Midterm 2 Flashcards
Epidemiology
Study of the distribution and determinants of health-related states to events and the application of this study to the control of diseases and other health problems
Outbreak
An incident in which 2 or more persons experienced a similar illness after ingestion of a common food
Case
1 individual experiences illness after ingestion of an incriminated food
Reasons for underestimation
Recognition of infection
Don’t seek medical attention
Need officials to investigate
Need resources, money
Food available for testing
Factors contributing to unknown etiology
Must seek medical attention
Contaminated food unavailable for testing
Long incubation period
Identification of cause is dependent on detection methods
Food recovered → nothing isolated → virus or toxin
Need state and fed resources to collect data/investigate/report
Foodborne disease
Any illness resulting from the consumption of food contaminated with one or more disease producing agents
Infection
A disease state caused by presence of viable, usually multiplying organisms at the site of inflammation
successful persistence of the pathogen, usually by multiplication on or within host tissues
Intoxication
A disease state caused by exposure to a toxic chemical that is not mediated immunologically and is not primarily the result of a genetic deficiency
Metabolic food disorder
Food intolerance resulting from genetically inherited defect in the ability to metabolize a food component
Food allergies
An abnormal response of the immune system to one or more specific foods or components in foods
Mediated through IgE antibody
Allergen severity factors
Individual
Amount of food ingested
Length of time since previous exposure
Idiopathic illness
Response to a food with an unknown cause
Ex: MSG
Why do future projections show an increase in foodborne illness
Demographics
Food preference
Technology
Global market
Water shortage
Microbes (adaption/evolution)
Microbial challenges
Spores
Low infectious dose
Unknown
Detection
Psychotropic
Evolution
At risk Population
Immunocompromised
Very young and old
Chronic illness
Pregnant women
Transplant recipients
AIDS patients
Why are some people more susceptible
Immune system
Environment
Previous exposure
Dietary restrictions
Mouth defenses
Saliva
Enzymes (lysozyme)
Antibodies
Stomach defenses
HCl (pH 1.8 - 2.2)
Pepsin
Duodenum defenses
Bile ducts
Antimicrobial step (kills microbes)
How do pathogens bypass the gastric phase?
When stomach is full (hide in matrix)
Rapid gastric emptying
Neutralization or decrease in acidity by food/illness
Protection by food component (protein/fat)
Small intestine defenses
Other microbes
Antimicrobial factors (lysosome, bile, pancreatic secretions)
Large intestine defenses
Other microbes
Microflora produce mucus (limit penetration)
Digestive enzymes
Bile
Peristalsis
Involuntary muscle structures
Push food in the right direction
Limit time microbe has to find a binding spot, bind, replicate
Innate immunity characteristics
Includes phagocytes, antimicrobial peptides
Rapid response (hours)
Fixed set of components
Limited # of specificities
Constant during response
Adaptive immunity characteristics
Includes B and T cells
Slow response (days to weeks)
Variable
Numerous highly selective specificities
Improve during response
Recognition of specific microbial agents
Leading causes of death
- Diseases of the heart
- Cancer
- Covid
- Accidents
- Stroke
- Chronic respiratory diseases
- Alzheimer’s
- Diabetes
High cost of foodborne illness due to
- Medical care
- Investigation
- Recalls
- Loss of productivity
- Loss of business
Cause of most cases of illness (estimated)
Viruses
Bacteria close behind
Cause of most cases of illness (reported)
Bacterial
Host defenses (summary)
Physical barriers
Mouth
Peristalsis
Mucin
Normal flora
Stomach
Lamina propria
Thin layer of connective tissue
Below epithelium
Contains antimicrobials: lymphocytes, plasma cells, macrophages, mast cells, leukocytes
M cells
Specialized epithelial cells of lymphoid tissue
Transport antigens from lumen to immune system