01/06/2010

Foodborne illnesses, also known as “toxi-infections”, are those pathologies which are caused by the consumption of foods which are contaminated with biological agents or their toxins.

These complaints are caused by the consumption of different bacteria, viruses or parasites. The illness can thus be caused by ingesting bacteria or viruses carried in the food (infection), or toxins produced by those already formed in the food (intoxication), or by parasites in specific stages of their life cycle (infestation).

Examples of infections would be Salmonellosis and Hepatitis A; of intoxication through ingestion of pre-formed toxins, Botulism and Staphylococcal enterotoxin gastroenteritis; of parasites, Trichinosis and Anisakiasis.

The systematic control and inspection of foods and processes have been shown to be very effective in the prevention of many of these problems. Nevertheless, in many cases it is consumers themselves who are really responsible for correct hygiene practices in the final stage of the food chain. It is also very important that those consumers, when buying and preparing foods, help to maintain the safety levels and guarantees reached in the previous phases of the chain.

With this in mind it is very useful to remember some basic concepts. Above all, we must not forget that microbial contamination, even at high levels, will not necessarily be evident in terms of deterioration of the food. Appearance is not enough.

Microorganisms are living beings: they feed, reproduce and interact with their environment. They therefore need the food they use as a vehicle and habitat to offer favourable conditions: availability of nutrients, correct temperature, a non-aggressive environment (acidity, salinity, humidity)…given such conditions, eubiotic, favourable for life, and given the necessary time, they will reproduce at an alarming rate, reaching infecting doses; those that are toxigenic will produce toxins…in short, they will convert harmless food into a dangerous product. If environmental conditions are not favourable, some can adopt resistant life forms, such as spores, which will germinate when conditions improve giving rise to infection.

We can and must avoid it!

The summer months are an especially critical period, as high temperatures favour the development of microorganisms. Also, during this period there is a greater tendency to eat outside. For this reason, the Spanish Agency for Food Safety and Nutrition (AESAN) recommends observing the following guidelines, based on the World Health Organisation’s Golden Rules for safe food preparation. Taking theses simple precautions will avoid many illnesses due to inadequate handling or conservation of foods.

1. Consume foods that have been treated or processed for safety.

Raw milk (milk that has not been pasteurised) must not be consumed. Meats, fish and pastries must be refrigerated or frozen. Catering establishments must use egg products for mayonnaise, sauces, creams, etc. If these products are prepared at home, they must be consumed immediately, without keeping leftovers in the fridge. If eggs are washed prior to use, as they have traces of dirt, this must be done immediately before use.

2. Cook food thoroughly.

Foods may be contaminated with microorganisms. If the foods are cooked well, these microorganisms can be destroyed by the heat. The cooking temperature must be sufficient so that the centre of the product reaches a minimum of 70º C.

3. Eat cooked foods immediately after cooking.

This is the best way of preventing the proliferation of germs. Never leave cooked foods at room temperature.

4. Cooked food is safe food.

Foods which are not consumed immediately or leftovers must be stored either under hot conditions, above 60ºC, or under cold conditions, below 7ºC. If you plan to eat raw or slightly cooked fish (items such as anchovies in vinegar) in the home, do so after having kept it frozen for a few days.

5. Reheat cooked foods thoroughly.

In order to be conserved following preparation, certain foods can be kept hot until they are eaten (soups, purées, stews…). Other types of food that cannot be kept hot (salads, cold soups, etc.), must be refrigerated immediately. It is not always possible to save leftovers from a meal, but if you decide to, always reheat to the maximum temperature before eating.

6. Avoid contact between raw foods and cooked foods.

Cooked foods can become re-contaminated through contact with raw foods or objects that have been in contact with raw foods (knives, chopping boards, surfaces, cloths, etc.). The kitchen cloth can be an excellent vehicle for contamination. It is preferable to use kitchen paper.

7. Ensure correct personal hygiene of those handling foods and thorough cleaning of all kitchen surfaces.

Those handling foods must observe strict personal hygiene practices. It is essential that hands are always clean, that they are washed whenever necessary and always after going to the toilet. It is very important to clean the kitchen daily, as a minimum. Take special care to store rubbish in smooth, washable, closed containers, making sure that they are not kept near to food.

8. Protect food from insects, rodents and other animals.

We must not forget that animals can carry pathogenic germs and parasites which can cause foodborne illnesses.

9. Use safe water.

Drinking water is just as essential for food preparation as it is for drinking. You should only use one of the following: bottled water or tap water from the public supply. Water from wells which has not been treated must not be drunk or used.

10. Do not eat perishable foods which have been left at room temperature.

In bars, cafés, restaurants, etc., all foods must be covered and kept under the correct sanitary conditions. They must be refrigerated whenever necessary. Consumers must demand these measures, and when they are not observed, the foods should be rejected.

Remember

Any microorganisms present in foods only need favourable conditions:

1. Nutrients on which to feed
2. Non-extreme temperatures and
3. Time to multiply.

• Never consume foods bought from non-authorised sources.
• Only use drinking water. Use drinking water for making ice.
• Thoroughly wash fruit and vegetables to be eaten raw.
• Do not interrupt the cold chain.
• Observe use-by dates.
• Reject damaged, rusted or deteriorated containers.