Healthcare epidemiology and Gram+ and Acid Fast Bacilli Flashcards
What is the definition of endemic?
occurring at a relatively constant state
What is the definition of epidemic?
occurring at a greater than expected frequency; suddenly see numbers clearly in excess of normal expectancy (disease-chronic or infectious, injury, or health related event)
How is incidence rate determined?
(# new cases for a time period/ population at risk) x 100
How is prevalence rate determined?
(# existing cases for a time period/ population at risk) x 100
How is relevant risk assessed?
incidence rate (exposed)/ incidence rate (not exposed)
what are some of the healthcare associated infections?
acinetobacter, varicella, C. Diff, MRSA, VISA, norovirus, legionella, VRE, TB, S. Pneumoniae, Group A Strep, CMV, SARS, Rubells, Influenza, Mumps, Hep A, B and C, Aspergillus, CJD, and atypical mycobacter
What are the leading nosocomial epidemics for hospitals?
S. Aureus, Resistant B (MRSA, VRE), Legionella, Aspergillus, Bacteremia, Gastroenteritis, and Hepatitis
What are the leading nosocomial epidemics for nursing homes?
Influenza, TB, Gastroenteritis, Conjuctivitis, URIs and scabies
How are outbreaks found?
surveillance, lab reports, other healthcare institutions, public health officials; in the end most discovered by observant healthcare personnel
Who does surveillance, how is it done, and why?
by epidemiologists, provides ideal information since rates are tracked overtime, may not be timely, review labs and chart notes to watch trends of various diseases
What are the steps in an epidemic investigation?
establish presence of epidemic, communicate and/or control, analyze outbreak, form hypothesis, test hypothesis and complete investigation
How do you establish the presence of an epidemic?
develop case deifinition, look at case findings, look for reporting artifacts, check the denominator, check baseline data, determine nature, location and severity of problem
how is a case definition developed?
initial case definition should be narrow enough to focus efforts but broad enough to catch all possible cases; scope depends on pathogen (spread, incubation, etc)
How is an epidemic communicated to others and cotroled? What is the focus?
implement emergency control measures (what is potential for spread), look for new cases, inform and minimize fears, prevent surprises
Who are interested parties in an epidemic?
patients, other health workers, facility administration, media (can be good or bad) and lawyers
What is the goal when implementing control measures?
stop transmission, not necessarily find the source, ok to implement a variety of measures targeting various possibilities based on initial observation (droplet, airbone, etc)
How is an outbreak analyzed?
line listing of variables, graph- cases vs time, study epidemic curve (primary, secondary, recurring), calculate attack rates, do analyses (analyze ariables, simple statistics), verify diagnosis (update case definition)
What are sources of information in a hospital to utilize for line listing of variables? What are you looking for?
log books (OR, ER, Nursing unit, ICU), microbio records, employee health records, infection control surveillance data, MR, Op notes, Path reports, Pharm records, Rdiology reports, hospital billing, central-service records, purchasing records; common factors in sick patients but not healthy
How is attack rate calculated?
(cases exposed to a factor/ total patients exposed to a factor) x 100
what goes into forming a hypothesis?
look at precipitating events, confounding factors, characterize outbreaks by etiology, sources and transmission, and review literature
what is a pseudo-outbreak? causes?
situation in wchi there is a rise in positive culture results without evidence of disease; may be surveillance artifact: new definition, new practitioners, new area or pop surveyed, change in culture/test frequency, new medical procedures
How is a hypothesis tested?
collect more data (cultures, special micro studies), institute control measures and see if epidemic stops, evaluate control measures, causality v. association, case control v cohort study
Why use pulse field gel electrophoresis?
may be different sources of the same thing, can id which share the same source
What must be done to complete an investigation?
thorough written report (CDC disseminates to other clinicians to learn from, track, etc.), keep records, keep isolates, educate, communicate continuously
what is something important to note about an outbreak investigation?
not linear or orderly, multiple steps simultaneously, steps are often repeated several times
What is a community source for information for a line list of factors?
public health question ill and those exposed to ill
