So Whodunit?

Isn’t it so natural that whenever there is a food borne illness incident the blame is laid squarely at the feet of the last food that was consumed before the symptoms of food poisoning began to emerge.

As a food safety practitioner I have heard again and again, when investigating food borne illness incidents, victims of food borne illness say “it was that mango that I ate in the morning, or it’s was the meal I had in the cafeteria during lunch time, or I shouldn’t have shared in the meat pie so and so was eating…etc etc”. However pointing an accusing finger at the last meal consumed could be misleading.

Firstly, the period between consumption of food and the first signs of illness is termed Onset Period in food safety parlance and it varies from as short as less than an hour to as long as 72 hours depending on a variety of factors.

So to simply assume that the last consumed meal is the culprit of a food borne illness is an oversimplification of how food borne illness plays out.

For instance chemical food borne illness (food borne illness caused by ingesting food contaminated by chemicals) can have a very short onset time (minutes instead of hours) between consumption and illness manifestation as the chemicals gets into the blood stream and circulates swiftly through the blood into the major organs of the body, triggering all forms of symptoms.

On the other hand the onset period of food borne illness caused by pathogenic bacteria could be influenced by amongst many other factors:

1. The time it takes the pathogen to multiply to dangerous levels in the body system.

2. The state of health of the person which has a bearing on the person’s resistance to infections. A sick or convalescing person may manifest symptoms of food borne illness faster than a healthy adult even if they both ate the same contaminated food. This refers to the resilience of ones natural body defenses, i.e. The time it takes for the antibodies to resist the germs before being overwhelmed and succumbing to the infection.

3. The dose (quantity) of the bacteria consumed, which is in turn dependent on the body mass weight of the person. For example children with lower body mass weight can get sickened quicker with a smaller amount of bacteria consumed in food than fully grown adults.

4. The classification of the bacteria i.e. Whether they are toxin forming bacteria (certain bacteria release poisons called toxins into the body system that act faster than a bacterium in causing illness).

From all these factors it can be seen that It is not an impossibility to begin to experience the symptoms of food borne illness several hours, or even days, after consuming contaminated food or drink even if one had eaten other food in the interval.

This has proved true in a number of food borne illness investigations. Typically when investigating incidents of food borne illness, investigators would want to know what and what the victim had eaten in the past 48 or 72 hours. This report will be needed among other reasons, to be compared with the results of causative agent determined from samples collected from the victim in an attempt to identify the culprit food or drink.

For example if the predominant bacteria isolated from feacal samples of a food borne illness victim is Vibrio parahaemolyticus, a food borne illness bacteria commonly associated with seafoods, and the victim had a meal of shellfishes like oysters and clams 3 days earlier and hadn’t eaten any such related foods thereafter, it’s is most likely that is the source of the food borne illness even if the victim had eaten other meals in the interval.

So…before passing a guilty verdict on the last meal that was eaten as being the cause of the food borne illness, further thought should be given to other meals that had been eaten down the line.

The Dirty Half-Dozen

Wall Geckos, Rats, Cockroaches, Flies, Ants, and Spiders. These fellas make up what I have dubbed “The Dirty Half-Dozen”.

Present in almost every place that man occupies, whether residential or commercial, these guys have been implicated in many food borne illness incidents. By defecating on, feeding on, walking on, or dying in food, they contaminate food without restraint. And when such food is consumed without adequate food safety preventive measures the results are incidents of food borne illness.

They all conduct their activities in similar manner i.e basically by being carriers/ vehicles of pathogenic bacteria (bacteria are largely static and needs to helped around) and spreading them into food.

I’ll try and profile them one by one:

Wall Geckos – The stealthiest of them all. In complete silence and with high reflexes, these creatures creep from kitchen walls and ceiling to shelves and cupboards contaminating every kitchen utensil in their path. When such utensils are used for eating it can result in food borne illness albeit not directly from the food.

Rats – Rats don’t waste much time with kitchen hardware. What they are after is the food itself. Leftover food in the sink, waste food in the dustbin, raw food in the larder are all their favorites. However they don’t just have a bite and move on…in many cases they routinely defecate on the food and by this introduce dangerous pathogens into the food. Inevitably they crawl around and over utensils in the kitchen like the geckos and contaminate these as well. Urine deposit of rats on canned foods have been implicated in a number of deadly food borne illness incidents.

Cockroaches – Cockroaches are known to carry various food borne illness bacteria. Being very versatile (they can climb, crawl and fly short distances), they are very difficult to eradicate once they gain a foothold in a place.

Flies – Perhaps the best known of the lot. Flies pose a danger to health because many pathogens have been found on and in flies and their droppings.

Flies contaminate food in four ways:
1. To feed, they regurgitate enzymes and partly-digested food from the previous meal;
2. They continually defecate;
3. They carry bacteria on the hairs on their body and legs;
4. Pupal cases, eggs, and dead bodies end up in our food.
(R.A. Sprenger 2005)

Ants – Ants are vigorously attracted to sweet foods and that’s where you would almost always find them. However where there are no sweet foods in sight, all other kinds of food may be attacked. Ants transmit bacteria picked up from the soil, from drains, from the toilet into food as they forage around. Their physical presence in food is an equally nuisance form of physical food contamination.

Spiders – Spiders are usually not considered as pests that propagate food borne illness bacteria. They seem to be harmless idyllic creatures lazily spinning their webs in obscure corners of the kitchen. Nevertheless behind this unassuming profile is a reputation of being a transmitter of food borne illness bacteria. What makes spiders a double worry when it comes to food borne illness is that they occupy a low rung in the animal kingdom food chain such that wherever there is widespread presence of spiders one can be certain that wall geckos would follow suit in search of food (spiders are perfect meals for wall geckos) further enhancing the infestation of the house with pests.

Having profiled these creatures, it must be mentioned that no matter how hard humans try, one or more of these folks will inevitably get into the house one way or the other. The trick is to prevent them taking a foothold to reduce the chances of food borne illness incidences in the home. This can be done by:

1. Good housekeeping – maintaining a clean and tidy environment to deprive them of food and harbourage.

2. Storing all food in closed covered containers where possible.

3. Ensuring waste food generated are disposed of quickly.

4. Avoid clutter in the house. Old newspapers, rags, empty cartons make very comfortable nests for rats and hiding places for cockroaches.

5. Employ the use of pesticides and rodenticides – although with caution as these may end up contaminating food if not used with great discretion.

6. Employ physical control means such as traps, nets etc.

7. When coming from the open market, decant the local produce into clean containers before bringing into the house to avoid bringing home these creatures from the market.

8. Keep kitchen utensils and crockery secured and well stored.

With these few steps and many more that can be devised, The Dirty Half-Dozen will be put in proper check and the frontier of food borne illness is pushed back further.

Common Foodborne Bacteria Might Be ‘Trigger’ For Multiple Sclerosis

“New research presented at a scientific meeting adds to a growing body of evidence that a toxin produced by a common food bug may trigger multiple sclerosis, an inflammatory disease of the central nervous system.” (C. Paddock 2014)

Read full story: Food-borne Illness Bacteria Linked To Multiple Sclerosis