Healthcare epidemiology and Gram+ and Acid Fast Bacilli

Question 1

What is the definition of endemic?

Answer 1

occurring at a relatively constant state

Question 2

What is the definition of epidemic?

Answer 2

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)

Question 3

How is incidence rate determined?

Answer 3

(# new cases for a time period/ population at risk) x 100

Question 4

How is prevalence rate determined?

Answer 4

(# existing cases for a time period/ population at risk) x 100

Question 5

How is relevant risk assessed?

Answer 5

incidence rate (exposed)/ incidence rate (not exposed)

Question 6

what are some of the healthcare associated infections?

Answer 6

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

Question 7

What are the leading nosocomial epidemics for hospitals?

Answer 7

S. Aureus, Resistant B (MRSA, VRE), Legionella, Aspergillus, Bacteremia, Gastroenteritis, and Hepatitis

Question 8

What are the leading nosocomial epidemics for nursing homes?

Answer 8

Influenza, TB, Gastroenteritis, Conjuctivitis, URIs and scabies

Question 9

How are outbreaks found?

Answer 9

surveillance, lab reports, other healthcare institutions, public health officials; in the end most discovered by observant healthcare personnel

Question 10

Who does surveillance, how is it done, and why?

Answer 10

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

Question 11

What are the steps in an epidemic investigation?

Answer 11

establish presence of epidemic, communicate and/or control, analyze outbreak, form hypothesis, test hypothesis and complete investigation

Question 12

How do you establish the presence of an epidemic?

Answer 12

develop case deifinition, look at case findings, look for reporting artifacts, check the denominator, check baseline data, determine nature, location and severity of problem

Question 13

how is a case definition developed?

Answer 13

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)

Question 14

How is an epidemic communicated to others and cotroled? What is the focus?

Answer 14

implement emergency control measures (what is potential for spread), look for new cases, inform and minimize fears, prevent surprises

Question 15

Who are interested parties in an epidemic?

Answer 15

patients, other health workers, facility administration, media (can be good or bad) and lawyers

Question 16

What is the goal when implementing control measures?

Answer 16

stop transmission, not necessarily find the source, ok to implement a variety of measures targeting various possibilities based on initial observation (droplet, airbone, etc)

Question 17

How is an outbreak analyzed?

Answer 17

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)

Question 18

What are sources of information in a hospital to utilize for line listing of variables? What are you looking for?

Answer 18

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

Question 19

How is attack rate calculated?

Answer 19

(cases exposed to a factor/ total patients exposed to a factor) x 100

Question 20

what goes into forming a hypothesis?

Answer 20

look at precipitating events, confounding factors, characterize outbreaks by etiology, sources and transmission, and review literature

Question 21

what is a pseudo-outbreak? causes?

Answer 21

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

Question 22

How is a hypothesis tested?

Answer 22

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

Question 23

Why use pulse field gel electrophoresis?

Answer 23

may be different sources of the same thing, can id which share the same source

Question 24

What must be done to complete an investigation?

Answer 24

thorough written report (CDC disseminates to other clinicians to learn from, track, etc.), keep records, keep isolates, educate, communicate continuously

Question 25

what is something important to note about an outbreak investigation?

Answer 25

not linear or orderly, multiple steps simultaneously, steps are often repeated several times

Question 26

What is a community source for information for a line list of factors?

Answer 26

public health question ill and those exposed to ill