Food-borne disease

1. Food-borne disease

FOOD-BORNE DISEASE
Elemanov
Nurlan

2. PLAN

I.
Food-borne diseases
II. Epidemiology
III. Diagnosis

3. I. Food-borne diseases

I. FOOD-BORNE DISEASES
Infectious diseases spread
through food or beverages
are a common, distressing,
and sometimes life threatening problem for
millions of people in the
United States and around
the world. The Centers for
Disease Control and
Prevention (CDC) estimates
that each year in the United
States, 1 in 6 Americans (or
48 million people) gets
sick, 128,000 are
hospitalized, and 3,000 die
of foodborne diseases.

4. I. Food-borne diseases

I. FOOD-BORNE DISEASES
There are more than 250
known foodborne
diseases. They can be
caused by bacteria,
viruses, or parasites.
Natural and
manufactured chemicals
in food products also can
make people sick. Some
diseases are caused by
toxins from the diseasecausing microbe, others
by the human body’s
reactions to the microbe
itself.

5. I. Food-borne diseases

I. FOOD-BORNE DISEASES
To better understand the
epidemiology (study of
disease origin and cause in
a community) of foodborne
diseases in the United
States, 10 states across the
country collect annual data
on the occurrence of new
cases of the most common
causes of bacterial and
parasitic infections through
the Foodborne Diseases
Active Surveillance
Network, a CDC-sponsored
program known as FoodNet.

6. I. Food-borne diseases

I. FOOD-BORNE DISEASES
Fo o dbo rn e di s ease i s a pe r va s ive
pro bl e m c a us e d by c o n s umpt ion o f
c o n t a minate d fo o d a n d dri n k . M o re
t h a n 2 0 0 pa t h o g e ns a re a s soc iate d
w i t h fo o dbo rn e di s e ase . An e s t imate d
76 m i llion c a s e s o c c ur a n n ua lly ( o n e i n
eve r y fo ur Am e ric ans), re s ul t ing i n
3 0 0 , 0 0 0 h o s pit aliza tions a n d 5, 000
de a t h s . Fewe r c a s e s a re do c um e nte d
be c a us e o f un de rre po r t i ng .
In te rn a t ional t rave l a n d fo o d
i m po r t a t ion h ave fur t h e r ex pa n de d t h e
pro bl e m . Th e o n s et o f fo o dbo rn e
di s e ase i s g e n erally a c ute , w i t h
re s o lut ion o f a n un c o m plic ate d i l l ness
i n 7 2 h o ur s fo r m o s t e pi sode s. P ro pe r
fo o d h a n dlin g a n d pre pa ra t i on,
pe r s o nal hyg i en e, a n d i m proved
m et h o ds o f de c o n t a minat ion o f
c o n s umer pro duc t s c o ul d s i g nific ant ly
re duc e t h e ex te n t o f m o rbi dit y a n d
m o r t a lit y o f t h i s c o m m on pro bl e m .

7. I. Food-borne diseases

I. FOOD-BORNE DISEASES
Fo o dbo rn e i l lness i s t ra c ke d i n t h e
Un i te d St a te s t h ro ug h a s y s te m c a l l ed
Fo o dN et , a j o int e f fo r t o f t h e U. S. Fo o d
a n d D rug Adm i n ist rat ion ( FDA) a n d t h e
U. S. D e pa r t m e nt o f A g ri c ul t ure ( USDA) .
D a t a a re c o l l ec ted a n n ua lly fro m te n
di f fe re nt m o n itoring s i te s t h ro ug h out
th e co un tr y ( re pre s ent ing 1 5 % o f t h e
p o p u l a t io n) a n d c o m p ile d by t h e C e n te r s
fo r D i s ease Co n t ro l a n d P reve n tio n
( CD C). On l y do c um e n ted c a s e s a re us e d
fo r re po r t i n g. Th e t a rg et o rg a nisms
i n c lu d e C a m py l ob acte r spp . , S a l m one l l a s
pp. , S h i ge l l a s pp. , L i s te ri a s pp. , Sh i g a
tox i n - p rod u c in g E s c h e ri c h i a
c o l i O157: H 7 ( STE C O1 57 ) , n o n - O1 57
S TE C , V i b ri o s pp. , Ye r s i n i a s pp . , C r y p tos p
o ri d i u m s pp. , a n d C yc l o s p or a s pp. Th e
h e m oly t ic- uremic s y n dro me ( H US) i s a l s o
t ra c ke d.

8. II. Epidemiology

II. EPIDEMIOLOGY
Fo o dbo rn e di s ease ca n be c a us e d
by ba c te ri a , pa ra s i tes, tox i n s, a n d
v i rus es. D e s pite e f fo r t s to
i nvest igate fo o dbo rn e di s e ase, l e ss
t h a n 5 0 % o f a l l o ut bre a k c a us e s
a re i de n t ified, us ua l ly be c a us e o f
l i mited di a g n ost ic c a pa bi lit ies.
V i rus es a re l i kely th e m o s t c o m m on
c a u s e o f fo o d b o rn e d i s e ase b u t a re
s e l dom i nvest iga ted a n d c o n fi rm ed
be c a us e o f t h e s h o r t dura t i o n a n d
s e l f -limite d n a t ure o f t h e i l lness. In
a ddi t i on, t h e i n h ere nt di f fi c ult y o f
l a bo ra to r y i nvest igat ion a n d
s ubs e que nt c o s t o f v i ra l s t udi e s
l e a d to a l a c k o f c l i nic ian
i nvest igat ion a n d t h e re fo re ove ra ll
un de rre po r t i ng. B a c te ri a a re t h e
m o s t c o m mon do c um e n ted c a us e .

9. II. Epidemiology

II. EPIDEMIOLOGY
Cul t ura l a n d de m o gra phic fa cto r s ,
a s we l l a s i n c re ased m o bi lit y, h ave
re s ul ted i n m a j or e pi de miologic
s h i f t s i n fo o dbo rn e di s e ase duri n g
re c e n t de c a de s . 2 P rev ious
o ut bre a k s o f fo o dbo rn e di s e ase
we re s m a ller a n d l i mite d i n s c o pe ,
m o re o f te n o ri g inate d i n th e h o m e,
a n d we re a s so ciate d
w i t h S t a phy l ococcus o r C l o s t ri d ium
s pp. Fa m ily pi c n i cs o r di n n e r s a n d
h o m e - c anne d fo o ds we re t h e
t y pi c a l s o urc e s fo r t h e o ut bre a k s .
To day, m a ny m o re pe o pl e di n e
o ut s i de t h e h o m e a n d t rave l m o re
ex te n sively. As a re s ul t, m o re th a n
8 0 % o f fo o dbo rn e di s e ase c a s e s
o c c ur fro m ex po s ure s o ut s ide t h e
h o m e.

10. II. Epidemiology

II. EPIDEMIOLOGY
Te c h n ology h a s p rov i d e d t h e m e a ns
fo r m a ss pro duc t i o n a n d
di s t ri but ion o f fo o d. Th e re fore ,
fo o dbo rn e di s e ase o f te n o c c ur s o n
a m a ssive s c a le, w h e re by h un dre ds
o r t h o us a nds a re ex po s ed a n d m ay
b e c o m e i l l. M o b i lit y a n d t rave l h ave
re s ul ted i n ex po s ure to fo o ds
a bro a d, w h e re re g ul a t ion o f fo o d
s a fet y a n d fo o d pro duc t s fo r s a l e
m ay va r y. Wh e n t rave ling, t h e
a x i o m “ bo i l i t , pe e l i t , c o o k i t , o r
fo rg et i t ” re m a ins t rue i n m a ny
a re a s o f t h e wo rl d. Trave ler s
bri n g ing h o m e un i q ue fo o ds a s
g i f ts m ay unw i tti ngly ex p o s e fa m i ly
m e m b e r s a n d fri e n d s to u n ex p e c te d
i l lness. In te rn a t io nal s h i ps
di s c ha rgin g t h e i r bi l ge i n po r t s a re
a n ot h er po s s ible m e a ns o f
di s seminat in g pa t h o g ens.

11. II. Epidemiology

II. EPIDEMIOLOGY
Food importation has
steadily increased to meet
the demand for seasonal
and nonseasonal foods.
Conditions of production
and harvest may be
unsupervised or
uncontrolled, with resultant
importation of
contaminated foods. Raw
manure is frequently used
as fertilizer, causing
contamination of fresh
produce. If improperly
cleaned, the fertilized
produce may cause illness
when consumed.

12. II. Epidemiology

II. EPIDEMIOLOGY
Unique ethnic food
preferences and preparation
have been associated with
several food-related illnesses.
One example is the African
American tradition of eating
chitterlings (cooked swine
intestines) during the
Christmas holiday season. This
food has been associated with
an outbreak of Yersinia
enterocolitica infection in
infants. Fresh cheese made
from unpasteurized milk has
been associated with episodes
of listeriosis in Hispanic
neighborhoods.

13. II. Epidemiology

II. EPIDEMIOLOGY
Foodborne disease is more
likely to af fect the
extremes of age as well as
immunocompromised
patients and pregnant
women. These groups suf fer
higher incidence, morbidity,
and mortality. The ef fect of
foodborne disease may
extend beyond the
immediate illness. This has
been shown by a Danish
study, which demonstrated
a greater than threefold
risk of dying in the year
after contracting a
foodborne illness.

14. II. Epidemiology

II. EPIDEMIOLOGY
Most foodborne disease has a
shor t duration of illness and a
self-limited cour se. Other s
may cause a more protracted
illness, such
as Cr yptosporidium andCyclos
pora. However, some
foodborne diseases are
associated with long -term
chronic sequelae. Salmonella,
Shigella, Yersinia,
and Campylobacter spp. are
linked to reactive
ar thritis; Campylobacter has
also been associated with the
Guillain-Barré syndrome, and
STEC O157:H7 has been linked
to renal failure.

15. II. Epidemiology

II. EPIDEMIOLOGY
The most commonly identified Almost any food can be a source of
pathogens foodborne disease. Some foods are
are Campylobacter spp., Salm more commonly associated with
onella spp., Shigella spp., and par ticular
STEC O157:H7. These
organisms. Salmonella has
organisms have evolved and
traditionally been associated with
now have greater cold, heat,
poultr y and
and acid tolerance, as well as
eggs, Campylobacter with chicken
resistance to multiple
and unpasteurized milk, and STEC
antibiotics. Increased drug
O157:H7 with ground beef. An
resistance has been
outbreak of STEC O157:H7 was
associated with prolonged
associated with steak that had been
illness and a greater risk of
needle-tenderized, thereby exposing
hospitalization. the center of the meat to sur face
organisms. When the steak was not
thoroughly cooked to an adequate
internal temperature, the
microorganisms sur vived and illness
occurred af ter consumption.

16. II. Epidemiology

II. EPIDEMIOLOGY
Wa te r m ay be th e ve ctor o f i l ln ess w h e n
c o n t a minate d w i t h v i ruses, ba c te ri a,
pa ra s ites, o r c h e mic als. C row di n g, po o r
s a n it at ion, di s rupt i on o f wa te r s uppl i es,
a n d n a t ura l di s a ster s a re c l o sely l i n ke d
to wa te rbo rn e i l lness. V i rus es a re t h e
m o s t c o m mon c a us e o f wa te rbo rn e
i l lness a n d i n cl ude rotav i ruses, e n te ri c
a de n ovirus, a s t rov irus , c a l i civiruses a n d
h e pa t i tis A v i rus . Out bre a k s o f
g a s t ro ente rit is a bo a rd c rui s e s h i ps i n
re c e n t ye a r s we re a re s ul t o f
n o rov iruses . S a l m one l l a s pp. , S h i ge l l a s
p p . , E . c o l i , a n d V i b ri o s pp. a re t h e
pre do m in ant ba c te ri al pa t h o g ens
i nvolved. C r y p to spori di um s p p .
a n d G i a rd i a l a m b l i a a re t h e pa ra s i tic
pa t h o g ens m o st c o m m only e n c o unte red
i n wa te r - bo rn e i l lness.
Im m un oc ompromised h o s t s, pa r t i c ularly
o rg a n t ra n s plant re c i pi ent s a n d H IV i n fe c ted pa t i e n t s, s h o uld exe rc i s e ex t ra
pre ca uti o n i n s i tua tions o f pote n t i al
wa te rbo rn e i l ln ess.

17. II. Epidemiology

II. EPIDEMIOLOGY
Incubation periods of foodborne disease
may of fer clues to the cause. Four time
frames may be envisioned: ver y brief,
shor t, intermediate, and long durations of
incubation. The ver y brief categor y (<8
hour s) is generally caused by preformed
toxins, which may be found in
staphylococcal or bacillus -contaminated
food. Shor t incubation periods (24 -48
hour s) are more typical of viral causes.
Intermediate incubation periods (1 -5
days) correlate with many bacterial
pathogens. The long -duration incubation
group (>5 days) approximates the time
cour se of parasitic infections. These time
frames are crude groupings and areas of
overlap exist between them. In addition,
the inoculum of organisms ingested may
influence the incubation period and the
rapidity of onset of illness —for example,
a large inoculum may cause a shor tened
time to onset of illness.

18. III. Diagnosis

III. DIAGNOSIS
D i a g nosis i s a cco m plished t h ro ug h a
c a re ful h i s tor y, phy s ic al exa m ina tion ,
a n d l a bo ra tor y eva lua t ion. Th e h i s tor y
s h o uld i n c lude q ue s t ioning a bo ut t h e
s us pe c ted t i m e o f ex po s ure , re c e n t
t rave l, t h e fo o d a n d dri n k c o n s umed,
ot h e r pe o pl e w h o m ay h ave be e n
pre s e n t a n d e a te n s i mila r fo o ds , a n d
t h e s pe c i fic s y m pto ms i nvolve d ( e . g. ,
n a us ea , vo mit ing, di a rrh e a w i t h o r
w i t h o ut v i sible bl o o d, c ra m pi ng, g a s ,
feve r, n e u ro l ogic s y m p toms, a l te ra t ion
o f m e n t al s t a t us ). D i et a r y h i s tor y m ay
i n c lude i n t a ke duri n g t h e l a s t 2 to 3
we e k s. Th e phy s i c al exa m in at ion
s h o uld fo cus o n v i tal s i gns, i n c ludin g
o r t h o s t at ic m e a surement s, s k in
t urg o r, m e n t al s t a t us , a bdo m i nal
fi n di ngs, a n d s to o l te s t i n g fo r bl o o d.
Fre s h s to ol s a m ples fo r c ul t ure a n d
a n a ly sis ( < 6 h o ur s o l d) prov i de t h e
h i g hest y i e ld.

19. III. Diagnosis

III. DIAGNOSIS
Th e c l i nic ian m us t be
k n ow ledg eable o f t h e l a bo rator y ' s
a s s ay pro c e dure s to fa c i lit a te
pro pe r s a m ple te s t i ng. Spe c i fi c
c ul t ure re q ue s t s fo r s us pe c te d
o rg a nisms m ay be n e c e ssar y, a s
we l l a s m i c ro sc opic exa m i nat ion o f
s to o l s a m ples fo r pa ra s ites. Th re e
s a m ples o n di f fe re n t day s w i l l
g e n e rally prov i de a de q ua te
di a g nost ic re s ul t s. Spe c i a l
c i rc um s t anc es m ay di c t a te t h e
n e e d to pe r fo rm s pe c i al a s say s fo r
tox i n s ( e . g . , bot ul i n um tox i n ) o n
g a s t ric a s pira tes o r s to o l s a m ples.
B l o od c ul t ure s a re o f te n us e ful ,
pa r t i c ul a rly
i f S a l mo ne l la o r L i s te ri a i s
s us pe c ted o r w h e n eva lua t ion
i nvolves h i g h - risk g ro ups a n d
i m mun oc ompromised h o s t s.