Outbreaks Flashcards
Who is in an outbreak control team?
Ccdc Environmental health officer Microbiologist Press officer Secretary Epidemiologist Infection control nurse Might need a vet/representative from a water company/occupational health depending on issue
How do you confirm existence of an outbreak?
Confirm numbers-interviews, lab reports, notified cases
Look at similarities
Review literature and surveillance data if available
Generate initial hypothesis
How do you define a case?
Time Place Person Symptoms Lab results Confirmed/probable/possible
What questions will you ask on an outbreak questionnaire?
Identify subject Susceptibility factors e.g. Age/co morbidity Exposures Other explanations e.g travel Clinical details Open and closed questions
How do you analyse data in an outbreak?
Present descriptive data Attack rates and relative risks Statistical significance- 2x2 tables Epidemic curves Look for confounding with logistic regression
Outbreak investigation process
CCDCs hate it Count cases Control outbreak Diagnosis verification Communicate result Surveillance continues to evaluate control methods Hypothesis formulation Additional studies Test hypotheses Epidemic confirmation Identify cases with case definition Tabulate and orient data
Define outbreak
A localised epidemic of two or more cases of disease related in time and or place in excess of normal expectancy
Calculate attach rate (food or organism)
No of people sick/no people ate food
No new cases in at risk pop/no person at risk in pop
Bio safety level 1,2,3,4
1- well known agents no risk to humans and environment. Masks, gloves and autoclave
2- minimal risk to humans e.g. C diff salmonella mumps. Use safety cabinets
3. Serious or potentially lethal e.g tb, legionella. Filters, vents, restricted access, clothing
4. Severe disease with no vaccine or treatment e.g. Ebola, Lassa and smallpox. Positive pressure, separate air supply for staff, showers, UV ligh, airlocks, separate building
