Food Poisoning Assoc. Prof.Dr. Yesim Gurol Slide 2 Slide 3 Slide
4 Percentage Change in 2012 compared to 2006-2008:
Campylobacter-14% increase, E. coli O157-no change, Listeria-no
change, Salmonella-no change, Vibrio-43% increase, Yersinia-no
change 2012 rate per 100,000 Population: Campylobacter-14.30, E.
coli O157-1.12, Listeria-0.25, Salmonella-16.42, Vibrio-0.41,
Yersinia-0.33 2020 target rate per 100,000 Population:
Campylobacter-8.5, E. coli O157- 0.6, Listeria-0.2,
Salmonella-11.4, Vibrio-0.2, Yersinia-0.3 Slide 5 Campylobacter O
Chicken is the most common food implicated as the source of
Campylobacter contamination. O Any raw poultry - chicken, turkey,
duck, goose meat and its juices may contain Campylobacter,
including organic and free range products. O Other foods include
unpasteurized (raw) milk, undercooked meats such as beef, pork,
lamb, and livestock offal, and occasionally shellfish, fresh
produce, and eggs. Slide 6 O Most cases of Campylobacter infection
occur as isolated, sporadic events, and are not usually part of
large outbreaks. O But, very large outbreaks (>1,000 illnesses)
of campylobacteriosis have been documented, most often from
consumption of contaminated milk or unchlorinated water supplies.
Slide 7 O C. jejuni is commonly present in the gastrointestinal
tract of healthy cattle, pigs, chickens, turkeys, ducks, and geese.
O Direct exposure to feces from animals carrying Campylobacter can
lead to infection. O People have become ill from contact with
infected dogs and cats. O Pets that may carry Campylobacter include
birds, cats, dogs, hamsters, and turtles. O The organism is also
occasionally isolated from streams, lakes, ponds, and dairy
wastewater (lagoons). Slide 8 O The incubation period for
Campylobacteriosis (the time between exposure to the bacteria and
onset of the first symptom) is typically two to five days, but
onset may occur in as few as two days or as long as 10 days after
ingestion of the bacteria. O The illness usually lasts no more than
one week but severe cases may persist for up to three weeks, and
about 25% of individuals experience relapses of symptoms. Slide 9 O
Diarrhea is the most consistent and prominent manifestation of
Campylobacter infection and is often bloody. O Typical symptoms
also include fever, nausea, vomiting, abdominal pain, headache, and
muscle pain. O A majority of cases are mild, do not require
hospitalization, and are self-limited. O However, Campylobacter
jejuni infection can be severe and life-threatening. O It may cause
appendicitis or infect other organs as well as the blood stream. O
It is estimated that about one in 1,000 cases of Campylobacter
infection results in death. Death is more common when other
diseases (for example, cancer, liver disease, and immune deficiency
diseases) are present. Slide 10 O Long-term consequences and
complications can sometimes result from a Campylobacter infection.
O Some people may develop a rare disease that affects the bodys
nervous system following infection. This disease is called
Guillain-Barr Syndrome (GBS).Guillain-Barr Syndrome (GBS) O It
begins several weeks after the diarrheal illness, may last for
weeks to months, and often requires intensive care. Full recovery
is common but some affected individuals may be left with mild to
severe neurological damage. O Two therapies, intravenous
immunoglobulin infusions and plasma exchange, may improve the rate
of recovery in patients with GBS. Slide 11 O Miller Fisher Syndrome
(MFS) is a related neurological syndrome that can occur with a
Campylobacter infection. In MFS, the nerves of the head are
affected more than the nerves of the body. O Another chronic
condition that may be associated with Campylobacter infection is a
form of reactive arthritis called Reiters Syndrome. Reiters
Syndrome O Reiters Syndrome typically affects large weight- bearing
joints such as the knees and the lower back. It is a complication
that is strongly associated with a particular genetic make-up;
persons who have the human lymphocyte antigen B27 (HLA-B27) are
most susceptible Slide 12 O The single most important and reliable
step to preventing Campylobacteriosis is to adequately cook all
poultry products. O Make sure that the thickest part of the bird
(the center of the breast) reaches 180F or higher. O It is
recommended that the temperature reaches at least 165F for stuffing
and 170F for ground poultry products, and that thighs and wings be
cooked until juices run clear. Do not cook stuffing inside the
bird. Slide 13 O Irradiation within approved dosages has been shown
to destroy at least 99.9% of common foodborne pathogens including
Campylobacter, which are associated with meat, poultry, and
secondary contamination of fresh produce. O Transport meat and
poultry home from the market in the coolest part of the vehicle
(generally the trunk in winter and cab in summer). O Defrost meat
and poultry in the refrigerator. Place the item on a low shelf, on
a wide pan, lined with paper towel; ensure that drippings do not
land on foods below. If there is not enough time to defrost in the
refrigerator, use the microwave. Slide 14 O Make sure that other
foods, such as fruits or vegetables, do not come into contact with
cutting boards or knives that have been used with raw meat or
poultry. O To avoid cross-contamination, carefully clean all
cutting boards, countertops, and utensils with soap and hot water
after preparing raw meat or poultry. Slide 15 O Rapidly cool
leftovers. Never leave food out at room temperature (either during
preparation or after cooking) for more than 2 hours. O Avoid
consuming raw milk and other unpasteurized dairy products and
untreated (not chlorinated or boiled) surface water. O Wash fruits
and vegetables carefully, particularly if they are eaten raw. If
possible, vegetables and fruits should be peeled. O Wash hands
thoroughly using soap and water, concentrate on fingertips and nail
creases, and dry completely with a disposable paper towel after
contact with pets, especially puppies or farm animals; before and
after preparing food, especially poultry; and after changing
diapers or having contact with an individual with an intestinal
infection. Children should always wash their hands on arrival home
from school or daycare. Slide 16 Slide 17 Botulism O Botulism is a
rare but serious paralytic illness caused by a nerve toxin that is
produced by the bacterium Clostridium botulinum. O Clostridium
botulinum is the name of a group of bacteria commonly found in
soil. O The bacteria are anaerobic, Gram-positive, spore-forming
rods that produce a potent neurotoxin Slide 18 O Sausages, meat
products, canned vegetables, and seafood products have been the
most frequent vehicles for foodborne botulism. Slide 19 O Classic
symptoms of botulism include double vision, blurred vision,
drooping eyelids, slurred speech, difficulty swallowing, dry mouth,
and muscle weakness. O Infants with botulism appear lethargic, feed
poorly, are constipated, and have a weak cry and poor muscle tone.
O These are all symptoms of the muscle paralysis caused by the
bacterial toxin. O If untreated, these symptoms may progress to
cause paralysis of the arms, legs, trunk, and respiratory muscles.
O In foodborne botulism, symptoms generally begin 18 to 36 hours
after consuming contaminated food, but they can occur as early as 6
hours or as late as 10 days after consumption. Slide 20 O Botulinum
toxin causes flaccid paralysis by blocking motor nerve terminals at
the myoneural junction. O The flaccid paralysis progresses
symmetrically downward, usually starting with the eyes and face,
then moving to the throat, chest, and extremities. O When the
diaphragm and chest muscles become fully involved, respiration is
inhibited and unless the patient receives treatment in time, death
from asphyxia results. Slide 21 O the most sensitive and widely
used method for detecting toxin is the mouse neutralization test,
which involves injecting serum or stool into mice and looking for
signs of botulism. This test typically takes 48 hours. O Culturing
of specimens takes 5-7 days. Slide 22 O If diagnosed early,
foodborne botulism can be treated with an antitoxin that blocks the
action of toxin circulating in the blood. This can prevent patients
from worsening, but recovery still takes many weeks. Slide 23 O
While botulism has been known to cause death due to respiratory
failure O The respiratory failure and paralysis that occur with
severe botulism may require a patient to be on a ventilator for
weeks, plus intensive medical and nursing care. O After several
weeks, the paralysis slowly improves. Slide 24 O Infant botulism O
Infant botulism is more common in the spring and the summer and is
rare in the winter. Infants younger than one year of age,
particularly between the ages of two to four months, are at highest
risk. Symptoms include muscle weakness, a weak cry, a poor suck
(difficulty in feeding), feeble crying, constipation, head lag,
increased heart rate and a decreased gag reflex. O A baby with
infant botulism is described as a "floppy baby," as the baby will
have weak muscles, especially in the arms, legs and neck. Infant
botulism has been associated with the ingestion of honey. O The
United States Center for Disease Control suggests that honey should
not be given to infants under the age of 6 months. The Honey
Industry Council extends that limit to one year of age to be extra
safe. Honey is not an essential food for infants and should not be
given. Slide 25 O Unlike adults, infants younger than 12 months are
vulnerable to Clostridium botulinum bacteria colonizing (growing
inside) the large intestine. O The disease starts when an infant
swallows spores at a moment in time when the baby's large intestine
is vulnerable to spore germination and toxin production. O It is
thought that most infants are exposed by swallowing spore-
containing dust which is naturally present in the environment. O
The spores are found in honey and honey has been clearly linked to
infant botulism. Other foodstuffs (such as corn syrup) have been
suggested as sources but links to other foods are uncertain or
disproven. For most cases of infant botulism, no specific source of
C. botulinum spores is ever identified. O After being swallowed,
spores can germinate in the intestine and, as the bacteria grow,
they produce botulinum toxin that is then absorbed into the
infant's body. O Although exposure to the spores is very common if
not universal in various parts of the world, only rarely do the
bacteria manage to get inside an infant at a vulnerable age,
germinate, and create the toxin. Slide 26 O Any food that is
conducive to outgrowth and toxin production, that when processed
allows spore survival, and is not subsequently heated before
consumption, can be associated with botulism. O Almost any type of
food that is not very acidic (pH above 4.6) can support growth and
toxin production by C. botulinum. O Botulinal toxin has been
demonstrated in a considerable variety of foods, such as canned
corn, peppers, green beans, soups, beets, asparagus, mushrooms,
ripe olives, spinach, tuna fish, chicken and chicken livers and
liver pate, and luncheon meats, ham, sausage, stuffed eggplant,
lobster, and smoked and salted fish. Slide 27 O Botulinum toxin is
heat-labile, or unstable if heated to a certain temperature, and
can be destroyed if heated and held at 80 degrees Centigrade (176
degrees Fahrenheit) for ten minutes or longer. Slide 28 Salmonella
O Salmonella is one of the most common enteric (intestinal)
infections O Salmonellosis the disease caused by Salmonella is the
second most common bacterial foodborne illness after Campylobacter
infection Slide 29 O Salmonella infection occurs when bacteria are
ingested, typically from food derived from infected animals, but
infection can also occur by ingesting the feces of an infected
animal or person. O Food sources include raw or undercooked
eggs/egg products, raw milk or raw milk products, contaminated
water, meat and meat products, and poultry. O Raw fruits and
vegetables contaminated during slicing have been implicated in
several foodborne outbreaks, as have foods contaminated by food
handlers who did not adhere to proper hygienic standards and
practice proper handwashing techniques. Slide 30 O The acute
symptoms of Salmonella gastroenteritis include the sudden onset of
nausea, abdominal cramping, and bloody diarrhea with mucous. O
Fever is almost always a symptom. Vomiting is less common than
diarrhea. O Headaches, myalgias (muscle pain), and arthralgias
(joint pain) are often reported as well. O The onset of symptoms
usually occurs within 6 to 72 hours after the ingestion of
Salmonella bacteria. The infectious dose is small, probably from 15
to 20 cells. Slide 31 O Reiters Syndrome, which includes and is
sometimes referred to as reactive arthritis, is an uncommon, but
debilitating, result of Salmonella infection. Reiters Syndrome O
The symptoms of Reiters Syndrome usually occur between one and
three weeks after infection, and include at least two of three
seemingly unrelated symptoms: reactive arthritis, conjunctivitis
(eye irritation), and urinary tract infection. O The arthritis
associated with Reiters Syndrome typically affects the knees,
ankles, and feet, causing pain and swelling. Slide 32 O Salmonella
infections usually resolve in five to seven days, and many times
require no treatment, unless the affected person becomes severely
dehydrated or the infection spreads from the intestines Slide 33
Slide 34 O To prevent salmonellosis, cook poultry, ground beef, and
eggs thoroughly before eating. In order to ensure that eggs do not
contain viable Salmonella they must be cooked at least until the
yoke is solid. Meat and poultry must reach 160F or higher
throughout. Be particularly careful with foods prepared for
infants, the elderly, and those with a compromised immune system,
including diabetics, pregnant women, HIV/AIDS patients, cancer
patients, and transplant recipients. O Do not eat or drink foods
containing raw eggs, such as homemade eggnog and hollandaise sauce.
Avoid drinking raw (unpasteurized) milk or products made from raw
milk. O Wash hands, kitchen work surfaces, and utensils with soap
and water immediately after they have been in contact with foods of
animal origin. Also, wash hands with soap after handling reptiles,
amphibians, or birds, or after contact with pet feces. Infants and
immune-compromised persons should have no direct or indirect
contact with such pets. Slide 35 Shigella O Shigella is a bacterium
that can cause sudden and severe diarrhea (gastroenteritis) in
humans. O Shigellosis is the name of the disease that Shigella
causes. The illness is also known as bacillary dysentery. Slide 36
O Shigella bacteria are found in the excrement (feces) of infected
individuals, and cause illness when ingested. O Infectious material
can be spread to new cases by person-to-person contact or via
contaminated food or water O Infected food workers can contaminate
food, or food can become contaminated during processing. Slide 37 O
Most people who are infected with Shigella develop diarrhea, fever,
and abdominal cramps. The severity of illness ranges from mild to
very severe diarrhea. Diarrhea is bloody 25-50 percent of the time
and most often contains mucus. Rectal spasms are common. O The
illness, shigellosis, starts 12 hours to six days, usually one to
two days, after exposure to the bacterium. Dehydration is also a
common symptom. Slide 38 O Frequent and careful hand washing with
soap and water should be done by both the ill individual and anyone
who is in contact with that person. O Supervised hand washing of
all children should be followed in day care centers and as soon as
children return home. O Childrens handwashing should be supervised
in daycare centers, and children should wash hands after returning
home. Young children with a Shigella infection, or with diarrhea of
any cause, should not be in contact with uninfected children. Slide
39 Staphylococcus aureus O Foods that are frequently a problem with
staphylococcal food poisoning include meat and meat products;
poultry and egg products; salads such as egg, tuna, chicken,
potato, and macaroni; bakery products such as cream-filled
pastries, cream pies, and chocolate eclairs; sandwich fillings; and
milk and dairy products. O Foods that require considerable handling
during preparation and that are kept at slightly elevated
temperatures after preparation are frequently involved in
staphylococcal food poisoning. Slide 40 O Staph may also be present
in raw milk and raw milk products. Staph can cause mastitis in
dairy cows, and other infections in meat animals. In this way, such
meat sources may cause staph outbreaks in people. Slide 41 O Some
S. aureus strains are able to produce staphylococcal enterotoxins
(SEs) and are the causative agents of staphylococcal food
poisonings. Unlike C. perfringens, C. botulinum, and B. cereus, S.
aureus does not form spores. O Thus, S. aureus contamination can be
readily avoided by heat treatment of food. Nevertheless, it remains
a major cause of FBD because it can contaminate food products
during preparation and processing. Slide 42 O Staphylococcal toxins
are fast acting, sometimes causing illness in as little as 30
minutes. Symptoms usually develop within one to six hours after
eating contaminated food. Patients typically experience several of
the following: nausea, vomiting, stomach cramps, and diarrhea. The
illness is usually mild and most patients recover after one to
three days. In a small minority of patients the illness may be more
severe. Slide 43 Vibrio parahaemolyticus O In Asia, V.
parahaemolyticus is a common cause of foodborne disease O Most
people become infected by eating raw or undercooked shellfish,
particularly oysters. Less commonly, this organism can cause an
infection in the skin when an open wound is exposed to warm
seawater. O When ingested, V. parahaemolyticus causes watery
diarrhea often with abdominal cramping, nausea, vomiting fever and
chills. Usually these symptoms occur within 24 hours of ingestion.
Illness is usually self-limited and lasts 3 days. Severe disease is
rare and occurs more commonly in persons with weakened immune
systems. Slide 44 Bacillus cereus O One type is characterized by
nausea and vomiting and abdominal cramps and has an incubation
period of 1 to 6 hours. It resembles Staphylococcus aureus food
poisoning in its symptoms and incubation period. This is the
"short-incubation" or emetic form of the disease. O The second type
is manifested primarily by abdominal cramps and diarrhea with an
incubation period of 8 to 16 hours. Diarrhea may be a small volume
or profuse and watery. This type is referred to as the "long-
incubation" or diarrheal form of the disease, and it resembles more
food poisoning caused by Clostridium perfringens. In either type,
the illness usually lasts less than 24 hours after onset. In a few
patients symptoms may last longer. O Starchy foods such as rice,
macaroni and potato dishes are most often involved. The spores may
be present on raw foods, and their ability to survive high cooking
temperatures requires that cooked foods be served hot or cooled
rapidly to prevent the growth of this bacteria. Slide 45
Clostridium perfringens O C. perfringens is found in soil, dust and
the gastrointestinal tracts of animals and man. When food
containing a large number of C. perfringens is consumed, the
bacteria produce a toxin in the intestinal tract that causes
illness. O C. perfringens can exist as a heat-resistant spore, so
it may survive cooking and grow to large numbers if the cooked food
is held between 40 degrees F and 140 degrees F for an extensive
time period. O Meat and poultry dishes, sauces and gravies are the
foods most frequently involved. Hot foods should be served
immediately or held above 140 degrees F. O When refrigerating large
volumes of gravies, meat dishes, etc., divide them into small
portions so they will cool rapidly. The food should be reheated to
165o F. prior to serving. Slide 46 Yersinia enterocolitica O Y.
enterocolitica is commonly present in foods but with the exception
of pork, most isolates do not cause disease. Like Listeria this
organism is also one that can grow at refrigeration temperatures.
It is sensitive to heat (5%) and acidity (pH 4.6), and will
normally be inactivated by environmental conditions that will kill
Salmonellae Slide 47 E.Coli O157:H7 O E. coli O157:H7 is the source
of an estimated 73,000 illnesses, 2,000 hospitalizations, and 60
deaths in the United States every year O E. coli O157:H7 was firmly
associated with hemorrhagic colitis. The majority of infections are
thought to be food-related, although E. coli O157:H7 accounts for
less than one percent of all food poisoning cases. Slide 48 O E.
coli O157:H7 bacteria are believed to mostly live in the intestines
of cattle but have also been found in the intestines of chickens,
deer, sheep, goats, and pigs. E. coli O157:H7 does not make the
animals that carry it ill; the animals are merely the reservoir for
the bacterium. O While a large number of foodborne illness
outbreaks associated with E. coli O157:H7 have involved ground
beef, such outbreaks have been increasingly associated with fresh
produce, such as lettuce and spinach, but outbreaks have also been
traced to unpasteurized apple and orange juices, raw milk, alfalfa
sprouts, and water. O Person-to-person transmission of the
bacterium has been documented in homes, hospitals, daycare centers,
nursing homes and many other locations. Slide 49 O characterized by
the sudden onset of abdominal pain and severe cramps, followed
within 24 hours by diarrhea. O As the disease progresses, the
diarrhea becomes watery and then may become grossly bloody. O
Vomiting, and rarely fever, can also be symptoms. The incubation
period for the illness (the period from ingestion of the bacterium
to the start of symptoms) is typically three to nine days, although
slightly shorter and longer periods are not that unusual. O An
incubation period of less than 24 hours would be unusual, however.
In most infected individuals, the intestinal illness lasts about a
week and resolves without any long-term problems. Slide 50 O about
five to ten percent of infected individuals develop hemolytic
uremic syndrome (HUS), a severe, life-threatening complication of
E. coli O157:H7 bacterial infection. HUS develops when E. colis
toxins enter the circulation by binding to special receptors.
hemolytic uremic syndrome (HUS) O During HUS, red blood cells are
destroyed and cellular debris accumulates within the blood vessels
while the bodys clot-breaking mechanisms are disrupted, causing
blockage of the terminal arterioles and capillaries
(microcirculation) of most of the major body organs, commonly the
heart, brain, kidneys, pancreas and adrenals. Slide 51 O Some
organs appear more susceptible than others to the damage caused by
these toxins. These organs include the kidney, pancreas, and brain.
O Eating undercooked ground beef has historically been the most
important risk factor for acquiring E. coli O157:H7 Slide 52 O
Persons who cook ground beef without using a thermometer can
decrease their risk of illness by not eating ground beef patties
that are still pink in the middle Slide 53 O Avoid spreading
harmful bacteria in your kitchen. Keep raw meat separate from
ready-to-eat foods. O Wash hands, counters, and utensils with hot
soapy water after they touch raw meat. O Never place cooked
hamburgers or ground beef on the unwashed plate that held raw
patties. O Wash meat thermometers in between tests of patties that
require further cooking. Slide 54 O Drink only pasteurized milk or
juice. Commercial juice with an extended shelf life that is sold at
room temperature (such as juice in cardboard boxes or vacuum-sealed
juice in glass containers) has been pasteurized, although this is
generally not indicated on the label. Most juice concentrates are
also heated sufficiently to kill pathogens. O Fruits and
vegetables, especially if not cooked, should be washed thoroughly.
Children under five years of age, people with weakened immune
systems, and elderly persons should avoid eating sprouts until
their safety can be assured. Methods to decontaminate alfalfa seeds
and sprouts are being investigated. O Drink municipal water that
has been treated with chlorine or other effective disinfectants, or
bottled water that has be sterilized with ozone or reverse osmosis
(almost all major brands use one or the other method). Slide 55 O
Avoid swallowing lake or pool water while swimming, especially pool
water in public swimming facilities. O Avoid petting zoos and other
animal exhibits unless there are good hand washing facilities
available and other sanitation measures have been taken. Wash your
hands and your childrens hands after touching animals. petting zoos
and other animal exhibits O Make sure that persons with diarrhea,
especially children, wash their hands carefully with soap after
bowel movements to reduce the risk of spreading infection, and that
persons wash hands after changing soiled diapers. Anyone with
diarrhea should avoid swimming in public pools or lakes, sharing
baths with others, and preparing food for others. Slide 56 STEC
infection O Some kinds of E. coli cause disease by making a toxin
called Shiga toxin. The bacteria that make these toxins are called
O Shiga toxin-producing E. coli (STEC) O verocytotoxic E. coli
(VTEC) O enterohemorrhagic E. coli (EHEC) O non-O157 STEC. O E.
coli serogroups O26, O111, and O103 Slide 57 O non-O157 serogroup
less likely to cause severe illness than E. coli O157 O some
non-O157 STEC serogroups can cause the most severe manifestations
of STEC illness. O incubation period is usually 3-4 days after the
exposure, O 1 day or 10 days. O The symptoms often begin slowly
with mild belly pain or non-bloody diarrhea that worsens over
several days. O HUS, if it occurs, develops an average 7 days after
the first symptoms, when the diarrhea is improving. Slide 58 O
Oral-feacal O consumption of contaminated food, consumption of
unpasteurized (raw) milk, consumption of water that has not been
disinfected, O contact with cattle, or contact with the feces of
infected people. O unpasteurized (raw) milk, unpasteurized apple
cider, O soft cheeses made from raw milk. O the contact is pretty
obvious (working with cows at a dairy or changing diapers, for
example), O like eating an undercooked hamburger or a contaminated
piece of lettuce O People have gotten infected by swallowing lake
water while swimming, O touching the environment in petting zoos
and other animal exhibits, O by eating food prepared by people who
did not wash their hands well after using the toilet. Slide 59 O
STEC typically disappear from the feces by the time the illiness is
resolved, but may be shed for several weeks, even after symptoms go
away. O WASH YOUR HANDS thoroughly after using the bathroom or
changing diapers and before preparing or eating food. WASH YOUR
HANDS after contact with animals or their environments (at farms,
petting zoos, fairs, even your own backyard). O COOK meats
thoroughly. Ground beef and meat that has been needle-tenderized
should be cooked to a temperature of at least 160F/70C. Its best to
use a thermometer, as color is not a very reliable indicator of
doneness. O AVOID raw milk, unpasteurized dairy products, and
unpasteurized juices (like fresh apple cider). O AVOID swallowing
water when swimming or playing in lakes, ponds, streams, swimming
pools, and backyard kiddie pools. O PREVENT cross contamination in
food preparation areas by thoroughly washing hands, counters,
cutting boards, and utensils after they touch raw meat. Slide 60
Campylobacter These bacteria are very common in poultry. It is
believed that half of all raw chicken is contaminated with it.
Other sources of infection include unpasteurized milk and
contaminated water. Clostridium botulinum This bacterium is common
in soil, and can lead to a deadly illness called botulism.
Food-borne botulism is rare because the organism needs specific
conditions in order to produce toxins; namely a temperature above
38 Fahrenheit and a lack of oxygen. Poorly canned vegetables and
fruits are a potential source for this type of food poisoning, but
modern canning methods have almost done away with the problem.
Honey can be a source of infant botulism. E. coli These bacteria
are the most common cause of travelers diarrhea. Drinking watereven
ice cubes floating in a drinkor eating peeled fruit while in a
foreign country can lead to infection. Undercooked ground beef and
unpasteurized milk are other havens for E. coli. There have been
several recent nationwide E. coli outbreaks in which the culprit
was a vegetable, rather than meat or water. An outbreak in 2006
affected more than 150 people and resulted in 3 deaths. Public
health officials eventually traced the outbreak to raw spinach, but
the ultimate source of contamination remains unknown.. Slide 61
Listeria monocytogenes This bacterium is usually picked up from
soft cheeses, undercooked meats, and foods prepared in
delicatessens Salmonella These bacteria are commonly found in raw
or undercooked meat, poultry, and raw eggs. Shigella These bacteria
thrive in food that is left out for long periods Staphylococcus
These bacteria are usually picked up from mayonnaise-based salads
(tuna salad, potato salad, egg salad) and cream-filled desserts.
Vibrio Normal marine bacteria. Usually acquired by eating raw
mollusks Slide 62 Staphylococ ci Intense vomiting and watery
diarrhea start 1-4 hours after ingestion and last as long as 24-48
hours. Enterotoxin acts on receptors in gut that transmit impulses
to medullary centers. Symptomatic treatment B cereus Contaminated
fried rice (emetic) Meatballs (diarrheal) Emetic enterotoxin (short
incubation and duration) Diarrheal enterotoxin (long incubation and
duration) - Symptomatic treatment C perfringens Inadequately cooked
meat, poultry Acute onset of abdominal cramps with diarrhea starts
8-24 hours after ingestion. Vomiting is rare Enterotoxin produced
in the gut, and food causes hypersecretion in the small intestine.
Symptomatic treatment C botulinum Canned foods (eg, smoked fish,
mushrooms, vegetables, honey) Descending weakness and paralysis
start 1-4 days after ingestion, followed by constipation. Mortality
is very high. Toxin absorbed from the gut blocks the release of
acetylcholine in the neuromuscular junction. Respiratory support
Intravenous trivalent antitoxin from CDC Slide 63 Listeria
monocytogenes Raw and pasteurized milk, soft cheeses, raw
vegetables, shrimp Highly motile, heat-resistant, Gram-positive
organism Enterotoxic E coli (eg, traveler's diarrhea) Contaminated
water and food (eg, salad, cheese, meat) Acute-onset watery
diarrhea starts 24-48 hours after ingestion. Concomitant vomiting
and abdominal cramps may be present. It lasts for 1-2 days
Enterotoxin causes hypersecretion in small and large intestine via
guanylate cyclase activation. Supportive treatment No antibiotics
Enterohemorrhagi c E coli (eg, E coli O157:H7) Improperly cooked
hamburger meat and recently spinach Most common isolate pathogen in
bloody diarrhea starts 3-4 days after ingestion. Usually progresses
from watery to bloody diarrhea. It lasts for 3-8 days May be
complicated by HUS or TTP Cytotoxin results in endothelial damage
and leads to platelet aggregation and microvascular fibrin thrombi
Supportive treatment No antibiotics Enteroinvasive E coli
Contaminated imported cheese Usually watery diarrhea (some may
present with dysentery) Enterotoxin produces secretion Shiga-like
toxin facilitates invasion. Supportive treatment No antibiotics
Slide 64 Enteroaggregative E coliImplicated in traveler's diarrhea
in developing countries Can cause bloody diarrhea Bacteria clump on
the cell surfaces Ciprofloxacin may shorten duration and eradicate
the organism V choleraContaminated water and food Large amount of
nonbloody diarrhea starts 8-24 hours after ingestion. It lasts for
3-5 days. Enterotoxin causes hypersecretion in small intestine.
Positive stool culture Prompt replacement of fluids and
electrolytes V parahaemolyticusRaw and improperly cooked seafood
(ie, mollusks and crustaceans) Explosive watery diarrhea starts
8-24 hours after ingestion. It lasts for 3-5 days. Enterotoxin
causes hypersecretion in small intestine. Hemolytic toxin is
lethal. Positive stool culture Prompt replacement of fluids and
electrolytes C jejuniDomestic animals, cattle, chickens Fecal-oral
transmission in humans Foul-smelling watery diarrhea followed by
bloody diarrhea Uncertain about endotoxin production and invasion
Culture in special media at 42C Slide 65 Shigella Potato, egg
salad, lettuce, vegetables, milk, ice cream, and water Abrupt onset
of bloody diarrhea, cramps, tenesmus, and fever starts 12-30 hours
after ingestion. Organisms invade epithelial cells and produce
toxins. Infective dose is 102-103 organisms. Enterotoxin-mediated
diarrhea followed by invasion (dysentery/colitis) Polymorphonuclear
leukocytes (PMNs), blood, and mucus in stool Positive stool culture
Salmonella Beef, poultry, eggs, and diary products Abrupt onset of
moderate-to-large amount of diarrhea with low-grade fever; in some
cases, bloody diarrhea Invasion but no toxin production Positive
stool culture Antibiotic for systemic infection Yersinia Pets;
transmission in humans by fecal-oral route or contaminated milk or
ice cream Acute abdominal pain, diarrhea, and fever (enterocolitis)
Gastroenteritis and mesenteric adenitis Direct invasion and
enterotoxin PMNs and blood in stool Positive stool culture Slide 66
Slide 67 Slide 68 Slide 69 Slide 70
