1- Intro Flashcards
commenalism
where microorganism live together, and do not damage one another
obligate parasites
are always pathogenic, and never found in normal flora
facultative parasites
depends on condition of host and microbe, predisposing risk factors, and members of the normal flora
oppertunistic parasites
are members of the environment, not pathogenic for healthy people, and they take adv of immunosuppression
contagiousness
is the ability of a microorganism to be transferred from one host to another host with routes of transmission
infection
the invasion and multiplication of microorganisms into a host
disease
the host generated response to the infection
pathogenicity
the capacity of a microbe to produce disease
virulence
the degree of pathogenicity (the capacity of a microbe to cause damage in a host)
infectiousness
the ability to invade and multiply in a host
infective dose
the minimal dose of microorganisms capable of ensuring infection
factors in a source chain
source, reservoir, vector, vehicle, incubation period
notes for transmission via droplets
- droplets (diameter >5 microm), shed through airways, fall on mucosae 1 m away, last in air for a short time
e. g. H influenza, N. meningitidis, influenza, C. diptheria, mycoplasma, rubella
airborne transmission details
for droplets (diameter <5 mm), stay in air for a long time, can read secondary sources very far from source e.g. TB, measles, german measles
parenteral transmission
microorganisms present in blood of source case, and are transmitted through contaminated vehicles
e.g. HIV, HCV, HBV
