Sunburn and bug bites are not the only hazards you may encounter this summer at the beach or at a picnic. During the summer season, we emergency doctors see a spike in food-borne illnesses – more commonly known as food poisoning.
There are 2 factors that contribute to this rise and provide the perfect environment for bacteria to grow and multiply on food. First, summer’s warmer weather and humidity increase the amount of germs or bacteria that naturally grow in water, air and soil. Secondly, when we are dining outdoors, we don’t have refrigeration’s well-controlled temperatures and cooking on the grill is not as temperature regulated as an oven.
According to the Centers for Disease Control and Prevention (CDC), even though food poisonings are underreported, they estimate about 76 million cases occur every year. Thankfully most cases are mild, but about 325,000 people require hospitalization and about 5,000 people die each year from food poisoning.
There is also a financial cost to food-borne illnesses. A report published from a research project funded by the Pew Charitable Trusts found that about $152 billion a year is spent in healthcare and other losses due to food poisoning. That means on average food-borne illnesses cost each American about $500 per year.
Certain bacterial infections that cause food poisoning are reportable to public health departments, such as Salmonella or E Coli O157:H7. Additionally, outbreaks as defined by each state can be reported to public health departments. For example, in the Maryland an outbreak is defined as 2 affected people not in the same household who have shared a common meal. Emergency physicians and the labs that diagnose these conditions usually do report to public health officials. Health departments also keep track and log individual’s calls and complaints. Then local health departments coordinate with state health departments and national authorities if need be, as was seen in the recent case of Salmonella food poisoning that was tracked back to a Georgia peanut product factory. This communicative chain is how public health officials keep our food supply safe.
In general, many of the clinical symptoms of food poisoning are similar; they include diarrhea, abdominal cramps and some times fever. Most healthy individuals usually recover on their own with rest and fluids. However, these infections are more dangerous in individuals with compromised immune systems due to an increased chance that infections will spread from their intestines into the blood stream, and that can be lethal. Those individuals at highest risk for serious illness and/or complications from food poisoning are very young children, pregnant women and the elderly, as well as immune compromised individuals, such as cancer patients on chemotherapy. These severe cases often require hospitalization and intravenous fluids as well as antibiotics therapy.
Below are 3 of the more common bacteria that cause food poisoning: Staph food poisoning, E Coli food poisoning and Salmonella food poisoning.
Staph Food Poisoning
This is one of the most common preformed toxin type food poisonings, which means it isn’t the Staph bacteria itself, but a toxin it produces in the food that makes you sick. Bacteria can produce the toxin can even at refrigerated temperatures and that is why we commonly see it in foods made by hand that don’t require cooking, like tuna, potato or chicken salads. It can also be associated with meats, cream-filled pastries, sandwich fillings, milk and dairy.
About 25% of healthy people are Staph carriers and have the potential to unknowingly spread the germ if they prepare food improperly. The food may not even have signs of spoilage. This food poisoning has a very short incubation period with symptoms that appear rapidly. Severity of symptoms does depend on one’s sensitivity to the toxin and the amount of food eaten, but in general, symptoms can appear within about 1-6 hours after eating.
Symptoms have an explosive onset including bad abdominal cramps, severe nausea, violent vomiting as well as some diarrhea. Patients do not have a fever. These symptoms are self-limiting and the illness is brief. Patients usually totally recover by 3 days. No antibiotics are necessary because the toxin, not the bacteria, causes the illness. Most people just need plenty of rest and fluids. At times, a medication can be prescribed to combat nausea and help keep fluids down. However high risk patients (the very old, very young and immune compromised individuals) are susceptible to dehydration and may need intravenous fluids.
E Coli Food Poisoning
This is a bacterium that lives in the intestines of animals and people. Many strains don’t cause disease inside the gastro-intestinal (GI) tract, but can be harmful outside of it. However there are pathogenic (disease causing) strains that can cause illness inside the intestines, non-pathogenic E Coli is a major cause of traveler’s diarrhea (40-60% of cases.) It is primarily caused from unsanitary conditions where human or animal fecal contamination occurs. Drinking contaminated water infects individuals, as well as using ice made from that water or eating unpeeled fruit washed with contaminated water.
The primary symptom of “simple” traveler’s diarrhea is watery diarrhea that can be treated with fluids and other-the-counter medicines like Pepto-Bismol (bismuth) or Imodium (loperamide) that slows motility of the bowel. But beware: drugs that slow bowel motility and stop diarrhea could actually increase the length of the illness. Diarrhea is our body’s defense mechanism, ridding itself of the bacteria. Prophylaxis, or preventative antibiotics, such as doxycycline, ciprofloxin, TMP/SMX trimethoprim and sulfamethoxazole can be taken on trips to avoid getting traveler’s diarrhea.
A more dangerous strain of E Coli is E Coli 0157:H7, also called enterohemorrhagic E Coli. This strain is a pathogenic strain causing disease and inflammation in the colon (colitis) that can lead to bloody diarrhea. It also produces a toxin that further damages the intestines. The strain is commonly associated with eating undercooked meats, especially ground beef with its increased surface area that provides bacteria with a perfect breeding ground. It is also caused from consuming raw unpasteurized milk and dairy products, as well as produce, grown and irrigated with water contaminated by human or animal waste.
Symptoms are bloody diarrhea and fever. Most healthy people recover in about a week, however about 7-10% of young children, the elderly or immune compromised individuals can develop a serious complication called hemolytic uremic syndrome (HUS). This complication causes severe anemia from the destruction of red blood cells, which in turn clogs up the kidneys resulting in dialysis-requiring kidney failure. Occasionally, it can even be fatal.
Salmonella Food Poisoning
Salmonella is a broad category for many different types of bacteria each distinctive to the specific species that carries it. Salmonella bacteria are found in turtles and other reptiles, chickens and other foul, as well as cats and dogs. Salmonella Typhi is the type that usually causes food poisoning in humans and accounts for about 10-15% of food-borne illnesses.
Salmonella gastroenteritis is “simple” food poisoning that causes loose, watery, mucous-like diarrhea usually associated with eating contaminated poultry and eggs. You can also get it from eating contaminated meats, peanuts and recently, highly publicized cases of Salmonella poisoning were caused by vegetable like tomatoes and spinach. Contamination results when human or animal feces come in contact with food during irrigation, harvesting or processing. As with the other types of food poisoning, those most susceptible are immune compromised, and very old or very young.
Typhoid fever, or enteric fever, occurs when the GI tract isn’t able to kill all the bacteria it needs to, and bacteria then gets into the bloodstream where it is carried to the spleen, liver and gall bladder. Bacteria can then grow in these vital organs. This type of infection, once resolved could result in a carrier state, where individuals can unknowingly shed the bacteria and infect others. The most famous case was a previously infected a cook named Mary Mallon who lived in the early 1900s. She was known to have infected over 50 people with Salmonella, hence the nickname, Typhoid Mary.
Symptoms of Typhoid include a high fever and many patients can experience low heart rate, called bradycardia. Sometimes a rash of slightly raised red or rose-colored spots on chest and abdomen is present.
People with Enteric or Typhoid Fever who have the infection in their bloodstream need the intravenous antibiotics floruquinolones or third generation cephalosporins, as well as intravenous fluids. However resistant strains of Salmonella can pose a problem.
Antibiotic treatment is a bit controversial when it comes to some cases of “simple” food poisoning. In fact, antibiotics can even prolong the carrier state of Salmonella. And that is why prevention is the best medicine! So here are some safety tips you can practice at home to help prevent food poisoning:
- Wash hands well with soapy warm water, clean and disinfect counter tops, plates and utensils before and during food preparation to avoid cross contamination.
- To prevent cross contamination, keep raw fish, poultry; meats and eggs separate from ready-to-eat foods such as fruits and vegetables by using different plates, cutting boards and utensils.
- Refrigerate all foods at the proper temperature (40F and freeze at 0F) and be sure to defrost foods in the refrigerator not on the countertops.
- Use a thermometer to ensure you cook all foods to the proper temperature, killing any bacteria. That’s about 150F for steaks, roasts and chops of beef, 165F for ground veal, pork or poultry, 180F for whole poultry (hint: the juices should run clear on properly cooked poultry).
- Don’t leave foods out for more than 2 hours without serving them on hot or cold plates.
- Reheat all leftovers to at least 165F.
If you comply with all those safety rules, then bon appetite!