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 ______