MODULE 1: METHODOLOGY AND TOOLS DEVELOPMENT FOR ADULT EDUCATORS

Foodborne diseases are caused by contamination of food and occur at any stage of the food production, delivery and consumption chain.

They can result from several forms of environmental contamination including pollution in water, soil or air, as well as unsafe food storage and processing.

(Source: WHO, 2021)

Salmonellosis

Among the most frequently occurring food-borne infections.

Salmonellosis is caused by Salmonella bacteria of several different types.

Bacteria can be found on fresh meat, poultry, shelled or cracked eggs, and shellfish from contaminated waters. Bacteria also can be found in foods made from these products and contaminated during preparation.

The presence of Salmonella bacteria in food is unnoticeable because the appearance, flavour, and odour of the food usually are not altered.

Symptoms of salmonellosis include nausea, vomiting, abdominal pain, diarrhea, headache, chills, weakness, drowsiness, and possibly fever. The illness usually lasts two or three days, but it may linger.

Symptoms of salmonellosis vary in severity, depending on an individual’s susceptibility to the infection, the total number of cells ingested, and the bacterial strains involved.

Salmonellosis can be avoided by reducing the possibility of food contamination during handling and processing, by adequately cooking vulnerable foods (which can be contaminated even under the best processing conditions), and by preventing the cross-contamination of foods during the preparation process.

Staphylococcal infection

Staphylococcus aureus bacteria are responsible for frequent outbreaks of food-borne illness. The most common source of staphylococcal contamination is the human body, where organisms are found on the skin and in the mouth, nasal passages, and throat of healthy people.

Toxins are produced when foods that support the growth of staphylococci are contaminated with the organism and are allowed to stand for a sufficient period at temperatures favourable for bacterial growth.

Bacteria are killed when subjected to temperatures of 60°C for 10 minutes, but toxins are highly resistant to heat, cold, and chemicals. Freezing, refrigerating, or heating foods to serving temperatures does not significantly reduce the amount of toxin. The more toxins a person ingests, the greater the reaction of the body.

Foods high in protein readily support the growth of staphylococci and have been involved in many outbreaks of food poisoning. Such foods include custards; meat sauces and gravies; fresh meats; cured meats; meat products; roasted poultry and dressing; poultry, egg, and fish salads and mixtures; raw milk; puddings; and cream-filled pastries. Any food that requires a considerable amount of handling during preparation is a possible source of food poisoning, particularly if it is not kept at safe temperatures during or after preparation.

Symptoms of staphyloccal infection usually occur two or three hours after consumption of the toxin-containing food. However, the time may vary from 30 minutes to six hours. Specific symptoms of staphylococcal food intoxication include nausea, vomiting, diarrhea, dehydration, cramps, and prostration.

Campylobacteriosis

Campylobacteriosis is a food-borne infection caused by the pathogen C. jejuni.

Food-borne outbreaks have been linked to raw or undercooked meat or poultry or these products being recontaminated after cooking by contact with C. jejuni–contaminated materials such as cutting boards.

C. jejuni is sensitive to heat and temperatures below 86ºF (30°C) and can be easily destroyed through proper food-handling practices. The growth of this bacterium quickly declines at room temperature and more slowly at refrigerated temperature. The organism also is sensitive to acidic conditions.

Listeriosis

L. monocytogenes is the species of bacteria that can cause listeriosis. The source of the bacteria is most often contaminated food.

Individuals most susceptible to listeriosis are persons older than 60, newborns, and patients whose immune systems are compromised. Individuals suffering from cirrhosis, diabetes mellitus, and ulcerative colitis are more at risk. Complications including miscarriage, meningitis, septicemia, pneumonia, and endocarditis can result from serious cases of listeriosis.

L. monocytogenes is particularly problematic in food service operations because the bacteria grow slowly at refrigeration temperatures and on moist surfaces, even sponges and drains.

Haemorrhagic colitis by E. coli 0157:H7

E. coli 0157:H7 is a bacterium that has caused many food-related out-breaks. The bacterium can cause haemorrhagic colitis (bloody diarrhoea) and renal failure (haemolytic uremic symptoms).

Undercooked or raw ground beef and red meat (lamb and pork) and unpasteurized milk have been implicated as transmitters of E. coli. E.coli 0157:H7, which has also been found in prepared foods (such as mashed potatoes, cream pies, finfish, and some cheeses).

To avoid this haemorrhagic colitis, it is recommended: Good food-manufacturing practices, proper heating of meats and following good hand-washing and personal hygiene practices at all times.