Download Issues of food borne diseases/illnesses, toxicity

Issues
of
food-borne
Issues of food-borne
diseases/illnesses
diseases/illnesses
Microbes & Toxins
Prepared by Winfried Scheewe, DED,
Marketing c#onsultant to CEDAC
for the
“Complying with market
requirements on Food Safety and
Product Quality”
Second Regional Training Workshop
Linking Small Farmers to Markets
January 19-23, 2009
Siem Reap, Cambodia
Food-borne illness

term used to describe
the adverse health
effects associated with
the consumption of
– biological,
(including parasites)
– chemical and
– physical
hazards in food.  More than 200 diseases
are spread through food
Food-borne illness


Each day millions of
people become ill
and thousands die
from a preventable
food-borne disease
WHO estimate:
Worldwide 5 – 10%
of the population
suffer from foodborne illnesses
annually

Food-borne diseases
are increasing
worldwide
Cambodia

Cambodia: High incidence of
deaths due to diarrhoeal
diseases
– can be attributed to
contaminated water and food

WHO:
Children under 5 years:
– 17% of deaths due to diarrhea
All age groups:
– 7% of deaths due to diarrhea
Cambodia (2)

Food-borne illnesses are one factor
contributing to the low life
expectancy (2004 data)
Cambodia
Region
Men
51 years
71 years
Women
58 years
75 years
Transmitted + originating
from food
We can distinguish:

Diseases transmitted through food:
– Hepatitis A
– Typhoid fever
– Cholera, etc.

Diseases originating
from the food:
– Spoilage
– Infected animals
Food Poisoning



Most food-borne diseases
food poisoning
any condition in which a food
causes a toxic reaction
Generally:
affecting the stomach and
intestines
= gastrointestinal disease
resulting from bacterial (or
sometimes viral) contamination
of foods
Food Poisoning

Other causes:
– fungal spoilage  mycotoxins
– a toxin naturally present in the
food
– pesticide residues
– contamination with industrial
chemicals
– a toxin acquired by the food as a result of
natural accident (such as contamination
of fish or shellfish by ‘red tide’)
Bacterial Food Poisoning



contamination of foods
with bacteria that do
not cause any obvious
spoilage,
food is still apparently
fit to eat,
but may contain hazardous amounts of
harmful organisms or
toxins
Bacterial Food Poisoning (2)


or
sufficient
numbers of
bacteria to cause
an infection
Some bacteria
already have
infected the
animal or plant
Symptoms


The symptoms poisoning
range from mild diarrhea,
through severe diarrhea
and vomiting, to
potentially life-threatening
illness.
In some cases the
symptoms develop within
a few hours of eating the
contaminated food

in other cases there may
be a delay of several
days, or even weeks,
before there are any
signs of infection
Food-poisoning Organisms



With most foodpoisoning organisms,
an intake of several
thousand is required
for infection,
but consumption of as
few as 10 of the
virulent enterohaemorrhagic E.coli
strain 0157 can cause
life-threatening illness.
Causes Of Food Poisoning




The way animals are
raised + crops cultivated
The way in which the
food is handled and
prepared
esp. lack of food
hygiene + personal
hygiene
Inadequate cooking of
Bacillus cereus:
contaminated raw food causes the "Fried Rice Syndrome"
(under-cooking)
Causes ... (2)




Inadequate reheating
Keeping cooked food at
temperatures that favor
the growth of bacteria
Cross-contamination
between raw and
cooked food
Poor personal hygiene
in food handlers
Major food-borne illnesses





Salmonellosis
Campylobacteriosis
E.coli infection,
esp. E.coli O157
Listeriosis
Cholera
(WHO ranking)
Special case: Botulism
Salmonellosis



Transmitted through
contaminated
poultry, eggs, and
certain other foods
Also found on citrus
fruits
Causes abdominal
pain, fever, nausea
and vomiting, and
diarrhea

Incubation period
is 8 to 48 hours,
and an attack may
last from three to
seven days
Salmonella



Usually destroyed
by adequate
cooking
Some types can
lead to typhoid
fever
The bacteria
survives in
dried food
Campylobacter jejuni


probably most common
bacterial cause of
gastroenteritis
worldwide
incidence of human
campylobacter
infections has been
steadily increasing
Gastroenteritis
inflammation of the lining
membrane of the stomach and
Campylobacter jejuni



Bacteria, which is
naturally part of the
intestinal microflora
Cannot be treated
with antibiotics
Can be caused by
cross-contamination
during food
preparation
Campylobacteriosis



Most people who
become ill develop
diarrhea,
cramping, abdominal
pain and fever
Symptoms: anywhere
from 2 to 5 days after
consuming a
contaminated food
Campylobacteriosis



Poultry (raw chicken)
is recognized as the
primary pathway
other sources include
unpasteurized milk
and non-chlorinated
water
common in cattle, pigs
and other animals
Control of Campylobacter


Aim: to develop
strategies to control
campylobacter in
the food supply
"from farm to fork"
campylobacter can
be reduced: natural
feed ingredients
(additive) caprylic
acid

naturally found in
coconut and breast
milk  antifungal and
antibacterial
properties
Escherichia coli Infection




Some 5 million E. coli
bacteria normally
inhabit intestinal tract
Vital to processing
vitamins in the diet
Several strains are
pathogenic and cause
gastroenteritis
Strain E. coli 0157:H7
potentially fatal form of
food poisoning
E. coli 0157:H7


Outbreaks in the US
linked to spinach
and other leafy
vegetables
E.coli 0157:H7
probably originates
from cattle
Botulism




Caused by a toxin produced by the bacteria
Clostridium botulinum
especially dangerous because a large
number of people can be poisoned by
eating a batch of contaminated food
derived from the soil, grows in many meats
and vegetables
Develops in anaerobe
conditions such as
canned food
Avoidance
Spoilage or decomposition
can be
 Killing
thedelayed:
micro-



organisms by heat
Observance of hygiene
(canning and
Storage in high salt or sugar concentrations or in
pasteurization)
weak acids (pickling);
Drying (desiccation) or cooling (refrigeration); and
Food contamination through
TOXINS


Mycotoxins are produced
by fungi, commonly
known as mold. These
toxins can develop
during production,
harvesting, or storage of
grains, nuts, and other
crops.
Mycotoxins are among
the most potent
mutagenic and carcinogenic substances known
Mycotoxins



They pose chronic health risks:
prolonged exposure through diet has been
linked to cancer and kidney, liver, and
immune-system disease
Mycotoxins occur more frequently under
tropical conditions

Many diets consists
heavily of food from
crops susceptible to
mycotoxins
Aflatoxins



naturally occurring
mycotoxins, produced by
many species of the
fungus Aspergillus,
Aflatoxins are highly
toxic and cause cancer
After entering the
body, aflatoxins are
metabolized by the
liver
Aflatoxins



Discovered after in
1960, mold-contaminated peanut meal
was shipped from
Brazil to England
caused of the death
of more than 100,000
turkey
Cause: liver damage
Avoidance of mycotoxins




Improved postharvest practices
Proper storage
Shift from cereal
based to pasture
based feeding
(instead of feedlots)
Free-range poultry
Unknown burden

commonly only a part of the cases
are reported  less than 10 percent
Common Problems



Indices of food-borne illnesses tend to increase
Often the pathogens cannot properly be
identified ( up to 80% of cases)
Resistance against antibiotics increasing (
drug-resistant Salmonella)
Problems (3)



Refridgertion can preserve the food
but also preserve many harmful
organisms
Globalization of food supply
 widely dispersed outbreaks
Often slow response by authorities
Outlook

The looming
climate change
will probably
worsen some
problems:
– Higher
temperature and
moisture
– More flooding
and extended
droughts
 polluted
water

may lead to new
problems with
food-borne
diseases
Conclusion


In view of the rapid
genetic adaptability
we could say:
“Microorganisms
are opponents
with whom we
cannot race on their
terms”
(Dr. Lederberg)

We only can try to
avoid conditions in
which harmful
microbes can develop
Thank you!