EPIDEMIOLOGY II Flashcards
the study of the frequency, distribution and determinants of diseases and other health related conditions in human populations,
EPIDEMIOLOGY
MAJOR COMPONENTS OF THE DEFINITION
- POPULATION
- FREQUENCY
- HEALTH RELATED CONDITIONS
- DISTRIBUTION
- DETERMINANTS
- APPLICATION OF THE STUDIES TO THE PROMOTION OF HEALTH AND TO THE PREVENTION AND CONTROL OF HEALTH PROBLEMS.
USES OF EPIDEMIOLOGY
- To make a community diagnosis.
- To monitor continuously over a period of time the change of health in a community.
- To practice surveillance for a specific disease in order to be able to act quickly and so cut short any outbreak
- To investigate an outbreak of a communicable disease, analyse the reasons for it, plan a feasible remedy and carry it out, and monitor the effects of the remedy on the outbreak.
- To plan effective health services.
is an event, condition, characteristic or a combination of these factors which plays an important role in producing the disease.
CAUSE OF DISEASE
these are the factors which are necessary for a disease to occur, in whose absence the disease will not occur.
PRIMARY CAUSES
term that can be used instead of primary cause for Infectious causes of diseases.
ETIOLOGIC AGENT
these are not the necessary causes of disease but they are important for a disease to occur.
RISK FACTORS
the sum total of all the factors (primary causes and risk factors) which contribute to the occurrence of the disease.
THE ETIOLOGY OF A DISEASE
depicts the relationship among three key factors in the occurrence of disease or injury
EPIDEMIOLOGIC TRIANGLE
a factor whose presence or absence, excess or deficit is necessary for a particular disease or injury to occur.
AGENT
a factor whose presence or absence, excess or deficit is necessary for a particular disease or injury to occur.
AGENT
includes all external factors, other than the agent, that can influence health.
ENVIRONMENT
encompasses a broad range of factors, including education, unemployment, culture regarding diet;
SOCIAL ENVIRONMENT
encompasses a broad range of factors, including education, unemployment, culture regarding diet;
SOCIAL ENVIRONMENT
encompasses a broad range of factors, including education, unemployment, culture regarding diet;
SOCIAL ENVIRONMENT
influences include vectors, humans and plants serving as reservoirs of infection.
BIOLOGICAL ENVIRONMENTAL INFLUENCES
influences include vectors, humans and plants serving as reservoirs of infection.
BIOLOGICAL ENVIRONMENTAL
progression of disease process in an individual over time, in the absence of intervention.
NATURAL HISTORY OF DISEASE
FOUR STAGES IN THE NATURAL HISTORY OF A DISEASE
- STAGE OF SUSCEPTIBILITY
- STAGE OF PRE-SYMPTOMATIC (SUB-CLINICAL) DISEASE
- STAGE OF CLINICAL DISEASE
- STAGE OF DISABILITY OR DEATH
in this stage, disease has not yet developed, but the groundwork has been laid by the presence of factors that favor its occurrence.
STAGE OF SUSCEPTIBILITY
in this stage there are no manifestations of the disease but pathologic changes (damages) have started to occur in the body.
STAGE OF PRE-SYMPTOMATIC (SUB-CLINICAL) DISEASE
at this stage the person has developed signs and symptoms of the disease.
CLINICAL STAGE
In others the disease may result in a residual defect, leaving the person disabled for a short or longer duration. Still, other diseases will end in death.
STAGE OF DISABILITY OR DEATH
In others the disease may result in a residual defect, leaving the person disabled for a short or longer duration. Still, other diseases will end in death.
STAGE OF DISABILITY OR DEATH
means to interrupt or slow the progression of disease.
DISEASE PREVENTION
promoting health, preventing exposure and preventing disease.
PRIMARY PREVENTION
keeps the disease process from becoming established by eliminating causes of disease or increasing resistance to disease.
PRIMARY PREVENTION
consists of general non-specific interventions that enhance health and the body’s ability to resist disease.
HEALTH PROMOTION
is the avoidance of factors which may cause disease if an individual is exposed to them.
PREVENTION OF EXPOSURE
development after the individual has become exposed to the disease causing factors.
PREVENTION OF DISEASE
the objective is to stop or slow the progression of disease so as to prevent or limit permanent damage.
SECONDARY PREVENTION
the objective is to stop or slow the progression of disease so as to prevent or limit permanent damage.
SECONDARY PREVENTION
is targeted towards people with permanent damage or disability.
TERTIARY PREVENTION
is an illness due to a specific infectious agent
COMMUNICABLE DISEASE
is an illness due to a specific infectious agent
COMMUNICABLE DISEASE
COMPONENTS OF THE INFECTIOUS PROCESS
- AGENTS
- RESERVOIR
- PORT OF EXIT
- MODE OF TRANSMISSION
- PORT OF ENTRY
- HUMAN HOST
in the infectious process range from viral particles to complex multi-cellular organisms
AGENTS
an organism or habitat, in which an infectious agent normally lives, transforms, develops and/or multiplies
RESERVOIR
person who does not have apparent clinical disease, but is a potential source of infection to other people
CARRIER
some diseases are transmitted to human beings from animals.
ZOONOSES
is the way the infectious agent leaves the reservoir.
PORTAL OF EXIT
include the various mechanisms by which agents are conveyed to other susceptible hosts
MODES OF TRANSMISSION
occurs when there is contact of skin, mucosa, or conjunctiva with infectious agents directly from person or vertebrate animal,
DIRECT CONTACT
is transmission by projection of saliva droplets during coughing, sneezing, singing, spitting or talking.
DIRECT PROJECTION
is transmission from mother to fetus through the placenta.
TRANSPLACENTAL
transmission occurs through indirect contact with inanimate objects fomites: bed sheets, towels, toys, or surgical instruments; as well as through contaminated food, water, IV fluids etc.
VEHICLE-BORNE
the infectious agent is conveyed by an arthropod to a host.
VECTOR-BORNE
if the agent is directly infective to other hosts, without having to go through a period of multiplication or development in the vector.
MECHANICAL VECTOR
if the agent multiplies in the vector before transmission.
BIOLOGICAL VECTOR
which may occur by dust or droplet nuclei
AIRBORNE
is the site where an infectious agent enters a susceptible host.
PORTAL OF ENTRY
the human host is the final link in the infectious process.
SUSCEPTIBLE HUMAN HOST
host resistance at the community (population) level
HERD IMMUNITY
which is concerned with describing the frequency and distribution of diseases and other health related conditions by time, place, and person.
DESCRIPTIVE EPIDEMIOLOGY
deals with the causes or determinants of diseases
ANALYTICAL EPIDEMIOLOGY
usually expressed on a monthly or annual basis.
OCCURRENCE
the major type of descriptive study designs. It is mainly concerned with the distribution of diseases with respect to time, place and person.
CROSS SECTIONAL STUDY
quantifies the magnitude of one occurrence or condition to another.
RATIO
quantifies the magnitude of one occurrence or condition to another.
RATIO
quantifies occurrences in relation to the populations in which these occurrences take place.
PROPORTION
most important epidemiological tool used for measuring diseases.
RATE
rates used to quantify the occurrence of disease. Measures of morbidity include incidence, period prevalence, and point prevalence rates.
MORBIDITY RATES
defined as the number of new cases of a disease that occur during a specified period of time in a population at risk for developing the disease.
INCIDENCE RATE
type of incidence rate which is mainly used during epidemics.
ATTACK RATE
type of incidence rate which is mainly used during epidemics.
ATTACK RATE
measures the number of people in a population who have a disease at a given time.
PREVALENCE RATE
measures the proportion of a population with a certain condition at a given point in time.
POINT PREVALENCE RATE
measures the proportion of a population with a certain condition at a given point in time.
POINT PREVALENCE RATE
measure the occurrence of deaths in a population using different ways.
MORTALITY RATES AND RATIOS
measures the proportion of the population dying every year, or the number of deaths in the community, per 1000 population.
CRUDE DEATH RATE
measures the proportion of the population dying every year, or the number of deaths in the community, per 1000 population.
CRUDE DEATH RATE
represents the probability of death among diagnosed cases or the killing power of a disease.
CASE FATALITY RATE
represents the probability of death among diagnosed cases or the killing power of a disease.
CASE FATALITY RATE
reflects the health of the community in which the child is being brought up.
INFANT MORTALITY RATE
reflects the standards of all aspects of maternal care
MATERNAL MORTALITY RATE
defined as a periodic count or enumeration of a population.
CENSUS
a system by which all births and deaths occurring nationnwide are registered, reported and compiled centrally.
VITAL STATISTICS
THE MAIN CHARACTERISTICS OF VITAL STATISTICS ARE:
§ COMPREHENSIVE – all births and deaths should be registered.
§ COMPULSORY BY LAW – should be enforced by law.
§ Compiled centrally so that it can serve as a source of information.
§ CONTINUOUS – it should be an ongoing process.
major source of health information.
HEALTH SERVICE RECORDS
studies conducted on a representative sample population to obtain more comprehensive data for monitoring the health status of a population.
HEALTH SURVEYS
two types of health surveys:
- SURVEYS OF SPECIFIC DISEASES
- SURVEYS OF GENERAL HEALTH STATUS
some diseases are usually present at a predictable level
EXPECTED LEVEL
presence of a disease at more or less stable level.
ENDEMIC
persistently high level of disease occurrence.
HYPER ENDEMIC
occasional or irregular occurrence of a disease
SPORADIC
occurrence of disease or other health related condition in excess of the usual frequency in a given area or among a specific group of people over a particular period of time.
EPIDEMIC
epidemics of shorter duration covering a more limited area.
OUTBREAK
an epidemic involving several countries or continents affecting a large number of people.
PANDEMIC
disease occurs as a result of exposure of a group of susceptible persons to a common source of a pathogen, often at the same time or within a brief time period.
COMMON SOURCE EPIDEMICS
the resulting cases develop within one incubation period of the disease
POINT SOURCE EPIDEMIC
if the exposure to a common source continues over time it will result in a ____________
CONTINUOUS COMMON SOURCE EPIDEMIC
the infectious agent is transferred from one host to another.
PROPAGATED/ PROGRESSIVE EPIDEMICS
begins with a single, common source of an infectious agent with subsequent propagated spread.
MIXED EPIDEMIC
an important tool for the investigation of disease outbreaks. the distribution of cases is plotted over time, usually in the form of histogram
EPIDEMIC CURVE
a map of locality where the outbreak has occurred, on which the location of cases is plotted.
SPOT MAP
the tool that is important for the analysis of disease outbreaks by personal characteristics
PERSON SPECIFIC ATTACK RATES
defined as the continuous (ongoing) scrutiny of the factors that determine the occurrence and distribution of diseases and other health related events through a systematic collection of data.
SURVEILLANCE
may be defined as a mechanism for routine surveillance based on passive case detection and on the routine recording and reporting system.
PASSIVE SURVEILLANCE
defined as a method of data collection usually on a specific disease, for relatively limited period of time.
ACTIVE SURVEILLANCE
It involves collection of data from communities such as in house-to-house surveys or mobilizing communities to some central point where data can be collected.
ACTIVE SURVEILLANCE
In this strategy several activities from the different vertical programs are coordinated and streamlined in order to make best use of scarce resources.
INTEGRATED DISEASE SURVEILLANCE SYSTEM
