Although food safety is always important, it is particularly important in summer. With the tropical storm Arthur recently there were many power failures and much spoilt food due to non-functioning refrigerators had to be discarded.
When there are parties and food is outside in warmer temperatures it does not take long before salmonella or enteric bacteria multiply in mayonnaise which acts like a growth medium. Ref.1 points out that traveler’s diarrhea is common in development countries. Bugs such as Shigella, enterotoxigenic E. coli, Campylobacter jejuni, Salmonella species and others are the most common bacteria. But the rotavirus subtypes and the parasites Entamoeba histolytica, Giardia lamblia, Cryptosporidium species and Cyclospora cayetanensis are also frequent offenders that make people sick, make them vomit or cause diarrhea.
How is food poisoning caused?
Causes of food poisoning vary from food to food and between developed countries to developing countries. Bacterial contamination of meats or poultry is particularly common and prompt refrigeration at 4 degrees Celsius or lower (38 F or lower) is important to prevent bacteria from multiplying. People with contaminated hands that handle food in the retail grocery business can introduce bacteria or noroviruses into the food chain. Cross contamination such as cutting meat on a cutting board and subsequently cutting lettuce for a salad that is uncooked is a common source of food poisoning. While the bacteria or viruses of the meat that was cut and subsequently cooked is now safe to eat, the salad with the bacteria or viruses is certainly causing food poisoning. As the link above shows, 75% of oysters harvested around the shelves in Great Britain are contaminated with norovirus. It is important therefore to boil the oysters well to inactivate the norovirus; half cooked or raw oysters are simply not acceptable.
Pay attention to food preparation:
- Before you prepare a meal, make sure that all of the ingredients that come from packages have an expiry date well beyond the date when you prepare the meal. Anything that is beyond the expiry date may have a larger number of bacteria or viruses in them that could transfer into the rest of the meal.
- Keep in mind that during the summer outside temperatures are well beyond room temperature and it does not take long for bacteria to multiply at higher temperatures. The danger zone is between 40°F (4°C) and 140°F (60°C) where bacterial growth can occur. On many occasions scientists have measured that bacterial growth can double every 20 minutes, so within only 1 or two hours food such as mayonnaise, milk or eggs are spoilt!
- Never leave barbecued meats lying around and only deep freeze them later. When you thaw them in preparation for another meal in the future, you are dealing with spoilt food that already has bacteria in it as they grew before you have frozen the spoilt meat. Spoilt meat remains spoilt meat, even when you have stored it in the freezer! Throw it out.
Interrupt the infectious chain:
The key in food preparation and cooking as well as in safe refrigeration storage is to interrupt the infectious chain. If you get meat from the store, cook it thoroughly so it is safe to eat. The cooking process will destroy bacteria.
Drink bottled or boiled water. Avoid ice cubes, as they may have been prepared with contaminated water. Avoid eating raw food. Eat salad only after it was thoroughly washed with clean water. In development countries or areas of questionable water supply go without salad until you enter a country where general hygienic standards are observed. Peel fruit yourself; don’t eat fruit salads prepared by others. Generally speaking food should be eaten hot. Avoid raw and poorly cooked seafood; invariably this is a risk for exposing yourself to unknown bacteria or viruses.
Eating in a restaurant is not as safe as eating at someone’s home.
When you think about summer recreation, think about swimming pools; think also about recreational pools that may also be contaminated. If there is no appropriate chlorination equipment present, it is unsafe to use that pool.
Treatment of traveler’s diarrhea:
If you should get abdominal pain, diarrhea and vomiting you likely got traveler’s diarrhea. If you can, see a physician to confirm the diagnosis. In Mexico you often can go directly to the pharmacist and get antibacterial medication over the counter. Often a 3 day course of fluoroquinolones (e.g. Cipro), trimethoprim-sulfamethoxazole, azithromycin, or rifaximin is effective.
Whether the antibiotic is effective depends on the area where you travel, which also determines the resistance pattern. Further, it depends on what organisms are present in the contaminated food or environment and it depends on the patient’s age. For children below 16 the recommended antibiotic is azithromycin, for persons older than 16 ciprofloxacin (Cipro) is used (Ref.1).
Prevention of food poisoning:
We can do a lot to avoid food poisoning. First of all, we need to wash our hands after having used the washroom and before we handle food. Avoid cross contamination as already described. Wash your hands again when you are finished handling raw meat, particularly hamburger meat. Make sure that meat is cooked until it is completely through. You may want to use a food thermometer, which will assist you to know that the meat is thoroughly cooked; as this link shows pork is done at 140°F, but chicken and ground poultry should be cooked until the meat temperature reaches 165°F. Ground beef requires 160°F. As the link shows, it is safer to include a 3-minute rest time following the reaching of the target temperature to ensure that no more live bacteria or viruses are left in the cooked meat.
More information on food safety: http://nethealthbook.com/health-nutrition-and-fitness/nutrition/food-safety/
Have a safe summer and enjoy backyard BBQ’s following the simple rules mentioned before. Should you travel, make sure it is safe and you prevent traveler’s diarrhea. The principles of safe food handling and food preparation are simple and can be learnt by anyone. Make sure any unused food is refrigerated right after the meal, not more than two hours later. Otherwise old food should be discarded.
1. Kliegman: Nelson Textbook of Pediatrics, 19th ed.Copyright 2011, Saunders.
Last edited Nov. 8, 2014