Chapter 1: Introduction
Foodborne illness better known as food poisoning, is illness caused by variety of agents which may be intrinsic that include certain foods which are toxic in themselves, or extrinsic causes include chemicals, parasite and micro-organisms. (Corry, Roberts and Skinner, 1982). Bacteria, viruses and parasites are infectious organisms and their toxins are the most common cause of foodborne illness
Some organisms cause an intoxication by the bacteria due to the toxins production in the foods before its consumption, often stimulated by the storage conditions of the foods which allow multiplication of the bacteria. Other bacteria cause infection that cause the disease after consumption where the toxins are multiply and elaborate in the intestine. (Mayoclinic.org). Food should be attractive and nourishing. It has to be visibly clean and it has to be also free from harmful materials. These harmful materials may be poisonous, even those that are harmless in small amounts, but in large quantity they are damaging and harmful. They may accidently enter the food during growth, preparation, cultivation, or other different ways. Micro-organisms may directly introduce from infected food animals or from workers or even environment.
During the production of food, contamination can occur at any point: growing, harvesting, processing, storing, shipping or preparing. This result in Cross contamination and the harmful organisms are transferred from one surface to another. This is especially troublesome for raw foods such as salads or other that have been produced or grown, especially by farming. Because these foods aren’t cooked, harmful organisms aren’t destroyed before eating and can cause food poisoning (Mayoclinic.org).
Food poisoning is not a new disease, it has been recognized throughout the ages which is characterized usually by vomiting, diarrhea and abdominal pains. (Hobbs and Roberts, 1987).
Investigation of the food poisoning is done by the following ways:
• Secure complete list of the people involved and their history
• Laboratory investigation
• Animal experiments
• Blood for the antibodies
• Environmental study
• Analysis data due to time, place and person
• A case control study
To avoid food poisoning we should:
• Throw away
Chapter 2: Bacterial food poisoning
The most prevalent cause of food poisoning is bacteria by far. So what are bacteria?
Bacteria are tiny living microorganisms, a few micrometers in length that normally exist together in huge amount and can be found everywhere (Medical News Today), like for example: soil, water, plants and animals. And they come in three main shapes:
1- Spherical —like a ball— (cocci)
2- Rod shaped (bacilli)
3- Spiral (spirilla)
Growth and multiplication
Bacteria can multiply under the suitable conditions of temperature and environment into two every 20 or 30 minutes by simple division. when each cell has grown to its maximum size, a constriction appears at both sides of the center axis, the outside membrane or envelope of the cell grows inwards and forms a division which finally splits, releasing two new twin cells (Hobbs and Roberts, 1987).
Condition for growth
A variety of media in the laboratory are made to suit the growth requirements of different types of bacteria. Agar is more suitable for bacterial media because of its special properties; it melts at a high temperature and sets at a low temperature. Blood, serum milk, or other protein matter may be added for enrichment.
Bacteria will multiply and live in many foodstuffs; sometimes the humidity of the kitchen and the type of food and the atmospheric temperature provide similar conditions to those used in the laboratory for cultivation. Thus food poisoning more frequently occurs in the warmth of summer than in the cold of winter (Hobbs and Roberts, 1987).
Most bacteria require air to live and they are called aerobes, but some can survive only in the absence of oxygen and called anaerobes.
Some of bacteria that can cause food poisoning. (Design)
Name of bacteria Original source Risky foods Time to develop Symptoms
Campylobacter jejuni Raw meat and poultry Undercooked meat a poultry; raw milk and cross-contaminated food 3-5 days of eating infected food Fever, sever pain and diarrhea
Clostridium botulinum (very rare) Soil Faulty processed canned meat and vegetables; cured meat and raw fish 1-7 days Affects vision, cause paralysis and can be fatal
Clostridium perfringens The environment Large joints of meat; reheated gravies 8-24 hours Nausea, pain and diarrhea
Escherichia coli E.coli O157:H7 is a very nasty strain it can be fatal The gut of all humans and animals Contaminated water, milk, inadequately cooked meat, cross-contaminated foods 3-4 days Inflammation, sickness and diarrhea
Listeria monocytogenes Everywhere Soft cheese, pre-packed salad; cook-chill products Varies Fever, headache, septicemia and meningitis
Salmonella Gut of birds and mammals including humans – spread by faeces into water and food Poultry, eggs and raw egg products, vegetables 6-48 hours Diarrhea, sickness and headache
Staphylococcus aureus The skin and noses of animals and humans Cured meat; milk products; unrefrigerated handled foods 2-6 hours Sickness, pain and sometimes diarrhea
Paying closer attention to five of the most common types of bacteria which cause food poisoning: Campylobacter, Salmonella, clostridium perfringens Listeria and E. coli 0157.
Campylobacter is the most common cause of bacterial food poisoning, caused by a campylobacter jejuni and cause the disease called campylobacteriosis (MedicineNet).
Source of Campylobacter
Normally inhabit and detected in the intestinal tract of warm blooded animals and in foods derived from them. It has been found mainly in poultry, red meat, unpasteurized milk and untreated water. Although it doesn’t grow in food it spreads easily, so only a few bacteria in a piece of undercooked chicken could cause illness (Ltd).
Most people who become ill with campylobacteriosis get: diarrhea, abdominal pain, and fever within two to five days after exposure to the organism. The diarrhea may be bloody. The illness typically lasts about one week.
Some infected persons do not have any symptoms. In persons with compromised immune systems, Campylobacter occasionally spreads to the bloodstream and causes a serious life-threatening infection.
Treatment is not usually required, but an electrolyte replacement and rehydration are done. In the invasive cases the antimicrobial treatment is recommended (erythromycin, tetracycline, quinolones).
Salmonella is the second most common cause of food poisoning after campylobacter.
People infected with salmonella should be careful with personal hygiene because they could infect another person who comes into direct contact with them (InjuryClaimCoach.com).
Sources of Salmonella
It has been found mainly in:
– unpasteurized milk
– Eggs and raw egg products
Salmonella bacteria or its toxins can survive if food is (cooked or refrigerated) improperly, or by cross-contamination, Salmonella quickly spreads when already infected food comes in contact with uncontaminated food.
Symptoms of Salmonella poisoning normally last from 24 to 48 hours
Clostridium perfringens are bacteria that produce harmful toxins and are found everywhere in the environment, these bacteria isn’t completely destroyed by cooking because it produces heat-resistant spores, not like other types of bacteria that cause food poisoning.
Food poisoning from Clostridium perfringens fairly common, but is typically not too severe, and is often mistaken for the 24-hour flu. (Foodborneillness.com)
Source of Clostridium perfringens
Undercooked meats, mostly foods prepared for large group in large quantities and left to sit out for long periods of time and foods with poorly controlled temperature that kept between 70 and 140 F, are the majority of outbreaks.
Meat products such as stews, casseroles, and gravy are the most common sources of illness from C. perfringens.
Symptoms of Clostridium Perfringens Infection
About 6-24 hours after ingestion and consuming the bacteria or toxins, the symptoms start to appear.
Clostridium perfringens toxins cause:
– Abdominal pain
– Stomach cramps
Fever and vomiting are not normally symptoms of poisoning by Clostridium perfringens toxins.
Illness from Clostridium perfringens is rarely fatal and generally lasts around 24 hours,
Complication from Clostridium perfringens
The Type C strain of Clostridium perfringens can cause a more serious condition called Pig-bel Syndrome. This syndrome can cause death of intestinal cells and can often be fatal.
Preventing a Clostridium Perfringens Infection
To prevent infection by Clostridium perfringens, follow these tips:
• Cook foods containing meat thoroughly
• If keeping foods out, make sure they maintain a temperature of 140 F (60 C)
• When storing food in the refrigerator, divide it into pieces with a thickness of three inches or less so that it cools faster
• Reheat foods to at least 165 F (74 C)
Listeria is the name of a bacteria has been found in low amount in foods. Eating foods containing higher levels of this bacteria causes the disease. And usually it’s sever and life threatening in vulnerable groups as pregnant women, babies, elderly and immunodeficiency people (Taylor and Francis, 2007). unlike many other germs it can grow even in cold temperature of the refrigerator.
Symptoms of Listeriosis
Usually people with listeriosis have fever and muscle aches, sometimes gastrointestinal symptoms and diarrhea.
When patients are diagnosed with listeriosis they mostly have it as invasive infection, as the bacteria spread beyond the gastrointestinal tract. The symptoms vary from person to person:
– Pregnant women: experience typically fever, fatigue and aches and other non-specific symptoms. During pregnancy infection can lead to premature delivery or life-threatening infection of newborn (Taylor and Francis, 2007) (Jackson KA, Iwamoto M, Swerdlow D, 2010).
– People other than pregnant women: symptoms can include stiff neck, loss of balance, headache, confusion, fever and muscle aches.
Escherichia coli is a member of the family Enterobacteriaceae. It’s a gram-negative bacillus growing aerobically and anaerobically at 37˚C, killed by high temperatures above 55˚C. It is found commonly in the intestine of human and animal (Hobbs and Roberts, 1987).
It’s normally found in undercooked and raw meat. Although, most strains of these bacteria are harmless, several are known to produce toxins that can cause diarrhea. One particular E.coli strain called 0157 can cause severe diarrhea and kidney damage.
Symptoms last from 7 to 10 days, and can include:
– bloody diarrhea
– kidney failure (in some cases)
Treatment for E.coli includes antibiotics.
Chapter 3: Parasite food poisoning
Parasites are organisms that cannot live independently, they live and depends in another organism called host. (Medical News Today)
Food poisoning caused by parasites is not as common as food poisoning caused by bacteria, but parasites spread through food are still very dangerous. Parasites can live in your digestive tract undetected for years. However, those with weakened immune systems and pregnant women risk serious side effects if parasites take up residence in their intestines.
They can be transmitted from one host to another through consumption of contaminated foods. Around 70% of parasites are microscopic in size, however some worm parasites can reach over 30 m in length. There are more than 1,000 known parasite species that can infect humans. Here are some examples:
• Endoparasite: live inside the host and are called intercellular parasites, it includes: heartworm, tapeworm, and flatworms.
• Epiparasite: feed on other parasites and this relationship called hyperparasitism.
• Parasitoid: usually the host dies because of the characteristics of predation.
Some of the most common parasites that causes foodborne illness are as following:
Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanensis and Toxoplasma gondii
Giardia duodenalis is a species of Giardia that causes diarrhea in vertebrates.
There are two developmental stages of the parasite: trophozoites and cysts.
Group Synonyms Host range Trophozoite size
G. duodenalis G. intestinalis, G. lamblia mammals (including man), birds, reptiles 12-15 x 6-8 µm
Flagellated trophozoites are found in the small intestines of the hosts swimming in the luminal and adhering to the gut mucosal surface with their ventral adhesive discs. The infections interfere with the normal absorptive functioning of the small intestines, causing osmotic overload of the large intestines resulting in watery diarrhea. Infections occurs by fecal-oral route of encysted parasite and may be detected by routine examination like the stained smears or sedimentation/flotation concentration techniques, but the test sensitivity is poor due to intermittent cyst excretion. Endoscopic techniques have been used in chronic cases to detect trophozoites in intestinal biopsy. Recently, sensitive and specific techniques in immunology have been developed to detect antigens of parasites in fecal. Similar monoclonal antibody immunoreagents are also used in many countries to detect cysts in water samples using immuno-magnetic separation techniques. (Parasite.org.au)
Treatment: Flagyl (metronidazole) is the drug of choice for giardiasis despite mild side-effects such as nausea. However, there are growing problems with metronidazole-resistant parasite strains. Other nitroimidazole derivatives (tinidazole), nitrofurans (furazolidone), acridine drugs (quinacrine) and microtubule inhibitor anthelmintics (albendazole) have been reported effective.
Toxoplasma gondii is a single-celled parasitic organism that can infect most animals and birds, it reproduces only in cats and causes a disease known as toxoplasmosis. (Cdc.gov)
A Toxoplasma infection occurs by the following:
• blood transfusion or organ transplantation.
• consuming undercooked, infected meat.
• mother-to-child transmission.
• Accidentally swallowing the parasite through contact with cat feces that contain Toxoplasma. This might happen by:
1. cleaning a cat’s litter box when the cat has shed Toxoplasma in its feces
2. touching or ingesting anything that has come into contact with cat feces that contain Toxoplasma
3. accidentally ingesting contaminated soil (e.g., not washing hands after gardening or eating unwashed fruits or vegetables from a garden)
symptoms of Toxoplasmosis vary. Usually it is asymptomatic, because our immune system keeps the parasite from causing illness. 10–20 % of patients have an acute toxoplasmosis and develop symptoms that last for several weeks and then go away. The parasites remain in the body as bradyzoites tissue cysts and reactive when the person becomes immunosuppressed. (Parasitesinhumans.org)
Diagnosis of toxoplasmosis is often difficult because the symptoms are similar to the flu symptoms. To test for infection in pregnant women, a doctor may conduct a blood test. The Centers for Disease Control and Prevention (CDC) recommends that tests be sent to a laboratory specializing in toxoplasmosis diagnosis.
Severe cases of toxoplasmosis in adults may be diagnosed using an MRI or a brain biopsy to check for lesions or cysts in the brain.
Healthy people do not require treatment for toxoplasmosis. However, otherwise-healthy individuals who experience severe symptoms of the disease can be treated with drugs, including Daraprim, an antimalarial drug, or Sulfadiazine, an antibiotic. The same drugs can be used to treat those with compromised immune systems. In extreme circumstances, these drugs can be administered to unborn babies to prevent further development of the infection, but cannot undo damage that has already occurred. If a pregnant woman is diagnosed with toxoplasmosis, she may be given Spiramycin, an antibiotic, to reduce the chance the infection will spread to the child. (Cdc.gov)
Chapter 4: Viral food poisoning
Virus is a Latin name that means poisoning. It is an infectious microscopic organism that can multiply in living cells only of animals, bacteria or plants (Encyclopedia Britannica). It consists of genetic material RNA or DNA surrounded by a protein, lipid, or glycoprotein coat. virus can also cause a foodborne disease and in rare cases it can be fatal.
The Norovirus, also known as the Norwalk virus, causes over 19 million cases of food poisoning each year, and 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.
Norwalk virus also called norovirus is the most common cause of acute gastroenteritis which is the infection of the stomach and intestine, and it is often called stomach flu. It can spread directly from infected people to others, or through food and drinks that have been contaminate before served. (Foodsafety.gov, 2016)
Sources Produce, shellfish, ready-to-eat foods touched by infected food workers (salads, sandwiches, ice, cookies, fruit), or any other foods contaminated with vomit or feces from an infected person
Incubation Period 12-48 hours
Symptoms Diarrhea, vomiting, nausea, and stomach pain. Diarrhea tends to be watery and non-bloody. Diarrhea is more common in adults and vomiting is more common in children
Duration of Illness 1-3 days. Among young children, old adults, and hospitalized patients, it can last 4-6 days.
What Do I Do? Drink plenty of fluids and get rest. If you cannot drink enough fluids to prevent dehydration, call your doctor.
How Do I Prevent It? • Wash hands frequently with soap and running water for at least 20 seconds, particularly after using the bathroom and before preparing food.
• If you work in a restaurant or deli, avoid bare-hand contact with ready-to-eat foods.
• Clean and disinfect surfaces contaminated by vomiting or diarrhea (use a bleach-based household cleaner as directed on the label). Clean and disinfect food preparation equipment and surfaces.
• If you are ill with diarrhea or vomiting, do not cook, prepare, or serve food for others.
• Wash fruits and vegetables and cook oysters and other shellfish thoroughly before eating them.
• Wash clothing or linens soiled by vomit or fecal matter immediately. Remove the items carefully to avoid spreading the virus. Machine wash and dry.
Norovirus infection can be detected via the following studies:
• Immune electron microscopy: Immune serum is used to aggregate virus in stool samples to aid detection
• Antigen detection immunoassay: Has high sensitivity but low specificity because of reactivity with antigenic variants and homologous viruses
• Nucleic acid amplification: Highly sensitive and specific (Tian and Mandrell, 2006)
Treatment of norovirus gastroenteritis includes the following:
• Oral fluid and electrolyte replacement: Generally adequate for the treatment of norovirus infections
• Intravenous fluid and electrolyte resuscitation: May be necessary in cases of severe volume depletion
• Antiemetics: For relief of nausea and vomiting
• Analgesics: For relief of myalgias and headache
• Antiperistaltic agents: Should generally be avoided in cases of infectious diarrhea but can be considered in patients with severe diarrhea (Emedicine.medscape.com)
Hepatitis A virus
Hepatitis A virus cause a highly contagious liver infection. This virus is one type of hepatitis viruses that affect the ability of liver to function and cause inflammation. You are most likely to get infected from contaminated food, water or from close contact with infected person. (Mayoclinic.org)
Hepatitis A signs and symptoms appear a few weeks after you have had the virus, and may include the following:
•Nausea and vomiting
•Abdominal pain or discomfort, especially in the area of your liver on your right side beneath your lower ribs
•Clay-colored bowel movements
•Loss of appetite
•Yellowing of the skin and eyes (jaundice)
Hepatitis A could be asymptomatic with no signs and symptoms developed, or could be mild illness that lasts a few weeks or a severe illness that lasts several months.
You’re at increased risk of hepatitis A if you:
•Travel or work in regions with high rates of hepatitis A
•Attend child care or work in a child care center
•Are a man who has sexual contact with other men
•Are HIV positive
•Have a clotting-factor disorder, such as hemophilia
•Use injected or noninjected illicit drugs
•Live with another person who has hepatitis A
•Have oral-anal contact with someone who has hepatitis A
Unlike other types of viral hepatitis, hepatitis A does not cause long-term liver damage, and it doesn’t become chronic. In rare cases, hepatitis A can cause loss of liver function that occurs suddenly, especially in older adults or people with chronic liver diseases. Acute liver failure requires hospitalization for monitoring and treatment. Some people with acute liver failure may require a liver transplant.
Tests and diagnosis
Blood tests are used to detect the presence of hepatitis A in your body. A sample of blood is taken, usually from a vein in your arm, and sent to a laboratory for testing. Testing for the presence of IgM antibodies is ordered when someone develop acute symptoms. (Labtestsonline.org)
What does the test result mean?
Results of hepatitis testing may indicate the following:
HAV IgM HAV IgG or Total Antibody (IgM and IgG) Results Indicate
Positive Not Performed Acute or recent HAV infection
Negative Positive No active infection but previous HAV exposure; has developed immunity to HAV or recently vaccinated for HAV
Not Performed Positive Has been exposed to HAV but does not rule out acute infection
Not Performed Negative No current or previous HAV infection; vaccine may be recommended if at risk
Food poisoning is a health problem affects human at different ages all over the world.
The clinical course is variable could be self-limiting symptoms or very serious disease with complication.
However, the uses of control measurement to prevent the occurrence of food poisoning are important to limit its spread and improve food safety.
• Corry, J., Roberts, D. and Skinner, F. (1982). Isolation and identification methods for food poisoning organisms. London: Academic Press.
• Medical News Today. (2016). What Is Bacteria? What Are Bacteria?. [online] Available at: http://www.medicalnewstoday.com/articles/157973.php [Accessed 15 Mar. 2016].
• Design, i. (2016). Microbiology Online | Microbiology Society | About Microbiology – Microbes and food – Food poisoning. [online] Microbiologyonline.org.uk. Available at: http://www.microbiologyonline.org.uk/about-microbiology/microbes-and-food/food-poisoning [Accessed 15 Mar. 2016].
• Ltd, A. (2016). Food Poisoning Bacteria – Salmonella, Listeria, E.coli 0157, Campylobacter. [online] Accepta.com. Available at: http://www.accepta.com/environmental-water-wastewater-knowledge/pathogen-control-knowledge/297-food-poisoning-bacteria-salmonella-listeria-e-coli-0157-campylobacter [Accessed 15 Mar. 2016].
• InjuryClaimCoach.com. (2016). Food Contamination and Poisoning Claims. [online] Available at: http://www.injuryclaimcoach.com/food-poisoning.html [Accessed 15 Mar. 2016].
• Foodborneillness.com. (2016). Clostridium Perfringens food poisoning. [online] Available at: http://www.foodborneillness.com/clostridium_perfringens_food_poisoning/ [Accessed 15 Mar. 2016].
• (Painter J & Slutsker L. Listeriosis in humans. In: E. T. Ryser & E. H. Marth., editor. Listeria, Listeriosis and Food Safety 3rd ed Boca Raton, Florida: Taylor and Francis Group; 2007. p. 85-110.)
• 4.Jackson KA, Iwamoto M, Swerdlow D. Pregnancy-associated listeriosis. Epidemiology and infection. 2010;138(10):1503-9.)
• MedicineNet. (2016). Food poisoning, Campylobacter. [online] Available at: http://www.medicinenet.com/script/main/art.asp?articlekey=16203 [Accessed 20 Mar. 2016].
• Hobbs, B. and Roberts, D. (1987). Food poisoning and food hygiene. London: E. Arnold.
• Mayoclinic.org. (2016). Welcome – About This Site – Mayo Clinic. [online] Available at: http://www.mayoclinic.org/about-this-site/welcome [Accessed 21 Mar. 2016].
• Medical News Today. (2016). What is a Parasite? What do Parasites do?. [online] Available at: http://www.medicalnewstoday.com/articles/220302.php [Accessed 31 Mar. 2016].
• Parasite.org.au. (2016). Giardia. [online] Available at: http://parasite.org.au/para-site/text/giardia-text.html [Accessed 1 Apr. 2016].
• Cdc.gov. (2016). CDC – Toxoplasmosis – General Information – Frequently Asked Questions (FAQs). [online] Available at: http://www.cdc.gov/parasites/toxoplasmosis/gen_info/faqs.html [Accessed 1 Apr. 2016].
• Parasitesinhumans.org. (2016). Toxoplasma Gondii. [online] Available at: http://www.parasitesinhumans.org/toxoplasma-gondii.html [Accessed 1 Apr. 2016].
• Encyclopedia Britannica. (2016). virus | biology. [online] Available at: http://global.britannica.com/science/virus [Accessed 8 Apr. 2016].
• Foodsafety.gov. (2016). Norovirus (Norwalk Virus) | FoodSafety.gov. [online] Available at: http://www.foodsafety.gov/poisoning/causes/bacteriaviruses/norovirus/index.html [Accessed 8 Apr. 2016].
• Emedicine.medscape.com. (2016). Norovirus Treatment & Management: Medical Care, Consultations, Diet. [online] Available at: http://emedicine.medscape.com/article/224225-treatment [Accessed 11 Apr. 2016].
• Tian, P. and Mandrell, R. (2006). Detection of norovirus capsid proteins in faecal and food samples by a real time immuno-PCR method. J Appl Microbiol, 100(3), pp.564-574.
• Mayoclinic.org. (2016). Hepatitis A Prevention – Mayo Clinic. [online] Available at: http://www.mayoclinic.org/diseases-conditions/hepatitis-a/basics/prevention/con-20022163 [Accessed 11 Apr. 2016].
• Labtestsonline.org. (2016). Hepatitis A Testing: The Test. [online] Available at: https://labtestsonline.org/understanding/analytes/hepatitis-a/tab/test/ [Accessed 11 Apr. 2016].
...(download the rest of the essay above)