Descriptive
Epidemiology
د
.
سهيلة شمس الدين
Triads in epidemiology
Person, place & time
Agent, host, environment
Person
1.
Age
Type of the disease
Birth trauma
Congenital anomalies
Infectious diseases
Degenerative diseases
Mechanism
Agents
Degree of communicability
Post infection immunity
Latency paper
Host
Immunity
Hormones
Environment
Exposure
2-Gender
Genetic sex-linked diseases.
Hormonal defieciency of female sex
hormone
Anatomical C cervix & prostate
Exposure work, nursing
3-Race & familial tendency
Family Genetic Vs common
exposure.
Race sickle cell anaemia
4-Scioeconomic status
Education Behaviour
Economy Environment, Access to
health care facilities.
Occupation Occupational diseases
5-Marital status
Dangerous occupation
Feeding
Stress
Place
Geographic location
temperature,
humidity,
winds,
animals,,,etc.
Time
Long term secular trend
Steady trend towards increase or
decrease over a long period of time.
1700 2000
Seasonal
Influenza, meningitis, food
poisoning.
Cyclic pattern
Measles in pre-vaccination era, RVF.
Rapid fluctuation
epidemics, weeks, days , hours.