Issues of food-borne diseases/illnesses Microbes & Toxins Issues of food-borne diseases/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 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 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 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 food- borne illnesses annually WHO estimate: Worldwide 5 – 10% of the population suffer from food- borne illnesses annually Food-borne diseases are increasing worldwide

Cambodia Cambodia: High incidence of deaths due to diarrhoeal diseases Cambodia: High incidence of deaths due to diarrhoeal diseases –can be attributed to contaminated water and food WHO: Children under 5 years: 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) Food-borne illnesses are one factor contributing to the low life expectancy (2004 data) CambodiaRegion 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 Most food-borne diseases  food poisoning any condition in which a food causes a toxic reaction any condition in which a food causes a toxic reaction Generally: affecting the stomach and intestines = disease resulting from bacterial (or sometimes viral) contamination of foods Generally: affecting the stomach and intestines = gastrointestinal disease resulting from bacterial (or sometimes viral) contamination of foods

Food Poisoning Other causes: 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 natural accident (such as contamination of fish or shellfish by ‘red tide’) of fish or shellfish by ‘red tide’)

Bacterial Food Poisoning contamination of foods with bacteria that do not cause any obvious spoilage, contamination of foods with bacteria that do not cause any obvious spoilage, food is still apparently fit to eat, food is still apparently fit to eat, but may contain hazar- dous amounts of harmful organisms or toxins but may contain hazar- dous amounts of harmful organisms or toxins

Bacterial Food Poisoning (2) or or sufficient numbers of bacteria to cause an infection sufficient numbers of bacteria to cause an infection Some bacteria already have infected the animal or plant Some bacteria already have infected the animal or plant

Symptoms in other cases there may be a delay of several days, or even weeks, before there are any signs of infection in other cases there may be a delay of several days, or even weeks, before there are any signs of infection The symptoms poisoning range from mild diarrhea, through severe diarrhea and vomiting, to potentially life-threatening illness. 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 some cases the symptoms develop within a few hours of eating the contaminated food

Food-poisoning Organisms With most food- poisoning organisms, an intake of several thousand is required for infection, With most food- poisoning organisms, an intake of several thousand is required for infection, but consumption of as few as 10 of the virulent entero- haemorrhagic E.coli strain 0157 can cause life-threatening illness. but consumption of as few as 10 of the virulent entero- haemorrhagic E.coli strain 0157 can cause life-threatening illness.

Causes Of Food Poisoning The way animals are raised + crops cultivated The way animals are raised + crops cultivated The way in which the food is handled and prepared The way in which the food is handled and prepared esp. lack of food hygiene + personal hygiene esp. lack of food hygiene + personal hygiene Inadequate cooking of contaminated raw food (under-cooking) Inadequate cooking of contaminated raw food (under-cooking) Bacillus cereus: causes the "Fried Rice Syndrome"

Causes... (2) Inadequate reheating Inadequate reheating Keeping cooked food at temperatures that favor the growth of bacteria Keeping cooked food at temperatures that favor the growth of bacteria Cross-contamination between raw and cooked food Cross-contamination between raw and cooked food Poor personal hygiene in food handlers Poor personal hygiene in food handlers

Major food-borne illnesses Salmonellosis Salmonellosis Campylo- bacteriosis Campylo- bacteriosis E.coli infection, esp. E.coli O157 E.coli infection, esp. E.coli O157 Listeriosis Listeriosis Cholera Cholera (WHO ranking) (WHO ranking) Special case: Botulism

Salmonellosis Transmitted through contaminated poultry, eggs, and certain other foods Transmitted through contaminated poultry, eggs, and certain other foods Also found on citrus fruits Also found on citrus fruits Causes abdominal pain, fever, nausea and vomiting, and diarrhea 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 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 probably most common bacterial cause of gastroenteritis worldwide incidence of human campylobacter infections has been steadily increasing incidence of human campylobacter infections has been steadily increasing Gastroenteritis  inflammation of the lining membrane of the stomach and the intestines characterized especially by nausea, vomiting, diarrhea, and cramps

Campylobacter jejuni Bacteria, which is naturally part of the intestinal microflora Bacteria, which is naturally part of the intestinal microflora Cannot be treated with antibiotics Cannot be treated with antibiotics Can be caused by cross-contamination during food preparation Can be caused by cross-contamination during food preparation

Campylobacteriosis Most people who become ill develop diarrhea, Most people who become ill develop diarrhea, cramping, abdominal pain and fever cramping, abdominal pain and fever Symptoms: anywhere from 2 to 5 days after consuming a contaminated food Symptoms: anywhere from 2 to 5 days after consuming a contaminated food

Campylobacteriosis Poultry ( raw chicken) is recognized as the primary pathway Poultry ( raw chicken) is recognized as the primary pathway other sources include unpasteurized milk and non-chlorinated water other sources include unpasteurized milk and non-chlorinated water common in cattle, pigs and other animals 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" 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 campylobacter can be reduced: natural feed ingredients (additive) caprylic acid naturally found in coconut and breast milk  antifungal and antibacterial properties naturally found in coconut and breast milk  antifungal and antibacterial properties

Escherichia coli Infection Some 5 million E. coli bacteria normally inhabit intestinal tract Some 5 million E. coli bacteria normally inhabit intestinal tract Vital to processing vitamins in the diet Vital to processing vitamins in the diet Several strains are pathogenic and cause gastroenteritis Several strains are pathogenic and cause gastroenteritis Strain E. coli 0157:H7 potentially fatal form of food poisoning 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 Outbreaks in the US linked to spinach and other leafy vegetables E.coli 0157:H7 probably originates from cattle E.coli 0157:H7 probably originates from cattle

Botulism Caused by a toxin produced by the bacteria Clostridium botulinum 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 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 derived from the soil, grows in many meats and vegetables Develops in anaerobe conditions such as canned food Develops in anaerobe conditions such as canned food

Avoidance Spoilage or decomposition can be delayed: Spoilage or decomposition can be delayed: Observance of hygiene Observance of hygiene Storage in high salt or sugar concentrations or in weak acids (pickling); Storage in high salt or sugar concentrations or in weak acids (pickling); Drying (desiccation) or cooling (refrigeration); and Drying (desiccation) or cooling (refrigeration); and Killing the micro- organisms by heat (canning and pasteurization) Killing the micro- organisms by heat (canning and pasteurization)

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

Mycotoxins They pose chronic health risks: They pose chronic health risks: prolonged exposure through diet has been linked to cancer and kidney, liver, and immune-system disease prolonged exposure through diet has been linked to cancer and kidney, liver, and immune-system disease Mycotoxins occur more frequently under tropical conditions Mycotoxins occur more frequently under tropical conditions Many diets consists heavily of food from crops susceptible to mycotoxins Many diets consists heavily of food from crops susceptible to mycotoxins

Aflatoxins naturally occurring mycotoxins, produced by many species of the fungus Aspergillus, naturally occurring mycotoxins, produced by many species of the fungus Aspergillus, Aflatoxins are highly toxic and cause cancer Aflatoxins are highly toxic and cause cancer After entering the body, aflatoxins are metabolized by the liver After entering the body, aflatoxins are metabolized by the 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 burden commonly only a part of the cases are reported  less than 10 percent commonly only a part of the cases are reported  less than 10 percent

Common Problems Indices of food-borne illnesses tend to increase Indices of food-borne illnesses tend to increase Often the pathogens cannot properly be identified (  up to 80% of cases) Often the pathogens cannot properly be identified (  up to 80% of cases) Resistance against antibiotics increasing (  drug-resistant Salmonella 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: In view of the rapid genetic adaptability we could say: “Microorganisms are opponents with whom we cannot race on their terms” (Dr. Lederberg) “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!