Transmissions of Infections Flashcards
what are the steps of the chain of infection?
- infectious agent
- reservoirs
- portal of exit
- means of transmission
- portal of entry
- susceptible host
what is meant by virulence?
the ability of the microbe to cause disease
what is meant by dose?
• the number of microbes entering the body
what is dose normally expressed as?
infectious dose 50 (ID50)
how do you know if a microbe is MORE infectious?
a LOW ID50
what are exotoxins?
a toxin released by bacteria into the external environment
what is an endotoxin?
a toxin that is released from GRAM NEGATIVE bacterial cell walls
what is an example of a periodontal pathogen?
P. gingivalis
what is a leukocidin?
a white cell toxin
what is an enterotoxin?
a toxin produced in/affecting the intestines
give examples of reservoirs:
- humans
- animals
- environment
- contaminated surfaces
give an example of an environmental pathogen?
CLOSTRIDIUM TETANI spores in soil
what are the different phases of an infection?
- patients in acute phase
- patients in the prodromal phase
- healthy carriers
what is meant by the incubation period of a pathogen?
the time between contamination and the development of symptoms
what do long incubation periods permit?
- longer time periods when the infecting microbe may be spread to others
- greater spread of the disease due to more human contact