FOOD INTOXICATIONSBritni Mahan and Beth Johnson

WHAT IS FOOD POISONING? Food poisoning is an illness caused by eating

foods that have harmful organisms in them. Includes: bacteria, parasites, fungi, and

viruses. Mostly found in raw meat, chicken, fish, and

eggs, but can spread to any type of food. Can also grow on food that is left out on

counters or outdoors or is stored too long before you eat it.

Sometimes food poisoning is caused by people not washing their hands before they touch food.

CAUSES Food poisoning can affect one person or it

can occur as an outbreak in a group of people who all ate the same contaminated food.

Food poisoning tends to occur at picnics, school cafeterias, and large social functions. In these cases, food may be left out of the refrigerator too long or food preparation techniques may not be clean. Food poisoning often occurs from eating undercooked meats, dairy products, or food containing mayonnaise (like coleslaw or potato salad) that have sat out of the refrigerator too long.

SIGNS AND SYMPTOMS Most commonly

Diarrhea Vomiting Stomach cramps Nausea Headaches Fever

TYPES OF FOOD POISONING

The microorganism itself grows inside your body and is the source of your symptoms

A chemical or natural toxin (often produced as a by-product of bacteria present in the food - known as an exotoxin)

Infection Intoxication

We will be focusing on food intoxications

TREATMENT FOR FOOD INTOXICATIONS In most cases, food intoxications go away on their

own in 2 to 3 days. Rest and plenty of fluids to prevent dehydration. Doctors recommend trying to eat normally as soon

as possible. But, follow a BRAT diet (Bananas, Rice, Applesauce and Toast) until you can eat without vomiting

Try to stay away from foods that are high in fat or sugar

Antibiotics are usually not used to treat food poisoning, they can actually worsen the symptoms.

Medicines that stop diarrhea (anti-diarrheals) can be helpful, but they should not be given to infants or young children.

COMPLICATIONS AND LONG TERM EFFECTS Most types of food poisonings only lead to severe

dehydration and do not lead to long term effects or conditions. Here are some examples that do.

Arthritis (Yersinia and Salmonella) Bleeding disorders (E. coli and others) Death (from mushrooms, certain fish poisonings,

or botulism) Kidney problems (Shigella, E. coli) Nervous system disorders (Botulism,

Campylobacter) Pericarditis Salmonella) Respiratory distress, including the need for

support on a breathing machine (botulism)

MOST COMMON TYPES OF FOOD POISONINGThe most common types of food poisoning are

caused by bacteria such as: Staphylococcus aureus Salmonella Clostridium botulinium Vibro parahaemolyticus Bacillus cereus Listeria monocytogens Campylobacter jejuni Versinia enterocolotica Enteropathogenic E. coli

FRIDAY’S SPECIALOOOPS… SHOULD HAVE BROWN BAGGED ITBy Dr. Beth JohnsonFlamingham General HospitalApril 23, 2009

PATIENT BACKGROUNDANATOMICAL AND EPIDEMIOLOGICAL DIAGNOSIS

Mary Kate De Sausalito 16 years old girl History of malaise since noon followed by severe

abdominal cramps, headache and weakness In transit to hospital patient experienced perfuse

and continuous vomiting.

PATIENT BACKGROUNDANATOMICAL AND EPIDEMIOLOGICAL DIAGNOSIS

Patient did not appear to be in acute distress, but did vomit a few more times during interview.

Patient also experienced profuse watery diarrhea during initial exam.

Patient claimed to have no family history. She was adopted and may have an identical twin sister, but there are no records.

CONTINUED EPIDEMIOLOGICAL DIAGNOSIS Mary Kate is a high school cheerleader and

frequently stays after school for practices and games. Being in heavily populated areas and in close contact with others on a regular basis can make one more susceptible to catch a contagious infection. In addition, Mary Kate gets her lunches from the school cafeteria, which also increases her risk of a food borne illness.

EXAM IN THE ERPatients vitals were taken and came back normal Patient Normal

Temp 37.1 C 37.0 C

Pulse 110 BPM 70-100 BPM

BP 110/9mmHg Systolic: 110 - 140mmHg

Diastolic: 70 - 90 mmHg

Respirations 20/Min 15-20 /Min

THE LIKELY SUSPECTS It was clear to me with Mary Kate’s vital

signs being normal coupled with her signs and symptoms, that she had become the victim of food poisoning (food-borne illness).

Food-bourne illness-(food poisoning) is any illness resulting from the consumption of food.

There are two types

THE LIKELY SUSPECTS Food borne infection and Food Intoxication

Food Infection- Refers to the presence of bacteria or other microbes which infect the body, after consumption of food.

Food Intoxication- Refers to the ingestion of toxins contained within the food, including bacterially produced exotoxins which can happen even when microbe which produced the toxin is no longer present.

THE LIKELY SUSPECTS Most Cases are caused by: A variety of pathenogenic bacteria Viruses ParasitesCommon Symptoms include: Nausea/Vomiting Abdominal Pain Diarrhea Fever Headache Fatigue Gastroenteritis

POTENTIAL MICROBES My initial differential diagnosis showed that

there were twenty seven microbes that could have been the potential cause of Mary Kate's illness.

But after careful research of the microbes, I ruled out 24 of them and focused on the four that were most like the signs and symptoms my patient was exhibiting.

AND

THE

CONTESTANTS

WERE

DIFFERENTIAL DIAGNOSIS Staphylococcus aureus-- Type of gram

positive food poisoning caused by infection with the Staphylococcus aureus bacterium. Bacteria multiply in foods and produce a toxin even at refrigeration temps. The toxin may be present in dangerous amounts in foods with no sign of spoilage.

Reason to consider- it is known for abrupt onset of intense vomiting and diarrhea for up to 24 hours with an incubation period of 2-8 hours. This microbe is a likely cause of the patients illness in regards to her vomiting and diarrhea.

DIFFERENTIAL DIAGNOSIS

Salmonella spp- (gastroenteritis) A gram neg food poisoning that grow in gut.

Reason to consider- Clinical features include gradual or abrupt onset of diarrhea and low grade fever, nausea, headache and muscle aches.

DIFFERENTIAL DIAGNOSIS Trichina spiralis- a parasitic worm that lives in

the intestines and causes a serious illness known as trichinosis. The eggs usually enter the body via raw or undercooked pork, sausage, or bear meat. The eggs hatch mature in the intestines and migrate to other parts of the body through the bloodstream and lymph system.

Reason to consider- Early symptoms include vomiting, diarrhea, and abdominal cramps. In time, a high fever and puffiness of face and muscle pain develop.

DIFFERENTIAL DIAGNOSIS Norwalk virus- (stomach flu) Intestinal illness

that often occurs in outbreaks, increasingly being recognized as the leading causes of food bourne disease in the U.S. Virus is passed in stool of infected person, people get infected by swallowing stool contaminated food or water. Also outbreaks are often linked to raw oysters.

Reason to consider- Signs and symptoms of this virus are nausea, vomiting, diarrhea, and stomach cramps. Similar to that of the patient.

SPECIMENS TESTEDSTOOL/VOMIT SPECIMENS WERE TESTED ON: BLOOD MAC SS CAMPY SELENITE HEBLOOD SPECIMENS WERE TESTED ON: BLOOD CHOC MAC ANA

RESULTS

THE RESULTS OF THE AGAR PLATES DEMONSTRATED NO SIGNS OF INFECTION. THE ONLY GROWTH ON PLATES WAS OF NORMAL FLORA THAT IS NORMALLY FOUND WITHIN THE GUTS OF HUMANS.

WBC COUNT MARY KATE NORMAL

SEGMENTED NEUTROPHILS 61%BANDEDNEUTROPHILS 1%

44-77%

0-5%

BASOPHILS 2%

0-2%

EOSINOPHILS 1%

0-7%

LYMPHOCYTES 31%

16-43%

MONOCYTES 4%

2-10%

RULING OUT The results of the WBC Counts helped me to

rule out the possibility of a parasitic infection. If the cause were Trichinosis, my patients white blood cell count would have been elevated due to an increase in antibodies created to fight off this infection.

Mary Kates wbc count would also have been elevated had my patient been infected with the Norwalk Virus.

A TOSS UP Now that the virus and parasites are ruled out,

the last of my possible candidates are: Salmonella spp and Staphylococcus aureus

Helping me to determine that the cause of Mary Kate's illness as Bacterial Gastroenteritis.

CONTINUED EPIDEMIOLOGICAL DIAGNOSIS Not long after my patients admission to the

hospital, 35 more students from Mary Kate’s High School of whom all share the same lunch period show up in the emergency room, all with the same symptoms.

I immediately called the hospitals infection control officer regarding a potential outbreak of food poisoning at a local school, and ordered test on the food that was served that day.

RESULTS OF TESTED FOOD When the cultures of the food came back,

the results showed gram positive cocci that were produced on TSA, BLOOD and PEA and there was no growth on the MAC.

No growth on the MAC ruled out the possibility of a the gram negative bacterial infection of salmonella.

Growth of gram positive cocci reinforced the likely hood of Staphylococcus aureus food poisoning.

THE CULPRITE Staphylococcus aureus Facultative anaerobic gram positive cocci

that makes ATP by aerobic respiration, if oxygen is present, but is also capable to switch to fermentation.

Microscopic -grape like clusters Macroscopic - golden yellow colonies 20 % of population are long term carriers

SOME INFECTIONS CAUSED BY STAPHYLOCOCCUS AUREUSIn addition to food poisoning, this bacteria can

also cause minor skin infections such as: Impetigo Pimples Boils CellulitisAs well as more life threatening diseases such

as Pneumonia Meningitis Toxic Shock Syndrome

WHAT IS STAPH AUREUS FOOD POISONING? Staphylococcal food poisoning is a

gastrointestinal illness caused be eating foods contaminated with the toxins produced by Staphylococcus aureus.

The most common way of contamination is through workers who carry the bacteria or through contaminated milk and cheeses.

Staphylococcus aureus produces an enterotoxin (a type of exotoxin or protein toxin that is released by microorganisms in the intestines).

WHAT IS STAPH AUREUS FOOD POISONING? Staphylococcus is salt tolerant and can grow

in salty foods like ham. As the germ multiplies in food, it produces

toxins that can cause illness. Staphylococcal toxins are resistant to heat

and cannot be destroyed by cooking. Foods at highest risk of contamination with

Staphylococcus aureus and subsequent toxin production are those that are made by hand and require no cooking such as puddings, some pastries and sandwiches.

SIGNS AND SYMPTOMS 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.

HOW DO KNOW IF I HAVE STAPH FOOD POISONING?Toxin-producing Staphylococcus aureus can be

identified in stool or vomit, and toxin can be detected in food items.

Diagnosis of staphylococcal food poisoning in an individual is generally based only on the signs and symptoms of the patient.

Testing for the toxin-producing bacteria or the toxin is not usually done in individual patients, but is usually reserved for outbreaks involving several persons.

INITIAL EXAM Abdominal examination was notable for abdominal

tenderness The remainder of her physical exam was unremarkable.

She had an “urgent” conversation with a nurse, who escorted her to the ladies’ room; the nurse immediately informed you that Ashley had profuse, watery diarrhea.

As you concluded your examination of Ashley, the admitting clerk warned you that tons of kids were throwing up all over the waiting room

Claimed to have no family history. She was adopted and may have an identical twin sister, but there are no records

TREATMENT The best treatments for these patients are

rest, plenty of fluids, and medicines to calm their stomachs.

Highly susceptible patients, such as the young and the elderly, are more likely to have severe illness requiring intravenous therapy and care in a hospital.

Antibiotics are not useful in treating this illness. The toxin is not affected by antibiotics.

Patients with this illness are not contagious. Toxins are not transmitted from one person to another.

PREVENTION It is important to prevent the contamination of food

with Staphylococcus before the toxin can be produced. Wash hands and under fingernails vigorously with soap

and water before handling and preparing food. Do not prepare food if you have a nose or eye

infection. Do not prepare or serve food for others if you have

wounds or skin infections on your hands or wrists. Keep kitchens and food-serving areas clean and

sanitized. If food is to be stored longer than two hours, keep hot foods hot (over 140°F) and cold foods cold (40°F or under).

Store cooked food in a wide, shallow container and refrigerate as soon as possible.

PROGNOSIS After a little TLC, Mary Kate and her classmates

were all back to normal the following day.

THE BEST CAFETERIA DAY OF THE MONTH

Ashley de Sanfrancisco 16 years old Chow mein lover By 5 PM:

severe abdominal cramps

headache felt weak

Sent to hospital and vomited on the way, but arrived in apparent “good health”

BEWARE THE IDES OF MARCH

HOSPITAL ADMISSION Vomited twice while being interviewed, but did not

appear in acute distress  

Normal Values Patient's

Body Temperature (T)

37oC 37.1oC

Heart Rate (Pulse) 60-100/min (higher for infants and children)

110 beats/min

Respiratory Rate (Respiration)

9-18/min (higher for infants and children)

20 breaths/min

Blood Pressure (BP)

90-150/50-90 (lower for infants and children)

110/90 mm Hg

SPECIMEN REQUEST’S

-BloodNO SMEAR – This Specimen is NOT Routinely Gram Stained BLOODCHOCMACANA

- Stool &VomitisNO SMEAR – This Specimen is NOT Routinely Gram StainedUpon Special Request - EXAMINATION FOR LYMPHOCYTES BLOODMACHESSCAMPY - Incubate at 42oCSELENITE - Place Remaining Specimen on Swab in Selenite Broth

CBC RESULTSComplete Blood Count (CBC) Normal Values Patient's

White Blood Cell (WBCs) 4,000-10,000/mm3

9500/mm3

- Neutrophils 47 - 77%62%

- Segmented Neutrophils 60 - 70%61%

- Banded Neutrophils 0 - 5%1%

- Basophils 0 - 2%2%

- Eosinophils 0 - 7%1%

Monocytes 2 - 10%4%

Lymphocytes 16 - 43%31%

LIKELY SUSPECTS The Stool and Vomitis specimens were still

pending.. 35 students were admitted with similar

symptoms, they all shared same lunch period S. aureus was my most likely suspect at this

point, but considering B.cereus because of the rice. The 2 pathogens have similar same signs and

symptoms and are often difficult to initially distinguish from one another

A sample of the rice that the students ate was ordered at this point to definitively identify the pathogen causing my patient’s illness.

CAUSE: BACILLUS CEREUS The cultures of the STOOL and VOMITIS grew

out “normal flora.” The cultures of the FOOD from the school

cafeteria produced Gram-positive bacilli that grew on TSA, BLOOD, and PEA, but “no growth” on MAC.

BACILLUS CEREUS Gram-positive, facultative

aerobic spore former which produces two types of toxins. Most B. cereus are motile

B. cereus is beta hemolytic (the bacteria's hemolytic enzymes completely break down blood cells)

The β-hemolysis pattern results in the media displaying clear halos around bacterial colonies.

B. Cereus on a blood agar plate

BACILLUS CEREUS FOODBORNE ILLNESSES Occur due to survival of the bacterial endospores

when food is improperly cooked. This problem is compounded when food is then improperly refrigerated, allowing the endospores to germinate.

Bacterial growth results in production of enterotoxin (a protein toxin released by a microorganism in the intestine), and ingestion leads to two types of illness: The emetic illness is caused by the ingestion of a heat-

stable toxin produced by the microorganisms in the food.

The diarrheal illness is caused by the ingestion of moderate to high number of B. cereus and their subsequent production of toxin in the stomach.

B. CEREUS FOOD POISONING

Diarrheal type food poisoning mimic signs and symptoms of Clostridium perfringens food poisoning. 6-15 hours after

consumption -watery diarrhea, abdominal cramps, and pain occurs *Nausea may accompany diarrhea, but vomiting (emesis) rarely occurs. Symptoms persist for 24 hours in most instances

Characterized by nausea and vomiting within 0.5 to 6 hours after consumption of contaminated foods.

Occasionally, abdominal cramps and/or diarrhea may also occur.

Duration of symptoms is generally less than 24 h. The symptoms of this type of food poisoning parallel those caused by Staphylococcus aureus foodborne intoxication

Diarrheal Emetic

SOURCES A wide variety of foods including meats, milk,

vegetables, and fish have been associated with the diarrheal type food poisoning.

The vomiting-type outbreaks have generally been associated with rice products; however, other starchy foods such as potato, pasta and cheese products have also been implicated.

DIAGNOSIS The rapid onset time to symptoms in the

emetic form of disease, coupled with some food evidence, is often sufficient to diagnose this type of food poisoning.

Isolation of B. cereus serotype in food and vomitis or stools of patients is also done

Large numbers of enterotoxigenic Bacillus cereus were isolated from the rice that was part of the lunch served to the students.

Reverse passive agglutination was used to demonstrate the presence of entertoxin type in the patient’s vomitis and in the leftover rice.

OTHER COMPLICATIONS ASSOCIATED WITH B.CEREUS Although no specific complications have been

associated with the diarrheal and vomiting toxins produced by B. cereus, other clinical manifestations of B. cereus invasion or contamination have been observed.

Bovine mastitis severe systemic and pyogenic infections gangrene septic meningitis cellulitis panophthalmitis lung abscesses infant death endocarditis

TREATMENT Due to the apparent nature of this outbreak of food

poisoning, I decided not to admit my patient for further diagnostic testing.

She was sent home with orders that included supportive therapy [drink plenty of fluids, etc.] but no antibiotic therapy was needed. Most cases of Bacillus cereus food poisoning resolve themselves without medical treatment

Antibiotics are normally not given, as the bacteria have been found to be resistant to penicillin and antibiotics are rarely needed for food poisoning. In some cases, antibiotics worsen the condition.

This illness cannot be spread by person to person contact. The only way to contract the illness is by consuming contaminated food.

PREVENTION To prevent food poisoning, take the following steps when

preparing food: Carefully wash your hands and clean dishes and utensils. Use a thermometer when cooking. Cook beef to at least

160°F, poultry to at least 180°F, and fish to at least 140°F. DO NOT place cooked meat or fish back onto the same plate

or container that held the raw meat, unless the container has been completely washed.

Promptly refrigerate any food you will not be eating. Keep the refrigerator set to around 40°F and your freezer at or below 0°F. DO NOT eat meat, poultry, or fish that has been refrigerated uncooked for longer than 1 to 2 days.

DO NOT use outdated foods, packaged food with a broken seal, or cans that are bulging or have a dent.

DO NOT use foods that have an unusual odor or a spoiled taste.

PREVENTION If you take care of young children, wash your hands often and

dispose of diapers carefully so that bacteria can't spread to other surfaces or people.

If you make canned food at home, be sure to follow proper canning techniques to prevent botulism.

DO NOT feed honey to children under 1 year of age. DO NOT eat wild mushrooms. When traveling where contamination is more likely, eat only hot,

freshly cooked food. Drink water only if it's been boiled. DO NOT eat raw vegetables or unpeeled fruit.

DO NOT eat shellfish that has been exposed to red tides. If you are pregnant or have a weakened immune system, DO NOT

eat soft cheeses, especially imported from countries outside the U.S.

If other people may have eaten the food that made you sick, let them know. If you think the food was contaminated when you bought it from a store or restaurant, tell the store and your local health department