Communicable diseases Flashcards
communicable disease definition
illness due to a specific infectious agent or its toxic products
capable of being directly or indirectly transmitted person to person, animal to person, animal to anima or from the environment to person
transmission from the environment
air
water
food
incidence
number of new cases in a given time period
cumulative incidence
expressed as a percent infected per year
incidence density
number per person time of observation
prevalence
number of cases at a given time expressed as a percent at a given time
product of incidence and duration of disease
little use if short term disease
epidemic
unusual occurrence in a community of disease
specific health related behaviour or other health related events clearly in excess of expected occurrence
can occur upon endemic states
endemic
refers to the constant presence of a disease or infectious agent within a given geographic area or population group
usual or expected frequency of disease within a population
exotic disease
those imported into a country in which they don’t otherwise occur
sporadic
scattered
cases occur irregularly, haphazardly from time to time and generally infrequent
few cases and separated widely in places they show no or little connection with each other
not a recognisable common source of infection
may be start of an epidemic
zoonosis
infection trasnmissable under natural conditions from vertebrate animals to people
rabies, plague,bovine, tuberculosis
epizootic
outbreak of disease in an anima population
enzootic
endemic occurring in animals
2 types of epidemic
common source
propagated
common source
point source
rapid rise and fall of incidence
arises from single source such as food poisoning
propagated
person to person
slow rise and fall in incidence
disease may be transmitted from each contaminated individual
what type of epidemic is this
point source
what type of epidemic is this
propagation
communicable period
infectious period
length of time a person can transmit disease
sheds the infectious agent
incubation period
time from exposure to development of disease
time interval between invasion by an infectious agent and the appearance of the first sign or symptom of disease in question
latent period
period between exposure and the onset of infectiousness
may be longer or shorter than incubation
nosocomial infection
hospital acquired
infection originating in a patient whilst in hospital or another health care facility
source/reservoir genera l
starting point for the occurrence of a communicable disease is the existence of a reservoir or source of infection
source of infection
the person/animal/object/substance from which an infectious agent passes or is disseminated to the host (immediate source)
reservoir definition
any person/animal/arthropod/plant/soil/substance or combination of these in which an infectious agent normally lives and multiplies
depends primarily for survival where it reproduces itself in such a manner that it can be transmitted to a susceptible host
natural habitat of infectious agent
types of reservoirs
human
animal
non-living
2 modes of transmission
direct
indirect
direct transmission
direct contact
droplet
contact with soil
inoculation into skin or mucosa
trans-placenta (vertical)
indirect transmission
vehicle-borne
vector-borne
air-borne
formite-born
unclean hands and fingers
types of vector borne
mechanical and biological
types of biological vector
propagative
cyclo-prop
cyclo-develop
eradication
termination of all transmission of infection by the extermination of the infectious agent through surveillance and containment
absolute process, all or none phenomenon
restricted to termination of infection from the whole world
elimination
sometimes used to describe the eradication
from a large geographical region
disease which are amenable to elimination in the meantime are polio, measles and diphtheria
management of infection in hospitals
director of infection prevention and control
infection prevention and control tea m
management of infections in the community
local health protection system
