What is food poisoning/Food-borne illness?
This
is any illness that results from consuming food that has been contaminated with
pathogenic microorganisms or disease causing organisms. Symptoms include
Nausea, Vomiting, Abdominal Cramp, diarrhea, fever.
Food-borne illness usually occurs during improper handling, preparation and
storage of the food. Some of the disease.
Food Infection: these are foods that contain bacteria or
other microbes that can infect the body after consumption.
Food Intoxication occurs when food that contains toxins including bacteria
produced exotoxins has been consumed. In this situation, the bacteria that
causes the toxin can no longer cause any infection or is not present anymore.
Food Contamination is the presence of harmful chemicals, micro-organisms in
food which can cause illness when consumed. In chemical contamination, the
impact is usually often noticed after so many years of processing with
prolonged exposure at low levels e.g. Cancer.
1. Environmental Contaminants:
This are chemicals that come into
the environment accidentally or intentionally but always as a result of human
activity. They are found in the environment in which food is grown, harvested,
transported, processed & packaged, and stored. Majority of the time, these
contaminants are manufactured for industrial use and does not break down easily
but when released into the environment, they get into the food chain. Although,
some environmental contaminants are naturally-occurring chemicals but due to
industrial activity, there is an increase in their mobility and an increase in
the amount available for the circulation in the environment thus enabling their
entry into the food chain at higher levels than would otherwise occur.
These are residues found in food
usually from cleaning agents, fertilizers/pesticides, mercury(fish),
contaminants in soil (e.g. cadmium, Perchlorates), packaging materials [e.g.,
Bisphenol A (BPA) - usually found in plastic containers], Antimony, Tin, Lead,
Benzophenone, Isopropyl thiaxanthone, Food-processing induced chemicals (e.g.
Dioxins and Furans, Acrylamide, Chloropropanols), Bromate, Per fluorinated
chemicals in food, Brominated flame retardants etc.).
2. Natural Toxins:
They are naturally produced by
living organisms. Although this toxins are not harmful to the organism
themselves, they are toxic to other creatures when consumed.
Examples are:
a. Bivalve Molluscan Shellfish
(clams and oysters) - They are filter feeders and accumulate neurotoxins called
"Saxitoxins"(i.e., if large numbers of toxic algae are present
in the water where they dwell, then the shellfish accumulates high levels of
this toxin. An example of a toxin producing algae is the "red tide").
The consumption can cause "Paralytic Shellfish Poisoning" and affects
the Nervous system. It is fatal in extreme cases particularly in children and
immunocompromised individuals.
Symptoms usually appear 10-30 mins after consumption and
may include; nausea, vomiting, diarrhea, abdominal pain, tingling or burning
lips, gums, neck, face, confused or slurred speech, shortness of breath and
loss of coordination could be possible.
b. Ciguatera: It is a toxin produced by
dinoflagellates (certain type of marine algae found in tropical and subtropical
areas of the world). Ciguatoxin is tasteless and odorless and cannot be removed
by conventional cooking. It is sometimes misdiagnosed as Multiple Sclerosis.
Its hallmark symptoms are; Gastrointestinal such as nausea, vomiting, and
diarrhea while the neurological symptoms include; headache, muscle ache,
ataxia, numbness, hallucinations and vertigo.
Symptoms may last from weeks to years and can lead to
long-term disability. It is seen in Large Reef fish that feeds on other smaller
fish like barracuda, jacks, king mackerel and large groupers & snappers.
Intravenous Mannitol has been suggested for use to treat the symptoms.
c. Scombrotoxic fish Poisoning:
This type of toxin is formed when the histamine on the fish flesh begins to
decay. It is caused by improper handling of the fish. Examples of fish species
are; tuna, mackerel, mahi-mahi, bluefish, herring, marlin. Since the toxin is not destroyed by cooking, this food
safety hazard must be prevented by making sure that these types of fish are
kept cold (below 40°F) on ice or under refrigeration from the time that they
are caught until they are eaten. The onset of symptoms begins 10-30mins of
ingestion and they include; facial flushing/sweating, nausea, dizziness,
burning/peppery taste sensations in the mouth or throat, headache, blurred
vision, respiratory distress and swelling of the tongue. In rare cases, it
results in death. Antihistamine and Epinephrine may be used to treat symptoms.
d. Amnesic shellfish poisoning: is
a rare syndrome caused by a toxin made by a microscopic, red-brown, salt-water
plant, or diatom called Nitzchia pungens. The toxin produced
by these diatoms is concentrated in shellfish such as mussels and causes
disease when the contaminated shellfish are eaten. Patients first experience
gastrointestinal distress within 24 hours after eating the contaminated shellfish.
Other reported symptoms have included dizziness, headache, disorientation, and
permanent short-term memory loss. In severe poisoning, seizures, focal weakness
or paralysis, and death may occur.
3. Physical Contaminants/hazards:
They
include dirt, staples, hair, broken glass, nails, bones or bits of
packaging etc. Foods can be contaminated physically at any stage of production
when an object is mixed with the food. This objects could injure
or may carry potential harmful bacteria, also food ingredients may also cause
the contamination.
4. Biological Contaminants:
They
include microorganisms such as Bacteria, Viruses, Yeasts, Mold, and Parasites.
They could be very deadly when ingested. Proper handling techniques are
required during preparation and storage of food.
5. Mycotoxin: It is a
toxic chemical compound produced by fungi that readily colonize crops.
a. Aflatoxins are a type of mycotoxin produced by Aspergillus species
of fungi, such as A.
flavus and A. parasiticus. The umbrella term aflatoxin refers to four
different types of mycotoxins produced, which are B1, B2, G1, and G2.
Aflatoxin B1, the most toxic, is a potent carcinogen and
has been directly correlated to adverse health effects, such as liver cancer, in
many animal species. Aflatoxins are largely
associated with commodities produced in the tropics and subtropics, such
as cotton, peanuts, spices, pistachios, and maize.
b. Citrinin is a toxin that was first isolated
from Penicillium citrinum, but has been identified in over a dozen species of Penicillium and
several species of Aspergillus. Some of these species are used to produce human
foodstuffs such as cheese (Penicillium
camemberti), sake, miso, and soy sauce (Aspergillus oryzae). Citrinin is associated with yellowed
rice disease in Japan and is nephrotoxic in all animal species tested. Although
it is associated with many human foods (wheat, rice, corn, barley, oats, rye, and food colored with Monascus pigment)
its full significance for human health is unknown. Citrinin can also act
synergistically with Ochratoxin A to depress RNA synthesis in
murine kidneys.
c. Ochratoxin is
a mycotoxin that comes in three secondary metabolite forms, A, B, and C. All
are produced by Penicillium and Aspergillus species. The three forms differ in that Ochratoxin B (OTB) is
a non-chlorinated form of Ochratoxin A (OTA), and that Ochratoxin C (OTC) is an ethyl ester form Ochratoxin A. Aspergillus ochraceus is
a contaminant of a wide range of commodities including beverages such
as beer and wine. Aspergillus
carbonarius is the main species found
on vine fruit, which releases its toxin during the juice making process. OTA has been labeled as a carcinogen and a
nephrotoxin, and has been linked to tumors in the human urinary tract, although
research in humans is limited by confounding
factors.
d. Patulin is
a toxin produced by the P.expansum,
Aspergillus, Penicillium, and P. aecilomyces fungal species. P.expansum is
especially associated with a range of moldy fruits and vegetables, in
particular rotting apples and figs. It is destroyed by the fermentation process
and so is not found in apple beverages, such as cider. Although
patulin has not been shown to be carcinogenic, it has been reported to damage
the immune system in animals. In 2004, the European
Community set limits to the
concentrations of patulin in food products. It currently stands at 50 μg/kg in
all fruit juice concentrations, at 25 μg/kg in solid apple products used for
direct consumption, and at 10 μg/kg for children's apple products, including
apple juice.
e. Fusarium: Toxins are produced by over 50 species of Fusarium and
have a history of infecting the grain of developing cereals such as wheat and maize.
They include a range of mycotoxins, such as: the Trichothecenes, which are most strongly associated with chronic and
fatal toxic effects in animals and humans; and Zearalenone, which is not correlated to any fatal toxic effects
in animals or humans. Some of the other major types of Fusarium toxins
include: beauvercin and enniatins, butenolide, equisetin, and fusarins.
f. Ergot Alkaloids: are compounds produced as a toxic mixture of
alkaloids in the sclerotia of species of Claviceps, which are common pathogens
of various grass species. The ingestion of ergot sclerotia from infected
cereals, commonly in the form of bread produced from contaminated flour, cause ergotism the human disease historically known as St. Anthony's fire.
There are two forms of ergotism:
gangrenous, affecting blood supply to extremities, and convulsive, affecting
the central nervous system. Modern methods of grain cleaning have significantly
reduced ergotism as a human disease, however it is still an important
veterinary problem. Ergot alkaloids have been used for pharmaceutical purposes.
Hazard Analysis and Critical Control Point (HACCP) is a
seven step procedure used to ensure that finished food is safe for consumption.
