Food poisoning

FOOD POISONING

DEFINITION OF FOOD POISONING

Food poisoning is general term for health problem arising from eating contaminated food by bacteria, viruses, or environment toxins that present within the food it self characterized by nausea, vomiting with/without diarrhea.

The contamination of food may occur at any stage in the process from the food production to consumption

Epidemiology of Food Poisoning

Food poisoning, occurs commonly throughout the world. It is estimated that in the United States alone, approximately 48 million episodes occur annually, resulting in approximately 3000 deaths per year.

In the United Kingdom about 2 million people a year suffer from an attack of diarrhea with/without vomiting due to food poisoning. Most do not consult their doctor and the cause is not often found.

In Malaysia, Melaka registered the highest incidence rate (IR)of food poisoning cases per 100,000 population at (108.6) followed by Perlis (102.3) and Terengganu (78.2). Meanwhile, W.P. Labuan recorded the lowest IR in 2012 at (1.1)

Type of food poisoningCAUSED BY BACTERIA

Salmonella

Salmonell

There are > 4000 salmonella serotypes

Most common salmonella spps

Salmonella Enteritidis

Salmonella Typhi

Two types of salmonella infections:

1) Systemic infections (enteric fever): S. Typhi, S. Paratyphi A – C

2) Gastroenteritis (salmonellosis): S.enteritidis

Pathogenesis :

with the invasion of intestinal epithelia

1. invasion continues and infection becomes generalized → little or no diarrhea, but pronounced fever & other general symptoms

2. infection is localized to ileocaecal region → diarrhea, nausea & vomiting, abdominal pain, temperature may be elevated

Source of infection by asymptomatic carriers, contaminated food & water,contaminated poultry animals & products.

Route of infection is faeco-oral route.

Laboratory diagnosis :

blood culture,

stool culture,

urine culture.

Widal test(agglutination test),ELISA.

Treatment:

for typhoid fever ciprofloxacilin/ceftriaxone/ampicillin.

Self limiting & symptomatic for gastroenteritis.

Clostridium

C. perfringens is found frequently in the intestine of humans, animals, present in soil and areas contaminated by human or animal feces.

results by eating improperly cooked and stored foods.

Commonly infected foods = meats, meat products, and gravy.

cause intense abdominal cramps and watery diarrhea.

*Stool culture and blood tests may be done to confirm the diagnosis.

*treat C. perfringens food poisoning by managing any complications (dehydration caused by diarrhea and vomiting)

Clostridium botulinum

Cl.botulinum-gram positive bacilli with sub terminal spores

causes botulinism

Pathogenesis by botulinum toxin.

Mode of infection by soil,contaminated food.

Treatment with penicillin,antitoxin.

Prevention

good food manufacturing practice.

adequate cooking of food before consumption

Staphylococcus aureus

Staphylococcus aureus –Gram positive cocci in cluster

Nonsporing,nonmotile,aerobic organisms.

2nd most reported food borne disease.

pathogenesis:

Heat resistant exotoxin acts as enterotoxin – boiling for 30 mins not sufficient to denature the exotoxin

Incubation period 1 – 6 hours; rapid recovery

Contaminated meats , fish, potato salad, custards, etc.

inoculated into foods during pre.paration

Mode of transmission: Human reservoir (nose), skin abscesses

Specimens-suspected food,vomits & faeces.

Microscopy

Culture on blood agar media grows beta haemolytic colonies.

Coagulase test-positive

Treatment:

Cloxacillin,vancomycin,linezolid etc

Bacillus cereus

Grows well on ordinary media like nutrient agar,blood agar,gelatin agar media.

Virulence factors enterotoxins .

Mode of infection by spores in soil &food.

Causes gastroentritis ie food poisoning.

Treatment-ciprofloxacin in anthrax cases & symptomatic treatment in food poisoning cases.

Prevention:

disinfection

Food hygiene.

Refrigerated cooked food should be reheated.

Vibrio cholerae

Vibrios-2 spps

vibrio cholerae

V.parahaemolyticus-comma shaped

Mode of infection is faeco-oral route.

Through ingestion of contaminated water or sea food or by exposure of disrupted skin and mucosal surfaces to contaminated water.

Pathogenesis:

Cholera toxin activates adenylate cyclase → hyper secretion of water & electrolytes → death by dehydration and electrolyte abnormalities

“Rice-Water” stools, painless, non-bloody diarrhoea

Severe Dehydration-thirst, oliguria, anuria, cramps, weakness, decrease turgor

Circulatory collapse- cyanosis, stupor, renal tubular necrosis, death

Metabolic Acidosis may be severe loss of bicrabonates.

Laboratory daignosis:

specimen-stool,rectal swabs in acute phase of diarrhoea.

Elisa

Culture on TCBS agar media yellow – green coloured colonies.

Serodiagnosis very less efficient agglutination& anti toxin test.

Treatment: rehydration & antimicrobial agents like tetracycline or doxycycline

Chloramphenicol,ampicillin or trimethoprim-sulfamethoxazole.

Prevention:

Chemoprophylaxis.

Vibrio cholerae

Investigation

Laboratory investigation

Gram staining and Loeffler methylene blue staining of the stool for WBCs help to differentiate invasive disease from noninvasive disease.

Perform microscopic examination of the stool for ova and parasites.

Bacterial culture for enteric pathogens, such as Salmonella becomes mandatory if a stool sample shows positive results for increase WBCs or if patients have fever or symptoms persisting for longer than 3-4 days.

Perform blood culture if the patient is notably febrile.

CBC with differential, serum electrolyte assessment, and BUN and creatinine levels help to assess the inflammatory response and the degree of dehydration.

Imaging investigation

abdominal radiographs should be obtained if the patient experiences bloating, severe pain, or obstructive symptoms or if perforation is suggested.

Invasive investigation

When a stool examination is nondiagnostic, performing sigmoidoscopy/colonoscopy with biopsy and esophagogastroduodenoscopy (EGD) with duodenal aspirate and biopsy may be beneficial.

Consider sigmoidoscopy in patients with bloody diarrhea. It can be useful in diagnosing inflammatory bowel disease, antibiotic-associated diarrhea, shigellosis, and amebic dysentery.

Prevention and Control of Food

Poisoning

Prevention

Individual

Wash hands thoroughly before handling food

always cook by your self. Reduce take outside food.

Keep food preparation surfaces and utensils clean and disinfected (e.g. anti-bacterial)

Prepare and store raw meat and 'ready-to-eat' food separately

Always keep raw and defrosting meat at the base of the refrigerator, below everything else

Ensure that refrigerator and freezer are operating properly. The refrigerator should operate at 5 degrees C or lower and the freezer at -18 degrees C or lower

Check the 'Use by' dates on food and ensure that you use the food before the date expires

Always store eggs in the refrigerator and do not eat food containing uncooked eggs

Keep pets away from food and food preparation surfaces

Defrost food, particularly meat and poultry thoroughly before cooking

Cook food thoroughly. Follow the manufacturers' guidelines and ensure that food is piping hot throughout before consumption

Government

Appropriate training for preventative control

Food handlers have a major role in the prevention of food poisoning during food preparation since they may cross contaminate raw and cooked foodstuffs as well as inadequately cook and store foods.

The Ministry of Health in Malaysia launched the Food Handlers’ Training Programme in 1996 to ensure hygienic practices during handling, preparation and sale of food.

Adoption of food safety management systems and risk models

Hazard Analysis Critical Control Point (HACCP) in food service establishments

system that helps food business operators look at how they handle food and introduces procedures to make sure the food produced is safe to eat.

Control

individual

Wash hands after contact with the sick person, and before handling food

Do not use the same towel or face cloth as someone who is suffering with food borne illness

Clear up soiling accidents straightaway, wash with hot soapy water and disinfect with a disinfectant or bleach

Disinfect door and toilet handles, taps and the toilet seat after use and disinfect the toilet bowl frequently

Drink plenty of fluids while you are ill to prevent dehydration

Government

Surveillance and monitoring

A Food Safety Information System of Malaysia (FoSIM) was launched in 2003 to assist in the management of food safety surveillance to ensure imported foods sold in Malaysia are safe for human consumption .

Food premises inspection and closures were carried out intensively if not follow certain criteria

Reference

http://www.moh.gov.my/index.php/pages/view/324

Compendium of environment statistic Malaysia 2013 by department statistic of Malaysia

http://www.who.int/foodsafety/areas_work/foodborne-diseases/en/

http://www.doctorslounge.com/gastroenterology/diseases/food_poisoning.htm

Microbial Food Poisoning 2nd Edition, Edited By Adrian R. Elay

THANK YOU