Health Surveillance (Epidemiology) Flashcards
(95 cards)
1
Q
*Define epidemiology
A
Study of the distribution and determinants of health and disease in human populations
2
Q
3 goals of epidemiology
A
- Monitor health
- Understand determinants of health
- Investigate interventions to prevent diseases
3
Q
- What are the 2 types of epidemiology
A
- descriptive
- Analytic
4
Q
*What is descriptive epidemiology?
A
Uses person, place, and time variables to describe disease patterns
-look at the what and where
5
Q
What are some potential person, place, and time variables?
A
- Age
- Sex
- Ethnicity
- Race
- Socioeconomic status
- Occupation
- Education
- Family status
6
Q
*What is analytic epidemiology?
A
examines complex relationships among determinate of disease
- Looks at why and how
- Lots of comparisons (populations)
7
Q
*Define communicable diseases
A
An infectious disease or infestation that is transmitted from one person or animal to another, directly or indirectly
8
Q
*Models for epidemiological investigation
A
- Epidemiological triangle
- Web of causation
-Identification of risk (listed on slide not explored as much in the rest of the ppt.)
9
Q
*What are the points of the epidemiological triangle?
A
- Host
- Agent
- Environment
-Vector (or time) in the center
10
Q
*Define an agent
A
An organism that is capable of producing an infection or infectious disease
11
Q
*What type of things is an agent typically?
A
Microorganism
- bacteria
- virus
12
Q
Is lice an infestation or infection?
A
Infestation
-often considered communicable disease/infection. ( which is still a communicable disease according to the definition, so I don’t get this point on the slide)
13
Q
*What are the 5 characteristics of an infectious agent?
A
- Infectivity
- Pathogenicity
- Virulence
- Toxicity
- Antigenicity
14
Q
*Define Infectivity
A
The ability of an agent to enter and multiply/replicate in a host
15
Q
*Define Pathogenicity
A
Ability of an agent to produce a specific clinical reaction after the infection occur
16
Q
*Define Virulence
A
Ability of an agent to produce a sever pathological reaction
-How severe is the reaction
17
Q
*Define Toxicity
A
Ability of an agent to produce a poisonous reaction
18
Q
*Define Antigenicity
A
Ability of an agent to stimulate an immunological response
19
Q
*Define a host
A
The human or animal in which a agent can survive/infect
20
Q
Define host resistance
A
Ability of the host to withstand infection
21
Q
*What are the 5 types of host resistance
A
- Natural immunity
- Acquired immunity
- Active immunization
- Passive immunization
- Herd immunity
22
Q
*Define natural immunity
A
innate/natural resistance in a species
23
Q
*Define Acquired immunity
A
A resistance gained due to a previous exposure to an infectious agent
24
Q
*Define Active immunization
A
Administration of an antigen which leads to production of the antibody by the host
-live vaccines will do this
25
*Define Passive immunization
The transfer of a specific antibody to a non-immunized person. (have antibody, but will not create their own)
-breastfeeding (mom-baby)
26
*Define infectiousness
A measure of the potential ability of an infected host to transmit the infection to other hosts
27
*Define environment (in relation to epidemiology)
All external factors outside/external to the human host
28
*Examples of environmental (epidemiological) factors
- Physical
- Biological
- Social
- Cultural
29
# Define a reservoir
(i want an example)
Location where an agent lives and reproduces under normal circumstances
30
# Define Source
(I want an example)
Location where the organism is immediately transmitted `to the host
31
*What are the 2 types/categories of transmission modes
- Vertical
| - Horizontal
32
*What are the 4 types of transmission
- Direct
- Indirect
- Vector-borne
- Airborne
33
*Define verticle transmission
An agent is passed from parent to infant
34
*Where/when vertical transmission can occur
- breast-milk
- Through the placenta
- Sperm
- Contact with the vaginal canal at birth
35
*Define horizontal transmission
person-to-person spreading
36
*define direct transmission (horizontal)
immediate transfer through physical contact
- Kissing
- Sex
37
*Define indirect transmission
| horizontal
infection spread through indirect contact with a vehicla
38
*Potential vehicles
- Food
- Water
- milk
- Biological secretions
- Objects (toys, dishtowels, counters, ect)
39
*Define vector-borne transmission
| horizontal
Carriers of the infectious agent, typically animals/insects
- Mosquitoes
- Lyme disease
40
*Define Airborne transmission
| horizontal
Infection spread through contaminated droplets in the air
- Coughing
- Sneezing
41
*Example of diseases spread through airborne transmission
- Flu
- Rubella
- TB
42
*What are the stages in the chain of transmission
Reservoir
Mode of transmission
Susceptible host
43
*What does the chain of transmission show?
There have to be certain things in place for a successful transmission/spread of an agent
44
Example of a reservoir
- Human
- Rat
- Body of water
45
*What is the web of causation?
A way of mapping out the interaction and complexity of risk factors that lead to chronic disease
46
*what is the person-place-time model used for?
Used in helping to define outbreak/endemic/epidemic in epidemiology.
47
*Person-place-time model: Person
'Who"
- Demographic characteristics (age, gender, ethnicity)
- Health and disease statistics
48
*Person-place-time model: place
"Where"
- Geographic location
- Climate
- Environmental condition
- Political/social environment
49
*Person-place-time model: time
"When"
- Time of day
- Week
- Moth
- Secular trends over months/years
50
*Define infection
Entry, development, and multiplication of the infectious disease in a host
51
*Define disease
One possible outcome of an infection
52
*Define incubation period
Time between the invasion/entry of an infectious agent and the first s/s of a disease
53
*Define communicable period
Interval in which an infectious agent can be transferred from one infected person to another
54
*Are the periods of incubation, entry, and being infectious independent?
NO
*image on slide 21*
55
What is an epidemic curve?
Graphic depiction of the number of outbreaks of a disease and when they occurred.
56
What can be seen/figured out from an epidemic curve?
- min, max, and average incubation period
- Secondary cases
- Time trend
- probable exposure
57
*Define endemic
Disease is constantly present in a given geographic area or population
ex/ pertussis in the us
58
*Define epidemic
A greater-than-normally expected occurrence of a disease in a community or region
ex/
59
*Define outbreak
Similar to an epidemic- greater than normally expected occurrence of a disease. BUT in a limited geographic area and smaller # of people.
(city vs country)
60
*Define pandemic
Worldwide epidemic affecting large populations
61
Define rate in relation to epidemiology
a measure of the frequency of a health event in a defined population in a specified period of time
62
What is the numerator and denominator in a rate
numerator- number of events
| denominator- population size in a specific time period
63
What does a rate measure?
A measure of how fast something is happening
64
What is a rate used for
-proportions to interpret raw data and make comparisons
65
*What is a morbidity rate
The rate of illness in a defined population
66
*What are the 3 primary morbidity rates
-incidence rates
~attack rates
-Prevalence rates
67
*Incidence rates describe...
the new cases of disease pr condition in a community over a period of time
68
*Attack rates are...
a type of incidence rate that documents the number of new cases of a disease in the people who have been exposed to that disease
69
*Prevalence rates describe...
the number of all cases of a specific disease in a population at a given point in time
70
*Prevalence is affected by what and how
- incidence (inc)
- recovery (dec)
- death (dec)
- duration (long inc)
71
Attack rate numerator and denominator
numerator- # of people who developed the disease
| denominator- # of people at risk
72
*What is a mortality rate
death rate
73
Why can mortality rates be wrong
They go off death certificates and they dont always have the correct cause of death
74
What is the crude death rate?
Just straight up the number of people who died for a given place at a given time
75
Age-specific death rate
the death rate for a particular age group
76
Sex-specific death rate
the death rate for a specific sex
77
Cause-specific death rate
the death rate for a specific cause or disease
78
infant mortality rate
the death rate for children from birth to 1yr old
79
Why are infant mortality rates misleading
-a neonatal/NICU baby who dies close to birth often has a very different cause of death than a infant closer to 1yr
80
What does epidemic control aim to do
Control the patient, contacts and immediate environment to avoid worsening/spreading of the situation/disease
81
Ways to exert epidemic control
-Isolation (lie in a 'bubble' or bodily fluids)
-Report
Restrain from sexual activity
-Disinfection
-Identification and quarantine of close contacts (possibly infected)
-Global awareness
82
*Primary prevention: to reduce the incidence of disease
- immunizations
- Promotion of safer sex
- Safe water and environment
- Consistent use of universal precautions
83
*Secondary prevention: to reduce disease prevelece
- skin testing for TB
- HIV testing
- Contact investigation in TB
- partner notification for AIDS and other STDs
- screening for disease (in their early stages)
84
*Tertiary prevention: reduces complications and disabilities of disease
-footwear/glove provision to leprocy patients to prevent trauma to these areas
85
Guidelines for screening programs
- want early DX
- should plan follow-up if positive
- treatment available
- confidentiality ensured
- test is cost effective and acceptable
- should have high sensitivity and specificity
86
What is sensitivity?
ability of a test to correctly identify those with the disease
87
What is specificity?
ability of the test to correctly identify those without the disease
88
High sensitivityhas...
few false negatives
or
many true positives
89
High specificity has...
few false positives
or
many true negatives
90
Low sensitivity has...
Many false negatives
or
few true positives
91
Low specificity has...
Many false positives
or
few true negatives
92
*methods used for epidemiology
- cross-sectional studies
- retrospective studies
- prospective studies
- experimental studies
93
*what is involved in the development of a disease?
- infection
- disease
- incubation period
- communicable period
94
*identification of risk factors
???
???
95
*Food outbreak statistics-attack rate
???
???
