Infection and Disease Flashcards
what is mutualism? name an example
when both organisms benefit. ie bacteria in the human colon
what is commensalism? name an example
when one organism benefits and nothing happens to the other.
ie staphyloccocus on the skin
what is parasitism?
when one organism benefits and the other is harmed
what are the five stages of disease?
incubation, prodromal, illness, decline and convalescence
what is the incubation phase?
time after infections but before signs and symptom
what is the prodromal phase like?
short with vague symptoms
what happens during the illness phase?
typical signs and symptoms.
what happens during the decline phase?
symptoms subside, fewer pyrogens
what happens during the convalescence phase?
symptoms disappear and patient returns to normal health
what is the difference between signs and symptoms?
signs are observed and measured by others while symptoms are only felt by the patient
what are exotoxins?
soluble proteins that are secreted by the bacteria to enter host cells
what is an endotoxin?
a toxic substance bound to the bacterial cell wall and release when bacterial cell ruptures
what are antitoxins?
antibodies that counteract toxins
what is a toxoid?
a chemically modified toxin from an organism that can be used as a vaccine
what are the six different modes of transmission?
via the eye, oral route, entry through skin, respiratory route, parenteral route, sexual transmission
what is the parenteral route?
pathogens injected into the bloodstream by an insect vector or a contaminated needle
what is an endemic?
disease is one that is always present in a community at a low rate; often
in an animal reservoir
what is a sporadic occurrence of disease?
disease is one when only a few cases occur within an area or population.
what is an epidemic?
disease is one in which the number of cases increases in a community
in a short time (above normal range
what is a pandemic?
disease is an epidemic that spreads worldwide.
