Module 8
Chapter 14 – Epidemiology
Pathology, Infection and Disease
- Pathology: the scientific study of ______
- Pathogen:______
- Three areas of primary concern in pathology
- Etiology: the ______of a disease
- Pathogenesis: how the ______
- Disease: an abnormal state in which the ______
- Infection: ______or ______of the body by ______
- Can include presence of microbe not normally found in that part of body
- Possible to have ______without detectable ______
Normal Microbiota
- ______microbiota: microbes that colonize human ______
- Aka “normal flora”
- ______microbiota: microbes that colonize human for a ______without causing disease
- Days, weeks, months
- Specific microbes are ______
- Propionibacterium – ______eyes
- Lactobacillus – mouth, ______
- Many factors affect distribution, composition of normal microbiota
- Diet, age, health, stress, hygiene, etc …
- Microbial ______: ______overgrowth of ______microorganisms, aka “______”
- Protect host against ______
- Protect simply by ______, taking ______
- Clostridium difficile has problems growing in intestines due to ______
- C. difficile commonly causes gastrointestinal infections ______
- Many normal microbiota ______
- ______: ______ingested to provide beneficial effect
- ______bacteria can prevent growth of pathogens
- Lactobacterium, Bifidobacterium
Relationship between host and microbe
- ______: relationship between microbes and host; “______”
- ______: a type of symbiosis in which one organism ______, the other is ______
- Many ______are commensals
- ______: a type of symbiosis in which ______
- E. coli in large intestine produces Vitamin K
- E. coli obtains nutrients
- ______: a type of symbiosis in which one organism ______of the other
- ______are parasites
Opportunistic Microorganisms
- ______: normally______bacteria that cause ______in certain conditions
- Under certain conditions, ______or ______microbes can ______
- Some ______are opportunistic pathogens
- E. coli is ______in intestines, ______in bladder
- Gain access through puncture wounds, in weakened or compromised patients
Classifying Infectious Diseases
- Every disease alters body structures and functions in particular ways
- Characteristic of disease
- ______: achangein body function that is felt by ______as a result of disease
- “______” changesnot apparent to ______
- Eg, Aches and pains, malaise
- ______: a change in a body that can be ______as a result of disease
- “______” changes that can be seen by
- Eg, temperature, swelling, hives
- ______: a specific group of signs and symptoms that ______
- ______disease: a disease that ______from one host to another
- ______disease: a disease ______from one host to another
- ______disease: ______host to host
Occurrence of disease
- ______: number of people in a population who ______over a specified time
- Indicator of ______of disease
- Incidence of AIDS in US in 2004 was 40,000
- ______: number of people in a population who ______with a disease at a specified time
- Indicator of how ______a disease affects a population
- Includes both ______cases
- Prevalence of AIDS in 2004 was 900,000
Occurence of a Disease
- ______disease: a disease that occurs only ______
- ______disease: a disease that is ______in a population
- ______disease: acquired by ______in a given area over a relatively ______
- ______disease: an ______disease that occurs ______
Severity or Duration of a disease
- ______disease: develops ______, lasts ______time
- ______disease: develops ______, disease is continual or recurring for ______
- ______disease: intermediate between ______
- ______disease: causative agent remains ______for a time, but then becomes ______to produce disease
- Rate at which disease spreads depends on ______of a population
- ______can provide barriers to ______of disease
- ______people can be protected from communicable disease if majority of population is vaccinated
- ______: population in which ______people are present
Extent of Host involvement
- ______infection: pathogen is ______of the body
- ______infection: pathogen (or products) are spread ______
- ______infection: ______of local infection to another ______of body
- Tetanus, dentist infections
- ______: toxic inflammatory condition arising from ______
- ______: systemic infection arising from multiple ______, aka blood poisoning
- Most common example of ______
- ______infection: acute infection that causes the ______
- ______infection: infection by ______after a primary (predisposing) infection ______
- Sometimes ______than primary infection
- ______(______) infection: does not cause ______
Reservoirs of Infection
- ______of the pathogen
- Provides conditions for ______
- ______
Sick people; ______may have inapparent infections
- ______
Aka ______
- ______
Soil, water
- Pathogens can be transmitted by three routes
Transmission of Disease
______transmission
- Direct: ______
- No ______involved
- Indirect: via ______object
- Spread by ______(______objects)
- Droplet: ______(______, ______)
- Travel only ______, < ______(______)
______transmission - transmission by a ______
- Waterborne: pathogens spread ______
- Contaminated with ______, ______sewage
- Foodborne: pathogen transmitted ______
- Usually ______, poorly ______, ______
- Airborne: spread by ______that ______
- Small droplets can remain airborne ______
______: ______that______from one host to another
- Arthropods most common
- ______: ______transport of pathogens on body parts
- ______: ______process
- Usually from bites
- Involves complex life cycle
Nosocomial Infections
- Disease that does ______of being present at time of ______
- Acquired as a result of ______
Source of infection
- Microbes ______
- Hospital is ______for microbes
- Many ______are ______
- Weakened or compromised state of host
- Compromised host – patient whose ______
- Chain of transmission
- ______from______to ______to ______
Epidemiology
- Epidemiology: study of ______diseases occur, how they are ______, ______of disease
- Centers for Disease Control and Prevention (CDC)
- ______epidemiological information in the United States
- ______:collection and ______of data
- Snow
- ______: controlled______
- Semmelweis
- ______:comparison of a ______group and a ______group
- Nightingale
- Epidemiologist looks at ______, important factors and ______of the people affected
- Case reporting: health care workers report ______to local, state, and national offices
- Nationally notifiable diseases: ______are required to report occurrence
The CDC
- ______: ______of a specific notifiable disease
- ______: ______fromnotifiable diseases
- ______: number of people affected in relation to the total population in a given time period
- ______: number of deaths from a disease in relation to the population in a given time
- Emerging Infectious Diseases: Diseases that are new, increasing in ______or showing ______to increase in the ______