The numbers of people officially suffering from salmonella has fallen during the last year but the number of people suffering from viral food poisoning has increased dramatically. �Small round structured viruses� are the commonest source of viral food borne infection. Viruses are found in uncooked shellfish as well as in contaminated water. They are hard to detect unlike food poisoning bacteria. The virus is spread quickly from person to person and sufferers are still infectious two days after all the symptoms have disappeared. Food handlers need to be aware that if they have had sickness and diarrhoea they could still be infectious when they return to work. Personal hygiene is paramount, hand washing, no sneezing or coughing on food etc. Training in basic food hygiene is also paramount for all people involved in preparing, handling, serving and selling food.
Aflatoxicosis: Aflatoxicosis is
poisoning that results from ingestion of aflatoxins in contaminated food or
feed. The aflatoxins are a group of structurally related toxic compounds
produced by certain strains of the fungi Aspergillus flavus and A. parasiticus.
Under favorable conditions of temperature and humidity, these fungi grow on
certain foods and feeds, resulting in the production of aflatoxins. The most
pronounced contamination has been encountered in tree nuts, peanuts, and other
oilseeds, including corn and cottonseed. Aflatoxicosis in humans has rarely
been reported; however, such cases are not always recognized.
Bacillus Cereus: This type of bacteria produce two types of poisoning. The first is relatively mild diarrhoea and stomach pains which occur 8 to 12 hours after eating contaminated food and last for about 12 hours. The second is more serious and causes vomiting and diarrhoea 1 to 5 hours after eating food. Both are caused by a poison produced by the bacteria and are not fatal. The first type may occur in a wide variety of foods including rehydrated dried vegetables, soya bean sprouts and potato products. The second type is mostly associated with cooked rice. Poisoning can be prevented by good hygiene and by not holding cooked foods for long periods at room temperature.Bacteria: Bacteria are
organisms made up of just one cell. They are capable of multiplying
by themselves, as they have the power to divide. Their shapes vary,
and doctors use these characteristics to separate them into groups.
Bacteria exist everywhere, inside and on our bodies. Most of them are
completely harmless and some of them are very useful. But some bacteria
can cause diseases, either because they end up in the wrong place in the
body, or simply because they are 'designed' to invade us. Helpful
bacteria can be used to make yogurt, vinegar and some cheeses.Botulism: Botulism is
caused by the organism Clostridium botulinum, a spore-forming
bacteria. Spores release a toxin that caused the illness.
Although widely spread throughout our environment, botulism
spores only become dangerous after producing a toxin in an
oxygen-free environment of low acidity. Botulism food poisoning
is very rare, but it can be life-threatening. Botulism may result
from eating improperly processed, low-acid foods such as green
beans, mush-rooms, spinach, olives and beef or fish. Improper
home canning methods account for many botulism cases. But,
improperly processed commercial products can cause botulism too.
Spores are highly resistant to destruction. They can survive hours
of boiling at 212°F (100°C). Pressure cooking at 240°F
(120°C) for 30 minutes can kill spores. The toxin (not the spores)
is readily destroyed by boiling at 212°F (100°C) for 10 minutes
or heating to 176°F (80°C) for 30 minutes.
Campylobacter Fetus: This type of bacteria cause food poisoning when eaten. The most common sources are contaminated water and unpasteurized milk, although poultry and other meats are also important sources. Proper chlorination of water and heating of foods will destroy these bacteria. Illness occurs 2 to 5 days after eating contaminated food and consists of diarrhoea, muscle pain and headaches with vomiting. It is usually brief and not fatal.Clostridium Botulinum: Though very
rare, this is a serious type of food poisoning that has many varied symptoms
and is often fatal (in about a third of all cases with prompt treatment, up to
two thirds of cases if there is no treatment available or if treatment is
delayed). It is most commonly caused by a poison produced by the bacteria in
sealed food containers, which have little air inside (eg canned meat and
vegetables) although the poison may also be produced in the gut after eating
contaminated food or it may enter a wound directly. There are four types of
poison, each of which is a powerful nerve poison. In fact they are some of the
most potent poisons known. They cause blurred or double vision, weakness,
difficulty in swallowing and breathing and, if untreated, paralysis,
unconsciousness and death. The symptoms appear with 18 to 36 hours of eating
the poison and should be treated promptly with a botulin anti-toxin. The poison
is destroyed by heating food to 90�C for at least 15 minutes but the bacterial
spores survive this processing and higher temperatures are required to destroy
them. The most common sources are canned meat, fish and vegetables, preserved
meats and fermented fish products. Technical assistance is needed when canning
low acid foods or preparing fermented meat and fish products.Clostridium Perfringens: The most
frequent cause of this type of poisoning is slow and inadequate cooking of
meats. The bacteria produce spores which rapidly germinate after eating and
produce a poison in the gut. It can be prevented by good sanitation, by heating
food adequately and keeping cooked food cool (below 10�C) or hot (above 60�C).
The symptoms are stomach cramps without vomiting and diarrhoea. They appear
within 8 to 24 hours of eating contaminated food and last for 24 hours. The
illness is not fatal.Cross Contamination: Cross
contamination is the transfer of bacteria from foods (usually raw) to other
foods. The bacteria can be transferred directly when one food touches (or
drips onto) another, or indirectly, for example from hands, equipment, work
surfaces, or knives and other utensils. Cross-contamination is one of the
major causes of food poisoning. When it comes to food allergies, it is
difficult to be careful enough. The same knife used to cut a peanut butter
sandwich and a cheese sandwich can leave enough residue on the cheese
sandwich to cause a serious allergic reaction.
Echoviruses: Echoviruses (EVs)
are RNA viruses of the genus Enterovirus and the family Picornaviridae.
EVs were first isolated from the feces of asymptomatic children early in
the 1950s, soon after the development of cell culture techniques. EVs
cause cytopathic effects in primate cell cultures, although not associated
initially with any disease condition. These orphan viruses were initially
termed ECHO, an acronym for enteric cytopathic human orphan virus, which
was later simplified to echovirus. Escherichia Coli: This bacterium
is also associated with sewage contamination of foods, water or poor personal
hygiene. The bacteria themselves can cause food poisoning or they can produce
a poison in the gut. The most common food source is red meat which is
contaminated at slaughter. Meat products, eg sausages and dairy products,
especially cheese are also potential sources of food poisoning. Other sources
(eg pasteurized milk, ice cream, cooked meats) indicate contamination after
processing and hence poor hygiene by the food handlers.
Fascioliasis: Fascioliasis is an
infection caused by flukes of the class Trematoda, most often characterized
by fever, eosinophilia, and abdominal pain, although as many as half of these
cases may be asymptomatic. Humans are incidental hosts for Fasciola hepatica
(Fh), commonly known as the sheep liver fluke, and Fasciola gigantica (Fg);
these flukes cause similar illnesses in those who become infected by ingesting
contaminated watercress or water. The illness occurs worldwide, particularly
in regions with intensive sheep or cattle production. Incidence of human
infection apparently is increasing over the past 20 years.Filariasis: Filariasis is a
disease group that affects humans and animals and is caused by nematode
parasites of the order Filariidae, commonly called filariae. Of the
hundreds of described filarial parasites, only 8 species cause natural
infections in humans.Foodborne Illness: An illness
caused by pathogenic bacteria that is carried or transmitted to humans by
food.
Giardia: Giardia lamblia is a
ubiquitous gastrointestinal protozoon that may be identified in individuals
with asymptomatic colonization or acute or chronic diarrheal illness.
Infection is recognized more commonly in children than in adults. Giardia
species are endemic in areas of the world that have poor sanitation. In
developing countries, the disease is an important cause of morbidity, and
water and food-borne outbreaks are common. Because of the small inoculum of
organisms necessary to cause infection, giardiasis is common in daycare
center attendees and institutionalized patients in developed countries. G
lamblia is a particularly significant pathogen for people with malnutrition,
immunodeficiencies, or cystic fibrosis. Beavers may be an important reservoir
host for G lamblia.Grayanotoxin (Honey Intoxication):
Honey intoxication is caused by the consumption of honey produced from the nectar
of rhododendrons. The grayanotoxins cause the intoxication. The specific
grayanotoxins vary with the plant species. These compounds are diterpenes,
polyhydroxylated cyclic hydrocarbons that do not contain nitrogen. Other names
associated with the disease is rhododendron poisoning, mad honey intoxication or
grayanotoxin poisoning. The intoxication is rarely fatal and generally lasts for
no more than 24 hours. Generally the disease induces dizziness, weakness, excessive
perspiration, nausea, and vomiting shortly after the toxic honey is ingested. Other
symptoms that can occur are low blood pressure or shock, bradyarrhythima (slowness
of the heart beat associated with an irregularity in the heart rhythm), sinus
bradycardia (a slow sinus rhythm, with a heart rate less than 60), nodal rhythm
(pertaining to a node, particularly the atrioventricular node), Wolff-Parkinson-White
syndrome (anomalous atrioventricular excitation) and complete atrioventricular
block.
Hepatitis A: This virus is transmitted from infected people to food. It is easily destroyed by heating and the main sources are therefore raw foods or foods which are contaminated after heat processing. It can be prevented by not allowing infected people to handle food.
Immuno-Compromised: An individual
with an existing disease or weakened physical condition who may be more
susceptible to becoming ill from foodborne illness.
Listeria: Listeria is a bacteria
that causes an infection known as Listeriosis. Listeria infections are still
quite rare and most healthy adults will not be affected by Listeria. Pregnant
women who have a Listeria infection later in their pregnancy can become ill
and the baby may die or be born prematurely. Also people whose immune systems
are not functioning well because of other illnesses or medication, may also
become seriously ill if affected with Listeria. Listeria is widely spread in
the environment and is commonly found in vegetation, water, soil, wild or
domestic animals, fish, birds as well as people. The main method of becoming
infected with Listeria is by eating contaminated foods that contain the
bacteria. The infection can be transferred to an unborn child during pregnancy
if the mother becomes infected. Listeria can grow and multiply at low
temperatures. Foodstuffs that have been implicated include meats, unpasteurized
milk, contaminated vegetables such as coleslaw and seafood. In particular foods
that require no further heat treatment or processing prior to being eaten and
have a longer shelf life.
Mycotoxins: Many foods are susceptible
to a wide variety of molds. Some mycotoxins (poisons produced by molds) can be
harmful if consumed in large amounts. When it occurs, mycotoxicosis is usually
traced back to beans, peanuts, corn, and other grains that have been stored in
warm moist places. Symptoms (after eating): May cause liver and/or kidney disease.
(This depends on the amount of mycotoxin and length of exposure.) Store foods
properly, and check for visible mold and "off" colour, odor, or texture. Discard
contaminated food and clean container or storage area. (Hard cheeses, salami, or
dry cured country ham may be salvaged by cutting out an inch of product on all
sides and below the moldy area.)
Noroviruses: A group of viruses
contracted when contaminated shellfish is eaten raw or partially cooked.
Also, spread by infected people who prepare food when they are ill with
these viruses. Symptoms (after eating): Onset: 24-48 hours; diarrhea, vomiting,
nausea, abdominal cramps, fever, chills, and body aches. Cook shellfish
thoroughly. Practice good personal hygiene and handle food in sanitary manner.
Do not prepare or serve food when ill with diarrhea or vomiting.
Parasites: Trichinella spiralis is a common food poisoning parasite found in meat (especially pork). It can be destroyed by heating the food to at least 60�C. Hygiene and sanitation are not involved as causes of this illness. Other parasites include protozoa on vegetables, intestinal worms in meat and fish and numerous other parasites (eg giardia and amoeba) in contaminated water.Perfringens: sometimes present
in the environment is found in animals, sewage and in soil. It is sometimes
called the :cafeteria germ". This would include cooked beef, turkey, gravy,
dressing, stews, and casseroles. Perfringens causes diarrhea and gas pains
and usually lasts no more than two days.Ptomaine: The dictionary defines
ptomaine poisoning as "food poisoning caused by bacteria or bacterial products."
Ptomaine poisoning is not a special kind of food poisoning and it is not a
deadlier type of food poisoning. Ptomaine is an old-fashioned general term for
any type of food poisoning caused by bacteria. The term "ptomaine food poisoning"
is not used medically anymore.
Salmonella: Salmonella are bacteria. The
Salmonella consist of a range of very closely related bacteria, many of which cause
disease in humans and animals. Most infections with Salmonella are traced back to
dairy, poultry and meat products, but Salmonella can grow on just about any food.
Chickens and eggs are particular high risk foods. After Salmonella is eaten it passes
through the stomach to the intestine. Here, it binds to the wall of the intestine, and
through some special proteins that it makes in response to the particular conditions in
the intestine it actually penetrates the barrier between us and the outside. Once it has
gained access to our insides, it is taken to the liver or spleen. For most other
bacteria, this journey would kill them, however Salmonella has evolved mechanisms to
prevent our immune system from doing its job efficiently. In the liver, the Salmonella
can grow again, and be released back into the intestine.Shigella: This is a bacterium associated
with sewage. Poisoning is caused by direct contact of food with sewage or by indirect
contact (eg by operators' hands, equipment or by contaminated water). Personal hygiene
and correct water treatment are therefore essential to prevent poisoning. Shigella is
found where poor hygiene exists. The symptoms are diarrhoea, fever and nausea which
appear from 7 hours to 7 days after eating contaminated food. They may last for a week
but are rarely fatal. Any food that requires manual preparation is a potential
source.Staphylococcus Aureus: This bacteria
produces a poison in food which can withstand heating. It is also resistant to
salt levels that kill many other types of bacteria (eg in pickles) and it can be
carried by workers and transmitted into processed food when they handle it. The
symptoms of poisoning are nausea, vomiting, diarrhoea and stomach cramps. They
appear within 1 to 4 hours of eating contaminated food and last for 10to 12 hours.
Poisoning is rarely fatal. The main sources of poisoning are dairy products,
especially cheese, processed meats and pastries. The bacteria are carried by
people, in the throat, and in infected cuts and other skin disorders. People
should not therefore handle food if they have coughs or skin complaints. This
type of poisoning is difficult to trace because the bacteria can produce the
poison before the food is processed. Heating can kill the bacteria but leave
the poison in the food.
Vibrio Parahaemolyticus: V.
parahaemolyticus is found on seafoods, and requires the salt environment of sea
water for growth. V. parahaemolyticus is very sensitive to cold and heat. Proper
storage of perishable seafoods below 40 degrees F, and subsequent cooking and
holding above 140 degrees F, will destroy all the V. parahaemolyticus on seafoods.
Food poisoning caused by this bacterium is a result of insufficient cooking and/or
contamination of the cooked product by a raw product, followed by improper storage
temperature. It is a major problem in Japan where many seafoods are consumed raw.
Vibrio vulnificus is another member of the vibrio genus that is found in the marine
environment. V. vulnificus is truly an emerging pathogen, but it can be controlled
with proper cooking and refrigeration.
Yersiniosis: Yersiniosis is an acute
bowel infection that is caused by bacteria of the Yersinia group multiplying in
the intestine. Symptoms begin 12 hours to 11 days, (but usually 24 to 48 hours)
after ingesting the bacteria and vary with age. Children under 5 years have
diarrhoea (sometimes containing blood), those over 5 suffer abdominal pain
(mimicking appendicitis) and fever. A sore throat, joint pain and a rash may
also occur. Those most at risk are the very young, very old and the debilitated,
and the condition can lead to other complications including arthritis, septicaemia
or meningitis. The diagnosis is confirmed by a laboratory test on a faecal
specimen.