Five Potential Sources of Food Poisoning This Summer. Foods to be Wary of in the Heat

Foods you may not think of when food poisoning comes to mind

Are you poisoning yourself and possibly your family without even being aware of it? Each year, one in six Americans get sick from contaminated food, according to the Centers for Disease Control and Prevention. This article highlights some of the common foods that cause food poisoning and offers tips on how to cut down risks to you and your family in the summer heat.

Not all cases of food poisoning are that serious, but they can still cost you a day or two of downtime and you may not even be aware of the fact it’s your food that has incapacitated you. Other cases can land you in the hospital and even be life-threatening.

With the current heatwave surging across the US, we thought we’d identify some of the common culprits, and you may be surprised by what can and often does make you ill, both in restaurants and at home.

1. Rice

Without a doubt, one of the most common causes of food poisoning is from rice, referred to as “fried rice syndrome” and it’s one most people are blithely unaware of. Rice contains Bacillus cereus, a toxin-producing bacteria that is one of the most common causes of food poisoning. How common are incidents?

An estimated 63,000 cases of food poisoning caused by B. cereus occur each year within the U.S., according to a 2019 article published in the journal Frontiers in Microbiology. Most cases however aren’t even reported, as the symptoms are usually mild enough to avoid a doctor’s visit, but uncomfortable enough to make you take the day off work.

How does it make you sick?

Leftover fried rice is a primary culprit, B. cereus occurs naturally on rice and no, you cant wash it off. You also can’t cook it to death. The bacteria release two types of toxins that each cause a different illness — one causes diarrhea while the other toxin elicits vomiting, according to the U.S. Food and Drug Administration (FDA) Bad Bug Book.

After you’ve cooked your rice, it’s usually left to stand at room temperature and then reheated later. Its this “resting phase” at room temperature that allows the bacteria to produce the toxins. Reheating will destroy the bacteria, but doesn’t kill off the toxins. The longer the rice is left standing around, the more toxins are likely to form.

The first type of toxin is released in the small intestine after the bacteria are ingested, and causes diarrhea, cramps, and occasionally nausea but rarely vomiting. Symptoms typically begin 6 to 15 hours after eating contaminated foods, which can include various meats, milk, vegetables, or fish. The symptoms typically subside after about a day.

The second type of toxin is released by the bacteria in the food before it’s consumed. Starchy foods, such as rice, are the most common sources of food affected. The toxin causes vomiting and nausea within 30 minutes to 6 hours after eating the contaminated food. Symptoms subside after about 24 hours.

Staying Safe with Rice

Keep your leftover rice at about twenty degrees above room temperature, or if you’re cooking to eat later, ensure it stays hot. This will help reduce the bacteria’s ability to produce toxins. If you’ve got rice that’s been standing out for a few hours or overnight, throw it away and cook a clean batch. 

Rice purchased from takeaway shops should never be “put away” for later consumption.

2. Chicken

One of our favorite foods and also a food with the potential to wreak havoc in your kitchen if not handled properly. It’s the raw meat and undercooked chicken that pose the most risk, particularly cross-contamination of cutting boards, working surfaces, storage areas, and knives.

Research from the UK, US, and Ireland found that 41–84% of raw chicken sold in supermarkets was contaminated with Campylobacter bacteria and 4–5% was contaminated with Salmonella. Sorry folks, but turkey and duck don’t perform any better.

Salmonella and Campylobacter are the most common pathogens found on raw chicken. Some other pathogens include:

  • Staphylococcus aureus
  • E. coli
  • Enterococcus
  • Klebsiella

How does it make you sick?

If you accidentally consume raw or undercooked chicken or contaminate other work surfaces, knives, or foodstuffs, the most common symptoms that occur from eating chicken that contains one or more of these pathogens are:

  • abdominal cramps
  • diarrhea
  • nausea
  • vomiting
  • fever
  • headache
  • muscle pain

Approximately 1 in 1,000 reported cases of Campylobacter infection result in Guillain-Barré syndrome, according to the Centers for Disease Control and Prevention.

In cases where Salmonella is involved, the diarrhea is usually very liquid. With Campylobacter, it’s often bloody. Symptoms usually occur within one to two days after consuming Salmonella and within 2 to 10 days after consuming Campylobacter. Symptoms usually go away after around four days. In severe cases of Campylobacter infection, antibiotics may be needed.

Staying Safe with Chicken

Always store your chicken in separate airtight plastic bags or containers, away from other meats and foodstuffs. Wash all utensils, boards, and surfaces that have been in contact with raw chicken before using them for other foodstuffs. This includes your hands. Ideally use a separate cutting board for chicken.

  • Use a meat thermometer to ensure the chicken has reached an internal temperature of 165°F (74°C).
  • Send back any chicken meal you order that you suspect is undercooked.
  • Avoid eating any trendy dishes that contain raw chicken. 
  • Place uneaten chicken into the refrigerator with an hour of letting it cool, particularly if the weather is sweltering. 
  • Avoid ordering dishes like chicken pie from food outlets that have a slow turnover in product, particularly in summer.
  • If chicken smells even remotely suspect while you’re preparing it, return it to the store or feed it to Fido. If the raw chicken disintegrates easily (smears), that is another sign of spoilt meat.

Thorough cooking will destroy all the pathogens chicken may carry, but with items like salads and other lightly cooked foods, you risk contracting the pathogens through cross-contamination. 

3. Shellfish

We’re going to focus on crayfish, lobsters, crabs, mussels, and yes, even shrimp, rather than traditional fish. The reason will soon become apparent. Although traditional fish can result in scombroid poisoning, the most dangerous and fatal cases of food poisoning belong to the crustacean clan.

People who suffer from any form of allergic reaction need to be particularly cautious when eating shellfish. Allergic reactions can be sudden, dramatic, and life-threatening, often resulting in anaphylaxis (constriction of the throat and an inability to breathe). Seek immediate medical care if you suspect shellfish poisoning.

Always ensure someone who tends to react easily to allergens has an EpiPen close to hand when sampling shellfish.

In shellfish poisoning, the poisonous ingredients are toxins made by algae-like organisms called dinoflagellates, which build up in some types of seafood. There are many different types of shellfish poisoning. The most well-known types are paralytic shellfish poisoning, neurotoxic shellfish poisoning, and amnesic shellfish poisoning.

  • Paralytic shellfish poisoning: About 30 minutes after eating contaminated seafood, you may have numbness or tingling in your mouth. This sensation may spread down to your arms and legs. You may become very dizzy, have a headache, and, in some cases, your arms and legs may become temporarily paralyzed. Some people may also have nausea, vomiting, and diarrhea, although these symptoms are much less common.
  • Neurotoxic shellfish poisoning: After eating contaminated clams or mussels, you will most likely experience nausea, vomiting, and diarrhea. These symptoms will be followed soon after by strange sensations that may include numbness or tingling in your mouth, headache, dizziness, and hot and cold temperature reversal.
  • Amnesic shellfish poisoning: This is a strange and rare form of poisoning that begins with nausea, vomiting, and diarrhea. These symptoms are followed by short-term memory loss and other less common nervous system symptoms.

Staying safe with Shellfish

You can still safely enjoy shellfish by following a few simple precautions. Never buy shellfish from fish markets or local vendors if there is a red tide in the area. Always ensure produce is fresh and if the product is dead, ensure it is packed in ice and does not smell overly “fishy”.

  • Store live clams, oysters, mussels, crabs, lobsters, and crayfish in a refrigerator as soon as possible, in well-ventilated containers, and cover with a damp cloth or paper towel. Place container in a second bowl filled with ice and store on the bottom shelf of the refrigerator.
  • Avoid buying clams, mussels, and oysters during the summer months. Hold on to your recipes till winter.
  • Avoid packages of frozen seafood containing ice crystals. This is a sign the seafood has previously thawed and been re-frozen.
  • Pick up seafood toward the end of your shopping trip and ask to have it bagged separately from other groceries.

When preparing your dish, follow these simple rules;

  • Keep raw and cooked seafood separate to avoid cross-contamination.
  • Use two separate cutting boards, one for raw seafood and the other for cooked seafood.
  • Thoroughly wash your hands, utensils, plates, and cutting boards that have touched raw seafood.
  • Defrost frozen seafood in the refrigerator, under cold running water, or in the microwave. Never defrost seafood on the counter.

When cooking live mussels, clams or oysters, discard any shells that do not open during cooking. Pregnant individuals, older people, young children, and people with weakened immune systems should avoid raw shellfish (oysters, clams, scallops, mussels, or ceviche)

Finally, a note on the physiology of shellfish. They don’t have lungs and obtain oxygen by having seawater filter over their flesh. Contaminants and pollutants are far more likely to seep into their flesh than with normal free-ranging fish that use gills. 

Yummy, definitely, but as to the toxins and environmental pollutants contained in the flesh of shellfish, we’d rather stick to traditional fish.

4. Vegetables and leafy greens

Finally, a reason not to eat your greens. Although you may not think it, vegetables, particularly raw vegetables, are one of the most frequent causes of food poisoning. In fact, fruits and vegetables have caused a number of food poisoning outbreaks, particularly lettuce, spinach, cabbage, celery, and tomatoes.

Between 1973 and 2012, 85% of the food poisoning outbreaks in the US that were caused by leafy greens such as cabbage, kale, lettuce, and spinach were traced back to food prepared in a restaurant or catering facility. 

How do they make you sick?

Vegetables and leafy greens can become contaminated with harmful bacteria, such as E. coli, Salmonella and Listeria. This can occur across various stages of the supply chain. Contamination can occur from unclean water and dirty runoff, which can leach into the soil that fruits and vegetables are grown in or dirty processing equipment and unhygienic food preparation practices can cause contamination. 

Leafy greens are especially risky because we love eating them raw.

Staying safe with your greens

By practicing a little common sense you can still safely consume your greens (sorry kids) without risking food poisoning.

  • Don’t buy salad mixes in packs where any of the product appears brown or spoilt.
  • Wash thoroughly and then, just to be on the safe side, give it another rinse off. Lettuce and similar leafy vegetables can benefit from a spinner to remove any impurities and the occasional wormy passenger.
  • Ensure you prepare your raw vegetable dishes well away from any raw meat or fish.
  • When dining out, reconsider that Ceasar salad. Cooked food in public areas is always far safer than raw food.
  • Buffets with pre-prepared salads that have been left to stand out for a period of time should also be avoided.

5. The humble Egg

One of our favorite foods, we use eggs to bake, to coat, to fry to poach, to scramble and they’re often found as an accompaniment in dishes. Cooked, particularly well-cooked eggs don’t pose a problem. It’s raw or undercooked eggs that can lead to food poisoning and occasionally, even death.

How do eggs make you sick?

It’s our old friend Salmonella, once again. Eggs can carry Salmonella bacteria, which can contaminate both the eggshell and the inside of the egg. In the 1970s and 1980s, contaminated eggs were a major source of Salmonella poisoning in the US, but since 1990, improvements have been made in egg processing and production, which has led to fewer Salmonella outbreaks.

Despite improvements in production, each year Salmonella-contaminated eggs cause about 79,000 cases of food poisoning and 30 deaths, according to the US Food and Drug Administration (FDA).

Staying safe with eggs

Avoid buying dirty eggs. That’s always a clear sign of possible contamination with Salmonella. Clean eggs aren’t a guarantee, but you’re far safer and ideally look for pasteurized eggs.

If you are going to eat your eggs raw, you should only ever purchase pasteurized eggs.

Always ensure your eggs are well cooked at a high temperature. If you tend to like your eggs runny then you’re potentially leaving a window open for the Salmonella. Again, consider rather purchasing pasteurized eggs.

Free-range eggs are often a far healthier alternative to caged eggs, but remember to wash off the eggs thoroughly and cook properly.


Medika Life has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by Medika Life

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