Flashcards in Epidemiology and Spread of Infectious Disease (L38) Deck (27):
what are the sources of infection for humans? (3)
- animal reservoirs (zoonotic disease)
- non-living reservoirs
- human carriers/cases
- nosocomial infection
what is the term for when there is an animal reservoir of disease?
what are some examples of zoonotic diseases?
rabies, anthrax, ringworm, giardia
what are fomites?
physical objects which become infected and can transmit infection to humans
how can infection be transmitted?
- contact: direct, indirect, droplet
- vectors: mechanical, biological
what are the 5 stages of an infectious disease?
- incubation period
- prodromal period
what occurs during the incubation period?
- individual has been exposed to the organism which is growing in tissues
- showing no signs or symptoms
how long does the incubation period last for and what determines this length of time?
may take a short or long time
- pathogen characteristics
- site of infection
what occurs during the prodromal period?
- show vague, general symptoms
- symptoms are non-specific and if infectious during this stage, may spread disease before you know you have it
why is the prodromal period an important stage of infectious disease?
because treatment during this stage may intercept the development of the disease
also may be important for differential diagnosis
what is the illness stage of infectious disease?
- the stage where the most characteristic signs and symptoms of the disease are evident
- most infectious stage
what is the decline stage of infectious disease?
- when immune response or medical intervention resolves infection which leads to decrease in pathogen numbers -> declining signs and symptoms
- immune parameters peak
what occurs during the convalescence period of infectious disease?
- no signs or symptoms
- tissues repaired as recovering from damage caused by infectious organism
what does the time period of convalescence depend on?
- amount of damage
- nature of pathogen
- infection site (CNS = lifelong effects)
- patient health and immune competence
what are nosocomial infections?
infections that occur in health care facilities
what are the types of nosocomial infection?
what are exogenous nosocomial infections caused by?
infection from someone else
what are endogenous nosocomial infections caused by?
infection from opportunistic pathogens on own body due to catheters (tubes inserted into body)
what are iatrogenic nosocomial infections caused by?
infection from someone else due to not using sterile instruments or washing hands
what are the 3 ways in which infectious diseases can be classified?
- body system
- taxonomic group
- longevity and severity
what are the categories within the infectious disease classification of longevity and severity?
will start and end within days
will either die or get better
go on for months or years
largely secondary infections
what are some examples of all the categories within the infectious disease classification of longevity and severity?
chicken pox -> shingles, herpes
what does it mean if a disease is epidemic?
occurs in a large number of people in a population at the same time
what does it mean if a disease is pandemic?
disease is widespread, usually worldwide
what does is mean if a disease is endemic?
the disease is constantly present in a population, usually at low incidences
what does it mean if a disease is sporadic?
disease only occurs in a few scattered cases