See also: Related OurFood News

Subsections

Food-Borne Diseases

Introduction

Search for food has always been a struggle to survive. The discovery of fire by the cave man was an important step in food handling. Spices triggered the great voyages looking for a new way to the spices from India.

Nowadays the rarest of dishes are available everywhere and there are no restrictions as to the seasons. Global trade of food has made it possible.

These modern achievements, however, bear the danger to destruct the economic, ecological and cultural isolated units destabilising the economy of a region because manpower and products of other regions, with lower production costs, compete with high cost regions. Ecology is endangered, due to increase of traffic, and last but not least, the culture and beliefs of isolated regions are washed out.

Growing international business leads to ever growing food batches, spreading them over great areas. The control of hazards in food production, transportation and handling and even the menace of terrorist actions are getting high priority in the concern of industry, commerce and food health departments of every nation and is subject of many international standards.

Food producers (agriculture, breeders, fishery, processing factories) are concerned about these hazards which may cause tremendous costs, loss of crops, and even lead to bankruptcy.

Catering service establishments and restaurants are liable to recourse in case of harmful food.

The loss of confidence of their customers due to headlines involving a recall of a spoiled brand is a nightmare for every manager of discount stores or global food trade business.

Food health departments and government ministry of consumer safety, such as Minister Kynast in Germany in the case of BSE scandal are top headlines.


Bacterial infections

Zoonotic disease in humans within the EU

[1]
Zoonoses are diseases or infections, which are transmissible from animals to humans. The infection can be acquired directly from animals, or through ingestion of contaminated foodstuffs.

The European Food Safety Authority analysed the data from 2005 and published a report on zoonotic diseases in humans in December 2006.

EFSA found campylobacteriosis as the most frequently reported zoonotic disease in humans within the EU. Reported Campylobacter cases increased by 7.8% compared to the previous year. Fresh poultry meat was found to have the highest contamination rate with Campylobacter with 66% of samples positive and was also commonly detected from live poultry, pigs and cattle. The largest Campylobacter outbreaks were caused by contaminated drinking water.

Salmonellosis remained the second most frequent zoonosis despite the fall of 9.5% compared to 2004.Salmonella was most often reported from fresh poultry and pig meat where proportions of positive samples up to 18% were detected. In table eggs, findings of positive samples ranged from 0% to 6%, but over the past 5 years an overall decreasing trend in occurrence of Salmonella in eggs was observed. In animal populations, Salmonella was most frequently detected in poultry flocks.

Egg and bakery products were the most common sources of Salmonella outbreaks, whereas broiler meat was an important source for both Salmonella and Campylobacter outbreaks. Foodborne virus outbreaks were most often caused by drinking water, fruit and vegetables.

For Verotoxigenic Escherichia coli (VTEC) infections and yersiniosis more informations are needed concerning the serotypes and other virulence factors related to human pathogenic serotypes. The authors of the Report call for a harmonisation of the analytical methodology.

[1]
  Incidence Number of
Disease 100,000 people reported cases
Campylobacteriosis 51.6 197.363
Salmonellosis 38.2 176.395
Yersiniosis 2.6 9.630
Verotoxigenic Escherichia coli VTEC 1.2 3.314
Listeriosis 0.3 1.439
Brucellosis 0.2 1.218
Echinococcosis <0.01 320
Trichinellosis <0.01 175
Tuberculosis due to M. bovis <0.01 119
Rabies <0.01 4
  Incidence Number of
Disease 100,000 people reported cases

Survey on the prevalence of Salmonella in EU poultry in 2006

[2]
European Community legislation foresees setting of Salmonella reduction targets for animal population including broiler flocks.

The survey was the second of several baseline surveys to be conducted in the Community. The sampling of the broiler flocks took place between October 2005 and September 2006.

A total of 11.0% of the broiler flocks was estimated to be positive for Salmonella Enteritidis and/or Salmonella Typhimurium, the two most common serovars found in Salmonella infection cases in humans. The Member State-specific observed flock prevalence of S. Enteritidis and/or S. Typhimurium varied also greatly, from 0% to 39.3%. The number of positive samples in a Salmonella positive flock ranged between one and five but at European Union level 42% of the positive flocks was found positive for all the five samples taken.

The five most frequently isolated Salmonella serovars from broiler flocks in the European Union were respectively in decreasing order S. Enteritidis, S. Infantis, S. Mbandaka, S. Typhimurium and S. Hadar. All these serovars, with the exception of S. Mbandaka, are frequent causes of Salmonella infections in humans within the European Union. S. Enteritidis was the most common serovar and it was detected in 37% of the Salmonella positive flocks. S. Infantis accounted also for an important proportion of positive flocks (20%). The serovar distribution varied amongst the Member States, many of them having a specific distribution pattern of their own.

While the Community reduction target will most likely be set for a transitional period only for S. Enteritidis and S. Typhimurium, it is recommended that Member States would address in their national Salmonella control programmes also other serovars when these serovars are of public health importance in their country.

Verotoxigenic Escherichia coli (VTEC) in foods

The majority of the data derives from food of bovine origin (bovine meat, raw milk, cheese and dairy products, other or mixed meat). The report also contains information about Bovine Spongiform Encephalopathy, Avian Influenza, Cysticerci and Sarcocystis parasites and Q fever in animal populations. [1]

Germany reported the highest number of tuberculosis due to Mycobacterium bovis in 2005, followed by The United Kingdom

Bovine tuberculosis and bovine or caprine/ovine brucellosis is still present in 3-4% in bovine/sheep/goat populations.The highest incidences of human brucellosis have been recorded in Greece, Italy, Portugal and Spain, mostly Brucella melitensis were responsible for the disease.

Yersinia enterocolitica 0:3 serotype was the dominant type found in the EU. Germany had the highest number of human infections. Y. enterocolitica is found in meat and milk, especially pig meat.

Q Fever increasing in Germany and The Netherlands

[3]
Q fever is an infectious disease caused by the bacterium Coxiella burnetii that affects both animals and humans. It has been reported to be present in a wide range of species, including cattle, sheep and goats, as well as birds and arthropods in many areas in the world.

It was first recognised as a disease transmissible from animals to humans in abattoir workers in 1935 in Australia. In recent years, the number of confirmed cases in humans increased, in particular in Germany and The Netherlands.

Coxiella burnetii does not usually cause clinical diseases in animals, although abortion in goats and sheep has been linked to infection with this bacterium. In humans, Q fever may cause flu-like symptoms, including fever and headache, diarrhea and vomiting. In some cases it can cause pneumonia and hepatitis. Chronic Q fever (characterized by an infection lasting more than 6 months) is uncommon but a much more serious disease with complications such as inflammation of the inner lining of the heart (endocarditis).

Most human infections result from the inhalation of dust contaminated with bacteria from the placenta and birth fluids or faeces from infected animals. In some cases the disease can be transmitted by the consumption of contaminated milk or contact with infected animals, especially animals that are giving birth. Other modes of transmission, including tick bites and human to human transmission are extremely rare.

French Cheese under safety concern

Various types of French cheese are prepared from raw milk. The definition of Camembert dated December 1986, says that temperatures not higher than 37° may be used during production process and only milk from cattle which tuberculosis and brucellosis free may be used. [4]

Safety concern which were nourished by a series of cheese poisoning by Listeria monocitogenes and salmonella made some producers like Lactalis to apply a mild heat of 60° (thermised milk), which may inactivate these pathogens. The AOC do not approve this safety measure claiming that quality and flavour of the camembert will be compromised. The AOC members voted to keep the definition of 1986 unaltered. It is expected that official ruling will forbid the use of raw milk for cheese production in France. [5]

Raw milk

[6]
The U.S. Food and Drug Administration (FDA)and the Centers for Disease Control and Prevention (CDC) are reminding consumers of the dangers of drinking milk that has not been pasteurized, known as raw milk. Raw milk potentially contains a wide variety of harmful bacteria - including Salmonella, E. coli O157:H7, Listeria, Campylobacter and Brucella - that may cause illness and possibly death.

Since 1987 FDA has required all milk packaged for human consumption be pasteurized before being delivered for introduction into interstate commerce. This also applies to other milk products, with the exception of a few aged cheeses.

According to FDA, proponents of drinking raw milk often claim that raw milk is more nutritious than pasteurized milk and that raw milk is inherently antimicrobial, thus making pasteurization unnecessary. Research has shown that these claims are myths. There is no meaningful nutritional difference between pasteurized and raw milk, and raw milk does not contain compounds that will kill harmful bacteria. In fact, raw milk, no matter how carefully produced, may be unsafe.

Listeria monocitogenes in US milk

[7]
The Massachusetts Department of Public Health located the source of the outbreak at the beginning of January 2007. after four people had become ill, two of whom fatally, The bacteria is believed to have entered the dairy's milk supply after it was pasteurized.

Milk pasteurisation and Listeria

[8] Current state and local regulations throughout the United States specify time and temperature conditions for pasteurization. These regulations call for milk to be heated to at least 71.7° C for 15 seconds (i.e., high-temperature short-time (HTST) process) or to 62.8 C for 30 minutes.
Viable L. monocytogenes could berecovered after minimum HTST treatment (71.7° C for 15 seconds), although not after treatment at 76.4 C-77.8° C for 15 seconds. This survival was attributed in part to protection of L. monocytogenes within leukocytes in milk (intracellular L. monocytogenes organisms are found in milk from infected cows but not in artificially inoculated milk), but these findings may not be applicable to usual production conditions.

In another study in which investigators identified cows that had been naturally infected with L. monocytogenes, proper pasteurization was found to inactivate L. monocytogenes in milk contaminated through natural infection as well as in artificially inoculated milk.

World Health Organization Working Group on foodborne listeriosis recently concluded that "pasteurization is a safe process which reduces the number of L. monocytogenes occurring in raw milk to levels that do not pose an appreciable risk to human health"

CDC concludes that improperly performedpasteurization and the occurrence of contamination after pasteurization are the most likely explanations for the presence of L. monocytogenes in pasteurized milk.

Efforts to ensure that milk is safe from L. monocytogenes contamination should focus on promoting proper methods of pasteurization and on identifying and eliminating sources of postpasteurization contamination.

This risk is ingreased in food processing environments, where Listeria bacteria tend to thrive, particularly in floor drains and other cool, damp areas. According to health officials, they suspect the Whittier Farms pasteurized milk was contaminated after the pasteurization process.

The Massachusetts Department of Public Health (MDPH) is recommending that consumers do not consume Whittier Farms milk products. Because the incubation period for Listeria can be as long as 70 days, anyone who has consumed the milk should watch for Listeria symptoms, including fever, muscle aches and sometimes gastrointestinal symptoms such as nausea or diarrhea. In pregnant women, the symptoms may be mild, but an infection can cause miscarriage, stillbirth or early delivery.

USDA measures to close recent food safety loopholes

[9]
In November 2007 the USDA launched a new Food Protection Plan, combining science and information technology to identify potential hazards before they have an impact. The Food Protection Plan comprises:

Prevention of foodborne contamination

This aims to increase corporate responsibility to prevent illness. It seeks to identify and assess vulnerabilities and expand understanding and use of mitigation measures.

Intervention at critical stages in the food supply chain

This includes inspections and risk-based sampling, risk-based surveillance, and better detection of signals that indicate contamination has occurred.

FDA more rapide respond to problems

This reduces the impact, and improve its communication on risks to the public, industry, and other stakeholders.

Growing resistance to antimicrobials

Relatively high proportions of Campylobacter and Salmonella isolates from animals and food were resistant to antimicrobials commonly used in treatment of human diseases. This is especially the case of resistance to fluoroquinolones in Campylobacter isolates from poultry, where up to 94% of isolates were reported resistant to ciprofloxacin. Foodborne infections caused by these resistant bacteria pose a particular risk to humans due to possible treatment failure. [1]

German Federal Institute for Risk Assessment (BfR) warn about pink duck breast

[10] High temperatures during preparation prevent Campylobacter infections
Examinations by the German official food control authorities of the federal states detected Campylobacter in around one-third of the poultry meat samples. Duck meat is also frequently involved.

Campylobacter infections in humans are frequently caused by poultry meat, including duck breast. Campylobacter bacteria are heat-sensitive and die when meat is cooked through. As duck breast in traditional recipes is often not cooked through ("pink duck breast"), its consumption can lead to unpleasant gastrointestinal disorders caused by Campylobacter bacteria. This risk, including Salmonella, Listeria, noroviruses and hepatitis viruses, can be completely ruled out when the internal temperature of the meat during preparation on the stove or in the oven is 74 degrees Celsius or higher for more than 10 minutes.


Basic hygiene rules for handling poultry: Kitchen hygiene and sufficient cooking

Thaw water and packaging should be disposed of appropriately.
All kitchen utensils and surfaces, which have been in contact with the meat, should be thoroughly cleaned.
Hands should be washed thoroughly after each stage of preparation.
During preparation internal temperature of 74 degrees Celsius or higher must be attained. The use of a meat thermometer is highly recommendated.

Antimocrobial-resistant bacteria draft opinion of the European Food Safety Authority

[11]
According to a draft opinion of the European Food Safety Authority's BIOHAZ Panel the use of antimicrobial agents produced resistant bacteria such as Meticillin-resistant Staphylococcus aureus which can be found in foods such as poultry meat, eggs, pork or beef and foods of plant origin like salads.

The panel cites some transmission ways to human: The Panel also said that bacteria deliberately introduced into the food and feed chain for manufacturing and preservation processes, such as fermentation cultures, and also probiotics, have on occasion exhibited antimicrobial resistance and should also be considered as a possible route for the transfer of antimicrobial resistance through food.


Escherichia coli

Escherichia coli is indicator of fecal pollution of drinking water supplies, swimming beaches, foods, etc. A few strains of Escherichia coli are pathogenic such as the strain 0157:H7 in raw hamburgers (Shiga toxin-producing Escherichia coli (STEC) O157 ).

Reduction of E. coli O157:H7 in cattle with feed strategy

Changing grain to forage

[12]
Callaway and colleagues found that feeding cattle with large grain rations, some starch escapes ruminal microbial degradation and passes to the hindgut where it is fermented to sugars. EHEC can use these sugars for their grow. The authors say that this may be the reason of E. coli O157:H7 shedding in barley fed cattle.

Changing high grain (corn) diet to a forage diet, generic E. coli populations declined 1000-fold within 5 d, and the ability of the faecal generic E. coli population to survive an acid shock similar to the human gastric stomach decreased, but this has not been observed in other studies. The authors conclude that switching cattle from grain to forage could potentially reduce EHEC populations in cattle prior to slaughter, but the economic impact should be taken into consideration.

Outbreak of deadly EHEC Escherichia coli in Germany spreads quickly

[13] A rising number of acute infections and fatalities caused by the Enterohemorrhagic Escherichia coli (EHEC) have occurred especially in Lower Saxony, Bremen and Schleswig-Holstein, but spreads quickly southward in May 2011.

The German Robert Koch Institute could not determine the infection source yet, however, it is supposed that contaminated vegetable and salads are to be blamed. In the actual epidemic the source is not raw milk, cream cheese or meat. Women are more often preparing food and are therefore at higher risk to be contaminated while washing and preparing vegetables. It is supposed that deposition of the life-threatening bacterium on vegetables and fruits resulting of spraying liquid manure in plantations are the cause of the epidemic. Escherichia coli O157:H7 can be found in the intestinal tract of cattle. Multiple factors contribute to the fact that the bacterium does not cause disease in ruminants and is considered commensal. [14]

Health officials advice to wash carefully vegetables, especially green leafy salads. Sanitise carefully cutting boards and knives and wash hands. Escherichia coli O157:H7 is an enterohemorrhagic strain of the bacterium Escherichia coli. Transmission is via the fecal-oral route, and most illness has been associated with eating undercooked, contaminated ground beef, swimming in or drinking contaminated water, and eating contaminated vegetables. Laboratory tests need 36 hours to be accomplished. Some strains of the German outbreak present antibiotics resistance.

Lactobacillus acidophilus in feed to counter E.coli O157:H7

[15]
According to Reillyl the prevention of outbreaks of E. coli O157:H7 should begin with a proper cattle management system together with a supplementation of cattle feed with probiotics such as Lactobacillus acidophilus as a possible antagonist to several pathogens in the intestine.

Escherichia coli and enterococci in water

Recent epidemiological studies indicate that E.coli and enterococci show a direct correlation with swimming-associated gastrointestinal illness rates, while fecal coliforms do not. As the concentration of E. coli and/or enterococci increase(s), the illness rates also increase.

These indicators are used as part of the bacterial water quality criteria and standards to enhance the protection of human health and the environment.


Enterococci

Enterococci, which include Enterococcus faecalis and Enterococcus faecium, are enteric bacteria used to indicate faecal contamination and the possible presence of pathogens, in water. Total and faecal coliform bacteria currently have been included in many water quality standards as indicators of bacterial contamination.


Salmonella

The enteric group also includes some other intestinal pathogens of human beings such as Shigella dysenteriae, cause of bacillary dysentery, and Salmonella typhimurium, cause of gastroenteritis.

Typhoid fever is an acute, life-threatening febrile illness caused by the bacterium Salmonella enterica serovar Typhi.


Old nomenclature

Bergy's Manual: "The names given to salmonellae do not follow the usual rules of nomenclature

Because of their importance in pathology, the first salmonellae were given names which indicated the disease and/or the animal from which the organism was isolated, and names of this kind (such as S. typhy, S. paratyphy-A, S. choleraesuis, S. typhymurium, S. abortusovis) continue to be used in clinical bacteriology.

Scientifically, none of the present methods of nomenclature of salmonellae is satisfactory. Nomenclature changes will be needed in order to account to new DNA findings."


New nomenclature according to DNA findings

The new nomenclature comprises only two species:


Salmonella enterica

meaning all human pathogens subdivided into serovars using the old genus names.
Example: Salmonella typhy = Salmonella enterica serovar Typhi, Abbreviation S. Typhi. Salmonella enteritidis = Salmonella enterica serovar Enteritidis, Abbreviation S.Enteritidis


Salmonella bongori

Associated with cold-blood animals. Most of human infections are due to contact with reptiles.


Basics of Salmonella prophylaxis

Never eat undercooked ground beef and poultry, raw eggs, not pasteurised dairy products. and raw shellfish.

Medical inspection of all people handling food is to be periodic repeated and documented.

This includes clinical inspection, bacteriological examination of faeces with regard to Salmonella bacteria, daily control of the personal to avoid purulent wounds, persons with diarrhoea and other problems to come in contact with food.

These persons should be transferred to areas were they cannot come in contact with unpacked food.


Salmonellosis

Salmonellosis ranges clinically from the common Salmonellae diarrhoea abdominal cramps, and fever to enteric fevers such as typhoid fever caused by Salmonella Typhi. The most common form of salmonellosis is a self-limited, uncomplicated gastroenteritis.


Non-typhoid salmonellosis

It is caused by any serotype of Salmonella other than Salmonella Typhi. It is a worldwide disease of humans and animals. Animals are the main reservoir, and the disease is usually food borne, although it can also be spread from person to person.


Typhoid fever

( Synonym: Enteric fever) is caused by Salmonella Typhi.

Incubation can last up to two months. It is therefore difficult to remember the food which might have been the source of infection. Hosts are humans, which became carriers after an infection. Several negative microbiological tests should be made, to let a food worker go back to his working place after a salmonellosis.

Should this not be a demand of the local medical regulations, auditing should try to get it listed as additional HACCP item.

Typhoid fever spread mainly from person to person via the fecal-oral route and have no significant animal reservoirs. Asymptomatic human carriers may spread the disease. Paratyphoid fever is caused by Salmonella paratyphi and is milder than typhoid fever. Host are humans, which became carriers after an infection.


Typhoid Mary

Here name was Marry Mallone. She was an Irish immigrant. She was a healthy carrier of typhoid fever. From 1900 to 1907 she worked as a cook, infecting many people.

Being caught after a long search, she was put in reclusion on North Brother Island and released in 1910 telling her not to work as cook again. In 1915 she was found working as cook in an Hospital infecting people there too. She was sent back to confinement where she died in 1938.

Other carrier such as Tony Labellaand Alphonse Cotils both handling foods remained free, being an inconsequent attitude of the health authorities managing the epidemic in NY. Please remember this, otherwise you will have typhoid Mary on your suppliers-list.

The major reservoir of Salmonella is poultry and livestock, ground meat and eggs.


Measures to reduce salmonellosis in poultry

All animal feed should be salmonellae free. Feed was the main cause of large distribution of Salmonella in poultry.

Slaughtering practices with reduced cross-contamination of carcasses.

Avoid cross-contamination of processed and raw food.

Training in hygienic practices for all food-handling personnel.

Cooking and refrigerating food adequately.

Radiation of poultry to reduce contamination by pathogenic bacteria, such as Salmonella and Campylobacter. Irradiation of food is, however, not much in use.


Shigella

Infection with Shigella is often cause of bloody diarrhoea, and stomach cramps starting a day or two after exposure to the bacterium, usually resolving in 5 to 7 days. Some persons who are infected may have no symptoms at all and pass the Shigella bacteria to others.

They are a menace in food production when basic hygiene, hand washing and disinfection habits are not observed. Contaminated food is the result.

Different kinds of Shigella bacteria:
Shigella sonnei, also known as "Group D" Shigella
Shigella flexneri,Shigella flexneri or "group B" Shigella, accounts for almost all of the rest.
Shigella dysenteriae type 1 causes deadly epidemics in the developing world.
Shigella boydii.


Common causes of food contamination with Shigella

Infected food workers who forget to wash their hands with soap and do not use disinfectant after using bathroom and before preparing food or beverages.
Vegetables which were contaminated with sewage.
Flies living on infected feces can contaminate food.
Drinking or swimming in contaminated water with sewage or sick person swimming in it.

Improvements in hygiene for vegetables and fruit picking, water used to rinse vegetable, appropriate packing may prevent shigellosis caused by contaminated products.

Other bacteria related to food born diseases

Listeria monocytogenes:Outbreaks in cheese and meat.
Yersinia enterocolitica: Causes enterocolitis in children.
Cryptosporidium parvum: Infects many herd animals (cows, goats, sheep among domesticated animals, and deer and elk among wild animals) and humans.
Cyclospora cayetanensis: Watery diarrhoea.
Campylobacter jejuni: It produces diarrhoea bloody stool, fever, lasting seven to ten days. It produces a heat-labile toxin that may cause diarrhoea.

Many chicken flocks are silently infected with Campylobacter jejuni, which can be easily spread through a common water source or contact with infected feces.

On occasion of slaughter it can be transferred from the intestines to the meat and giblets, especially the liver.

Not pasteurised milk can become contaminated if the cow has an infection in her udder or the milk is contaminated with manure. Surface water and mountain streams can become contaminated from infected feces from cows or wild birds.

It is often isolated from healthy cattle, chickens, birds and even flies. There are pathogenic and nonpathogenic strains.

Cooking chicken, pasteurising milk, and chlorinating drinking water will avoid the bacteria to spread.

Not pasteurised milk is therefore a possible source of bacteria such as Campylobacter and tuberculosis. Pasteurisation time/temperature standards should be 145F for 30 minutes (63C for 30 minutes).

Bacteria Rapid Detection Using Optical Scattering Technology

[16]
Arun K. Bhunia and colleagues developed an identification process using an imaging approach, analysing bacterial colonies grown on solid surfaces. Using a laser scatterometer, the system classifies scatter patterns formed by Listeria monocytogenes colonies. Different strains and pathogenic of Listeria can be recognised with a low error rate. It is based on Zernike moment invariants. The detection of other pathogenic bacteria may also be included in the system. The authors point out the feasibility of image-based biodetection systems.


Cholera

Vibrios (which have a curved rod morphology or comma shape) are very common bacteria in aquatic environments. Pseudomonads favour fresh water and vibrios prefer salt water. The genus Vibrio contains an important human pathogen.

Vibrio cholerae, the cause of Asiatic cholera. Cholera is an intestinal disease with a pathology related diarrhoeal diseases caused by the enteric bacteria. The source of the contamination is usually the feces of an infected person. Incubation is one to two days.

The cholera bacteria produces a toxin that inhibits the absorption of liquids by the body. It kills because it dehydrates the body.

The disease can spread rapidly in areas with inadequate treatment of sewage and drinking water, brackish rivers and coastal waters, raw or undercooked shellfish from the Gulf of Mexico.

In 1991 Cholera was present in coastal areas of Peru. The disease spread rapidly throughout Peru and into other countries in South, Central and North America.

The Minister of Fishery of Peru wanting to restore public confidence on marine food ate in a TV-show an undercooked fish. The day after he was hospitalised with cholera.

Cholera is a disease associated with poverty, inadequate sanitation and low medical care. The key to effective control is environmental sanitation. Whenever these conditions are present in a region from where food and raw materials are imported, auditing should keep this in mind.

Contaminated water and food are the main cause of cholera in Zimbabwe

[17]
Cholera is a disease associated with poverty, inadequate sanitation and low medical care. The key to effective control is environmental sanitation.

The cholera bacteria (Vibrio cholerae) produces a toxin that inhibits the absorption of liquids by the body. It kills because it dehydrates the body.

Zimbabwe's cholera outbreak, one of the world's largest ever recorded, is far from being brought under control. An enhanced response is needed to urgently reverse an epidemic that has so far infected more than 60,000 people and killed more than 3,100 since August 2008. Former Cholera outbreaks took place in Gorna in 1994 affecting Rwandan refugees and killed 50,000 people within 3 weeks. The outbreak in 2006 killed 2.700 persons in Angola.

Transmission of Cholera through contaminated food and water

[18]
Cholera is mainly transmitted through contaminated water and food and is closely linked to inadequate environmental management. Recent interruptions to the water supplies, together with overcrowding, are aggravating factors in this epidemic.
Communities are being encouraged to protect themselves against cholera by adhering to proper food safety practices as well as to good personal hygiene. Early rehydration at home by using oral rehydration salts is paramount to diminishing mortality.

Mass chemoprophylaxis with antibiotics is strongly discouraged, as it has no effect on the spread of cholera, can have adverse effects by increasing antimicrobial resistance and provides a false sense of security.


How to reduce cholera risk in epidemic regions

[19] [20]
- Drink water that you have boiled for at least one minute or treated with chlorine or iodine. Other safe beverages include tea and coffee made with boiled or treated water, as well as drinks that have been bottled and sealed (such as bottled water, carbonated drinks, and sports drinks).

-Do not put ice in drinks, unless the ice is made from boiled or treated water.
- Eat only foods that have been thoroughly cooked and are still hot, or fruit that you have peeled yourself.
- Do not eat undercooked or raw fish or shellfish, including ceviche.
- Make sure all vegetables are cooked. Do not eat salads or other raw vegetables.
- Do not eat foods and drink beverages from street vendors.

Cholera epidemic 2010 in Haiti

[21]
Cholera is transmitted through fecal contamination of water or food and causes an acute, severe, watery diarrhoea that can result in hypovolemic shock and death if not treated with fluid replacement promptly.

The cholera epidemic in Haiti killed 1400 people. 50000 went sick and are being medicated. According to Dr. Scott Dowell of CDC it is not possible to find out how the cholera came to Haiti.

Cholera can be treated with antibiotics but the usual best course is giving intravenous fluids, salts and sugars to restore what is lost through diarrhoea and vomiting. It seems hard to get the bacterium out of Haiti and the country will have to deal with the disease for a long time.

Genetic tests show the Vibrio cholerae bacteria isolated in Haiti is almost identical to one another, which supports the theory of a single source. It is the same strain previously found in countries in South Asia and elsewhere, and can be trace. Back to a pandemic in Indonesia 49 years in Sulawesi, Indonesia. The outbreak of cholera in Haiti was first seen affecting workers in rice paddies in the Artibonite Department. They were drinking untreated water and practiced open defecation. Haiti lacks piped, treated water and adequate sanitation.

The Haitian population has no pre-existing immunity to cholera. The toxigenic strain Vibrio cholerae O1, serotype Ogawa, biotype El Tor was identified. The strain is susceptible to tetracycline, ciprofloxacin, and kanamycin; and resistant to trimethoprim-sulfamethoxazole, furazolidone, nalidixic acid, sulfisoxazole, and streptomycin. The CDC stresses the importance of preventing infection by promoting water treatment, adequate sanitation and hygiene, and safe food preparation. [22]

Prevention and control measures

[23]
The CDC reports that prevention and control measures are focused on 1) providing better access to treated drinking water; 2) providing education on improvement of sanitation, hygiene, and food preparation practices; 3) advising ill persons to begin using oral rehydration solution immediately and seek health care at the onset of watery diarrhoea; 4) enhancing cholera treatment capacity at existing health-care institutions; and 5) establishing cholera treatment centres.

Individual protection from Cholera

[24]
The CDC recommends individual measures to protect from the disease:
- Drink and use safe water. Boil it for at least 1 minute, or treat it with chlorine.
- Wash your hands often with soap and safe water.
- Use latrines or bury your faeces; do not defecate in any body of water. If there are no latrines installed, defecate at least 30 meters away from any body of water and then bury your faeces.
- Cook food well, especially seafood, keep it covered, eat it hot, and peel fruits and vegetables. Boil it, Cook it, Peel it, or Leave it.
- Clean up safely - in the kitchen and in places where the family bathes and washes clothes. Read more at http://www.cdc.gov/haiticholera/pdf/cholera_preventionmessages.pdf

Ongoing cholera epidemic in Congo and Haiti in 2011

[25] Cholera is an acute intestinal infection transmited by faecal contaminated food or drinking water. The agent of the disease is the Vibrio cholerae bacterium. The disease has an incubation period of 1 to 2 days causing watery diarrhoea, vomiting, severe dehydration and death if treatment is not administered promptly. Vomiting also occurs in most patients.

According to WHO cholera no longer poses a threat to countries with high standards of hygiene, however, it remains a challenge in countries with unsafe drinking water and inappropriate sanitation.

Congo: The disease has spread to the provinces of Equateur, Bandundu and the capital, Kinshasa, from where it spreads downstream along the River Congo. At least 3,896 cases, with 265 fatalities have been reported in the Democratic Republic of Congo (DRC) since March. In the Republic of Congo 181 cases are suspected, and six people died, following a report issued by WHO.

The WHO and partners, together with the government promote hygiene campaigns, send experts to the affected regions, set up water chlorination points and provide treatment for infected persons.

Cholera cases increasing in Haiti

[26] Cases of cholera are on the rise in Haiti and neighbouring Dominican Republic. Since the beginning of the outbreak last October til 12 June 2011, there had been 344,623 cases of cholera and 5,397 deaths. Access to clean water and proper sanitation in Haiti remains the main challenge in fighting the epidemic, according to WHO.

In the Dominican Republic there have been 1,727 confirmed cases, including 46 deaths. The country is improving water quality and sanitation services, and public awareness campaigns on prevention.

Consumers feel no health benefits of bottled water over tap water, says study

[27]
Bottled water became an important business. It is a bulky department of food stores. Ward and colleagues 2009 assessed the health beliefs of consumers concerning bottled mineral water. The authors found that drinking bottled water was motivated by the believe it may confer general health benefits linked to the minerals in bottled water. This, however, plays a minor role in the decision to buy bottled water, where convenience, cost and taste are the important criterion. Links between plastic bottle and cancer, also detrimental effect on the environment were of concern.

This study supports an earlier study of Napier and Kodner 2008 which say that health benefits of bottled water for routine use is unclear. The authors stress, however the importance of bottled water in handling emergencies or natural disasters, compromising safety of tap water. [28]

US Regulations for bottled water

[29]
The Institute of Food Technologists: published in 2008 an overview of drinking water standards and regulations, freshwater resources, water pollution and predominant sources of contamination, and the effects of agriculture and food processing on water quality and wastewater treatment. The overview also describes bottled water as defined by the U.S. Food and Drug Administration (FDA) as water intended for human consumption that is enclosed in a sanitary container, contains no added ingredients (except or optional antimicrobial agents or FDA-specified amounts of fluoride), and meets all applicable federal and state standards. It must comply with FDA's standards of quality, standards of identity (including labelling requirements), and current good manufacturing practices, and FDA's standards of quality (21 CFR §165.110[b]) [30] establishing maximum allowable levels of contaminants such asd chemical, physical, microbiological, and radiological in bottled water.


Staphylococcus aureus

Staphylococcus aureus causes suppurative infections in animals and man. It can form toxins which cause food poisoning. The contamination of food with Staphylococcus aureus occurs due to contact with infected wounds of animals or hands of food workers. That is why gloves are indispensable.

Contaminated fish caused intoxication with staphylotoxin which is resistant to heat. The fish had been left for hours without cooling, the bacteria produced the toxin which can be present in deep frozen fish and its products.

Half of US meat and poultry found contaminated with antibiotic resistant Staphylococcus aureus

[31] Waters et al. 2011 found that 47 % of meat and poultry were contaminated with Staphylococcus . aureus, of which 52 % were resistant to at least three classes of antibiotics. The genotypes and resistant profiles suggest that the source of these bacteria come from food animals.

Low doses of antibiotics used as feed supplements industrial farms are ideal places for the development of drug-resistant bacteria.

Staphylococcal enterotoxin is resistant to cooking temperatures

Staphylococcus aureus causes cause a range of illnesses from skin infections to life-threatening diseases, such as pneumonia, endocarditis and sepsis in animals and man. Important for the food industry is the fact that Staphylococcus aureus may form toxins which cause food poisoning.

Contamination of meat, poultry or even eggs may be traced back to contact with infected wounds of animals or hands of food workers. Waters and colleagues 2011 stress the need to wear gloves when handling foodstuffs and refer to proper cooling of meat and poultry to avoid the development of staphylococcal enterotoxin. There are about 14 different staphylococcal enterotoxins which are highly resistant to digestion by proteolytic enzymes such as pepsin and trypsin. Staphylococcus enterotoxins are highly resistant to heat.

Staphylococcal enterotoxin A in pasteurised milk

[32] Staphylococcal enterotoxin A is an exotoxin is resposible for frequent staphylococca food poisoning worldwide. The toxin is heat-resistant, and are not completely inactivated by usual cooking procedures. Sospedra et al. 2011 describe a method to detect Staphylococcal enterotoxin A from pasteurised milk.

Ham staphylococcal food poisoning

[33] Staphylococcal enterotoxin D production in boiled ham, smoked ham and dry-curred Serrano after 7 days at room temperature were analysed by Márta et al 2011. Smoked ham developed nine times less Staphylococcal enterotoxin D per colony-forming unit of Staphylococcus aureus than in boiled ham. In boiled ham, the SED levels unpredictably decreased after three days of incubation. The authors stress that production levels of SED vary in the different ham products, but after five days all ham products developed staphylococcal enterotoxin D sufficient to cause staphylococcal food poisoning.

Other bacteria producing toxins

Powerful toxins are also known from Bacillus anthracis causing Anthrax, a disease of cattle, sheep and humans. Clostridium botulinum causes food poisoning, mainly in low acidic foods.

Clostridium perfringens also produces an enterotoxin and is an important cause of food poisoning and infections such as gas gangrene. (Ernest Hemingway describes a case of gas gangrene in his book " The snows of Kilimanjaro ").

Botulism: Many human deaths have also been attributed to the consumption of food or water containing the toxin.

Clostridium botulinum is widely dispersed in soils. Ingestion of the organism is not harmful. It becomes dangerous only when conditions are favourable for its growth and subsequent toxin formation. The organism in an environment containing decaying plant or animal organic material. Stagnant pools or damp areas with buried decaying matter are danger areas for toxin development Decaying carcasses are a frequent source of the toxin, as are many insects feeding in the same tissue.

The insects may contain enough toxin to cause the disease in any bird and chicken that ingests it. Since the toxin is water soluble, water sources may become contaminated and provide a reservoir for the disease.Keeping the environment clean is important to avoid botulic poisoning of birds and water contamination.

There are different types of the toxin; types A and C cause the disease in birds while type B frequently produces the disease in man.


Moulds

Some strains of moulds produce mycotoxins. Mycotoxins in eggs and meat is mainly influenced by the concentration of mycotoxins in fodder. Auditing should always look after fodder quality of breeding stations.
Bad hygienic condition during harvest, drying, transport of figs and weather conditions such as high humidity and high temperatures are the cause of rising mould spoilage. Consumer should look inside the figs and discard those which are dark.

Several brands of dried figs with origin from Turkey and Greece have high amount of aflatoxin B1,B2, G1 and G from Aspergillus flavus. The aflatoxins which are found on these samples are located in the interior of the fruits.

As spoiled figs are detected under UV light when they are packed, only the fruits with mould contamination from inside are not removed and are often eaten despite a high level up to 900 microgram/kg of aflatoxin B1. (Only 2 micrograms are allowed).

It is estimated that 25 per cent of all agricultural crops worldwide are contaminated by molds that produce mycotoxins. The toxins are mostly found in cereals, nuts, cocoa and coffee beans and other foods like dried fruits and meat, particularly when the water content/activity and the temperature are poorly controlled. The EC Scientific Committee for Food endorsed in 2004 a provisional maximum TDI (Tolerable Daily Intake) for:

Patulin 0.4 µg/kg bw/day
Ochratoxin A 5 ng/kg bw/day


Prevention and reduction of mycotoxin contamination in cereals

The complete elimination of mycotoxin such as Ochratoxin, Zearalenone, Fumonisis and tricothecenes is not achievable at this time, according to Codex CAC/RCP- 2003.

Good agricultural practices (GAP) represent the measures against contamination of cereals with mycotoxins during handling, storage, processing, and distribution of cereals for human food and animal feed.

Wheat and maize are hosts to Fusarium. A crop rotation using potato, other vegetables, clover and alfalfa can reduce the spores of the mold in the field. Old seed heads should be removed, destroyed or plowing under. Make soil tests to ensure adequate soil pH and optimal fertilisation. Seed varieties particularly resistant to molds and pests should be used.

Moisture boosts mould infections. Irrigation during flowering and during the ripening of the normal crops, specifically wheat, barley, and rye, should, therefore, be avoided.

If the crop is harvested with a water activity higher than 0.70, the grain must be dried immediately to less than 14% moisture content in small grain.

Moisture levels of the crop during storage should be less than 15%. Kernels containing symptomless infections cannot be removed by standard cleaning methods. Seed cleaning procedures, such as gravity tables, may remove some infected kernels.

A temperature rise of 2-3C may indicate microbial growth and/or insect infestation in stored grains.

Intermediate storage

Buffer storage resulting from low drying capacity should only be made when the moisture is less than 16%, the storage time is less than 10 days, and the temperature is less than 20 C.

Organic acids, like propionic acid may be used as preservatives. These acids are effective in killing various fungi and thus prevent the production of mycotoxins in grains intended only for animal feed. The salts of the acids are usually more effective for long-term storage. Care must be taken because these compounds can negatively affect the taste and odour of the grain.

Small, shriveled grain may contain more zearalenone than healthy normal grain. Winnowing grains at harvest or later will remove shriveled grain.

Mature grains should not remain in the field for extended periods of time, particularly in cold, wet weather. T-2 and HT-2 toxins are not usually found in grains at harvest, but can result from grains that are water-damaged in the field or grains that become wet at harvest or during storage.

Candida albicans as example of microorganism which can act as opportunists

Candida albicans can cause infections of mouth and digestive tract by persons with weak immunological system. Yeasts being found in food should be controlled on regard of the presence of Candida albicans.


Infectious coryza

Infectious coryza is a specific respiratory disease in chickens The disease is caused by a bacterium known as Hemophilus gallinarum.


Pullorum Disease

It is caused by Salmonella pullorum and is primarily egg transmitted. It is also known as "bacillary white diarrhoea" Fowl typhoid It is caused by Salmonella gallinarum. The transmission includes eggs. The poultry infections with Salmonella gallinarum and Salmonella pullorum killed large numbers of birds and were therefore eradicated in the 1970s. They had not cause harm in humans and were acting as a natural vaccine against Salmonella enteritidis. The chickens' immunity was lost and this opened the door for Salmonella enteritidis.


Fowl Cholera

It is an infectious disease of turkeys caused by Pasteurella multocida with watery yellowish orgreen diarrhoea.The current bird flu scenario should not cause panic and fear; instead it calls for rational and immediate action to fight the disease at its origin - that means in animals.

Avian influenza is first of all an animal disease that requires a veterinarian response.

The virus can be defeated and contained if countries and the international community work closely together and set up efficient surveillance and disease control programs. Virus outbreaks in animals need to be detected at a very early stage, infected poultry must be slaughtered and animals at risk have to be vaccinated. Reducing avian influenza in animals contributes directly to protecting people's health.

Affected countries in Southeast Asia are proving that the virus can be successfully contained. Thailand has obtained an impressive reduction of outbreaks through massive investment in controlling the disease in poultry, using slaughtering and improved surveillance and active disease search.

In Viet Nam, improved on-farm hygiene, farming practices, poultry movement controls and vaccination campaigns will reduce the frequency of bird flu outbreaks. Several countries such as Malaysia, South Korea and Japan have eliminated the disease rapidly after the occurrence of new outbreaks.

Regrettably, most of the public discussion focuses on the human-health aspects of bird flu, while the weak state of veterinary services in many poor countries is being ignored. Affected countries and the international community urgently need to invest more in support of veterinarians and animal health workers, because they represent the first line of defence against the virus. [34]

A Swedish study leaded by Anna Thorson says that epidemiological data from a rural Area in Vietnam suggest that transmission of highly pathogenic avian influenza to humans could be more common than anticipated, though close contact seems required.

Thorson's group found that simply having sick or dead poultry in the house did not significantly increase the risk of flu-like illness; those people only showed a 14 percent higher risk of flu-like illness compared to someone without poultry. However, having direct contact with sick or dead poultry raised that increased risk to 73 percent, Thorson said. [35]

Disaster plans

Every business, especially those which are engaged in food production should develop a disaster plan. This plan should be integrated in the biological safety plan to avoid major business disruptions:
Key points of a disaster plan should be:

Review of pathogens heat-resistance

[39] O'Bryan and colleagues summarize the heat-resistance of several strains of pathogenic bacteria The authors conclude that heat-resistance of these organism are influenced by : Processors may find useful data in this review for the validation of times and temperatures for thermal processing of meat and poultry.

They stress that under the HACCP regulations, 9 CFR 417, employees of food processing operations must validate the elements of their HACCP plans through: references to scientific publications that demonstrate pathogen reduction under laboratory conditions somewhat similar to those used in the production plant, the use of HACCP consultants who are processing authorities or they can validate their plan using experiments using surrogates, non-pathogenic organisms that can mimic pathogens killed in a process. Using data reported from laboratory inactivation of pathogens and predictive models is much more rapid and less expensive than testing surrogate organisms under actual processing operations.

However, almost all of the reported thermal inactivation has been done in a media solution under ideal single culture laboratory conditions and not in an actual food matrix under conditions approximating commercial thermal processing.

Because of USDA-FSIS Notice 25-05, it was suggested that computer modelling should not be used solely as validation of RTE products and that independent microbiology laboratories be used for complete and thorough analysis. Therefore, this thermal inactivation validation is also useful in combination with computer modelling for aid in HACCP compliance (USDA-FSIS 9 CFR 417).

The authors point out the need to know key descriptive factors should be considered such as the particular pathogen of interest, the log or stationary phase, freshness state , frozen, or cooked and fat content of the meat, or other ingredients instead of one single element, validating the lethality of thermal processes.

The authors encourage the development of surrogates able to be used in an actual environment.

Cattle ranch as source of spinach contamination with Escherichia coli 0157:H7

[40]
In September 2006 199 people in 26 US states diseased with Escherichia coli 0157:H7 strain and three died after eating contaminated spinach.

Heath officials said that the bacteria could have been transmitted by irrigation water, fertilizer, farm equipment or workers, livestock and wild animals, or it could have contaminated the spinach inside processing plants, during transport or on store shelves.

Later, in October 2006 three samples of cattle fecal matter from one ranch in California's Salinas Valley have tested positive for the same strain of E. coli bacteria which had caused the disease.

The ranch included both a beef cattle operation as well as fields where spinach and other ready-to-eat produce were grown. The fecal-matter specimens were found half a mile to a mile from the produce fields themselves. Officials said that wandering livestock, substandard worker hygiene, irrigation practices or even wild boar could have transported the bacteria to the spinach fields.

The proximity of fresh produce fields to farm animals has long been a concern to agricultural and health authorities, and a minimum distance between them must be found out.

HACCP plans for fresh produce

[41] [42]

The Fresh Produce Safety Act of 2007

A legislation was introduced by by Senate Agriculture Committee Chairman Tom Harkin requiring the FDA to assess farms and processing facilities on the basis of risk. Producers will be required to maintain written hazard control plans.

High-risk facilities that washes and bags salad greens would be inspected at least once a growing season instead of once every 5 or 10 years. The FDA would also develop standards and practices for manure application, irrigation water, and for excluding domestic animals from fields where produce is grown.

The bill would also require rulemaking to ensure that imported produce has been grown and processed with the same standards that we will have in the U.S. The bill follows the great recalls of spinach and lettuce.

Strategies to reduce person-to-person transmission during epidemics

[43]
Seto and colleagues 2007 studied the spinach Escherichia coli O157:H7 (E. coli O157) outbreak in the United States in 2006 with 173 cases and one death.

During the spread of the disease the Centers for Disease Control and Prevention CDC and the US Food and Drug Administration advised consumers not to eat spinach as the primary strategy for protecting against foodborne transmission of E. coli O157. No warnings, however, were issued regarding the prevention of person-to-person (secondary) transmission.

The authors assume that a combination of possible intervention strategies to interrupt secondary transmission would have a range of possible levels of effectiveness in epidemics like this. These strategies would include strongly recommending handwashing, avoiding contact with persons with diarrhoea, meticulously preparing food, and avoiding work or school when ill with any gastrointestinal sign or symptom.

The researchers found in this study that an intervention such as a campaign to encourage handwashing and isolation of persons with diarrhoea can substantially reduce secondary transmission. Even if a campaign were initiated relatively late in the outbreak, the number of cases would be reduced. Such advice was not a focus of the public health messages disseminated for the 2006 E. coli O157 outbreak. The interruption of secondary transmission might have had a useful role as an additional tool in managing this outbreak.

Public Health Implications

Public health strategies for preventing secondary transmission could include public media campaigns reminding the population of the importance of handwashing, avoiding contact with faeces, minimizing nonessential contact with persons with diarrhoea, meticulous care when preparing and consuming food, and staying at home from work or school when having any diarrhoea during the outbreak period. Messages for all of these strategies can be delivered inexpensively to large or targeted populations through a variety of media (television, radio, print, Internet)

The authors conclude that health officials should consider rapidly delivering widespread public health messages with specific advice on how to interrupt secondary transmission of E. coli O157. Such an intervention, even if only modestly successful, could meaningfully reduce the number of cases. Erwinia chrysanthemi

Pathogens on raw produces

[44]

Pathogen contamination of produce

typically consumed raw has caused large scale foodborne illness. According to Robert Mandrell and colleagues 2008 pathogenic microbes often need the help of other microbial species to make the jump from their usual residents (in the intestines of warm blooded animals) to inhabit plants

Pathogens on lettuce, tomatoes and herbs

The researchers at US ARS found that pathogens such as Eschericia coli and Salmonella develop better on younger leaves with about three times as much nitrogen as in the middle leaves. Therefore strategies to minimise use of nitrogen fertilisers may help reduce E. coli contamination of produce.

On romaine lettuce and on the herb cilantro E. coli and Salmonella are aided by Erwinia chrysanthemi which causes soft rot of the vegetable and biofilms of E. coli and Salmonella.

Xanthomonas campestris (bacterial leaf spot of tomato) helps Salmonella to bind and grow on or in tomato plants. The researchers say that Xanthomonas campestris may disable the plant's immune response, allowing both it and Salmonella to multiply. Soil flooded with Salmonella contaminated water remained infectious to tomato seeds for six weeks and may infect the new plant. Crop debris can also serve as a reservoir of viable Salmonella for at least a week. The authors recommend a fallow period of about two weeks, before replanting fields with lettuce and tomatoes. The team suggest that potentially contaminated fields could benefit from a fallow period of perhaps a few weeks.

The bacterium Wausteria paucula enhances E. coli survival on lettuce leaves by six fold. However, Enterobacter asburiae, living on plants such as beans, cotton and cucumbers without harming them, reduces levels of E. coli and Salmonella on seeds of thale cress. The survival rate of E.coli fell by 20 - 30 fold when Enterobacter asburiae, Wausteria paucula and E.coli come together.

The authors suggest to control and to introduce certain microbes to crops in order to reduce the risk of pathogen spread on fresh produce like tomatoes lettuce and cilantro.

Safety of fresh-cut produces

[45]
According to the USDA, between 1996 and 2006, there were 24 reported incidents of foodborne illness caused by contaminated fresh-cut produce in the United States, such as the E. coli O157:H7 contamination of spinach. To increase the safety of fresh-cut produces the department published some important recommendations:

Farming

Anything that comes into contact with fresh produce has the potential to contaminate it, such as indirect or direct contact with feces. Sources of fecal contamination include animals, untreated manure used as a soil amendment, water, infected workers, or conditions in the field or packing facility, such as unclean containers and tools used in harvesting and packing.

Multiple farming activities come close together making it harder to keep livestock and produce separate. Livestock and wildlife are likely to be drinking from the same creek that irrigates a crop field.

Transport

Transport also presents opportunities for contamination, such as unclean floors and walls of the vehicles or unclean containers.

Processing facilities

Processing fresh produce into fresh-cut products further increases the risk of contamination by breaking the natural exterior barrier of the produce. The release of plant cellular components when produce is shredded or chopped provides a nutritive medium in which pathogen can grow and contamination can spread.

Improper sanitation during processing is another major potential point of contamination by pathogens, followed by the absence of a lethal process, such as a heat step during production to eliminate pathogens; and the potential for temperature change during processing, storage, transport, and retail display.

Ultrasound cleaning of equipment

[46]
Ultrasound technology is being used to sterilize equipment without chemicals. Utrasound treatments, around 20 kHz, collapse bubbles in the cleaning liquid and releases energy that kills bacteria.

Rapid microbe removal

Bacteria such as Listeria monocytogenes on the belt surfaces are eliminated in only 10-20 seconds.

Cleaning with ultrasound saves about 50 percent of energy and water, and avoids blind spots of the conveyor. The sanitation system includes precleaning with degreasers and caustics, followed with ultrasonic sterilization of the belt surface.

The USDA said that researchers at its Produce Quality and Safety Laboratory (PQSL) in Maryland have been focusing on ways to keep salads safe at processing plants before and after bagging. Cutting fresh produce during harvesting removes natural protective barriers, exposing cut surfaces to potential contaminants. Combining sanitizers with ultrasound, optimizing oxygen conditions and not reusing washing water can reduce bacterial contamination of lettuce and leafy greens. Young leaves of lettuce have higher risk of pathogen contamination.

Nitrogen fertilizers may increase risk of pathogens on lettuce

[47]
Brandl and Amundson 2008 found that the increases in population size of E. coli O157:H7 on lettuce plants was 10-fold higher on the young (inner) leaves than on the middle leaves, suggesting that leaf age affects preharvest as well as postharvest colonization. The authors say that young-leaf exudates were 2.9 and 1.5 times richer in total nitrogen and carbon, respectively, than middle-leaf exudates. The low nitrogen limits the growth of pathogens on these leaves. The authors concluded that leaf age and nitrogen content in young lettuce leaves may be associated with a greater risk of contamination with E. coli O157:H7.

Maria Brandl calls for a strategy of reduction of nitrogen fertilizers to increase safety of lettuce.

Washing and ultrasound

[48]
Yaguang Luo, studied the safety and quality of precut lettuce. He found that sliced romaine lettuce leaves rinsed in fresh wash water, dried, packed in bags and stored for 14 days by 5° had lower bacterial counts than leaves which were unwashed or were washed with reused water. Luo also found that the combination of a sanitizer with ultrasound treatment for industrial-scale reduced substantially the number of bacteria on the surface of vegetables.

Irradiation of spinach and lettuce

[49]
The FDA announced that it will allow food processors to irradiate some leafy greens (spinach and iceberg lettuce). The Center for Science in the Public Interest (CSPI) says that this action may be safe and effective in treating some pathogens, however, it will not solve all problems of pathogenic bacteria on leafy vegetables.

The CSPI recommends FDA to adopt a series of preventive measures starting at the farm that could control foodborne pathogens. Our suggestions, outlined in 2006 petition to FDA, include common-sense food safety control measures:

1. Farmers and processors should be required to keep a written food safety plan specific to the environmental conditions on that particular farm.
2. FDA should develop uniform standards to evaluate those plans, for water quality, worker sanitation, and manure use and management.
3. Written plans should be audited once per season, either by FDA or a 3rd party auditor (whose audits should be reviewed by FDA).

With the approval of irradiation on spinach and lettuce, FDA should also specify that these products should be clearly labelled with the radura symbol and the words "treated with irradiation." This labelling-required for other irradiated products-provides consumers with the information to make choices about the food they purchase.

It is clear that produce safety must become a priority for FDA, starting at the farm. Congress should also act to ensure that the agency has the authority and the resources to fulfill its critical public health mandate.

The CSPI Petition also includes further details: [50]

Manure

Appropriate manure management is required. Composting of manure intended for use on food crops should be monitored and records should be maintained to ensure effective controls are used to destroy pathogens. Domestic animals should be excluded from fields and orchards during the growing and harvesting season, and growing areas should have wildlife deterrents.

Water

Growers and producers should ensure that the water supply used for irrigation and in food processing plants is suitable for its intended use.
Facilities should have an environmental monitoring program that includes sampling for pathogens to detect areas of harborage and to verify the effectiveness of cleaning and sanitizing programs in preventing cross-contamination.
Water used for washing produce should be monitored for the presence of pathogens at a rate adequate to ensure highly contaminated batches are identified and either destroyed or sent for further processing.

Hygiene

Growers and processors should ensure that employees have close access to bathrooms and that handwashing facilities are visible to supervisors. Employees with direct and indirect access to the production areas should be trained in preventive controls that will help to eliminate or minimize contamination of produce.

Traceback

Processors should mark packaging to ensure easy traceback to the farm of origin when fruits and vegetables are implicated in an outbreak.

Modified atmosphere and temperature may alter bacterial resistance to gastric juice

[51]
Arvind Bhagwatand colleagues 2008 studied the effect of low-oxygen based modified atmosphere packaging (MAP) and temperature after 8 days storage of fresh lettuce.

The authors found that bacteria acquired resistance to synthetic gastric juice when stored under extremely low-oxygen conditions ( between 0,5 and one per cent of oxygen) and at temperatures of 15° or above. No resistance was induced among bacteria stored under extremely low-oxygen conditions and at temperatures of 10° or below. Proper storage temperatures are, therefore, essential to minimize bacterial growth and adaptability inside sealed, bagged salad greens under MAP. The authors concluded that MAP must be supported by proper storage temperature to minimizing bacterial adaptability.

Improved sanitation of large food systems

HACCP programs place greater emphasis on record keeping and personal accountability, which, in turn, puts greater demand on systems and employees.

Manually operated, sanitation depend on the people which do not exclude human failures. An automated system is more reliable, because it follows a prescribed cleaning pattern. However, failure of automatic valves and dead ends in the system must always be considered by those who are in charge of the safety of the production.

Sanitation Performance Standards Compliance Guide

[52]
The Sanitation Performance Standards issued by the Food Safety and Inspection Service (FSIS) establishes a flexible regulatory method based on HACCP philosophy. It defines rule on sanitation requirements for meat and poultry plants.

The standards define the desired sanitation results, but not the specific means to achieve those results abolishing specific methods for cleaning equipment and utensils. The new standards remove obstacles to innovation, allowing innovative sanitation processing procedures. Past FSIS regulations and guidance, as well as recommendations from the 1999 Food Code and other technical sources, are included or cited.

Construction problems with stainless tubes, tanks and vessels

[53]
Fit and finish troubles with equipment that make it difficult to clean. Smoothness of welds and open bearings may present problems in food plants.

The American Welding Society published a guideline regarding tubes, pipes stainless tanks. describing the welding requirements for tubing systems pipes and stainless steel tankls built to 3-A standards, but also apply to meat production:


Sanitizing chemicals ozone and chlorine

Ozone is making strides as a safe alternative and a powerful oxidant that destroys microbes, being nearly 3,000 times faster than chlorine. It is used as the primary agent of sanitation for more than 80 percent of the bottled water supplied to the U.S.

Aqueous ozone is used both to clean apples and its juice storage tanks. Salad makers uses aqueous ozone to disinfect vegetables and its associated equipment, replacing chlorine. Ozonated water is used to sanitize work areas and processing equipment used at the meat industry. Ozone rapidly decomposes into oxygen. Chlorine rinses uses 100 ppm chlorine. The same effect is attained with water containing 1 ppm ozone.

Bonamia ostreae oyster parasite in UK

[56]
The UK Department for Environment, Food and Rural Affairs has issued a notice in 2007 confirming the presence of the parasite Bonamia ostreae in a bed of native oysters from Whitstable Bay.

The area subject to movement controls has been selected to ensure maximum protection against further spread of the disease. Bonamia ostreae causes the serious disease Bonamiosis in native oyster stocks, but does not have any clinical effect on any other species of shellfish. Cefas will be monitoring the extent and effect of the disease in the controlled area.

It is not expected that the controls will interfere with current commercial activity. Bonamiosis has no implications for human health, and native oysters from this area can still be eaten.

The Notice, issued under Regulation 14 of the Fish Health Regulations 1997 (as amended), restricts the movement of any live molluscan shellfish out of the specified area, for the purposes of relaying or re-immersion in the aquatic environment, without the prior written consent of Defra.

Bonamia ostreae is a protistan parasite (2-3µm) infecting the blood cells of the flat oyster (Ostrea edulis). The bonamiasis disesas is considered as a haemocytic parasitosis developing in older oysters. The transmission of the parasite can occur between cohabiting oysters. The parasite is present at the coasts of the USA, continental Europe and the Irish and English coastlines. Once Bonamia gets into an area it is not possible to eradicate the disease. However, stocks Irish oysters seem to have developed a degree of resistance to the disease. [57]


Antimicrobial Products

Non-public health products

are used to control growth of algae, odour causing bacteria, bacteria which cause spoilage, deterioration or fouling of materials and microorganisms infectious only to animals. They are used in cooling towers, jet fuel, paints, and treatments for textile and paper products. Public health products They are intended to control microorganisms infectious to humans in any inanimate environment. The more commonly used public health antimicrobial products are:


Sterilisers (Sporicides)

Used to destroy or eliminate all forms of microbial life including fungi, viruses, bacteria and their spores.
The term Sporicide is to be considered synonymous with "Steriliser". Sterilisations used to control infection and is widely used in hospitals on medical and surgical instruments and equipment. Types of sterilisers include steam under pressure (autoclaving), dry heat ovens,UV rays, low temperature gas (ethylene oxide), and liquid chemical sterilants. Gaseous and dry heat sterilisers are used primarily for sterilisation of medical instruments. Liquid sterilants are primarily used for delicate instruments which cannot withstand high temperature and gases.


Disinfectants

Disinfectants are used to destroy or inactivate infectious fungi and bacteria but not necessarily their spores. There are the type for hospital and the type for general use. Hospital type disinfectants They are the most critical to infection control and are used on medical and dental instruments, floors, walls, bed linens, toilet seats, and other surfaces.

General disinfectants

They are the major source of products used in households, swimming pools, and water purifiers.


Sanitizers

Sanitizers reduce, but not necessarily eliminate, microorganisms from the inanimate environment to levels considered safe. Sanitizers include food contact and non-food contact products. The food contact sanitizers are used to rinse surfaces and cooking utensils, as well as equipment of food-processing plants, and eating and drinking establishments.


Non-food contact surface sanitizers

include carpet sanitizers, air sanitizers, laundry additives, and in-tank toilet bowl sanitizers.

Bibliography

1
http://www.efsa.europa.eu/etc/medialib/efsa/science/monitoring_zoonoses/reports/zoonoses_report_2005.Par.0001.File.dat/Zoonoses_report_2005.pdf.
The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial Resistance and Foodborne Outbreaks in the European Union in 2005, The EFSA Journal (2006), 94.

2
http://www.efsa.europa.eu/en/science/monitoring_zoonoses/reports/zoon_report_finbroilers.html.
Report of the Task Force on Zoonoses Data Collection on the Analysis of the baseline survey on the prevalence of Salmonella in broiler flocks of Gallus gallus, Part A, The EFSA Journal (2007) 98, 1-85.

3
http://www.efsa.europa.eu/en/ahawtopics/topic/qfever.htm?
Q fever. EFSA.

4
http://www.camembert-aoc.org/unil-uk/htm/aoc-uk.htm.
AOC: Définition du Camembert.

5
http://www.foodsafety.iastate.edu/news/.
Food Safety Consortium, Iowa State University: FRANCE: Raw milk camembert poses safety concern says manufacturer. 14.03.2008.

6
http://www.fda.gov/bbs/topics/NEWS/2007/NEW01576.html.
FDA News, March 1, 2007: FDA and CDC Remind Consumers of the Dangers of Drinking Raw Milk.

7
http://www.mass.gov/?pageID=pressreleases&agId=Eeohhs2&prModName=dphpressrelease&prFile=080108_listeria_investigation.xml.
The Massachusetts Department of Public Health (MDPH): MDPH continues Listeria investigation.

8
http://www.cdc.gov/mmwr/preview/mmwrhtml/00001316.htm.
CDC: Epidemiologic Notes and Reports Update Listeriosis and Pasteurized Milk. December 16, 1988 / 37(49);764-766.

9
http://www.fda.gov/oc/initiatives/advance/food/plan.html.
FDA: Food Protection Plan: An integrated strategy for protecting the nation's food supply. November 2007.

10
http://www.bfr.bund.de/cd/10703.
BfR: Risky delicacy: Pink duck breast. High temperatures during preparation prevent Campylobacter infections. 28.01.2008.

11
http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1178700897302.htm.
EFSA: The role of food in human exposure to antimicrobial resistant bacteria.

12
http://jds.fass.org/cgi/content/full/86/3/852.
Callaway, T.R.; Elder, R.O.; Keen, J.E.; Anderson, R.C. and Nisbet D.J.: Forage Feeding to Reduce Preharvest Escherichia coli Populations in Cattle, a Review; J. Dairy Sci. 86:852-860.

13
Gefährlicher darmkeim. erste todesopfer nach ehec-infektion. 24.05.2011.
Spiegel Online.
http://www.spiegel.de/wissenschaft/medizin/0,1518,764576,00.html.

14
Quantrell RJO, Naylor SW, Roe AJ, Spears K, and Gally DL.
Ehec o157:h7 - getting to the bottom of the burger bug.
Microbiology Today, 31(8), 2004.
http://www.sgm.ac.uk/pubs/micro_today/pdf/080407.pdf.

15
http://www.ansi.okstate.edu/research/1996rr/8.pdf.
Reilly1, S. S.; and Gilliland, S. E: Inhibition of Escherichia coli O157:H7 by Lactobacillus acidophilus isolated from calves.

16
Bulent Bayraktar, Padmapriya P. Banada, E. Daniel Hirleman, Arun K. Bhunia, J. Paul Robinson and Bartek Rajwa: Feature extraction from light-scatter patterns of Listeria colonies for identification and classification; J. Biomed. Opt. Vol. 11, 034006 (May. 19, 2006).

17
http://www.who.int/mediacentre/news/releases/2009/cholera_zim_20090130/en/index.html.
WHO: Global, national efforts must be urgently intensified to control Zimbabwe cholera outbreak.

18
http://www.who.int/csr/don/2008_12_02/en/index.html.
WHO: Cholera in Zimbabwe 2.12.2008.

19
http://wwwn.cdc.gov/travel/contentCholeraZimbabwe.aspx.
CDC: Cholera in Zimbabwe and Neighboring Countries. January 16, 2009.

20
http://wwwn.cdc.gov/travel/contentSafeFoodWater.aspx.
CDC: Safe Food and water.

21
http://www.who.int/csr/don/2010_11_24/en/index.html.
Cholera in Haiti - update 4 WHO Cholera Tahiti 24.11.2010.

22
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5943a4.htm.
Centers for Disease Control and Prevention (CDC): Cholera outbreak - Haiti, October 2010. MMWR Morb Mortal Wkly Rep. 2010 Nov 5;59(43):1411.

23
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5945a1.htm.
Centers for Disease Control and Prevention (CDC): Update.

24
http://www.cdc.gov/haiticholera/pdf/cholera_preventionmessages.pdf.
Protect Yourself from Cholera. CDC Prevention Message.

25
UN.
Congolese cholera outbreak continues to spread, un health agency says. un 15 jul 2011.
7 2011.
http://www.un.org/apps/news/story.asp?NewsID=39145&Cr=cholera&Cr1=.

26
UN.
Cholera cases increasing in haiti and dominican republic, un reports. 24 jun 2011.
6 2011.
http://www.un.org/apps/news/story.asp?NewsID=38834&Cr=haiti&Cr1=.

27
http://www.ncbi.nlm.nih.gov/pubmed/19545357.
Ward, L.A.; Cain, O.L.; Mullaly, R.A.; Holliday, K.S.; Wernham, A.G.; Baillie, P.D.; Greenfield, S.M.: Health beliefs about bottled water: a qualitative study. BMC Public Health. 2009 June 19;9(1):196.

28
http://www.ncbi.nlm.nih.gov/pubmed/18928830.
Napier, G.L.; Kodner, C.M..: Health risks and benefits of bottled water. Prim Care. 2008 Dec;35(4):789-802.

29
http://members.ift.org/NR/rdonlyres/54EF1203-B11E-4A0B-A78B-525CB8D98ED3/0/JustAddWater.pdf.
Tarver, T.: Just add water: regulating and protecting the most common ingredient. The Institute of Food Technologists:Vol. 73, Nr. 1, 2008-Journal of Food Science.

30
http://cfr.vlex.com/vid/165-110-bottled-water-19705533.
21 CFR 165.110 - Bottled water.

31
A. E. Waters, T. Contente-Cuomo, J. Buchhagen, C. M. Liu, L. Watson, K. Pearce, J. T. Foster, J. Bowers, E. M. Driebe, D. M. Engelthaler, P. S. Keim, and L. B. Price.
Multidrug-resistant staphylococcus aureus in us meat and poultry.
Clinical Infectious Diseases, 2011.
http://cid.oxfordjournals.org/content/52/10/1227.

32
Sospedra I, Soler C, Manes J, and Soriano JM.
Analysis of staphylococcal enterotoxin a in milk by matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
Anal Bioanal Chem, 400(5):1525-31, 5 2011.
http://www.ncbi.nlm.nih.gov/pubmed/21442364.

33
Márta D, Wallin-Carlquist N, Schelin J, Borch E, and Radström P.
Extended staphylococcal enterotoxin d expression in ham products.
Food Microbiol, 28(3):617-20, 5 2011.
http://www.ncbi.nlm.nih.gov/pubmed/21356473.

34
http://www.fao.org/newsroom/en/news/2005/1000105/index.html.
Jacques Diouf, FAO Director-General: How to Stop Bird Flu; 28 October 2005, Rome.

35
Anna Thorson, MD, PhD; Max Petzold, PhD; Nguyen Thi Kim Chuc, PhD; Karl Ekdahl, MD, PhD: Is Exposure to Sick or Dead Poultry Associated With Flulike Illness?A Population-Based Study From a Rural Area in Vietnam With Outbreaks of Highly Pathogenic Avian Influenza; Arch Intern Med. 2006;166:119-123.

36
http://www.fao.org/newsroom/en/news/2006/1000240.html.
FAO Newsroom:Escalating bird flu crisis jeopardizes global poultry trade prospects. Reduced consumption is lowering poultry prices and import demand. 28 February 2006. Rome.

37
http://www.who.int/mediacentre/news/releases/2005/pr66/en/index.html.
FAO: No bird flu risk for consumers from properly cooked poultry and eggs.

38
http://www.who.int/foodsafety/fs_management/No_07_AI_Nov05_en.pdf.
WHO: Highly pathogenic H5N1 avian influenza outbreaks in poultry and in humans: Food safety implications.

39
http://www3.interscience.wiley.com/journal/118601213/abstract.
OBryan CA, Crandall PG, Martin EM, Griffis CL, and Johnson MG: Heat Resistance of Salmonella spp., Listeria monocytogenes, Escherichia coli 0157:H7, and Listeria innocua M1, a Potential Surrogate for Listeria monocytogenes, in Meat and Poultry: A Review; JFS Online, April 2006, Vol 71, Nr. 3.

40
http://www.nlm.nih.gov/medlineplus/news/fullstory_39955.html.
MedlinePlus: Cattle ranch may be source of spinach contamination.

41
http://www.cspinet.org/new/200709201.html.
CSPI: Food Safety Act Calls For Inspections on Produce Farms. Bill Comes One Year After Massive Spinach Recall.

42
http://agriculture.senate.gov/news2/record.cfm?id=283764.
Press Release of Agriculture, Nutrition & Forestry DEM Committee. Harkin measure creates first of its kind national food safety framework for all fresh produce.

43
http://www.cdc.gov/eid/content/13/6/860.htm.
Seto EYW, Soller JA, Colford JM Jr. Strategies to reduce person-to-person transmission during widespread Escherichia coli O157:H7 outbreak. Emerg Infect Dis. 2007 Jun.

44
http://www.ars.usda.gov/is/AR/archive/jul08/pathogen0708.htm.
FDA: Outmaneuvering Foodborne Pathogens. July 2008.

45
http://www.ars.usda.gov/is/AR/archive/jul08/form0708.htm.
USDA: Forum-Making Sure Leafy Greens and Other Produce Stay Safe.

46
http://www.ars.usda.gov/is/AR/archive/jul08/greens0708.htm.
USDA Agricultural Research Service: Which treatment to use. July 2008 - Vol. 56, No. 6.

47
http://aem.asm.org/cgi/content/abstract/74/8/2298.
Brandl,M.T.; Amundson, R.: Leaf Age as a Risk Factor in Contamination of Lettuce with Escherichia coli O157:H7 and Salmonella enterica. Appl. Environ. Microbiol. 2008 74: 2298-2306.

48
http://www.ars.usda.gov/is/pr/2008/080724.htm.
USDA Agricultural Research Service: Cold Temperature is Key to Quality of Bagged Salads. Agricultural Research Magazine. July 2008 - Vol. 56, No. 6.

49
http://www.cspinet.org/new/200808212.html.
FDA Approves Irradiation for Spinach, Lettuce. Statement of CSPI Food Safety Director Caroline Smith DeWaal. 21.08.2008.

50
http://www.cspinet.org/new/pdf/fda_produce_petition.pdf.
CSPI: Citizen Petition. November 15, 2006.

51
http://www.ars.usda.gov/is/AR/archive/jul08/greens0708.htm.
USDA Agricultural Research Service: Safe Leafy Greens-Before and After Bagging. Agricultural Research Magazine. July 2008 - Vol. 56, No. 6.

52
http://www.fsis.usda.gov/OPPDE/rdad/frpubs/sanitationguide.htm.
FSIS: Sanitation Performance Standards Compliance Guide.

53
http://www.tubenet.org.uk/technical/arctech3_m.html.
Henon, Barbara K.; Brond Angel: Latest Developments in Welding Specifications for Sanitary Process Piping. Tubenet.org, The Site for Tube and Pipe Industries.

54
http://webstore.ansi.org/RecordDetail.aspx?sku=AWS+d18.1-1999-all-color.
AWS D18.1Specification for Welding of Austenitic Stainless Steel Tube and Pipe Systems in Sanitary (Hygienic) Applications AWS d18.1-1999-all-color.

55
http://engineers.ihs.com/document/abstract/XNYMIBAAAAAAAAAA.
AWS D18.3/D18.3M Specification for Welding of Tanks, Vessels, and Other Equipment in Sanitary (Hygienic) Applications. Document AWS D18.3/D18.3M.

56
http://www.defra.gov.uk/news/2008/080215b.htm.
Department for Environment, Food and Rural Affairs: Confirmation of oyster parasite in north Kent. 15 February 2008.

57
http://www.bonamia.com/.
BOLCI - Bonamia ostreae life cycle investigations:The Latest Research on the Flat Oyster Disease Bonamia ostreae.

See also: Related OurFood News
Copyright © 1998 - 2013 by K. H. Wilm - Impressum