EPIDEMIOLOGY AND NOSOCOMIAL INFECTIONS CHAPTER 15 1 What

EPIDEMIOLOGY AND NOSOCOMIAL INFECTIONS CHAPTER 15 1

What is Epidemiology? 2

Table 33 -1 3

Epidemiology n What is Epidemiology? n Etiology n Incidence n Prevalence causation a/a+b 4

Epidemiological Terms n Morbidity n Mortality 5

Figure 33 -6 6

Diseases in Populations n Endemic n Pandemic n Epidemic n Sporadic 7

Figure 33 -2 8

Incidence Types 9

Disease Spread n Common Source Outbreak n Propagated Epidemic 10

Epidemiologic Studies n Descriptive n Analytical n Experimental 11

The Basic Triad Of Descriptive Epidemiology THE THREE ESSENTIAL CHARACTERISTICS OF DISEASE WE LOOK FOR IN DESCRIPTIVE EPIDEMIOLOGY: TIME n PLACE n PERSON n 12

Time n Changing or stable? n Seasonal variation. n Clustered (epidemic) or evenly distributed (endemic)? n Point source or propagated. 13

Place Geographically restricted or widespread (pandemic)? n Relation to water or food supply. n Multiple clusters or one? n 14

Person n Age n Socio-economic status n Gender n Ethnicity/Race n Behavior 15

The Basic Triad Of Analytic Epidemiology THE THREE PHENOMENA ASSESSED IN ANALYTIC EPIDEMIOLOGY ARE: HOST AGENT ENVIRONMENT 16

Agents n n n n Nutrients Poisons Allergens Radiation Physical trauma Microbes Psychological experiences 17

Host Factors Genetic endowment n Immunologic state n n Age n Personal behavior 18

Environment Crowding n Atmosphere n Modes of communication – phenomena in the environment that bring host and agent together, such as: n – Vector – Vehicle – Reservoir 19

Infection Reservoirs n Human n Animal n Non-living 20

Microbe Spread n Portals of Entry 21

Microbe Spread n Portals of Exit 22

Modes of Disease Transmission n Contact n Vehicles n Vectors 23

Problems in Disease Transmission Disease Cycles n Herd Immunity n 24

Controlling Disease Transmission n Biosafety 25

Public Health Organizations n Center for Disease Control (CDC) n World Health Organization (WHO) 26

Notifiable Diseases n Definition: n Nationally Notifiable Infectious Diseases 27

Nosocomial Infections n Sources 28

Nosocomial Infection Risks Susceptibility n Transmission n Universal Precautions n 29

Figure 33 -9 Other 17% Surgical site infections 22% Pneumonia 15% Bloodstream infections 14% Urinary tract infections 32% 30

Risks Equipment/Procedures n Sites of Infection n 31

Bioterrorism 32

Anthrax 33

Smallpox 34