Food Poisoning LectV2 for Med Students
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Transcript of 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
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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
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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.
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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
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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
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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.
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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. ,
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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.
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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.
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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.
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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
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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
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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.
Prevention of Food Poisoning 2
f
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Prevention of Food Poisoning 3
•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.