1. FOOD BORNE DISEASES Lecture Group A

2. Classification of food borne diseases
Food borne diseases are classified into:
Food borne infections
Food borne intoxications

3. Food Infection
Any infectious illness caused by eating food contaminated with viruses, bacteria, worms, or other organisms.

4. Food borne infections
Food borne infections are caused by the entrance of pathogenic microorganisms contaminating food into the body, and the reaction of the body tissues to their presence.
These can either be fungal, bacterial, viral or parasitic
Food borne infections tend to have long incubation periods and are usually characterized by fever

5. Food Borne Infections cont..
Bacterial food borne infections include Cholera, salmonellosis, typhoid fever, shigellosis, Yersiniosis Escherichia coli infection Campylobacteriosis, Vibrio parahemolyticus and Listeriosis Mycotoxic food borne infections include ( aflatoxin , Ochratoxins and T2 toxin ) Viral food borne infections include hepatitis A , Norwak virus and poliomyelitis virus

6. salmonellosis Symptoms
There are many different kinds of these bacteria,Salmonella
Serotype Typhimurium and Salmonella serotype Enteritidis are the most common type responsible for infections
Symptoms
diarrhea
Fever
abdominal cramps
chronic arthritis.
They develop 12 to 72 hours after infection, and the illness usually lasts 4 to 7 days . A small number of people who are infected with salmonellosis develop Reiter's syndrome.
Reiter syndrome is a type of reactive arthritis, it happens as a reaction to a bacterial infection in the body.

7. Source of infection
Food: Contaminated eggs, poultry, meat, unpasteurized milk or juice, cheese, contaminated raw fruits and vegetables (alfalfa sprouts, melons), spices, and nuts
Animals and their environment:  including raw or lightly cooked eggs, undercooked ground beef or poultry, and unpasteurized milk
not washing hand proper

8. Pathogenesis:
After a short incubation period of a few hours to one day, the bacteria multiply in the intestinal lumen, causing an intestinal inflammation. Most people with salmonellosis develop diarrhea, fever, vomiting, and abdominal cramps 12 to 72 hours after infection. Diarrhea is often mucopurulent (containing mucus or pus) and bloody. In most cases, the illness lasts four to seven days, and most people recover without treatment. In some cases, though, the diarrhea may be so severe that the patient becomes dangerously dehydrated and must be taken to a hospital. In severe cases, the Salmonella infection may spread from the intestines to the blood stream, and then to other body sites, and can cause death, unless the person is treated promptly with antibiotics

9. Campylobacteriosis:
Campylobacter are a group of tiny strictly micro-aerophilic curved or spiral gram negative rods Campylobacter jejuni and Campylobacter coli ,Campylobacter jejuni occur in large numbers in cattle feces, and poultry as normal flora.
Symptoms :
The most common symptom of a Campylobacter infection is diarrhea, which is often bloody . Infection occurs 2 to 5 days after a person eats contaminated food , but may take up to 10 days to appear.
Fever
Vomiting
Abdominal pain
Headache
Muscle pain

10. Source of infection poultry meat stool of an ill dog or cat
cross-contamination
of other foods
4.Cow products

11. Pathogenesis:
To initiate infection the organism must penetrate the gastrointestinal mucus, which it does by using its high motility and spiral shape. The bacteria must then adhere to the gut enterocytes and once adhered can then induce diarrhea by toxin release. C. jejune releases several different toxins which vary from strain to strain, mainly enterotoxin and cytotoxins, and these correlate with the severity of the enteritis.

12. Symptoms Escherichia coli O157:H7
Escherichia coli are potential food poisoning pathogens which are widely distributed in food environments. E.coli is a normal flora in the intestine of most animals & human as well.
Symptoms
usually begin two to five days after infection
sudden onset of cramps
abdominal pain
diarrhea within 24 hours. Diarrhea will become increasingly watery, and then noticeably bloody.

13. Source of infection Undercooked beef meat unpasteurized (raw) milk
Contaminated water
Feces of infected people

14. Pathogenesis:
Once a pathogenic bacterium has gained entry to a host, it has to have some means of attaching itself to host tissues. Most pathogenic bacteria have surface molecules called adhesions or ligands that bind to preexisting cellular receptors. However, enteropathogenic E. coli manufacture receptors and inject them into the host cells. The bacteria then bind to these receptors. Once many enteropathogenic bacteria have adhered to the intestinal lining, symptoms of the infection (diarrhea) commence.

15. Symptoms Shigellosis (Bacillary dysentery)
Shigellosis is caused by members of the genus Shigella. The species involved include Shigella dysenteriae, Shigella flexneri. All strains of shigella posses potent exotoxins which are carbohydrate-lipid protein complexes.
Symptoms
Most people who are infected with Shigella develop:
fever
Stomach cramps
Bloody Diarrhea contain mucus

16. Source of infection They are the normal habitat of
intestinal tract and in the
stools of infected people,
where personal hygiene is poor

17. Pathogenesis
Shigella infection is typically by ingestion (fecal–oral contamination); depending on age and condition of the host, fewer than 100 bacterial cells can be enough to cause an infection.Shigella causes dysentery that results in the destruction of the epithelial cells of the intestinal mucosa in the cecum and rectum. Some strains produce the enterotoxin shiga toxin, which is similar to the Vero toxin of E. coli O157:H7 and other Vero toxin-producing E. coli. Both shiga toxin and verotoxin are associated with causing hemolytic uremic syndrome.

18. Cholera Cholera Symptoms
Vibrio cholerae, the bacterium that causes cholera,is usually found in food or water contaminated by feces from a person with the infection.
Cholera Symptoms
Symptoms of cholera can begin as soon as a few hours or as long as five days after infection.
watery diarrhea
vomiting
dehydration

19. Source of infection Municipal water supplies
Ice made from municipal water
Foods and drinks sold by street vendors
Vegetables grown with water containing human wastes
Raw or undercooked fish and seafood caught in waters
polluted with sewage

20. Prevention Practice meticulous personal hygiene
Be sure to clean and sanitize all imported and domestic fruits or vegetable especially if beef is being served.  This requires being very mindful of the surfaces (especially cutting boards) and the utensils used during meal preparation that have come in contact with uncooked beef and other meats.  This even means that utensils used to transport raw meat to the cooking surfaces should not be the same that are later used to remove the cooked meat (or other foodstuffs) from the cooking surfaces
Do not expose the food , cover them properly
Proper handling, preparation and food storage
Do not leave eggs, meats, poultry, seafood, or milk for extended periods of time at room temperature.
Cocking meat properly and using thermometer
Keep hot food warm and cold food cool

21. References :