Epidemiology & Surveillance Flashcards

Question

Hyper-endemic

Answer 1

persistently high levels of diseases occurrence

Answer 2

Irregular pattern of occurance

Answer 3

Occurrence in an area in excess of what is expected for a given time period

Answer 4

Epidemic widespread over several countries

Answer 5

2 or more cases of a disease that are linked OR occurrence of a disease (can be just 1 case) that is not expected in an area e.g. Ebola in UK If cases aren't linked (and not unexpected disease) its not an outbreak its a cluster

Answer 6

When a group of persons have been exposed to a common source of an infectious agent or toxin. e.g. at the same restaurant

Answer 7

When the exposure to an infectious agent or toxin has occurred over a brief period of time

Answer 8

 When an outbreak is gradually spreading from person to person. Epidemic curve is initially separate waves and then they start to merge together as incubation periods etc. start to overlap

Answer 9

describe background level of infection (what level for how long) Describe increase at what week and to what level Then describe if there is a decline after that

Answer 10

Latent period = point in time where person acquires the infection until the point they become infectious. AND Asymptomatic infectious period Then when symptoms develop incubation period stops

Answer 11

Includes when asymptomatic but infectious and when symptomatic

Answer 12

organ/tissue damage (not the same as symptoms

Answer 13

a primary contact of the index case

Answer 14

quantity of microorganisms needed to produce infection in the host

Answer 15

proportion of exposed persons who become infected aka attack rate

Answer 16

proportion of infected persons that develop the disease

Answer 17

the proportion of persons who develop the disease who become severely ill or die

Answer 18

number of NEW cases occurring over a given time period in a defined population at risk (that are disease free initially)

Answer 19

the number of new cases of a disease divided by the number of persons at risk for the disease. (in a certain time period)

Answer 20

Number of EXISTING cases at a given point in time in a defined population Point prevalence (point in time) vs Period prevalence (over a time period). If prevalence is dropping its because people are dying

Answer 21

proportion exposed that get ill?

Answer 22

Proportion of cases who die from it

Answer 23

measure of the likelihood of one event occurring compared to another event odds = number of event A occurring/number of event B occurring event A normally = cases of disease. event B normally = number of those who don't get it

Answer 24

Odds ratio: This is ratio of one set of odds against another. Odds ratios are frequently calculated from case-control studies where we compare the experience of CASES (e.g. persons with disease) against CONTROLS (persons without disease).

Answer 25

protective effect of a vaccine reduction in disease incidence among people who have been vaccinated compared to disease incidence in those unvaccinated

Answer 26

1. Planning and system design 2. data collection 3. data analysis 4. interpretation of results of analysis 5. dissemination & communication of information 6. application of information to public health programs and practice

Answer 27

incomplete data non standardised data overlapping/changing categories loss of data duplication of data (multiple recording systems) not incentivised not comparable e.g. cases of covid between countries due to different testing etc

Answer 28

what criteria would you use to define a case Clinical criteria vs microbiological criteria Not the same as a diagnosis

Answer 29

reports from clinicians lab reports screening primary care reporting e.g. sentinel GPs Death certification surveillance units e.g. British paediatric surveillance unit enhanced surveillance (e.g. TB, meningitis) International surveillance

Answer 30

Detection of any changes in a disease Track changes in disease Detection of new diseases monitoring and evaluation of prevention & control measures to aid prioritisation decisions

Answer 31

need to look at trends because the actual numbers are unreliable because: only a proxy measure - not every case detected/reported Spurious/artificial - failing to notify, notifying wrong changes in diagnostic methods changes in attention of the observer change in observer random variation Is it a true outbreak? Or is it seasonal variation etc.

Answer 32

Passive Active Enhanced Sentinel

Answer 33

most surveillance systems e.g. routine lab/clinician notifications of disease to a surveillance center surveillor doesnt do anything - the data comes to them degree of incompleteness often get very little information about the case

Answer 34

used in situations where complete reporting is required requires negative reporting also e.g. for serious/highly contagious disease; monitoring of vaccine failure etc. Expensive & time consuming - have to contact hospitals/clinicians to ask about cases etc. Usually only done over a short period of time

Answer 35

Form of active surveillance (but less active) usually limited to a specific area, time period and disease type for a specific purpose. Health units are required to report cases of diseases that would not normally be routinely monitored. Often provide incentives

Answer 36

Incentivise some sentinel sites to report information – e.g. some GP practices etc. extrapolate from those clinics. Works best for common diseases - more likely to miss rarer conditions

Answer 37

disease determinants of disease animal and bird reservoirs

Answer 38

System of thinking where you can't understand the system by looking at individual actors - sees healthcare as a dynamic process

Answer 39

Heterogeneity, interact —> emergence 1. heterogenous agents (e.g. people, organisations, pathogens, animals etc.) 2. agents interact with each other and evolve their behaviour over time 3. interactions lead to a pattern called emergence - where the network of actors behave in difficult to understand ways. Emergence disguises cause and effect in positive and negative ways. e.g. ant colonies

Answer 40

aims to integrate multiple categorical surveillance and response systems - linking surveillance, laboratory & other data with public health action. Example: WHO/AFRO IDSR guidelines combine event based & indicator based framework with disease priority framework and one health approach to zoonotic/vector born disease

Answer 41

detect outbreaks, using official and unofficial reports, need to verify reports meet specific case definition (most credible when supported with labs). Can be reported early, even before been to Dr (because informal); can be used anywhere; used for all PH events involving potential disease including with unknown cause

Answer 42

detects outbreaks, define disease trends, seasonality, burden, risk factors Reports of cases from health providers (drs, labs etc.). --> usually credible as HCPs told to only report those that meet case definition (but most credible supported by lab). Timescale: reported after patient has sought medical attention (so can be delayed); only used where there is healthcare infrastructure & willing HCPs; usually only used for known diseases

Answer 43

1. Epidemic-prone diseases/conditions/events that require immediate reporting (can be passive or active) - case-based identification using standard case definitions for high-priority diseases. e.g. acute haemorrhagic fever syndrome, anthrax, bacterial meningitis, cholera etc. 2. Diseases targeted for eradication or elimination (may be part of case based strategies or may have dedicated eradication programmes) e.g. Buruli ulcer, bacterial meningitis, leprosy, malaria, measles 3. Other major diseases/events/conditions of PH importance e.g. HIV, TB, Malaria, viral hepatitis, adverse events following immunisation

Answer 44

population wide immunity - after 1 wave people either die or become immune, then as a few years pass you get new population (e.g. babies, migrants) and loss of immunity - so then you get another spike (cyclical pattern of infection)

Answer 45

Mistrust of authority (particularly within minority groups) Misinformation Lack of scientific literacy

Answer 46

e.g. to authorise use of antivirals for influenza - outside of flu season you can't use antivirals (economic and clinical reasons - outside of flu season/epidemic levels it is unlikely that it actually flu over another virus)

Answer 47

intracellular parasite - biggest cause of non viral diarrhoea

Answer 48

peak age of incidence: 1-5y marked reduction over 35y

Answer 49

Faeco-oral transmission - Person-person spread nurseries, food handlers, animal contact, MSM. Occupational: vets, animal handlers, farm workers Common in lamb & calf diarrhoea - transmitted in surface run off water - so incidence can be seasonal and related to rainfall Waterborne transmission: - oocysts are resistant to chlorination & many disinfectants - unboiled tapwater, swimming pools

Answer 50

GI tract of animals & humans

Answer 51

Self limiting in most, chronic in immunodeficient & AIDS. Low infectious dose Symptoms: watery diarrhoea lasting 2-4 days, abdominal cramps, fever, vomiting, anorexia. Likelihood of recurrence: autoinfection

Answer 52

Enteric precautions (hand washing, don't use alcohol hand rub, hygiene etc., gown and glove) Safe disposal of faeces Exclusion until 48 hours after first normal stool Avoid using swimming pools for 2 weeks after first normal stool Immunocompromised should boil drinking water

Answer 53

Info: when & where was sample; no. of oocysts per 10L, results of viability testing; source of the affected water; how was water treated; distribution area of water supply; any problems with water supply; any recent changes in treatment/source of water; how fast does water travel through distribution area; history of sampling/previous outbreaks Options for action: 1. take no action 2. Convene incident management team: give advice to special groups, enhanced surveillance for human cases, request alternative source of water, boil water notice

Answer 54

Morbidity & Mortality Report (CDC) Global Networks e.g. GOARN International collaborations: EISS (european influenza surveillance scheme), EU-IBIS (EU Invasive Bacterial Infections Surveillance), Enter-net, Pro-MED (programme for monitoring emerging diseases)

Answer 55

Updated in 2005. WHO member states are required to notify WHO for certain diseases. Health related rules for international trade and travel Health organisation: measures for deratting, disinfecting, disinsecting ships etc.

Answer 56

Always notifiable: small pox; poliomyelitis due to wild type poliovirus; human influenza caused by new subtype; SARS. PHEICs: H1N1 Influenza (2019-2010) Polio (2014-present) Ebola Zika Virus Covid-19 MPox

Answer 57

Public Health Emergency of International Concern extraordinary event which is a public health risk to other states AND potentially requires a coordinated international response

Epidemiology & Surveillance Flashcards

(81 cards)