Food Poisoning LectV2 for Med Students

8/3/2019 Food Poisoning LectV2 for Med Students

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Food Poisoning

Freddie BwangaM.B;Ch.B, M.Med (Microb), PhD

Tues 24th

Nov 2010





Definition Food poisoning

An illness caused by the consumption of food or watercontaminated with bacteria and/or their toxins, orwith parasites, viruses, or chemicals.

Characteristics of a food-borne disease outbreak: Similar illness

Often gastrointestinal

Minimum of 2 people

Evidence of food as the source



Symptoms - varying degree and combination

• Abdominal pain• Vomiting

• Diarrhea

• Headache

• Most illnesses are mild and improve without treatment.

• Some patients have severe disease and requirehospitalization, aggressive hydration, and antibiotic treatment.

• More serious cases can result in life-threatening neurologic,hepatic, and renal syndromes leading to permanent disabilityor death.



Burden of Food Poisoning

•Worldwide problem

•More common in developing countries

CDC estimates in the United States:

76 million illnesses

325,000 hospitalizations

5,000 deaths each year

•Travelers to developing countries often encounter food poisoning inthe form of traveler's diarrhea

•Terrorist can use food toxins as weapon



Causes food Poisoning…1 1. Pathogens causing non-inflammatory diarrhea (NID)

NID is due to the action of enterotoxins on the secretory mechanisms of the mucosa of the small intestine, without invasion. – Large volume watery stools +- profound dehydration

– No blood or pus in stool

– No severe abdominal pain

– The enterotoxins may be either preformed before ingestion or produced in the gutafter ingestion. Organisms involved

Bacteria: Vibrio cholerae, Enterotoxic Escherichia coli Clostridium perfringens Bacillus cereus Staphylococcus aureus.

Viruses:Rotavirus,Norovirus (genus Norovirus , previouslycalled Norwalk virus), and Adenovirus.

Parasites:Giardia lamblia Cryptosporidium



In some types of food poisoning (eg, staphylococci, B cereus ),vomiting is caused by a toxin acting on the central nervous

system.

The clinical syndrome of botulism results from the inhibition of acetylcholine release in nerve endings by the botulinum.



Causes food Poisoning..2 2. Pathogens causing Inflammatory diarrhea (ID)

Parasites•Entamoeba histolytica, and

Bacetria:•Campylobacter jejuni,•Vibrio parahaemolyticus, •Enterohemorrhagic and•Enteroinvasive E coli •Yersinia enterocolitica,•Clostridium difficile,•Salmonella •Shigella

ID Charcterstics•Mucosal invasion & destruction•Colon or the distal small bowel commonly involved•Patients usually febrile and may appear toxic.•Diarrhea stool: small vol, usually bloody, mucoid & leukocytes +ve•Dehydration is less likely because of smaller stool volumes.•Organisms may penetrate the mucosa and proliferate in the local lymphatic

tissue, followed by systemic dissemination. ,



Causes food Poisoning…3 3. Non-Infectious causes

• Mushrooms

• Toadstools

• Heavy metals [eg, arsenic, mercury, lead])

• For these non infectious causes, the pathophysiologicalmechanisms that result in acute gastrointestinalsymptoms are not well known.



Suspicion of causative agentIndicator /Symptom Suspected cause

Vomiting Staphylococcus aureus, B cereus, Norovirus ]

A profuse rice-water stool

Painful abdominal muscle cramps

Cholera

Bloating Giardiasis

Severe Abdominal pain Inflammatory processes

Symptoms similar to those of appendicitis Yersinia enterocolitis

Proctitis syndrome ie

Frequent painful bowel movement

Stool contains blood, pus, and mucus. Tenesmus and rectal discomfort

Shigellosis (dysentry)

Undercooked meat/poultry Salmonella, Campylobacter, Shiga toxin

E coli, C perfringens.

Raw seafood Norwalk-like virus, Vibrio organism ,

Hepatitis A.

Homemade canned foods C botulinum Unpasteurized soft cheeses Listeria, Salmonella, Campylobacter , Shiga

toxin, E coli, Yersinia.

Deli meats notoriously Listeriosis

unpasteurized milk or juice Campylobacter, Salmonella, Shiga toxin E

coli, and Yersinia.

Raw eggs Salmonella

Reactive arthritis Salmonella, Shigella, Campylobacter, and Yersinia infections.



When To Seek Medical Care •Nausea, vomiting, or diarrhea lasts for more than two days.

• Younger than three years.

•The abdominal symptoms are associated with a low-grade fever.

•Symptoms begin after recent foreign travel.

•Other family members or friends who ate the same thing are also sick.

•The ill person cannot keep any liquids down.

•Immunosuppressive conditions (e.g. HIV/AIDS, cancer and undergoingchemotherapy, kidney disease).

•Nervous system symptoms e.g. slurred speech, muscle weakness, doublevision, or difficulty swallowing.

http://www.emedicinehealth.com/script/main/art.asp?articlekey=58728




Signs of emergencePatient collapses, become dizzy, lightheaded, or have problems with vision,speech or swallowing

•T >39°C occurs + abdominal symptoms

•Sharp or cramping pains do not go away after 10-15 minutes

•Swollen abdomen

•The skin and/or eyes turn yellow• Vomiting blood or having bloody bowel movements

•

Oligouria/anuria, or have dark urine

•Difficulty or rapid breathing

•One or more joints swell or a rash breaks out on the skin

•Patient or caretaker considers the situation to be an emergency



Safe food preparation

Keep everything clean!

Wash hands after the toilet, and before touching foods/utencils/cutlery

Wash hands before and after handling raw meat and poultry

Sanitize cutting boards often in a solution of one teaspoon chlorinebleach in one quart of water

Do not cross-contaminate. Keep raw meat, poultry, fish, and their

juices away from other food.

After cutting raw meats, wash hands, cutting board, knife, and countertops with hot, soapy water.

Prevention of Food Poisoning 1





Safe cooking

• Through cooking of meats/poultry before eating• Keep hot foods hot and cold foods cold.• Use cooked leftovers within four days.• Microwave: Cook meat and poultry immediately after microwave

thawing.


f




•Safe shopping•Buy cold foods last during your shopping trip. Get them home fast.•Never choose torn or leaking packages.•Do not buy foods past their "sell-by" or expiration dates.•Keep raw meat and poultry separate from other foods.

•Safe storage of foods•Keep it safe; refrigerate.•Unload perishable foods first and immediately refrigerate them.•Place raw meat, poultry, or fish in the coldest section of yourrefrigerator.•

Check the temperature of your appliances.•To slow bacterial growth, the refrigerator should be at 2-8oc, thefreezer at minus 20°C.

•Cook or freeze fresh poultry, fish, ground meats, and variety meatswithin two days.

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Food Poisoning LectV2 for Med Students