EMERGING FOODBORNE PATHOGENS KHAWAR MAHBOOB

 Despite advances in hygiene, consumer knowledge, food treatment and processing, foodborne diseases mediated by pathogenic microorganisms or microbial toxins still represent a significant threat to public health worldwide.

 Globally, the WHO has estimated that approximately 1.5 billion episodes of diarrhea and more than 3 million deaths occurred in children under 5 years of age, and a significant proportion of these results from consumption of food mainly food of animal origin with microbial pathogens and toxins

Emerging Foodborne Pathogens  Definition: Pathogens which causing illnesses that have only recently appeared or been recognised in a population or that are well recognised but are rapidly increasing in incidence or geographic range Pathogens which causing illnesses that have only recently appeared or been recognised in a population or that are well recognised but are rapidly increasing in incidence or geographic range

 Appeared recently  Extended to new vehicles of transmission  Started to increase rapidly in incidence or geographic range  Been widespread for many years but only recently identified through new or increased knowledge or methods of identification and analysis of the disease agent Emerging Foodborne Diseases

 Pose a threat to all persons; no matter on age, sex, lifestyle or socio-economic status etc.  Feel pain and death  Economic impact Emerging Foodborne Diseases

–Changes in environment (technology, climate, etc) –Mass production and globalisation of food supply –Economic development –International travel and trade –Changing character of the population –Breakdown in public health –Lifestyle changes –Microbial adaptation Emerging Foodborne Diseases Major trends

Trend of Emerging Foodborne Diseases  Before Salmonella spp., Shigella spp., Clostridium botulinum & Clostridium botulinum & Staphylococcus aureus. Staphylococcus aureus.  During C. perfringens & B. cereus.  In Rotavirus & Norovirus  In 1980 & Campylobacter, Yersinia, Listeria monocytogenes, New strain of monocytogenes, New strain of Escherichia coli O157:H7, Escherichia coli O157:H7, Cryptosporidia & Cyclospora. Cryptosporidia & Cyclospora today---- Salmonella spp., Campylobacter spp. & E.coli today---- Salmonella spp., Campylobacter spp. & E.coli  Recently Listeria monocytogenes

Emerging Foodborne Pathogens –Bacteria –Viruses –Parasites –Prion

Emerging foodborne bacteria  Salmonella (multidrug resistant strain)  Campylobacter jejuni  E. coli O157:H7  Listeria monocytogenes  S. aureus MRSA

 Vibrio vulnificus  Yersinia enterocolitica  Arcobacter spp.  Mycobacterium paratuberculosis

Emerging foodborne viruses  Hepatit A and E  Norovirus  Avian influenza A

Emerging foodborne parasites  Cryptosporidium parvum  Cyclospora cayetanensis  Anisakis spp.

High risk groups  Pregnant women, unborn –Listeria  Infant –Campylobacter, E. coli, Listeria  Elderly –Salmonella, Campylobacter, Listeria  HIV /AIDS, TB –All pathogens

Antibiotic resistance  It’s a global concern of the antibiotic resistance of major foodborne pathogens such as; Salmonella Typhimurium DT 104 Campylobacter spp. Listeria monocytogenes E. coli O157:H7 Staphylococcus aureus (MRSA) Enterococcus (VRE)

Mathicillin-resistant S. aureus (MRSA)  Increasing cause of Nosocosmial infection worldwide  NT-MRSA or sequence type-ST398 is most common  Found in food producing animals along with horses, dogs, cats, rabbits, seals and birds  Very low concentration ( < 10cfu/g ) can be detected  Food associated MRSA is an emerging zoonotic problem

A novel bacteria A novel bacteria  1983, chronic gastritis (gastric ulcer; duodenum ulcer) –Helicobacter pylori –world-wild infection rate ~ 60% –2~6 folds increase risk of gastric cancer

Farm to table; main contamination points

Surveillance Risk managementEpidemiological evaluation / Risk assessment Research

Control of Foodborne Disease  From farm to table approach  Implementation of GMP and HACCP

Food Safety Management Systems  Codex general Principles of Food Hygiene (GMP)  Legislative Requirements  Hazard Analysis and Critical control points (HACCP)  Integration and linking  Total Food Safety System

Public Health Approach  Public health system  Surveillance  Epidemiology for earlier diagnosis  Early response to outbreaks  Provide to disease patterns changing  Public health lab. support for rapid and accurate diagnosis  Rapid communication links  Communication to public  Education on prevention and/or detection

GMP guidelines  Operational Methods and Personnel Practices –Storage methods, handling of material –Personal hygiene  Cleaning Practices –Cleaning schedule, procedure and equipment  Pest Control –Crawling / flying (What’s happening after hours?)  Maintenance for Food Safety –Building, equipment and services  Adequacy of Food Safety Program –Procedures, records, recall –Supplier quality assurance

Approach to control  HACCP  Sampling programs  End product testing  Environmental monitoring plan  Sanitation  Irradiation

Program Needs 1. Develop Good Agricultural Practices for 1. Develop Good Agricultural Practices for livestock and poultry production livestock and poultry production Should include input of experts in food safety with experience in animal production. Should include input of experts in food safety with experience in animal production. 2. Develop HACCP/GAPs for composting / 2. Develop HACCP/GAPs for composting / manure treatment manure treatment Should include input of experts in food safety with Should include input of experts in food safety with experience in animal waste handling experience in animal waste handling

Cont….  3. Research program (case-control studies) to identify principal risk factors associated with transmission of target pathogens in livestock and poultry production

4. Research program to develop effective intervention strategies to: a. Reduce carriage/fecal shedding of pathogens by livestock and poultry by livestock and poultry ● EHEC 0157:H7 - Cattle ● Campylobacter - Poultry, Cattle ● Salmonella - Poultry, Cattle ● Cryptosporidium – Cattle b. Treat manure to kill pathogens before used for soil application, or contaminates irrigation or processing water b. Treat manure to kill pathogens before used for soil application, or contaminates irrigation or processing water

5. Develop educational program for producers/farmers ● Should include involvement of: ● A. Extension Service at Land Grant Universities ● B. Veterinary Schools/Veterinarians ● C. Veterinary Pharmaceutical Companies ● D. Representatives of food service, food retail and food processing industries ● E. Public relations firm to simplify messages and present them for effective communication present them for effective communication

Campylobacter  Most common cause of diarrhoea;  Sources: raw and undercooked meat, poultry, raw milk and untreated water poultry, raw milk and untreated water  14 species  Campylobacter jejuni  Campylobacter coli  Europe – adults 18 –23years of age  SA – children 2 – 6 years of age  High frequency among animals  From penguins to professors

Salmonella  Second most common cause of foodborne illness. illness.  Responsible for millions of cases/year Sources: raw and undercooked eggs, Sources: raw and undercooked eggs, undercooked poultry and meat, undercooked poultry and meat, dairy products, seafood, fruits and vegetables dairy products, seafood, fruits and vegetables  2200 serotypes  Gastrointestinal tract of animals, birds, pets, frogs, turtles etc  Foods –Beef, poultry eggs, milk –Chocolate –Salads

Salmonella disease  Low infective dose 10 5 – 10 6 cells  Symptoms within a day  Individual remains a carrier for several months  Abdominal cramps, diarrhea, vomiting, chills, fever  Can be fatal for infants and elderly  Mortality rate 1% (15% elderly and in HIV patients)

Entarohaemoragic E.coli  A bacterium that can produce a deadly toxin (Shiga toxin) deadly toxin (Shiga toxin)  Sources: red meat, poultry, especially undercooked or raw hamburger, undercooked or raw hamburger, produce and raw milk produce and raw milk  E. coli O157:H7  Ready-to-eat foods –Hamburgers –Apple cider –Salads –Strawberries  Mortality rate 2%

E.coli O157:H7  First outbreak – USA 1982 – severe bloody diarrhoea  Become wide spread after than  Causes illness and 250 deaths annually in USA  Second outbreak – UK 1985  non-O157 VTEC is common in ruminants  New strain of VTEC is O103: H25 isolated during an outbreak in Norway

Listeria monocytogenes Causes listeriosis, a serious disease of pregnant women, newborns and adults with a weakened immune system Sources: soil and water dairy products including soft cheeses raw and undercooked meat poultry seafood

Emerging Pathogens 2. New infections resulting from changes or evolution of existing organism Verotoxigenic E. coli? A diverse group of E. coli A diverse group of E. coli – All produce exotoxins, called verotoxins (VT), Shiga toxins (STX), Shiga-like toxins (SLT) VTEC vary in their ability to cause disease VTEC vary in their ability to cause disease – Virulent VTEC such as E. coli O157:H7 cause: er ot o xi g e ni c E. c ol i? t ar e v er ot o xi g e ni c E. W h at ar e v er ot o xi g e ni c E. c ol i? c ol i?

Conti… Diarrhea; Bloody diarrhea (hemorrhagic colitis) Hemolytic uremic syndrome (HUS) Hemolytic uremic syndrome (HUS) – Children and the elderly are most susceptible – Most infections (80%) are sporadic Over 400 VTEC serotypes isolated from humans Over 400 VTEC serotypes isolated from humans – >90% of known infections are caused by fewer than 10 serogroups

Entrohaemoragic E.coli cont…  E.coli strains isolated from intestinal diseases have been grouped into 6 different diarrhoeagenic E.coli (DEC) groups, based on specific virulence factors and phenotypic traits such as – Enteropathogenic E.coli (EPEC) –Enterotoxigenic E.coli (ETEC) –Enteroinvasive E.coli (EIEC) –Enteroaggregative E.coli (EAggEC) –Diffusely adherent E.coli (DAEC) –Vero cytotoxin-producing E.coli (VTEC) or Shiga toxin-producing E.coli (STEC)

Emerging Pathogens 3. Known infections spreading to new geographic areas or populations Vibrio cholera  The Latin American epidemic strain found off the coast of southern US in 1991 may have been introduced when a cargo ship discharged contaminated ballast water Likely a similar mechanism led to the introduction of cholera for the first time this century into Peru in 1991 from Asia and Africa Likely a similar mechanism led to the introduction of cholera for the first time this century into Peru in 1991 from Asia and Africa Serogroups O1, non-O1 and O139 (which emerged in Bengal, India in 1992) are foodborne illness threats Serogroups O1, non-O1 and O139 (which emerged in Bengal, India in 1992) are foodborne illness threats Seven distinct pandemics have occurred since 1817 Seven distinct pandemics have occurred since 1817 Able to directly take up DNA present in the environment Able to directly take up DNA present in the environment

Emerging Pathogens 4.Older pathogens reemerging as a result of their appearing in new vehicles VehiclesMelons Tomatoes, melons, mango, fruit salad Raspberries, basil, snow peas Pathogen E. coli O157:H7 SalmonellaCyclospora

Produce – “New” Vehicles C. botulinum CampylobacterShigella Hepatitis A Norovirus Carrot juice Snow peas Sugar snaps, baby corn Watercress, green onions Fresh-cut fruit

Emerging Pathogens 5. Previously unrecognized and now potential foodborne infections  C. difficile  MRSA  Ebola  Chagas

Clostridium difficile New Zoonotic agent Increasing prevalence of “outbreak strain” 027/NAP1 in various countries : Increasing prevalence of “outbreak strain” 027/NAP1 in various countries : – Hospitals; Outbreaks, severe disease – Hospitals; Outbreaks, severe disease – Animals – cattle, pigs – Animals – cattle, pigs – Food – retail ground meat, raw vegetables – Food – retail ground meat, raw vegetables Animal isolates often indistinguishable from pathogenic human strains Animal isolates often indistinguishable from pathogenic human strains Animal reservoirs via food are possible sources of C. difficile infection Animal reservoirs via food are possible sources of C. difficile infection

 Vulnerable populations – elderly, children, antibiotic use Antimicrobial resistant; heat-tolerant, disinfection resistant Antimicrobial resistant; heat-tolerant, disinfection resistant Some of the community-acquired C. difficile infections do not appear to be linked to recent antibiotic therapy, increased age, co-morbidity or prior hospital admission Some of the community-acquired C. difficile infections do not appear to be linked to recent antibiotic therapy, increased age, co-morbidity or prior hospital admission Rate of community-acquired C. difficile is increasing; 3% of healthy adults and up to 80% of infants are carriers Rate of community-acquired C. difficile is increasing; 3% of healthy adults and up to 80% of infants are carriers

MRSA as a foodborne pathogen?

Chagas’ Disease Transmitted by the protozoan parasite Trypanosoma cruzi Transmitted by the protozoan parasite Trypanosoma cruzi Worldwide incidence estimated at 200,000 cases per year Worldwide incidence estimated at 200,000 cases per year WHO estimates that about 5-6 million people are infected WHO estimates that about 5-6 million people are infected Acute and chronic phases of infection occur Acute and chronic phases of infection occur

Conti…  Principally transmitted by infected insects which contaminate fruits under inadequate harvest, transport, storage and manufacturing conditions  Where Chagas’ is endemic, it should now be considered a potential foodborne disease

Emerging Pathogens 6. Organisms on which to keep a watchful eye Organisms to Watch Laribacter hongkongensis Laribacter hongkongensis Plesiomonas shigelloides Plesiomonas shigelloides Cronobacter spp. Cronobacter spp. Mycobacterium avium subsp. paratuberculosis Mycobacterium avium subsp. paratuberculosis

Conti… Streptococcus zooepidermicus/S. suis Campylobacter concisus Campylobacter concisus Hafnia alvei Hafnia alvei Escherichia albertii Escherichia albertii Helicobacter pullorum Helicobacter pullorum Enterocytozoon bieneusi Enterocytozoon bieneusi

Factors Affecting Food Control  Poor infrastructure, poor environmental  hygiene and sanitation, poor public health  funding, weak surveillance systems  Civil strife, boarder conflicts, droughts,  floods, weak communication and  information systems: delays response to  public health crises

Prevention and control  Merely sampling final products for penal action not adequately protect the consumer Reduced risk achieved by applying the principle of prevention from production through processing, marketing and consumption – Looking at the whole chain Reduced risk achieved by applying the principle of prevention from production through processing, marketing and consumption – Looking at the whole chain The critical points for prevention: the farm, retail or household levels The critical points for prevention: the farm, retail or household levels

Prevention and Control cont…  Food processing technologies: pasteurization, sterilization, fermentation, irradiation Education of food handlers and consumers Education of food handlers and consumers Enforcement/compliance of laws and regulation on levels Enforcement/compliance of laws and regulation on levels Rigorous control and monitoring Rigorous control and monitoring

Sources of foodborne pathogens Preharvest:  Inherent toxicants— acorns, cassava, olives, etc.  Zoonoses— enterohemorrhagic E. coli, Trichinella spiralis, (Brucella, Coxiella burnetii, Mycobacterium bovis, prions of BSE), etc.  Field contaminants —Cryptosporidium parvum, enterohemorrhagic E. coli, Vibrio parahaemolyticus, etc.

Sources of foodborne pathogens Harvest or slaughter:  Cross-contamination— Listeria, Salmonella  Water— enterohemorrhagic E. coli, hepatitis A virus, etc.  Humans— hepatitis A virus, Salmonella, etc.?

Sources of foodborne pathogens Processing:  Problems rare in developed countries  Colonization of facilities by Listeria, Salmonella  If bakeries are included, viruses Storage and distribution— most problems with temperature control, rather than contamination

Sources of foodborne pathogens Final preparation and serving  Opportunities for human source contamination –Bacteria & viruses –Bacteria & viruses –Giardia lamblia –Giardia lamblia –Taenia solium etc. –Taenia solium etc.

FOODBORNE DISEASE cont..  Factors that influence the incidence of foodborne disease  Emerging pathogens  Outbreak investigation  Risk assessment  Role of Government and Industry  Consumer education

Factors in the Emergence of Pathogens  Microbial adaptation and change Human susceptibility to infection Human susceptibility to infection Climate and weather Climate and weather Changing ecosystems Changing ecosystems Human demographics and behavior Human demographics and behavior Economic development and land use Economic development and land use

FACTORS cont….. FACTORS cont…..  International travel and commerce  Technology and industry  Breakdown of public health measures  Poverty and social inequality  War and famine  Lack of political will  Intent to harm

Sanitation  Safety and Quality –Consumer driven –Long shelf life –Defect free  The “enemy” - Listeria  4 x 4 –Pre-rinse –Wash to remove soil –Rinse –Sanitize – to kill/reduce Listeria  Control and Validation –Training

Foodborne Viruses Virus Family Culturable Disease Hepatitis A Picornaviridae Yes1 Hepatitis Hepatitis E Hepeviridae No Hepatitis Norovirus Caliciviridae No Gastroenteritis Sapovirus Caliciviridae No Gastroenteritis Rotavirus Reoviridae Yes Gastroenteritis Astrovirus Astroviridae Yes1 Gastroenteritis Adenovirus Adenoviridae Yes1 Respiratory, eye & GI infection eye & GI infection Enterovirus Picornaviridae Yes Poliomyelitis, meningitis & encephalitis meningitis & encephalitis  Not all strains within the genus are culturable; wild-type strains are often difficult to culture Foodborne Viruses Adapted from: Greening G.E., Human and Animal Viruses in Food In Viruses in Foods (2006)

Nontyphoidal Salmonellosis Source: Source:  Eggs Poultry Eggs, Poultry, Undercooked meat, Unpasteurized dairy products, sea food. Incubation period: 6-48 hours The serotypes are: The serotypes are: –Typhimurium (19%) –Enteritidis (18%) –Newport (10%) –Heidelberg (6%) Antibiotic Resistance: Antibiotic Resistance: S. typhimurium DT104- resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracyclines.

Concluding thoughts Continue to be evolutionary conflicts between rapidly evolving and adapting foodborne pathogens and their slowly evolving hosts Continue to be evolutionary conflicts between rapidly evolving and adapting foodborne pathogens and their slowly evolving hosts Compounded by a backdrop of environmental and behavioral changes Compounded by a backdrop of environmental and behavioral changes These changes provide new ecological niches into which evolving microbes can easily fit and prosper These changes provide new ecological niches into which evolving microbes can easily fit and prosper Must do more to try and keep one step ahead Must do more to try and keep one step ahead

Taxonomic classification of foodborne pathogens  Prions  Viruses  Bacteria  Fungi  Protozoa  (Algae, cyanobacteria)  Metazoan parasites  Toxic plants and animals

Infectious agents  Properties of foodborne infections:  Agent must be present in food in viable (infectious) form at the time of ingestion  Agent multiplies to cause illness (incubation period)  Prions— new variant CJD  Viruses— hepatitis A, noroviruses, etc.  Bacteria— Campylobacter, Clostridium perfringens, Escherichia coli, Listeria, Salmonella, Shigella, Vibrio, etc.

 Protozoa— Cryptosporidium parvum, Entamoeba histolytica, Giardia lamblia, Toxoplasma gondii, etc.  Metazoan parasites— roundworms, tapeworms, flukes

 Despite advances in hygiene, consumer knowledge, food treatment and processing, foodborne diseases mediated by pathogenic microorganisms or microbial toxins still represent a significant treat to public health worldwide  Globally, the WHO has estimated that approximately 1.5 billion episodes of diarrhea and more than 3 million deaths occurred in children under 5 years of age, and a significant proportion of these results from consumption of food mainly food of animal origin with microbial pathogens and toxins

Control of Foodborne Disease  From farm to table approach  Implementation of GMP and HACCP

Public Health Approach  Public health system  Surveillance  Epidemiology for earlier diagnosis  Early response to outbreaks  Provide to disease patterns changing  Public health lab. support for rapid and accurate diagnosis  Rapid communication links  Communication to public  Education on prevention and/or detection

OUTLINE Challenges for Food Safety Regulators in the Challenges for Food Safety Regulators in the African Region Strategies for assuring food safety Strategies for assuring food safety Role of Food-borne disease surveillance and monitoring in food control programs Role of Food-borne disease surveillance and monitoring in food control programs WHO Food-borne Disease Surveillance activities WHO Food-borne Disease Surveillance activities

PREVALENCE OF FOODBORNE DISEASE PREVALENCE OF FOODBORNE DISEASE  episodes of diarrhea per child per  year occur in children  70% due to consumption of contaminated  complementary food  30,660 African children die every year  from consumption of contaminated  food

Aetiological Agents of Diarrhoea and Foodborne illness  Bacteria: Pathogenic Escherichia coli (EPEC,  EAggEC, ETEC, EHEC), Shigella sp.,  Campylobacter sp., Salmonella sp., Vibrio  parahaemolyticus, Vibrio cholerae  Parasites: Entamoeba histolytica, Giardia  lamblia  Viruses: Rotavirus, Parvovirus, Adenovirus  Fungal toxins especially aflatoxins

Consequences of Unsafe food  Two-fold Impact of Food-borne illness  – Human suffering  – Substantial economic losses: loss of income,  loss of manpower, loss of food, medical costs,  decrease in tourism and foreign trade  – Such economic impact has a compounding  effect and leads to a vicious cycle of increased  poverty and malnutrition.

Role of Foodborn Disease Survillence in Food Control – Key component of Food Control Systems – Fundamental to planning and development of strategies for control – A tool to estimate who gets what disease, from which food, how often and under what conditions – Measures incidence and patterns of disease, identifies risk factors and makes recommendations to prevent or minimise risk

Development and Food Control Strategy  Requires collection and collation of data for Country Profiles Epidemiological data on food-borne diseases: key component of a country profile Epidemiological data on food-borne diseases: key component of a country profile

Transmission of Foodborn Pathogens  Campylobacter jejuni and Salmonella sp. –Carried in intestinal tract of poultry and other animals –Fecal contamination of skin during grow out and processing  Salmonella enteritidis –Colonize ovarian tissue of poultry –Internal contents of eggs are contaminated

Potential Vehicles of Transmission of Foodborne Pathogens in the Production Environment  Manure  Drinking water  Feed  Environment  Rodents, insects, wildlife

 E. coli O157:H7 –Carried in intestinal tract of cattle –Direct or indirect contact with cattle manure is likely most frequent origin  Manure can contaminate food through: –Use of manure as a soil fertilizer –Polluted irrigation water –Defecation of cattle in vicinity of produce or foods of animal origin foods of animal origin

Food Processing environment  Floors and floor drains  Standing water  Residues and food contact surfaces  Ability to attached to stainless steel  Cleaning tools  Refrigeration condensation units  Measures to control of Listeria will have to be applied more rigorously and with more attention to detail than measures for the control of “traditional” pathogens

A novel bacteria A novel bacteria  1983, chronic gastritis (gastric ulcer; duodenum ulcer) –Helicobacter pylori –world-wild infection rate ~ 60% –2~6 folds increase risk of gastric cancer