Disease and Epidemiology Flashcards
Pathology
the study of disease
etiology
cause of disease
pathogenesis
development of disease
infection
invasion/colonization of body by pathogen
disease
abnormal state where body isn’t performing normal functions
koch’s postulates
- same pathogen presented in every case of disease
- pathogen is isolated from host and grown in pure culture
- grown pathogen causes disease when injected into animal
- pathogen is isolated from innoculated animal and shown to be the same as the original
Exceptions to koch’s postulates
- some pathogens cause several diseases
- some diseases are caused by several pathogens
- some pathogens only cause disease in people
- some microbes have never been cultured (syphilis only lives in the body)
symptoms
changes in body function that are felt by patioen as result of disease
signs
measurable changes in the body as result of disease
syndrome
specific group of signs and symptoms that accompany a disease
infectious
can grow in a host and cause disease
contagious
easily/rapidly spread from 1 host to another
noncommunicable
not spread from 1 host to another
incidence
number of people who develop a disease during a time frame
prevalence
number of people who have a disease during a time frame (new and old cases)
sporadic disease
disease that occurs only occassionally
endemic disease
disease that’s always present in a population
epidemic disease
aquired by many people in short time
pandemic
worldwide epidemic
acute disease
symptoms develop rapidly but disease lasts short time
chronic disease
symptoms develop slowly
latent disease
causative agent is inactive for a tie, but then activates and produces symptoms
herd immunity
immunity in most of the population
local infection
pathogens are limited to small area of body
systemic/generalized infection
infection throughout body
focal infection
one that started local and became systemic
sepsis
toxic, inflammatory condition arising from spread of microbes, especially bacteria and their toxins, from a focus of infection
bacteremia
bacteria in blood
septicemia
growth of bacteria in blood (blood poisoning)
toxemia
toxins in blood
primary infection
acute infection that causes initial illness
secondary infection
opportunistic infection after primary infection
predisposing factors
- gender
- climate
- lack of vaccination
- fatigue
- age
- lifestyle
- nutrition
- chemotherapy
- inherited state
Steps of developing a disease
- incubation period (time bt infection + 1st symptoms)
- prodromal period (early mild symptoms)
- period of illness (height of disease)
- period of decline (signs and symptoms subside)
- period of convalescence (body returns to pre-disease)
Reservoirs of infection
Human reservoirs –> AIDS and gonorrhea–> carriers may have inapparent infections or latent disease
Animal reservoirs –> rabbies and lyme –> zoonoses are diseases transmitted by animals
Nonliving reservoirs –> botulism and tetanus –> soil and water
Direct contact transmission
requires close association bt infected and succeptible host
congenial transmission
transmission from mom to fetus or newborn at birth
indirect contact transmission
spreads to host by nonliving object, called fomite
droplet transmission
transmission via airborne droplets less than a meter away
vehicle transmission
transmission from an inanimate reservoir (air, water, food)
vectors
agents that carry and transmit diseases
- arthropods, especially fleas, ticks, and mosquitos
- use mechanical transmission (on feet) or biological transmission (through bite or feces)
Emerging infectious diseases
ones that’re new, increasing in incidence, or whowing the potential to increase
-usually vector born viruses
contributing factors to emerging infectious disease
-genetic recombination
-emerging strains
-weather
-modern transportation (boats take up water)
insect vectors
natural disasters
animal control methods
public health failure
bioterrorism
