Discover causes, symptoms, and prevention of food poisoning. Stay informed and protect your health with Meri Sehat.

Food Poisoning

Medilink Consultant clinic

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ZAKA CLINIC GULBERG LAHORE

Saad Ullah Siddiqui

Overview

Food poisoning is a foodborne illness. It is caused due to the consumption of spoiled, contaminated, or toxic food. This is not a serious issue and is very common in populations all over the world. The most common types of bacteria responsible for food poisoning are Escherichia coli or E. coli, and Salmonella; even a virus like norovirus is a common culprit for causing food poisoning<a href="#accordion">[19]</a>.

Food poisoning is a prevalent illness in countries and environments of all kinds. According to WHO, 1 in 10 people suffer from food poisoning after eating contaminated food, totaling around 600 million people all over the world. Around 420,000 people die every year due to food poisoning.&nbsp;

Food-borne diseases victimize children under 5 years 40% of the time, which has resulted in an estimated 125,000 deaths per year<a href="#accordion">[26]</a>. Food contamination is not only limited to outside food but can also occur at any point of production or processing, even in highly controlled environments. Even home-cooked food can get spoiled or contaminated with improper handling or preparation. Food poisoning generally is not a medical emergency and can be treated easily. However, in severe cases, it is recommended to visit the hospital or see your doctor immediately.

&nbsp;

There is no such thing as complete sterilization of anything. You cannot escape microorganisms. While some can be good for us, or have no impact on our health, there are several harmful bacteria, viruses, and parasites that contaminate your food and are known to cause over 200 diseases, ranging from mild diarrhea to cancer. Moreover, some diseases can even prove to be fatal<a href="#accordion">[26]</a>. Here are some of the most common types of food poisoning to look out for: 
&nbsp;

<h5>Large Intestine Food Poisoning</h5>

The structure of the intestinal wall of the large intestine allows for the absorption of water and nutrients. When infected with a bacterium or a virus, it opens pores in the intestinal wall allowing water and other nutrients with it to flood back into your intestines, resulting in the gut passing watery, thin stool<a href="#accordion">[1]</a>. 
&nbsp;

<ul>
	<li>Shigellosis</li>
</ul>

Shigella species are known to cause shigellosis. This is a type of bacteria known to spread easily and has affected over 450,000 people in the United States alone<a href="#accordion">[7]</a>. It is regarded as one of the most common causes of dysentery. The gram-negative, anaerobic bacterium belongs to the family of Enterobacteriaceae. This type of family of bacteria, as the name suggests, inhabits the intestines of warm-blooded animals including humans.&nbsp;

Shigellosis is characterized by gastrointestinal disorders, including diarrhea and bacterial gastroenteritis<a href="#accordion">[13]</a>.&nbsp;The bacterium enters your body through food and initiates multiplication in the small intestines, and moves onto the large intestine to exert their effects. It results in the sharp cramping that people often experience along with diarrhea. It is easily spread through feces<a href="#accordion">[23]</a>.

Commonly experienced symptoms of Shigella include:

1. Fever

2. Nausea

3. Stomach and abdominal pain

4.&nbsp;Diarrhoea

5. Tenesmus or the feeling that you need to use the bathroom while having an empty stomach and intestines 
&nbsp;

<ul>
	<li>Salmonellosis</li>
</ul>

The flagellated gram-negative Salmonella is commonly found in the intestines of birds, humans, and other warm-blooded animals. The common causes of salmonellosis include raw or uncooked meat especially chicken, turkey, or pork, unpasteurized dairy products, raw eggs, and processed foods<a href="#accordion">[24]</a>.

Salmonella works by entering your body through ingested food. It survives the HCl-induced acidic environment of the stomach and starts producing toxins in small and large intestines through the invasion of their mucosa. The intestinal mucosa is made of epithelial cells. Damage and invasion of these cells trigger the secretion of pro-inflammatory&nbsp;cytokines. Pro-inflammatory&nbsp;cytokines are produced and released by macrophages, a type of WBC responsible for killing any foreign harmful matter. The pro-inflammatory cytokines cause inflammation that leads to diarrhea<a href="#accordion">[10]</a>. Salmonellosis is characterized by:

1. Blood in stool

2. Fever

3.&nbsp;Diarrhoea

4. Headache

5. Abdominal pain

The symptoms start showing after 8-72 hours of infection of the bacteria and the illness usually lasts up to a week<a href="#accordion">[24]</a>. 
&nbsp;

<ul>
	<li>Campylobacteriosis</li>
</ul>

Campylobacter species are responsible for causing over 1.5 million infections each year in the United States<a href="#accordion">[5]</a>. In Europe, it is responsible for over 246,000 reported cases annually. However, the actual figure may be close to 9 million<a href="#accordion">[9]</a>.&nbsp;Campylobacter is very similar to Salmonella. The bacterium is found in the digestive system of animals and is usually transmitted through unpasteurized milk and uncooked meat. After getting exposed to the bacteria, the symptoms occur within 2-5 days. Common symptoms of Campylobacter infection include:

1. Bloody&nbsp;diarrhea

2. Abdominal cramps

3. Fever

Severe cases of Campylobacter may cause arthritis, temporary paralysis, and irritable bowel syndrome<a href="#accordion">[4]</a>. Campylobacter can be fatal for people with a weakened immune system.&nbsp; 
&nbsp;

<ul>
	<li>Vibrio Parahaemolyticus</li>
</ul>

Vibrio parahaemolyticus belongs to the same family as Vibrio cholerae. It is a gram-negative enteric bacterium and is commonly found in coastal waters and sea waters. They increase in numbers in warmer climates or seasons. Due to their abundance in waters, it is common to find V. parahaemolyticus in shellfish. The consumption of raw shellfish during summer is one of the most common ways of contracting this bacterial infection<a href="#accordion">[3]</a>.

V. parahaemolyticus has been the most common cause of food poisoning in Taiwan and has increased its occurrence in developing countries<a href="#accordion">[11]</a>.&nbsp;It takes 12-24 hours after getting infected for symptoms to appear. The illness itself lasts for an average of 3 days, but in some cases, it may last up to a week. The symptoms include:

1. Fever

2. Headaches

3. Nausea

4. Vomiting

5. Appearance of blood in stool&nbsp;

6. Watery stool

7. Abdominal pain

It is diagnosed with the help of culture tests done on a stool sample for the detection of V. parahaemolyticus<a href="#accordion">[3]</a>. 
&nbsp;

<h5>Small Intestine Food Poisoning</h5>

Infections that affect small intestines, and often cause inflammation, are called Enteritis. There are a total of three mechanisms through which pathogens can cause diarrhea or food poisoning in the small intestine. The very first mechanism involves the production of toxins in the food before ingestion. The second mechanism involves the production of toxins inside the body after ingestion, and lastly comes the mechanism that involves damaging the mucosal surface of the intestine<a href="#accordion">[2]</a>. 
&nbsp;

<ul>
	<li>Vibrio Cholerae</li>
</ul>

Pakistan has recently faced a cholera outbreak with reports of over 2,000 cholera cases from Jan 1st to May 17th only. The main cause was believed to be the contaminated water crises faced by the country. Baluchistan suffered the most followed by Khyber Pakhtunkhwa<a href="#accordion">[8]</a>.&nbsp;

Like the rest of the food poisonings, cholera also causes diarrhea. This is due to a toxin that cholera produces. The toxin acts on the enzyme adenylate cyclase. Adenylate cyclase is responsible for the conversion of ATP to cAMP. Cyclic AMP has an inhibitory effect on the migration potential of the intestine. This action leads to the secretion of chloride ions in the intestine which causes the accumulation of fluid in the gut<a href="#accordion">[22]</a>.&nbsp;

Apart from thin stool discharge, which is also described as &ldquo;rice-water stools&rdquo;<a href="#accordion">[6]</a>, the following are the symptoms that commonly occur in cholera:&nbsp;

1. Excessive dehydration and thirst

2. Severe leg cramps

3. Increased heart rate

4. Low blood pressure

5. Reduced or loss of skin elasticity

Cholera requires immediate attention due to its possible worsening that may even lead to kidney failure, shock, coma, and in some cases even death<a href="#accordion">[6]</a> 
&nbsp;

<ul>
	<li>Escherichia Coli&nbsp;</li>
</ul>

Escherichia coli are commonly found in the gut of many healthy people and even animals. They play a vital role in keeping your gut health intact and are some of the very few gram-negative bacteria that stay in the body. However, there are some strains of E. coli out there that make you sick. They<a href="#accordion">[16]</a> invade our bodies through contaminated food or drinks and tend to damage the lining of the small intestine. Symptoms of E. coli infection include:

1. Bloody diarrhea

2. <a href="https://www.merisehat.pk/disease/pneumonia" target="_blank">Pneumonia</a>

3. Urinary tract infection

4. Seizures

5. Kidney failure

6. Haemolytic&nbsp;uremic syndrome

Symptoms occur after 2-5 days of infection and patients with a healthy immune system normally get better within a week. 
&nbsp;

<ul>
	<li><a href="https://www.merisehat.pk/disease/botulism" target="_blank">Botulism</a></li>
</ul>

<a href="https://www.merisehat.pk/disease/botulism" target="_blank">Botulism infection</a> is rare but can be fatal. Botulism is caused by a bacteria called Clostridium botulinum<a href="#accordion">[15]</a>. The infection is considered a medical emergency due to its fast and severe activity depending on how much of the toxin is ingested. When it comes to food-borne botulism, home-canned foods are the ideal place for them to grow and produce their toxins, due to the lower levels of oxygen<a href="#accordion">[15]</a>. This is due to the anaerobic nature of the bacterium. Botulism targets the nerves of the body, and results in a severe illness. The following are the symptoms commonly found in botulism:

1. Muscle weakness

2.&nbsp;Diarrhoea

3. Blurry vision

4. Difficulty breathing

5. Dry mouth

6. Paralysis 
&nbsp;

<ul>
	<li>Viruses</li>
</ul>

There are several food-borne viruses out there that have been the culprits of food poisoning, but the most common ones include norovirus, rotavirus,<a href="https://www.merisehat.pk/disease/hepatits-abcde-59" target="_blank"> hepatitis A and E</a>. Common source of virus transmission is sewage contamination<a href="#accordion">[20]</a>.&nbsp;Viral infections are mostly found in infants and children, but it is hard to differentiate between bacterial and non-bacterial gastroenteritis. Unlike bacteria, viruses do not grow or produce toxins while they are outside the host&rsquo;s body. However, the symptoms of viral food poisoning are like that of bacterial food poisoning. It just follows a different drug therapy for its treatment, since the antibiotics employed for bacterial infection are not effective on viral infections<a href="#accordion">[14]</a>.

&nbsp;

Signs And Symptoms

Depending on the type of microorganism that has infected the patient, some symptoms may differ or be more severe than others. They include:

<ul>
	<li>Diarrhea</li>
	<li>Nausea</li>
	<li>Vomiting</li>
	<li>Loss of appetite</li>
	<li>Fever</li>
	<li>Muscle weakness</li>
	<li>Headache</li>
	<li>Blurry vision</li>
	<li>Difficulty speaking</li>
	<li>Dry mouth</li>
	<li>Severe dehydration</li>
	<li>Severe abdominal pain</li>
	<li>Blood in urine, stool, or vomit</li>
</ul>

&nbsp;

If you experience any of these symptoms, immediately contact your healthcare provider to avoid them from getting worse.

&nbsp;

Causes

The biggest culprits of food poisoning are bacteria, viruses or parasites. These microorganisms enter our body through various sources, the most common being food. The biggest reason, to this day, for food-borne illnesses is poor hygiene practice associated with the preparation of food. Processed foods, ready-to-eat foods, raw food especially protein-rich foods like egg, poultry, red meat and fish etc. are some of the most common causes of food-borne infections<a href="#accordion">[17]</a>. Poor storage provides the ideal environment for bacterial growth. Food that is left out for too long, or stored poorly is also a common cause of food poisoning.

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Diagnosis

The most common way of diagnosing food poisoning is through symptoms. However, in cases of certain complications, it is best to conduct diagnostic tests to get to the root of the problem and also to determine the type of infection for better treatment. Following are the tests commonly employed to test for food poisoning and its types: 
&nbsp;

<ul>
	<li>Stool Culture Tests</li>
</ul>

These are the most common tests to check for food poisoning. With symptoms of nausea, diarrhea, stomach pain, and fever, it is very common for healthcare practitioners to order a stool sample test. Stool sample tests aid in determining the type of food poisoning. It can tell you if the infection is bacterial or viral. A lot of information can be extracted, including the type of microorganism that has infected you through its DNA fingerprint. Compared to bacterial infection, viruses are harder to identify whereas parasites can be observed under a microscope<a href="#accordion">[25]</a>. 
&nbsp;

<ul>
	<li>Blood Tests</li>
</ul>

Blood tests are often ordered for serious cases that involve the spreading of the infection into the bloodstream. Listeria monocytogenes and Hepatitis A are best identified through this. Blood tests also aid in determining the severity of your situation by giving information about the inflamed areas of the body<a href="#accordion">[25]</a>.

&nbsp;

Treatment

Treatment is best done when you know what type of food poisoning you have. However, there are some common measures taken for every type of food poisoning due to similar symptoms. In some cases, people recover without any form of treatment because they tend to excrete the parasite. Common measures taken for food poisoning are:

<ul>
	<li>Avoiding solid foods and resorting to easy-to-digest light food</li>
	<li>Replenishing lost fluid through a liquid diet involving fruit juices and broths</li>
	<li>Keeping yourself hydrated</li>
	<li>Resort to oral rehydration solution if vomiting and diarrhea persists</li>
	<li>Antibiotics are prescribed based on the type of poisoning you have. In cases of listeria food poisoning, the patient is administered I/V antibiotics. They do not work in case of viral food poisoning.</li>
	<li>Probiotics are also believed to treat diarrhea. However, not enough research is done to fully understand the therapeutic extent of the use of microbes to treat diseases. 
	&nbsp;</li>
</ul>

<h4>Food poisoning can often increase your blood pressure. Head on over to the <a href="https://www.merisehat.pk/page/sehat-scan/" target="_blank">sehat scan </a>and check your reading today. </h4>

The severity and complications of food poisoning can range from simple dehydration to life-threatening conditions. Dehydration is a common experience of food poisoning. Due to constant vomiting and diarrhea, you are bound to lose precious electrolytes, nutrients, and water excessively. This is one of the reasons why hydration is such a crucial aspect of the treatment<a href="#accordion">[18]</a>. Dehydration can be a nuisance in children and older adults with a weakened immune system. It can lead to organ damage, shock, coma, or death.

The hemolytic uremic syndrome is another common complication that occurs when the patient is infected with E. coli. Other bacteria may also cause this infection. It is most prevalent in children of age 5 or less<a href="#accordion">[18]</a>.

Guillain-Barre syndrome is another complication caused by bacteria or viruses, but most commonly Campylobacter jejuni is the main cause of this infection. Irritable bowel syndrome, reactive arthritis, and breathing issues are also common complications that are prevalent in different types of food poisoning.

&nbsp;

In cases of pregnancy, the fetus is prone to get affected due to severe dehydration caused by food poisoning and the loss of nutrients. Infection by listeria in pregnant women is also responsible for stillbirth or miscarriages<a href="#accordion">[18]</a>.

&nbsp;

Anyone can have food poisoning but there are people at a higher risk of getting more severe food poisoning than others. These include: 
&nbsp;

<ul>
	<li>Immunocompromised Individuals</li>
</ul>

Since food poisoning itself is caused by microorganisms, having a weak immune system diminishes your body&rsquo;s ability to fight and eradicate the threat. This leads to them being at a greater risk of getting food poisoning.&nbsp;

<ul>
	<li>Older Adults And Young Children</li>
</ul>

Older populations and children younger than 5 have weaker immune systems. They are easily affected by severe dehydration which may lead to bigger issues like organ damage. Food poisoning in these age groups is more severe than the rest.

<ul>
	<li>Pregnant Women</li>
</ul>

Pregnant women are more at risk due to the drastic body changes that they are going through and their increased need for nutrition and electrolytes which are often lost in excretion during food poisoning. In many cases, food poisoning also badly affects the fetus. 
&nbsp;

Considering the causes of food poisoning, it is safe to deduce that the biggest preventive measure would be the safe handling of your food. However, foods like meat, eggs, poultry, fish and shellfish are more likely to cause food poisoning based on how they are stored and prepared. Several infectious agents are killed by exposure to high heat. Following further steps will ensure that your food is safe to consume:<ul><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Avoiding unheated deli meats and hot dogs</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Avoiding minced beef containing meat from multiple cows</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Avoiding unpasteurised&nbsp;dairy</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Stop consumption of unwashed, or raw fruits and vegetables</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Ensuring that your hands are washed and cleaned before handling food</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Ensuring that your food is properly stored at the right temperature</li><li style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;">Thoroughly cooking your proteins </li></ul>

On the topic of increased food wastage, researchers have pondered upon the use of fruit peels and their possible applications to reduce wastage. It was found out that several fruit peels contain crucial bioactive compounds that can aid in better safety of the food and can have several other benefits, including anti-inflammatory action, treating cough, muscle pain, digestive problems, etc. Hesperidin is a great example of peel-extracted chemicals. It has potent anti-inflammatory, anti-carcinogenic, antioxidant, and most importantly, antimicrobial effects<a href="#accordion">[12]</a>.

&nbsp;

Researchers at the University of Exeter, UK have reported on the potential of fast-growing bacteria evading antibiotic treatment. In several cases of food poisoning, healthcare practitioners are often met with high antibiotic resistance. Due to the fast-growing nature of bacteria, they have high expression of active ribosomes. This aids in the avoidance of the accumulation of macrolides that leads to resistance in antibiotic therapies<a href="#accordion">[21]</a>. 
&nbsp;

Key Points

<ul>
	<li>Food poisonings are commonly characterized by diarrhea, dehydration, vomiting, and stomach ache.</li>
	<li>Symptoms vary in food poisonings, depending on the type of microorganism that has caused it. The severity and occurrence also vary based on that.</li>
	<li>Most cases of food poisoning&nbsp;heal on their own, but there are cases where there is a need for the use of antibiotics or more serious measures based on the severity.</li>
	<li>The most common causes include poor handling of&nbsp;food&nbsp;and ingestion of raw or poorly processed food.</li>
	<li>The best way to diagnose food poisoning is through stool sample tests that allow for the better detection of the root cause of the illness.</li>
	<li>Immunocompromised individuals, pregnant women, people of older age, and children younger than 5 are at a higher risk of contracting the bacteria or virus that causes food poisoning, and may even experience it with a higher severity than normal individuals.</li>
</ul>

&nbsp;

[1] BBC Science Focus, n.d. What happens in my body when I get food poisoning?. [Online]

[2] Cangemi, J. R., 2011. Food Poisoning and Diarrhea: Small Intestine Effects. Curr Gastroenterol Rep , Issue 13 , p. 442–448.

[3] CDC - BC Centre for Disease Control , n.d. Vibrio parahaemolyticus. [Online]

[4] Centers for Disease Control and Prevention, 2019. Campylobacter (Campylobacteriosis). [Online]

[5] Centers for Disease Control and Prevention, 2019. Campylobacter (Campylobacteriosis). [Online]

[6] Centers for Disease Control and Prevention, 2020. Cholera - Vibrio cholerae infection. [Online]

[7] Centers for Disease Control and Prevention, 2020. Shigella - Shigellosis. [Online]

[8] Crisis 24, 2022. Pakistan: Cholera outbreak onoging nationwide, especially in Balochistan Province, as of May 17. [Online]

[9] European Food Safety Authority, n.d. Campylobacter. [Online]

[10] Giannella, R. A., 1996. Salmonella. 4th Edition ed. Galveston (TX): University of Texas Medical Branch at Galveston.

[11] John E. Bennett MD, i. M. D., 2003. Vibrio parahaemolyticus. In: Encyclopedia of Food Sciences and Nutrition (Second Edition). Tokyo: s.n., pp. 5988-5992.