Question

Food Poisoning Case:

About 3 pm on July 20^th, 2017, some people who worked in the same factory had abdominal pain, vomiting, diarrhea and fever. The number reached peak at 11 pm. Until the next morning there were 120 patients in total.

Most patients had abdominal colic at first, then nausea, vomiting (most 1-3 times, a few over 5 times) and then frequent diarrhea (most 1-8 times). Besides, their stool was watery with mucus and blood. Half of the patients’ body temperature were between 37 to 39 ℃.

Q1. If you were the physician of this factory, what would you do?

Q2. Can you confirm whether it is food poisoning or occupational poisoning? What else need to do to diagnose?

The physician suspected it was food poisoning and reported to CDC. Results of the investigation: all patients had breakfast in the factory and ate pickled cucumbers or yellow croaker. Fresh cucumbers were bought and preserved in salt one month ago. The chef took out cucumbers without rinsing and cut them with the knife which had cut yellow croaker. Then the pickled cucumbers were stored in 27-28 ℃ overnight and sold the next morning.

The yellow croaker was left over from the day before and stored in 27 ℃ overnight. It was served in the next morning after being heated for less than 10 minutes.

The container had been filled with raw fish and rinsed with tap water right before use.

Q3. Is this a food poisoning case? If yes, which type is it?

Q4. Which meal caused the food poisoning? Which food may cause food poisoning?

Q5. What are the possible reasons for the food poisoning?

Examination:

There was no salmonella or staphylococcus in the pickled cucumbers, yellow croaker soup or patients’ stool.

Huge amounts of vibrio parahaemolyticus was detected in salt medium.

The separated bacteria had agglutination reaction with patients’ serum.

Q6. How to treat patients with bacterial food poisoning?

Q7. How to avoid this kind of poisoning accident?

Answer 1

Ans.

( 1 )

Illness caused by food contaminated with bacteria, viruses, parasites or toxins.

Infectious organisms or their toxins are the most common causes of food poisoning.

The most common symptoms of food poisoning are:

1. Upset stomach.
2. Stomach cramps.
3. Nausea.
4. Vomiting.
5. Diarrhea.
6. Fever.

Bloody diarrhea is more likely to be a symptom of food poisoning. Projectile vomiting and stomach cramps are often caused by the norovirus, a type of stomach virus. Stomach viruses take longer to develop but usually go away in about 24 to 28 hours after symptoms begin. Food poisoning often lasts longer.ok

At least 250 different kinds of food poisoning have been documented, but the most common ones are e. coli, listeria, salmonella, and norovirus, which is commonly called "stomach flu." Other less common illnesses that can be transferred from food or food handling are botulism, campylobacter, vibrio, and shigella

Commonly, these types of food poisoning are transferred from:

• Unwashed hands handling food
• Unwashed raw fruit or veggies, or any raw produce with bacteria
• Undercooked or raw meat
• Room temperature food that should be refrigerated
• Cross-contamination of food bacteria
• Incorrectly prepared or stored deli meats, hot dogs, or ground beef
• Unpasteurized milk
• Spoiled dairy products or soft cheeses
• Cutting boards, bowls, or knives that are unwashed or cross-contaminated with bacteria

( 2 )

food poisoning as a workplace hazard, an outbreak caused by contaminated foods or liquids can lead to a significant amount of lost time. Given that the effects of food poisoning often last for two or three days, a worker could easily miss a couple days as he or she recovers. For people with other health problems, a bout of food poisoning can lead to more serious conditions and even hospitalization.

The nature of workplaces and behavior of workers can increase the potential for food poisoning. For example, workers may bring their food to the jobsite and store it improperly, such as failing to refrigerate items that must be kept cool to be safe. Or workers may buy their meals at restaurants where sanitation may be lacking. People who work at remote sites for a long periods of time — such as construction contractors working in rural settings — may have few choices for food purchases and limited options for storage.

The good news is that the vast majority of food poisoning incidents are preventable by properly preparing and handling food. By being aware of basic safety and handling food correctly, workers can minimize the potential for discomfort and lost time.

( 3 )

Commonly, these types of food poisoning are transferred from:

• Unwashed hands handling food
• Unwashed raw fruit or veggies, or any raw produce with bacteria
• Undercooked or raw meat
• Room temperature food that should be refrigerated

• Cross-contamination of food bacteria
• Incorrectly prepared or stored deli meats, hot dogs, or ground beef
• Unpasteurized milk
• Spoiled dairy products or soft cheeses
• Cutting boards, bowls, or knives that are unwashed or cross-contaminated with bacteria

( 4 )

Vegetables and Leafy Greens

In fact, fruits and vegetables have caused a number food poisoning outbreaks, particularly lettuce, spinach, cabbage, celery and tomatoes (10). Vegetables and leafy greens can become contaminated with harmful bacteria, such as E. coli, Salmonella and Listeria.

Most food poisoning can be traced to one of the following three major causes:

Bacteria

Bacteria is by far the most prevalent cause of food poisoning. When thinking of dangerous bacteria, names like E. coli, Listeria, and Salmonellacome to mind for good reason. Salmonella is by far the biggest culprit of serious food poisoning cases in the United States. According to the CDCTrusted Source, an estimated 1,000,000 cases of food poisoning, including nearly 20,000 hospitalizations, can be traced to salmonella infection annually. Campylobacter and C. botulinum ( botulism)are two lesser-known and potentially lethal bacteria that can lurk in our food.

Parasites

Food poisoning caused by parasites is not as common as food poisoning caused by bacteria, but parasites spread through food are still very dangerous. Toxoplasmais the parasite seen most often in cases of food poisoning. It’s typically found in cat litter boxes. Parasites can live in your digestive tract undetected for years. However, people with weakened immune systems and pregnant women risk serious side effects if parasites take up residence in their intestines.

Viruses

Food poisoning can also be caused by a virus. The norovirus, also known as the Norwalk virus, causes over 19 million casesTrusted Source of food poisoning each year. In rare cases, it can be fatal. Sapovirus, rotavirus, and astrovirus bring on similar symptoms, but they’re less common. Hepatitis A virus is a serious condition that can be transmitted through food.

How does food become contaminated?

Pathogens can be found on almost all of the food that humans eat. However, heat from cooking usually kills pathogens on food before it reaches our plate. Foods eaten raw are common sources of food poisoning because they don’t go through the cooking process.

Occasionally, food will come in contact with the organisms in fecal matter. This most commonly happens when a person preparing food doesn’t wash their hands before cooking.

Meat, eggs, and dairy products are frequently contaminated. Water may also be contaminated with organisms that cause illness.