Food borne Diseases: By: Dr. Amr El-Dakroury Dept. of Medical commission Supreme Council of Health

The etiology of Food-borne diseases: Food-borne diseases are those diseases that are the result of exposure to pathogenic microorganisms, such as bacteria, viruses and parasites, which tend to have acute effects on human health. However, chronic, and in some cases acute, food-borne illness may also be caused by the presence of various chemical substances including residues of pesticides and veterinary drugs, unlawful food additives, mycotoxins, biotoxins and radionuclides that enter the food intentionally or unintentionally. The problems :due to consumption of contaminated food and its detrimental effect on human health .

Epidemiology of FBD : WHO estimates that one in three people worldwide suffer from a food-borne disease every year, 1.8 million die from severe food and waterborne diarrhea ,related illness Most of these illnesses are due to microorganisms and chemical contaminants, which may occur naturally or be introduced at some point along the food chain. Campylobacter and Salmonella species account for over 90% of all reported cases of bacteria related to food poisoning worldwide. As most cases of food borne disease are not reported, the true dimension of the problem is unknown. Today food safety is one of WHO’s top eleven priorities

Food safety and security : The World Food Summit, organized by FAO in 1996, recognized that access to safe food is in itself an element of food security, The World Health Assembly Resolution on Food safety from May 2000 stated that : 1. Everyone should have the right to an adequate supply of safe, nutritious food , 2. Encourages WHO member states ‘‘to implement and keep national and, when appropriate, regional mechanisms for food borne disease surveillance’’ 3. Governments should take the necessary measures to ensure the availability of safe food for all in order to sustain the health and economic development of their people.

The Response in Qatar The Programme on Food- and Waterborne Diseases and Zoonoses (FWD) in Qatar was set up with the establishment of SCH , One of the key objectives for the programme is improving and harmonizing the surveillance system in Qatar in order to increase the scientific knowledge regarding etiology, risk factors and burden of food- and waterborne diseases and zoonoses. at present covers the following diseases: brucellosis, campylobacteriosis, cholera, giardiasis, hepatitis A, salmonellosis, shigellosis, toxoplasmosis, typhoid and paratyphoid fever, Escherichia coli infection,

Objectives of the FWD programme : Improving and harmonizing surveillance and control interventions of FWD Improving knowledge of prevention and control of FWD Strengthening SCH and Stakeholders capacities in the area of FBD . Improving early detection and coordinated response to Qatar-wide FWD outbreaks ,as well as control interventions . Facilitating collaboration between public health, municipality veterinary and food sectors

surveillance activities in Qatar Food borne disease data collected through : 1. Routine surveillance activities 2. Outbreaks investigations and 3. Conducting special studies.

Aims of FBD surveillance system : Food borne disease surveillance is essential for: 1. Estimating the burden of food borne diseases, and monitor trends; 2. Identifying priorities and setting policy in the control and prevention of food borne diseases; 3. Detecting, controlling and preventing food borne disease outbreaks; 4. Identifying emerging food safety issues; and evaluating food borne disease prevention and control strategies.

Overview Organisms Epidemiology Transmission Foodborne illness Prevention and Control

Organisms There are an estimated 250 pathogens that can cause foodborne related illnesses. Foodborne illness is defined as two or more cases of a similar illness resulting from ingestion of a common food. It can result from consuming foods contaminated with various pathogens. In most cases bacteria are the major pathogen followed by viruses, then parasites. However, natural or manufactured chemicals and toxins from organisms can also cause foodborne illnesses. The most commonly recognized foodborne infections are caused by Campylobacter, Salmonella, E. coli O157:H7 and by caliciviruses (better know as Norwalk viruses.)

Epidemiology

Epidemiology Many foodborne illnesses are not recognized or go unreported for a variety of reasons: First, routine surveillance may not detect a mild foodborne illness. second, some of the same pathogens that cause foodborne illness can also be transmitted in water or from person to person. Lastly, some pathogens are emerging and are not yet identifiable or able to be diagnosed. Considering these factors, the above listed number of illnesses, hospitalizations and death may be obsolete.

High Risk Groups The elderly Children Immunocompromised individuals are usually at the greatest risk for these illnesses.

Transmission

Transmission Transmission of foodborne pathogens occurs via the oral route. How those pathogens contaminate food can vary based on the organism, its reservoir, food handling/processing, and cross-contamination prior to serving. Some organisms rely on a human reservoir, such as Norwalk-like virus, Shigella, Campylobacter. Others have an animal reservoir such as Campylobacter, Salmonella, E. coli 0157:H7, Listeria, and Toxoplasma.

Transmission Contamination can occur at several points along the food chain On the farm or in the field At the slaughter plant During processing At the point of sale At home

Produce Processing Animal products are not the only food that can be contaminated. Various foodborne disease outbreaks have occurred due to fruits and vegetables. This table indicates the many possible sources for contamination during the processing of produce.

Important Organisms Although many pathogens can cause foodborne illnesses, we will briefly cover those of greatest impact. These may also be potential bioterrorism agents for food sources.

Important Organisms Norwalk-like viruses Campylobacter Salmonella E. coli O157:H7 Clostridium botulinum Shigella Toxoplasma Emerging organisms

Norwalk-like Viruses Norovirus; Caliciviridae family They are an important cause of sporadic gastrointestinal disease outbreaks throughout the world. It is considered the most common foodborne infectious agent and an estimated 23 million cases occur each year. Sources Person-to-person : Shed in human feces (up to 2weeks), vomitus. Outbreaks in daycares, nursing homes, cruise ships Contaminated raw shellfish.

Campylobacter jejuni Leading cause of bacterial diarrhea. It is considered the leading bacterial cause of foodborne related diarrhea affecting 2.4 million people each year (5-14% of all diarrheal illnesses worldwide). Usually these are children under the age of 5 and young adults (15-29 years of age). Very few deaths are caused by this organism. Recently Guillain-Barré Syndrome has been associated with a small number of Campylobacter cases. This syndrome is the leading cause of acute paralysis and develops 2-4 weeks after a Campylobacter infection (after diarrheal signs disappear).

Campylobacteriosis Sources Clinical signs It is caused primarily by Campylobacter jejuni, but also C. fetus and C. coli. Sources Raw or undercooked poultry Non-chlorinated water Raw milk Infected animal or human feces Poultry, cattle, puppies, kittens, pet birds Clinical signs Diarrhea, abdominal cramps, fever, nausea Duration: 2-5 days

Salmonellosis Salmonella is a gram negative bacteria with many serotypes that cause foodborne related illnesses. The ones we most commonly associated with human foodborne illness are S. typhimurium and S. enteritidis They account for about 41% of all human cases reported causes an estimated 1.4 million reported cases annually with 580 deaths

Salmonellosis Sources Signs Raw poultry and eggs Raw milk Raw beef Unwashed fruit Reptile pets: Snakes, turtles, lizards Signs Onset: 12-72 hours Diarrhea, fever, cramps Duration: 4-7 days

E. coli O157:H7 Escherichia coli is another major pathogen of foodborne related illnesses. Harmless strains of E. coli are found in nature, including the intestinal tracts of humans and animals. Diarrheal disease is caused by several different strains of harmful E. coli. The most dangerous type is enterohemorrhagic E. coli (EHEC). It gets its name because it can cause bloody diarrhea and can lead to kidney failure in children or immunocompromised persons. E. coli O157:H7 is the most common EHEC and its enterohemorrhagic toxin is what actually causes the disease

E. coli O157:H7 Signs Sequela Watery or bloody diarrhea, nausea, cramps Onset: 2-5 days Duration: 5-10 days Sequela Hemolytic Uremic Syndrome (HUS) Most commonly affecting children. HUS is the most common cause of acute kidney failure in children.

Botulism Botulism is caused by a neurotoxin from Clostridium botulinum This toxin causes flaccid paralysis and cranial nerve deficits, and can lead to death. The most common sources are home-canned foods, fermented meats and honey Signs Double vision, drooping eyelids, difficulty speaking and swallowing Onset: 18-36 hours

Shigellosis Shigellosis is also known as bacillary dysentery Most cases are caused by Shigella sonnei. However, S. dysenteriae, S. flexneri and S. boydii can also cause foodborne related illnesses. Sources: Human fecal contamination of food, beverages, vegetables, water Signs: Watery or bloody diarrhea, nausea, vomiting, cramps, fever Onset: 2 days Duration: 5-7 days

Toxoplasmosis Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii It is one of the three leading causes of death from a foodborne disease the others were Salmonella and Listeria Pregnant women and immunocompromised individuals, especially HIV positive patients, are at the greatest risk of toxoplasmosis The source of this protozoan include infected cats shedding in their feces, soil, undercooked meat, and mechanical vectors such as cockroaches and flies Clinical signs in humans can by asymptomatic to fever, headache, and swollen lymph nodes. If the protozoan cysts develop in tissue, other more severe clinical signs can be observed. To prevent infection, gloves should be worn while gardening, changing cat litter boxes and thoroughly washing raw fruits and vegetables before eating. Irradiation and thoroughly cooking meat to 160oF internal temperature to destroy the Toxoplasma cysts.

Emerging Pathogens Cyclospora (Protozoan) Sources >>>> Imported raspberries Listeria monocytogenes Sources Ready-to-eat meats, soft cheeses Signs Human abortions and stillbirths Septicemia in young or low-immune As stated earlier listeriosis is one of the 3 most common causes of food borne related death.

Prevention and Control

HACCP Food producers and processors have implemented the HACCP program in their operation to reduce the possibility of food-borne pathogens. The Hazard Analysis Critical Control Point (HACCP) program is used to monitor and control the production process by identifying food safety hazards. Additionally, critical control points in production, processing and marketing are identified. Critical limits for each of these points is established and monitored for food quality and safety. It is applied to the meat, poultry and egg industries.

On Farm Strategies To help control Salmonella Testing and removal this is done through: Serologic testing, fecal or hide culturing of animals to identify carriers of the bacteria Vaccination It is important to remember that vaccines are not 100% effective, and with the various serotypes of bacteria and immune status of animals, they should be used in accordance with other prevention methods. Minimize rodents, wild birds as they are often carriers of bacteria, will also help reduce the transmission. Isolation of new animals will also help decrease the chance of spread.

At the Slaughter Plant FSIS (Food Safety Inspection Service) has Identified target organisms : Salmonella and E. coli Control points Removal of internal organs. Minimize contact between carcasses. Proper movement through facilities . Chilling . Cooking processes (proper time, temperature).

At Home Drink pasteurized milk and juices. Wash hands carefully and frequently After using the bathroom. Changing infant’s diapers. Cleaning up animal feces. Wash hands before preparing food.

At Home Wash raw fruits and vegetables before eating After contact with raw meat or poultry Wash hands, utensils and kitchen surfaces. Hot soapy water. Defrost meats in the refrigerator

At Home Cook beef/beef products thoroughly Internal temperature of 160oF Cook poultry and eggs thoroughly Internal temperature of 170-180oF Eat cooked food promptly Refrigerate leftovers within 2 hours after cooking Store in shallow containers

Special Attributes to Dr. Farah

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