CPHM: intro to epidemiology Flashcards
Study the occurrence and distribution of diseases as well as distribution of determinants of health state or events in specified population and the application of this study to control health problems
EPIDEMIOLOGY
Field of science dealing with the relationship of the various factors which determine the frequencies and distribution of an infectious process. A disease or a physiological state in human community.
EPIDEMIOLOGY
• Study of the behavior of disease in the community rather than in individual patients and includes the study of reservoirs and sources of human disease.
EPIDEMIOLOGY
Studies the patterns of disease occurrence in human populations and the factors that influence this pattern.
The term obviously is related to the epidemic (derived from the Greek word” upon the people” meaning leading the people)
EPIDEMIOLOGY
“the diagnostic discipline of public health.”
-C-E. A. Winslow, the great public health leader of the early 20th century,
epidemiology
an increase in the frequency (incidence) of a disease above the usual and expected rate, which is called the endemic rate., thus epidemiology count cases of a disease, and when they detect the sign of epidemic, they ask who, when and where questions.
Epidemic
• Who is getting the disease
• Where and when the disease is occurring
Epidemic
From this information, they can often make informed guesses as to why it is occurring.
Epidemic
surveillance made by the government before many people start dying.
reporting it allows public health authorities to detect an emerging epidemic at an early stage.
Notifiable disease
Outbreak of hepatitis and Food poisoning example of___
typical Epidemiologic Investigation
The ultimate goal is to use this knowledge to control and prevent the spread of disease.
epidemiology
-father of modern epidemiology
- Study about cholera.
John Snow
t or f
the Two main areas of investigation
1. Describes the distribution of health status in terms of age, gender, race, geography, and time.
2. Patterns of disease distribution in terms of causal factor
true
• In epidemiology of any disease or event, one studies the factor which contribute to its causation and behavior
AGENT, HOST, ENVIRONMENT
t or f
Epidemiology concept maintains that there can be no single cause of disease
true
1.Study the history of the health population and the rise and fall of diseases and changes in their character
2. Diagnose the health of the community and the condition of the people.
3. Study the work of health services with a view of improving them
4. Estimate the risk of diseases, accidents, detects and the changes avoiding them
5. Complete the clinical feature of chronic disease and describe their natural history
6. Search for cause of health and disease
Uses of Epidemiology
any element, substance or force whether living or non-living thing; the presence or absence can initiate or perpetuate a disease process.
AGENT
- This could be living or non-living things, physical or mechanical in nature such as extremes of temperature, light electricity.
- They could be chemicals- endogenous (within the body) or exogenous (poison)
Types of Agent
physical feature, biological requirement, chemical composition, resistance
Inherent characteristics
refers to the reservoir and source of infection and modes of transmission.
Characteristic in relation to the environment
Characteristic directly related to man
ability to gain access and adapt to the human host to the extent of finding of finding lodgement and multiplication
Infectivity
Characteristic directly related to man
measures the ability of agent when lodged in the body set up a specific reaction
Pathogenicity
Characteristic directly related to man
refers to the severity of the reaction produce and is usually measured in terms of fatality.
Virulence
Characteristic directly related to man
ability to stimulate the host to produce antibody
Antigenicity
Modes of Transmission
immediate transfer of infectious agent a receptive portal of entry
Direct transmission
Modes of Transmission
Vehicle borne
Vector-borne
Mechanical vector
Biological vector
Indirect transmission
Modes of Transmission
dissemination of microbial aerosols to a suitable portal of entry usually the respiratory tract
(droplet nuclei and dust)
Airborne
usually small residues which result from the evaporation of fluid from droplets emitted by an infected host
Droplet nuclei
contaminated inanimate objects or materials
Vehicle borne
from other living organisms (ex. Insects)
Vector-borne-from
these are cells in our body like plasma cells and lymphocytes that produce antibodies to neutralize harmful effects of the infectious agents and body fluids in our body that possess substance that have antimicrobial properties
Humoral defense
there are cells in our body like macrophages and neutrophils involve in the process of phagocytocis
¿Cellular defense
sum total of an organism’s external surrounding conditions and influences that affect its life and development
• Physical Environment
• climate
• Geography and location
• Biologic Environment-
Environment
certain disease have seasonal distribution
climate
living environment of man consist of plants, animals and fellow human beings.
Biologic Environment
Time between exposure to infectious agent up to the time of appearance of the earliest signs and symptoms
Incubation Period
the time between exposure to a pathogenic organism and the onset of symptoms of a disease.
Clinical incubation period
The time taken by the parasite to complete its development in the definite host (from the time of entry of the infective larvae to the presence of microfilariae) is called the Intrinsic incubation period (Biological incubation).
Biological Incubation Period
As applied to patient, separation for the period of communicability, of infected persons or animals from others in such places and under such conditions as to prevent or limit the effect of the direct or indirect transmission of the infectious agent from those infected to those who are susceptible or who may spread the disease agent.
• ISOLATION
this category is designed to prevent transmission of highly contagious or virulent infectious that may spread by direct contact or droplet.
Strict isolation
for less highly transmissible or serious infections, for disease or conditions which are spread primarily by close or direct contact.
Contact isolation-
to prevent transmission of infectious diseases over short distance through the air
Respiratory isolation
for patient with pulmonary tuberculosis who have a positive sputum smear or chest x-rays which strongly suggest active tuberculosis
Tuberculosis isolation (AFB isolation)
for infectious transmitted by direct or indirect contact with feces purulent
material or
drainage from an infected body site
Enteric Precautions
to prevent infections transmitted by direct or indirect contact with purulent material or drainage from an infected body site.
Drainage/secretion Precautions
to prevent infections that are transmitted by direct or indirect contact with infected blood or body fluids.
Blood/body fluid Precautions
restriction of the activities of a well persons or animals who have been exposed to a case of communicable diseases during its period of communicability to prevent disease transmission during incubation of infection should occur.
QUARANTINE
Limitation of movement of those exposed to a communicable disease for a period of time not longer than the longest usual incubation period of that disease.
Absolute or Complete Quarantine
Selective, partial limitation of freedom of movements of contacts
Modified Quarantine
This is the phase before man is involved. Through the interaction of the agent, the host and environmental factors, the agent finally reaches man.
- It maybe said that everyone is in the period of pre-pathogenesis of many diseases because agents are present in the environment where man lives
Pre-pathogenesis
This phases includes the successful invasion and establishment of the agent in the hos
Pathogenesis
- Condition in the environment must be favorable to the agent or the agent must be able to adapt in the environment
- Suitable reservoirs must be present
- A susceptible host must be present
- Satisfactory portal of entry into the host
- Accessible portal of exit from the host
- Appropriate means of dissemination and transmission to a new host
six requirements for the successful invasion of the host ay an infectious agent.
