Epidemiology
11/8/2013
Organization of Presentation
Disease Stages, Transmission of
Pathogens, and Epidemiology
COS Headings: Microbial Growth and Microbes in the Environment
Microbiology Demystified: chapter 13
•
•
•
•
•
•
•
•
•
Disease terminology
Types of Microbiota
Disease classification
Host involvement of diseases
Stages of disease
Modes of transmission and reservoirs of diseases
Portals of entry and exit
Nosocomial infections and emerging diseases
Epidemiology
Course Mentor: Kim Shahi, PhD
Vocabulary
• Pathology: Study of disease
• Pathogenesis: Development of disease
• Pathogen:
Pathogenic agents have special properties that allow them to invade the human body or produce toxins.
• Etiology: the study of the cause of a disease
• Infection: invasion and growth of pathogens in the body
• Disease: Abnormal state in which the body is not functioning normally.
The Normal Microbiota (Flora)
Microbial antagonism due to competition between microbes. Resident flora = Normal microbiota (acquired at passage through birth canal)
Establish permanent colonies on/inside body without producing disease. Protect the host by
1. Occupying niches that pathogens might occupy
(Competitive exclusion)
2. Producing acids
3. Producing bacteriocins
4. Stimulation of immune system
i.e.: infectious agent overcomes body’s defenses
1
11/8/2013
Transient Microbiota (Flora)
Location
Certain microbes are present for various periods
(days, weeks, or months) – then disappear.
Probiotics: Live microbes applied to or ingested into the body, intended to exert a beneficial effect Dynamic nature of resident flora: changes due to age, type of food consumed, Hormonal state, antibiotics
Various Co-existance Relationships
Between Bacteria and Host
• Symbiosis
• Mutualism: microbe and host benefit from co-existence, neither suffers
• Commensalism: microbe benefits but host doesn’t (is unaffected)
• Parasitism: microbe benefits, host suffers
• Opportunistic pathogens cause disease under
special
Organization of Presentation
Disease Stages, Transmission of
Pathogens, and Epidemiology
COS Headings: Microbial Growth and Microbes in the Environment
Microbiology Demystified: chapter 13
•
•
•
•
•
•
•
•
•
Disease terminology
Types of Microbiota
Disease classification
Host involvement of diseases
Stages of disease
Modes of transmission and reservoirs of diseases
Portals of entry and exit
Nosocomial infections and emerging diseases
Epidemiology
Course Mentor: Kim Shahi, PhD
Vocabulary
• Pathology: Study of disease
• Pathogenesis: Development of disease
• Pathogen:
Pathogenic agents have special properties that allow them to invade the human body or produce toxins.
• Etiology: the study of the cause of a disease
• Infection: invasion and growth of pathogens in the body
• Disease: Abnormal state in which the body is not functioning normally.
The Normal Microbiota (Flora)
Microbial antagonism due to competition between microbes. Resident flora = Normal microbiota (acquired at passage through birth canal)
Establish permanent colonies on/inside body without producing disease. Protect the host by
1. Occupying niches that pathogens might occupy
(Competitive exclusion)
2. Producing acids
3. Producing bacteriocins
4. Stimulation of immune system
i.e.: infectious agent overcomes body’s defenses
1
11/8/2013
Transient Microbiota (Flora)
Location
Certain microbes are present for various periods
(days, weeks, or months) – then disappear.
Probiotics: Live microbes applied to or ingested into the body, intended to exert a beneficial effect Dynamic nature of resident flora: changes due to age, type of food consumed, Hormonal state, antibiotics
Various Co-existance Relationships
Between Bacteria and Host
• Symbiosis
• Mutualism: microbe and host benefit from co-existence, neither suffers
• Commensalism: microbe benefits but host doesn’t (is unaffected)
• Parasitism: microbe benefits, host suffers
• Opportunistic pathogens cause disease under
special