Flashcards in Introduction and Approach to studying ID Deck (35):
What are three ways vaccinations are made?
produced from inactivated microbial strains
produced from live viruses
produced from viral particles
Chemotherapeutic agents are used for?
used to treat infectious disease can be synthetic drugs or antibiotics.
Antibiotics are used for?
are chemicals produced by bacteria and fungi that inhibit or kill other microbes.
Quinine is used for?
from tree bark was long used to treat malaria.
Biological stains for bacteria?
KOH, lactophenol blue, India ink, silver stains in tissue
Mycobacteria stains? (TB)
acid fast stains
trichrome stain, Wright’s stain
Viruses—antibody conjugated dyes
an upset in the homeostasis of the host, resulting in generation of observable changes
Whats the normal host-parasite relationship?
Factors that influence infection multifactorial?
Site specific Infections
Degree of Pathogenicity
A compromised immune system, however, presents an "opportunity" for the pathogen to infect
Factors Required for Infection to Occur
Contact the host - be transmissible
Colonize the host - adhere to and grow or multiply on host surfaces
Infect the host - proliferate in host cells or tissues
Evade the host defense system - by avoiding contact that will damage it
Damage host tissues - by physical (mechanical) or chemical means
Pathogenesis of Infection
has a consistant pattern. Describe it?
1. parasite enters body
2. organisms adhere to site specific target tissue
3. organisms multiply establishing local or primary lesions
--tubular structures (bronchus/ureter)
Whats the incubation period?
What can the length of the incubation period be affected by/dependant on?
Pathogen replicates without any recognizable symptoms
Length may be affected by the general health of host, portal of entry, infectious dose of the pathogen and the virulence of the organism
Describe the prodromal stage?
1. Initial appearance of symptoms in host
2. Clinical presentation may be VERY vague (general malaise)
3. Fever, myalgia, headache and fatigue may be present but are very non-specific
Describe the acute stage?
1. Host experiences maximum impact due to rapid proliferation and dissemination of pathogen
2. Toxic byproducts of microbial metabolism, cell lysis, and immune response combine to produce tissue damage and inflammation
3. Symptoms are usually more pronounced and focused than during prodrome pointing to site and possible pathogen
Describe the convalescent stage?
1. Containment of infection, progressive elimination of pathogen, repair of damaged tissue, and resolution of associated symptoms
2. Length is variable depending on host and pathogen (days to months)
3. Total elimination of pathogen from the body without residual signs or symptoms of disease
What kind of infectious diseases have a protracted/irregular course?
Chronic infectious diseases
WHat are Subclinical or Subacute illness?
progresses from infection → resolution without symptoms
The prodromal period is lengthy?
Abrupt onset of symptoms with little or no prodrome?
Portal of entry types?
Port of entry does NOT mean that is final site of infection
What are the sources of infection?
1. Endogenous = from patient’s own normal flora
2. Exogenous = From outside source
3. Zoonoses = diseases passed from other animals to humans
4. Nosocomial = hospital acquired infections (pneumomias are more pathogenic these types)
Source can also refer to the body substance that was the most likely vehicle for transmission. Examples?
feces, urine, sputum, blood, body fluids
What is the collection of signs and symptoms expressed by the host during the disease process?
“clinical picture” or “disease presentation"
What is the outward expression of the struggle between invading organisms and the retaliatory inflammatory and immune responses of the host?
Describe how different symtpoms prevent?
May be specific and show site of infection (diarrhea)
May be non-specific and reflect overall battle (fever)
May be overt (chickenpox lesions) or hidden (elevated WBC count)
Cinical features suggestive of infection?
GI Upset (gram neg)
Leukocytosis/Leukopenia (overwhelming infection)
GI upset is often precent with what kind of bacteria?
Common Community Acquired Infections
Common Hospital Acquired Infections
Diagnosis of Infectious Disease
Direct Microscopic evaluation
Indirect evidence of infection?