
it
h P
r o c e s si
n g a nd P
r e p a r at
i
o nC
l
o st
rid i
um p
e rf
ri
ng
e ns2
S
t
ap h y l
o c o c c u s a u r e u s1
B
a cil l
u s c e r e u s2
2 8
9
6
T
ot
al
o ut b
r e ak
s/
c a s e s ^U
nk
n ow
n age nt
s^:4 0
8 8
4 7 6
3
,2
7
1
2
,1 9 8
5
,0 9 8
*C
e nte r sf
o rD i
s e a s eC
o nt
r ol
a nd P
r e v e nt i
o n ,A tl
a nt
a,G
e o rg i
a **R i p p
ey
a nd V
e rb
e r,N
o rt h
e a st T
e ch
ni
c al
S
e r vi
c e sU
nit
,F D
A
,S
h
el lf
i sh
S
a nit
at
i
o nB
r a n ch
,D
a vi
s vi l l
e,R h
od
eI
sl
a nd
.,