EPIDEMIOLOGY AND NOSOCOMIAL INFECTIONS

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EPIDEMIOLOGY AND NOSOCOMIAL INFECTIONS

• CHAPTER 15

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What is Epidemiology?
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Table 33-1
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Epidemiology

• What is Epidemiology?
• Etiology
• Incidence
• Prevalence

causation
a/ab
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Epidemiological Terms

• Morbidity
• Mortality

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Figure 33-6
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Diseases in Populations

• Endemic
• Epidemic

• Pandemic
• Sporadic

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Figure 33-2
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Incidence Types
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Disease Spread

• Common Source Outbreak
• Propagated Epidemic

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Epidemiologic Studies

• Descriptive
• Analytical
• Experimental

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The Basic Triad Of Descriptive Epidemiology

• THE THREE ESSENTIAL CHARACTERISTICS OF DISEASE
  WE LOOK FOR IN DESCRIPTIVE EPIDEMIOLOGY
• TIME
• PLACE
• PERSON

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Time

• Changing or stable?
• Seasonal variation.
• Clustered (epidemic) or evenly distributed
  (endemic)?
• Point source or propagated.

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Place

• Geographically restricted or widespread
  (pandemic)?  
• Relation to water or food supply.  
• Multiple clusters or one?

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Person

• Age
• Socio-economic status
• Gender
• Ethnicity/Race
• Behavior

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The Basic Triad Of Analytic Epidemiology

• THE THREE PHENOMENA ASSESSED IN ANALYTIC
  EPIDEMIOLOGY ARE

HOST
ENVIRONMENT
AGENT
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Agents

• Nutrients
• Poisons
• Allergens
• Radiation
• Physical trauma
• Microbes
• Psychological experiences

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Host Factors

• Genetic endowment
• Immunologic state
• Age
• Personal behavior

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Environment

• Crowding
• Atmosphere
• Modes of communication phenomena in the
  environment that bring host and agent together,
  such as
• Vector
• Vehicle
• Reservoir

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Infection Reservoirs

• Human
• Animal
• Non-living

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Microbe Spread

• Portals of Entry

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Microbe Spread

• Portals of Exit

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Modes of Disease Transmission

• Contact
• Vehicles
• Vectors

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Problems in Disease Transmission

• Disease Cycles
• Herd Immunity

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Controlling Disease Transmission

• Biosafety

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Public Health Organizations

• Center for Disease Control (CDC)
• World Health Organization (WHO)

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Notifiable Diseases

• Definition
• Nationally Notifiable Infectious Diseases

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Nosocomial Infections

• Sources

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Nosocomial Infection Risks

• Susceptibility
• Transmission
• Universal Precautions

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Figure 33-9
Blood- stream infections 14
Other 17
Surgical site infections 22
Urinary tract infections 32
Pneumonia 15
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Risks

• Equipment/Procedures
• Sites of Infection

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Bioterrorism
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Anthrax
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Smallpox