HCARE_LEC4 Flashcards
Diseases in which biological agents or their
products are the cause and are transmissible from one person to another.
Communicable or Infectious Diseases
Illness that cannot be transmitted.
➔ Often called ____, as many factors such as genetic,
environmental, or behavioral determinants
may contribute to the disease.
Noncommunicable or Non-infectious diseases; multicausational diseases
● Peak severity of symptoms occurs and subsides within 3 months (or sooner), and recovery is usually complete.
● Sometimes, aside from having complete recovery, there are acute diseases that give you lifetime immunity
Acute Diseases
● symptoms continue loner than 3 months, and in some cases, for the remainder of one’s life.
● Recovery is slow and sometimes incomplete
Chronic Diseases
the ability of a biological agent to enter, grow and multiply in a host and spread to other hosts
Infectivity
infectious agent’s ability to produce a disease
Pathogenicity
●___– the element that must be present for
disease to occur
● ___– any susceptible organism. (plant, animal, or human) invaded by the infectious agent.
● ___ – includes all other factors – physical, biological, or social, that inhibit or promote
disease transmission
Agents, Host, The environment
○ Your environment is like your regulator for
the transmission of a disease. So it either
inhibits, promotes, or propagates the
transmission of disease.
Chain of Infection Model
● Pathogen
● Reservoir
● Portal of Exit
● Transmission
● Portal of Entry
● Establishment of infection in new host
____A communicable disease transmissible under natural conditions from vertebrate animals to humans
____a disease which only
infects humans.
Zoonosis; Anthroponosis
what portal of exit?
● ____– common colds, influenza, measles, tuberculosis.
● ____– Gonorrhea, syphilis, herpes, AIDS. (STIs)
● ____ – amebic dysentery, shigellosis,
polio, typhoid fever, and cholera.
● ____ – ring-worm and jock itch.
● ____– rubella virus, syphilis, spirochetes, hepatitis B virus.
Respiratory tract
Urogenital tract
Digestive tract
Skin
Transplacental
what mode of transmission?
immediate transfer of the disease agent between infected and susceptible individual by:
➔ touching, biting, kissing, sexual intercourse, or direct projection (Droplet
spread.)
➔ Examples: AIDS, syphilis, gonorrhea,
rabies, and the common cold.
Direct transmission
what mode of transmission?
➔____: dissemination of microbial aerosols (dust or droplet nuclei made up or in part of microorganisms) to suitable portal of entry (usually respiratory tract.)
➔ Examples: tuberculosis, influenza,
measles.
Airborne; Airborne
What indirect transmission?
➜ Contaminated materials or objects
(fomites) serving as vehicle
➜ Communicable agents are transferred to a
susceptible host
Ex. toys, handkerchiefs, utensils, water,
food, milk, blood, serum, plasma, organs,
tissues
Vehicle- borne transmission
What indirect transmission?
➔ Transfer of disease by a living organism
(e.g. mosquito, fly, tick)
➔ Transmission may be mechanical or biological
➔ Mechanical: contaminated mouth parts or feet of vector (e.g. cockroach can carry
disease on their feet)
➔ Biological: multiplication or
developmental changes of agent in the vector before transmission
Vector-borne transmission
➜ Implies planning for and taking action to
prevent or forestall the occurrence of an
undesirable event
Prevention
