Food borne Illness Prevention
This information provided by the Environmental Public Health Specialist with the New Madrid County Health Department. There are two disease pathways with food borne illness. One is the fecal-oral route the other is allowing bacteria to reproduce to levels high enough in food for illness to occur. The second one is significant for most food borne illness bacteria require large numbers to result in disease. Cross-contamination like moving from handling raw meat to making ready-to-eat food without washing hands or putting on gloves can also come in to play with number two.
Without knowing detailed knowledge of the bacteria and viruses associated with disease relating to food there are four factors that go a long way to preventing illness caused by these organisms.
1. Proper Handwashing. This means keeping hands lathered for at least 20 seconds before rinsing.
2. Keeping hot food hot (1350F or more) and cold food cold (410F or lower). This includes a cool-down time from 1350F to 700F in two hours or less and from 700F to 410F in four hours or less for a total cool-down time of six hours or less. The reason for this is most food borne illness bacteria requires large numbers for illness to occur and most reach their highest numbers in the shortest time between 1200F and 700F.
3. Preventing bare-hand contact with ready-to-eat-food.
4. Using sanitizer solution at the concentration for use on food-contact surfaces. With unscented bleach this is 50 – 100 parts per million free available chlorine. Quaternary ammonia sanitizers have a maximum concentration of 200 parts per million. Iodine as a sanitizer has a range of 12.5 to 25 parts per million. Bleach (chlorine) is the most common and mixing ½ capful or ½ teaspoon of bleach in one gallon of water gives approximately 100 parts per million.
The sanitize step is the last in the 3-step wash, rinse and sanitize process for dishes, utensils, etc. – anything that is used in the cooking process and/or that comes in contact with food. These steps can be done in a three-vat sink, a two-vat sink with a portable tub for sanitizing or three portable tubs. Either way the three-step process is one of the ways to break the food borne illness cycle.
Now that we have general knowledge of disease pathways associated with food and some of the preventive measures that can be effective to stop illness then we can begin to apply this to lessen the risk for illness associated with food. One of the first steps is to identify potentially hazardous foods that can support the growth of pathogenic organisms for these provide a suitable climate for bacteria to reproduce and thrive.
There is a rather lengthy definition in the 2009 Missouri Food Code but it does provide insight for foods most likely to contribute to illness. Potentially hazardous food is one that is natural or synthetic and that requires temperature control because it is in a form capable of supporting:
(1.) The rapid and progressive growth of infectious or toxigenic microorganisms;
(2.) The growth and toxin production Clostridium botulinum; or
(3.) In raw shell eggs, the growth of Salmonella Enteritidis.
Potentially hazardous food also includes animal foods that are raw or heat-treated (cooked) and plant foods that are cooked or consists of raw seed sprouts, cut melons or garlic-in-oil mixtures that are not modified (such as acidified) so they no longer support bacterial growth.
It is also insightful to remember what is not a potentially hazardous food. Three factors can be used to identify potentially and non-potentially hazardous foods. These are water activity, pH (specifically a pH of 4.6 or below) and a temperature range allowing for rapid growth of bacteria. Laboratory instruments are not always necessary to identify foods with one or both or all for once you know what to look for identification is much simplified.
This definition for potentially and non-potentially hazardous is not all inclusive as documented in the Missouri Food Code but it does provide a basis upon which to identify foods that are likely to support bacterial growth.
Water Activity (Aw)
Water Activity is measured on a scale from 0 to 1.0 with distilled water having a water activity of 1.0. Aw refers to the availability of water and bacteria need water, suitable temperature and food to grow and reproduce. Potentially hazardous foods have water activity values of above 0.85. From this we know that ‘wet’ foods have the potential for supporting bacterial growth. So how can we apply this? Food buffets, salad bars and other hot and cold holding areas provide numerous examples. Shredded cheese is not considered potentially hazardous because the water activity is too low to support microbial growth. On the other hand, cottage cheese has sufficient water activity to support microbial growth. As a general rule, raw meats, cooked meats and cooked potentially hazardous foods have sufficient water to support growth whereas dried meats like jerky do not.
pH
pH is measured on a scale from 0 to 14.0 with 7.0 being neutral. Our interest in limiting bacterial growth stems from the fact that foods with a pH of 4.6 and below are seldom implicated in food borne illness because most bacteria cannot grow well in foods within this pH range. Meats and poultry products generally have a pH above 4.6 and thus can support bacterial growth. Tomatoes, citrus fruits and commercially prepared mayonnaise all have a pH below 4.6. Even though commercially prepared mayonnaise contains eggs it is not considered potentially hazardous due to the pH below 4.6 does not support microbial growth well.
Temperature
Reheated cooked foods have more potential for bacterial growth than raw foods. In addition, the longer a potentially hazardous food is within the ideal bacterial incubation temperatures of 1200F - 700F the greater the likelihood that growth will occur to levels sufficient for illness to occur. Therefore, cooling temperature requirements are based on growth parameters of bacteria that multiply rapidly under temperature and time abuse.
The great thing about cooking is that it kills bacteria and viruses. Once you go above 1300F you are killing both and the higher the temperature the more you kill in a shorter period of time. This is where keeping hot food hot and cold food cold and cooling potentially hazardous foods down to certain temperatures within certain time frames comes in to play. With potentially hazardous foods often times the trick is to not contaminate it after cooking for cooking results in a sterile product if heated long enough at a high enough temperature.
Stopping Food borne Illness Before It Starts
Now that we know the two disease pathways with food borne illness, have some idea of measures to prevent illness, have some idea on how to identify a potentially hazardous food and we know a little about the microbiology of the organisms we are dealing with then we are ready to apply this knowledge to a menu or food. Microbiology along with the other parameters is important for ultimately preventing illness is what you want and prevention is the key. It’s a lot easier and cheaper to prevent something from happening than to deal with it after the fact. Remember the adage ‘an ounce of prevention is worth a pound of cure’ - this applies to illness associated with food as well.
Applying the four factors from page one on a regular basis plus identifying potentially hazardous foods on your menu plus taking steps to stop the growth of bacteria to large numbers – all greatly reduce the risk for illness to occur.
Mold and Mildew Removal
The first step is to eliminate water such as leaking plumbing, leaky roof or any other source. Fungus needs moisture to grow and reproduce. If it looks wet or feels wet that would be enough for growth to occur so if you remove water then you have no mold or mildew. Air conditioners can be used to keep humidity low in a residence.
Bleach and water can be used to remove mold and mildew from whatever it is growing on. Cellulose-based products are a typical food source for fungus (wood, kraft paper on insulation, paper covering on drywall – anything that has wood on or in it). Kilz paint (it has some antifungal properties) can also be applied.
If mold and mildew returns after cleaning (and painting if this was done) the next step is to replace what it is growing on.
The most common symptoms to mold and mildew exposure are shortness of breath and/or headaches. There are typically no long-term health effects from these symptoms but they will persist until exposure is stopped. Some individuals have a reaction to fungus and some do not. A good indication that a certain location is causing a problem is if you leave for 1 to 3 hours and start feeling fine then come back and the symptoms return. This should be a consistent pattern until exposure to the mold and mildew is eliminated.
This information provided by the Environmental Public Health Specialist with the New Madrid County Health Department.
Bed Bugs
In recent years bed bugs have become a widespread, resilient pest that must be effectively controlled to prevent their spread. With the advent of chlorinated insecticides several decades ago this largely eliminated them as a pest in the United States but they are now back on the rise. Persons spread them from an infested location to a new one by hitchhiking in items moved from one place to the next. These bugs take a blood meal like ticks and are most often found where persons lay or sit for extended periods like on a mattresses or chair. Five feet or less where persons lay or sit is typically where they are found. They are active at night and hide in dark places during the day. No diseases are known to be transmitted with secondary infections the most common complication from bed bug feeding.
Control
It is always recommended to use the services of a qualified pest control person capable of eliminating these insects. Not all pest control operators have the ability to treat for and thus eliminate bed bugs. There are steps that homeowners can use.
- Heat can be used to kill all life cycle stages but the temperature must be 1300F or higher. For items that can be washed this means either the washer or dryer must be able to reach or exceed 1300F. Steam cleaning equipment can be used but it must reach 1300F or higher. Sealing up rooms and using heat is another way.
- Powders and sprays are also available. Powders provide the longest-lasting residual control. As an example, Tempo 1% can provide an effective residual for several months which is better than a liquid providing good contact control but only a short residual. There are other insecticides or growth regulators that can be used but most of these are not available to the general public. Be sure to follow label directions - it must say that will kill or control bed bugs otherwise it will not work. Burning infested items is another control as well as wrapping mattresses and other items in airtight plastic or plastic bags. The lack of oxygen will kill the ones present in about 2 weeks with the plastic barrier preventing new ones from taking up residence.