Issues of food-Issues of food-

borne borne

diseases/illnessesdiseases/illnesses

MicrobesMicrobes & & ToxinsToxins

Issues of food-Issues of food-

borne borne

diseases/illnessesdiseases/illnesses

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 WorkshopLinking Small Farmers to Markets

January 19-23, 2009

Siem Reap, Cambodia

Food-borne illnessFood-borne illness

term used to describe term used to describe the adverse health the adverse health effects associated with effects associated with the consumption of the consumption of – biological,biological,

(including parasites)(including parasites)– chemical and chemical and – physical physical

hazards in food.hazards in food. More than 200 diseases are

spread through food

Food-borne illnessFood-borne illness

Each day millions of Each day millions of people become ill people become ill and thousands die and thousands die from a preventable from a preventable food-borne diseasefood-borne disease

WHO estimate: WHO estimate: Worldwide 5 – 10% of Worldwide 5 – 10% of the population suffer the population suffer from food-borne from food-borne illnesses annually illnesses annually Food-borne diseases are

increasing worldwide

CambodiaCambodia Cambodia: High incidence Cambodia: High incidence

of deaths due to diarrhoeal of deaths due to diarrhoeal diseasesdiseases– can be attributed to can be attributed to

contaminated water and foodcontaminated water and food

WHO: WHO: Children under 5 years:Children under 5 years:– 17% of deaths due to diarrhea17% of deaths due to diarrhea

All age groups:All age groups:– 7% of deaths due to diarrhea7% of deaths due to diarrhea

Cambodia (2)Cambodia (2)

Food-borne illnesses are one Food-borne illnesses are one factor contributing to the factor contributing to the low life low life expectancyexpectancy (2004 data)(2004 data)

CambodiCambodiaa

RegionRegion

MenMen 5151 years years 7171 years years

WomenWomen 5858 years years 7575 years years

Transmitted + originating from foodWe can distinguish:

Diseases transmitted through food:– Hepatitis A– Typhoid fever– Cholera, etc.

Diseases originating from the food: – Spoilage– Infected animals

Food PoisoningFood Poisoning

Most food-borne diseases Most food-borne diseases food poisoning food poisoning

any condition in which a food any condition in which a food causes a toxic reactioncauses a toxic reaction

Generally:Generally:affecting the stomach and affecting the stomach and intestines intestines = = gastrointestinal disease disease resulting from bacterial (or resulting from bacterial (or sometimes viral) sometimes viral) contaminationcontamination of foods of foods

Food PoisoningFood Poisoning

Other causes:Other causes:– fungal spoilage fungal spoilage

mycotoxinsmycotoxins – a toxin naturally present in a toxin naturally present in

the food the food – pesticidepesticide residues residues– contamination with industrial contamination with industrial

chemicalschemicals – a toxin acquired by the food as a a toxin acquired by the food as a result ofresult of natural accident (such as natural accident (such as contaminationcontamination of fish or shellfish by ‘red tide’)of fish or shellfish by ‘red tide’)

Bacterial Food Bacterial Food PoisoningPoisoning

contamination of contamination of foods with bacteria foods with bacteria that do not cause that do not cause any obvious spoilage, any obvious spoilage,

food is still food is still apparently fit to eat, apparently fit to eat,

but may contain but may contain hazar-dous amounts hazar-dous amounts of harmful organisms of harmful organisms or toxinsor toxins

Bacterial Food Poisoning Bacterial Food Poisoning (2)(2)

oror sufficient sufficient

numbers of numbers of bacteria to bacteria to cause an cause an infectioninfection

Some bacteria Some bacteria already have already have infected the infected the animal or plant animal or plant

SymptomsSymptoms

in other cases there in other cases there may be a delay of may be a delay of several days, or even several days, or even weeks, before there are weeks, before there are any signs of infectionany signs of infection

The symptoms poisoniThe symptoms poisoning range from mild ng range from mild diarrhea, through diarrhea, through severe diarrhea and severe diarrhea and vomiting, to potentially vomiting, to potentially life-threatening illness. life-threatening illness.

In some cases the In some cases the symptoms develop symptoms develop within a few hours of within a few hours of eating the eating the contaminated foodcontaminated food

Food-poisoning Food-poisoning OrganismsOrganisms With most food-With most food-

poisoning organisms, poisoning organisms, an intake of several an intake of several thousand is required thousand is required for infection, for infection,

but consumption of but consumption of as few as 10 of the as few as 10 of the virulent entero-virulent entero-haemorrhagic E.coli haemorrhagic E.coli strain 0157 can strain 0157 can cause life-cause life-threatening illness. threatening illness.

Causes Of Food Causes Of Food PoisoningPoisoning

The way animals are The way animals are raised + crops raised + crops cultivatedcultivated

The way in which the The way in which the food is handled and food is handled and preparedprepared

esp. lack ofesp. lack of food food hygiene hygiene + personal + personal hygienehygiene

Inadequate cooking of Inadequate cooking of contaminated raw food contaminated raw food (under-cooking) (under-cooking)

Bacillus cereus: causes the "Fried Rice Syndrome"

Causes ... (2)Causes ... (2)

Inadequate reheating Inadequate reheating Keeping cooked food Keeping cooked food

at temperatures that at temperatures that favor the growth of favor the growth of bacteriabacteria

Cross-contamination Cross-contamination between raw and between raw and cooked foodcooked food

Poor personal hygienPoor personal hygiene in food handlerse in food handlers

Major food-borne Major food-borne illnesses illnesses SalmonellosisSalmonellosis Campylo-Campylo-

bacteriosisbacteriosis E.coli E.coli infection, infection,

esp. E.coli O157esp. E.coli O157 Listeriosis Listeriosis CholeraCholera

(WHO ranking)(WHO ranking)

Special case: Botulism

SalmonellosisSalmonellosis

Transmitted Transmitted through through contaminated contaminated poultrypoultry, eggs, and , eggs, and certain other foodscertain other foods

Also found on Also found on citrus citrus fruits fruits

Causes abdominal Causes abdominal pain, fever, nausea pain, fever, nausea and vomiting, and and vomiting, and diarrhea diarrhea

Incubation period Incubation period is 8 to 48 is 8 to 48 hours, and an hours, and an attack may last attack may last from three to from three to seven daysseven days

SalmonellaSalmonella

Usually destroyed by adequate cooking

Some types can lead to typhoid fever

The bacteria survives in dried food

Campylobacter jejuniCampylobacter jejuni

probably most probably most common bacterial common bacterial cause of cause of gastroenteritis gastroenteritis worldwide worldwide

incidence of human incidence of human campylobacter campylobacter infections has been infections has been steadily increasingsteadily increasing

GastroenteritisGastroenteritis inflammation of the lining inflammation of the lining membrane of the stomach membrane of the stomach and the intestines and the intestines characterized especially by characterized especially by nausea, vomiting, diarrhea, nausea, vomiting, diarrhea, and crampsand cramps

Campylobacter jejuniCampylobacter jejuni

Bacteria, which is Bacteria, which is naturally part of the naturally part of the intestinal microflora intestinal microflora

Cannot be treated Cannot be treated with antibiotics with antibiotics

Can be caused by Can be caused by cross-contamination cross-contamination during food during food preparationpreparation

CampylobacteriosisCampylobacteriosis

Most people who Most people who become ill develop become ill develop diarrhea, diarrhea,

cramping, abdominal cramping, abdominal pain and fever pain and fever

Symptoms: anywhere Symptoms: anywhere from 2 to 5 days after from 2 to 5 days after consuming a consuming a contaminated food contaminated food

CampylobacteriosisCampylobacteriosis

Poultry (Poultry (raw chicken)raw chicken) is recognized as the is recognized as the primary pathwayprimary pathway

other sources include other sources include unpasteurized milk and unpasteurized milk and non-chlorinated water non-chlorinated water

common in cattle, pigs common in cattle, pigs and other animalsand other animals

Control of Control of CampylobacterCampylobacter Aim: to develop Aim: to develop

strategies to strategies to control control campylobacter in campylobacter in the food supply the food supply "from farm to fork""from farm to fork"

campylobacter can campylobacter can be reduced: natural be reduced: natural feed ingredients feed ingredients (additive) caprylic (additive) caprylic acid acid

naturally found in naturally found in coconut coconut and breast and breast milk milk antifungal and antifungal and antibacterial antibacterial propertiesproperties

Escherichia coli Escherichia coli InfectionInfection

Some 5 million E. coli Some 5 million E. coli bacteria normally bacteria normally inhabit intestinal tractinhabit intestinal tract

Vital to processing Vital to processing vitamins in the diet vitamins in the diet

Several strains are Several strains are pathogenic and cause pathogenic and cause gastroenteritisgastroenteritis

Strain Strain E. coli E. coli 0157:H70157:H7potentially fatal form potentially fatal form of food poisoningof food poisoning

E. coli 0157:H7E. coli 0157:H7

Outbreaks in the Outbreaks in the US linked to US linked to spinach and spinach and other leafy other leafy vegetablesvegetables

E.coli 0157:H7 E.coli 0157:H7 probably probably originates from originates from cattlecattle

BotulismBotulism

Caused by a toxin produced by the Caused by a toxin produced by the bacteria bacteria Clostridium botulinumClostridium botulinum

especially dangerous because a especially dangerous because a large large number of peoplenumber of people can be poisoned by can be poisoned by eating a batch of contaminated foodeating a batch of contaminated food

derived from the soil, grows in many derived from the soil, grows in many meats and vegetables meats and vegetables

Develops in anaerobe Develops in anaerobe conditions such as conditions such as canned food canned food

AvoidanceAvoidance

Spoilage or Spoilage or decomposition can decomposition can be delayed:be delayed:

Observance of Observance of hygienehygiene

Storage in high salt or Storage in high salt or sugar concentrations sugar concentrations or in weak acids or in weak acids (pickling); (pickling);

Drying (desiccation) Drying (desiccation) or cooling or cooling (refrigeration); and (refrigeration); and

Killing the micro-Killing the micro-organisms by heat organisms by heat (canning and (canning and pasteurization)pasteurization)

Food contamination Food contamination throughthroughTOXINSTOXINS

Mycotoxins are Mycotoxins are produced by fungi, produced by fungi, commonly known as commonly known as mold. These toxins can mold. These toxins can develop during develop during production, harvesting, production, harvesting, or storage of grains, or storage of grains, nuts, and other crops. nuts, and other crops.

Mycotoxins are among Mycotoxins are among the most potent the most potent mutagenic and mutagenic and carcino-genic carcino-genic substances knownsubstances known

MycotoxinsMycotoxins

They pose chronic They pose chronic health risks:health risks:

prolonged exposure prolonged exposure through diet has through diet has been linked to been linked to cancercancer and kidney, and kidney, liver, and immune-liver, and immune-system disease system disease

Mycotoxins occur Mycotoxins occur more frequently more frequently under tropical under tropical conditionsconditions

Many diets consists Many diets consists heavily of food heavily of food from crops from crops susceptible to susceptible to mycotoxinsmycotoxins

AflatoxinsAflatoxins

naturally occurring naturally occurring mycotoxins, produced mycotoxins, produced by many species of the by many species of the fungus Aspergillus, fungus Aspergillus,

Aflatoxins are highly Aflatoxins are highly toxic and cause cancertoxic and cause cancer

After entering the After entering the body, aflatoxins are body, aflatoxins are metabolized by the metabolized by the liver liver

Aflatoxins

Discovered after in 1960, mold-conta-minated 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 post-

harvest practices Proper storage Shift from cereal

based to pasture based feeding (instead of feedlots)

Free-range poultry

Unknown burdenUnknown burden commonly only a part of the commonly only a part of the

cases are reported cases are reported less than less than 10 percent10 percent

Common ProblemsCommon Problems

Indices of food-borne Indices of food-borne illnesses tend to illnesses tend to increaseincrease

Often the pathogens Often the pathogens cannot properly be cannot properly be identified (identified ( up to up to 80% of cases)80% of cases)

Resistance against Resistance against antibiotics increasing antibiotics increasing (( drug-resistant drug-resistant SalmonellaSalmonella)

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

ConclusionConclusion

In view of the In view of the rapid genetic rapid genetic adaptability we adaptability we could say:could say:

““Microorganisms Microorganisms are are opponentsopponents with whom we with whom we cannot race on cannot race on their terms”their terms”(Dr. Lederberg)(Dr. Lederberg)

We only can try to avoid conditions in which harmful microbes can develop

Thank you! Thank you!