Lecture 14: Incidence and Impact of foodborne diseases Flashcards
What is food safety
Science of protecting our food supply from contamination by disease causing bacteria, viruses, chemicals and other threats to health
What does foodnet monitor and how many states
Monitor 8 pathogens in 10 U.S states-represents only about 15% of the U.S. population
What are the objectives of foodnet
- Determine the burden of foodborne illness in the US
- Monitor trends in specific foodborne illness over time
- Attribute foodborne illnesses to specific foods and settings
- Develop and asses interventions to reduce foodborne illness
What are the 8 foodborne pathogens in the foodnet
- Camplyobacter
- Salmonella
- Eschierichia coli
- Shigella
- Vibrio
- Years India
- Cyclospora
- Listeria
What location has the highest % of food outbreaks
Restaurants
What food commodity has the largest % of outbreaks
Mollusks
What food group has the greatest % of outbreaks
34%
How many people get sick from foodborne illness each year in US
48 million
How many foodborne illness are from consumption of dairy products
760 illnesses and 22 hospitalizations per year
What are the top 3 factors in newly emerging foodborne illnesses
Human demographics and behavior, technologies within the food industry, international travel and commerce
Human demographic and behavior
Aging population, higher consumption of fresh fruits and vegetable, organic doesn’t mean safer, more food consumed outside the home
Technologies within the food industry
Food transported over longer distances, larger production facilities, point source contamination has greater impact
International travel and commerce
Traveler’s diarrhea, travelers often take food with them on trips
What are some additional factors in newly emerging foodborne illnesses
Microbial adaption, economic development and land use, shortfalls in public health education
Microbial adaption
Traditional preservation techniques don’t work as well, antimicrobial resistance patterns
Economic development and land use
Average number of animals on each farm increased significantly, seafood affected warmer waters
Shortfalls in public health education
Health in schools focused on other topics, parents have not taken up the issue in home
What are the two types of foodborne illnesses
Infections and intoxications
What is an infection
Pathogen enters the body and must grow to cause effect, can be bacterial, viral, parasitic, or fungal, typically have a longer incubation periods and cause fever
What is an intoxication
Preformed toxin enters the body and directly exerts effect, most foodborne toxins are bacterial in origin, typically have shorter incubation period
What type of bacteria is salmonella enterica
Gram negative bacteria
What are two types of salmonella enterica
Salmonella enteritidis (nontyphoidal)
Salmonella typhoid and paratypli (typhoid fever)
What are commonly implicated foods in salmonella enterica
Raw or improperly pasteurized milk, raw meats and poultry, eggs
Source of contamination in salmonella enterica
Nontyphoidal- domestic and wild animals, long term carrier state in animals rare
Nontyphoidal and typhoidal- humans
Is salmonella enterica Infectious or intoxication
Infection
Incubation period for salmonella enterica
GI (nontyphoidal): 6-72 hours after exposure
Thypoidal: 1-3 weeks after exposure
Major symptoms of salmonella enterica
GI type (nontyphoidal)- nausea, vomiting, cramps, diarrhea, fever, headache, generally lasts up to a weak , low CFR
Typhoidal- high fever, lethargy, abdominal pain +/-diarrhea, rash of flat rose colored spots, last 2 weeks, untreated CFR=10%
What are some control measures for salmonella enterica
Thorough cooking of food, strict food handling hygiene, pre-travel vaccination, handwashing after handling raw foods or animals
Which salmonella enterica zoonotic
Nontyphoidal serotypes
What type of bacteria is campylobacter jejuni
Gram negative non-spore forming bacteria
What are the most commonly implicated foods in camplyobacter jejuni
Raw poultry, raw milk and cheeses, water
Source of contamination
Normal gut flora of most food producing animals- contaminates both food and water
Is camploybacter jejuni infectious or intoxication
True infection
What is the incubation period for campylobacter jejuni
2-5 days
What are the major symptoms for camplyobacgter jejuni
Fever, nausea, headache, diarrhea, vomiting and cramping, self-limiting cases, pregnant women can experience miscarriage or still birth, Guillain Barre syndrome is a known sequela
What are some control measures used against camplyobacter jejuni
Hygienic slaughter processing, clean/rise FF&V, prevent cross-contamination, refrigerate foods and leftovers, do not consume unpasteurized dairy
What type of bacteria is enterohemorrhagic Eschericia coli
Gram negative bacteria, produces a shiva-toxin
What is the predominant strain of enterohemorrrhagic eschericia coli in US
Stereotype O158:H7
What are some commonly implicated foods in enterohemorrhagic escherichia coli
Ground meats, raw milk and juices, fresh vegetables, apple cider, yogurt, mayonnaise
What is the source of contamination for enterohemorrhagic escherichia coli
Cattle and other ruminants, human to human transmission uncommon
How is shiga toxin formed
After ingestion of bacteria, toxin is not preformed
Is enterohemorrhagic escherichia coli infectious or intoxication
Toxico-infection
What is the incubation period for enterohemmorrhagic escherichia coli
3-4 days after ingestion (1-9 days)
Major symptoms of enterohemmorrhagic escherichia coli
Hemorrhagic colitis- most common
- severe abdominal cramps, Nashua, vomiting, diarrhea
Hemolytic uremia syndrome- most common in children, acute renal failure
What are some control measures for enterohemorrhagic escherichia coli
Cook ground beer well, do not consume unpasteurized products, soft cheeses are more commonly implicated, frequent handwashing
What type of bacteria is listeria monocytogenes
Gram positive bacteria
Commonly implicated foods in listeria monocytogenes
Raw milk and soft cheeses, smoked fish and other seafood, deli meats, raw vegetables
Is listeria monocytogenes an infection or intoxication
Infection
What is the source of contamination for listeria monocytogenes
Ubiquitous in environment worldwide, livestock food and silage-livestock handling and slaughter
What signs does listeria monocytogenes cause in livestock
Neurologic disease
What is the incubation period of listeria monocytogenes
Gastroenteritis can appear from a few hours-3 days after
Invasive form varies from 3 days to 3 months after ingestion
What are the major symptoms of listeria monocytogenes
GI: mild fever, nausea, vomiting, +/- diarrhea, very low CFR
Invasive: headache, stiff neck, confusion, loss of balance, convulsions, CFR: 15-30%
What are some control measures for listeria monocytogenes
No raw milk or dairy products, avoid ready to eat foods unless hot, wash FF&V, thoroughly cook meat products, prevent cross-contaminaiton
What type of bacteria is clostridium perfringens
Gram positive spore forming bacteria
Commonly implicated foods in clostridium perfringens
Meats- beat and poultry, Mexican foods, vegetables
What is the source of contamination for clostridium perfringens
Ubiquitous in soil- contaminated by human or animal feces
Is clostridium perfringens infectious or intoxication
Intoxication- sometimes toxico-infection
What is the incubation period for clostridium perfringens
16 hours after ingestion
What are the major symptoms of clostridium perfringens
Watery diarrhea and mild cramping, self limiting
What is pigbel disease
Rare symptom of clostridium perfringens- highly fatal causes necrotizing enteritis, associated with consumption of contaminated pork, most common in Papua New Guinea
What are some control measures for clostridium perfringens
Refrigerate to eat foods very soon after cooking, wash FF&V
What type of bacteria is staphylococcus aureus
Gram positive bacteria
What are some commonly implicated foods in staphylococcus aureus
Almost any food that requires extensive handling and has been left long enough to incubate and generate toxin
What is the source of contamination for staphylococcus aureus
Ubiquitous in nature
Is staphylococcus aureus zoonotic or no
Zoonotic
Is staphylococcus aureus infectious or intoxication
Intoxication
- heat stable enterotoxin survives cookie and preformed enterotoxin is ingested
What is the incubation period for staphylococcus aureus
Rapid 1-7 hours
What are the major symptoms for staphylococcus aureus
Vomiting, diarrhea, nausea, cramping, dehydration, lowered BP, headache, self limiting
What are some control measures against staphylococcus aureus
Strict food handling hygiene, keep cold foods cold and hot foods hot
What type of bacteria is bacillus cereus
Gram positive spore forming
What are some commonly implicated foods in bacillus cereus
Vomiting type outbreak: usually rice and starchy foods
Diarrhea type outbreaks: many foods
What is the source of contamination for bacillus cereus
Ubiquitous in environment- soil and vegetation
Fecal oral contamination
Inadequate personal hygiene, cross contamination between raw and cooked foods
Is bacillus cereus infectious or intoxication
Both types are intoxication
Vomiting type: heat stable
Diarrhea type: heat labile
What is the incubation period for bacillus cereus
Vomiting type: 30 minutes-6 hours
Diarrhea type: 6-15 hours
What are the major symptoms of bacillus cereus
Vomiting- nausea and vomiting, self limiting
Diarrhea- watery diarrhea, abdominal pain, cramping, nausea, self limiting
What are some control measures for bacillus cereus
Refrigerate cooked and leftover foods promptly, reheat foods rapidly and thoroughly
What type of bacteria is clostridium bontulinum
Gram positive spore forming bacteria
What are some commonly implicated foods in clostridium botulinum
Low oxygen foods (canned), infant botulism associated with honey
What is the source of contamination in clostridium botulinum
Spores are globally ubiquitous, frequently recovered from agricultural products- meats, produce, honey, fish, shelfish
Is clostridium botulinum an intoxication or infection
Intoxication- potent neurotoxin formed by bacterial phase- most lethal natural toxin known
How do you inactive clostridium botulinum
Boiling for greater than 5 minutes
What is the incubation period for clostridium botulinum
18-36 hours after ingestion
Major symptoms for clostridium botulinum
Double or blurred vision, slurred speech, difficulty swallowing, muscle weakness, untreated may lead to paralysis or suffocation
Infant botulism- constipation, flat facial expression, weak cry or muscles
What are some control measures for clostridium botulinum
Boil canned foods for 10 minutes, process foods to be below 4.6pH, do not feed honey to infants less than 1 year old
What type of bacteria is hepatitis A
Environmentally hard RNA virus
What are some commonly implicated foods in hepatitis A
Person to person is more common than foodborne, contaminated water, shellfish, salads
What is the source of contamination for hepatitis A
Feces of infected people, rarely chimpanzees or other primates
Is hepatitis A an infection or intoxication
Infection
What is the incubation period for hepatitis A
30 days, long incubation period makes ID of source very difficult
What are the major symptoms of hepatitis A
Asymptomatic in children <6 years, initial: fever, nausea, abdominal discomfort a few days later become jaundice
1-2 week duration
CFR-2.4%
What are the control measures for hepatitis A
Wash hands frequently, thorough cooking of foods, hepatitis A vaccine
What type of bacteria is norovirus
Environmentally hardy RNA virus
What foods are commonly implicated in norovirus
Any food prepared by infected person, shellfish grown in infected water
What is the source of contamination for norovirus
Humans, contaminate water is the vehicle
Is norovirus an infection or intoxication
Infection
What is the incubation period for norovirus
24-48 hours
What are the major symptoms of norovirus
Self limiting, vomiting, headache, mild fever, cramping, chills, aches, malaise
What are some control measures for norovirus
Handwashing, basic food handling hygiene
