Module 3 Flashcards
Components of epidemiological triad
Interaction of susceptible host, infectious agent/toxin, environment
Mode of agent transmission (2)
Horizontal = individual to next in same generation, either direct (contact, projections, exposure) or indirect (vehicle borne like fomites or blood transfusion, vector borne, airborne like droplet nuclei or duct)
Vertical = from mother to offspring
Endemic
Habitual presence of disease within given geographical area (usual occurrence)
Methods of investigation
Phenotypic: gene expression, little discrimination power (serotyping, phage-typing, MLEE)
Genotypic: genetic structure (RE-based, amp-based, sequence-based)
Disease outbreak investigation
verify diagnosis, establish case definition (person, place, time), identify cases, verify you have an epidemic, develop hypotheses, test them, recommend + implement control/prevention, communicate findings
Epidemiological clues
Unusual presentation/geography/incidence
Microbial forensics
extension of epidemiological principles to enable investigation of unlawful acts involving biological agents
Targeted collection
Use of biological agent suspected, info on source of possible biological agent available
Bayesian acceptance sampling model
sampling after decontamination to demonstrate cleanliness of area
Sampling approaches
bulk, portion (Vacuum), liquid/swab
Primary goal of collecting microbial evidence
sufficient agent to support species/strain or toxin ID and complete signature characterization for lead information
Limitations in microbial forensics
unique ID difficult due to clonal reproduction (no signature), class characteristics categorization
Recommendations
Databases, validation, discipline-wide validation criteria, sample collection guidelines, seeding surfaces
