- Study of diseases upon population is called as epidemiology. It is a Greek word, epi="upon" demos="population" and logos="study".
- Epizootology is the study of diseases upon animal population.
- Epinartics is the study of diseases upon avian population.
- Study of distribution, determinants and frequency of diseases for prevention, control and eradication of diseases is also called as epidemiology.
- The difference b/w epidemiology and clinical medicine is that epidemiology is based on population while clinical medicine is based on individuals.
Selection of diseased people with reference to, “who”, “when” and “where” is called as distribution. It can also be called as selection of diseased people with reference to, “person”, “place” and “time”.
Causative agents of the disease are known as determinants. These are also called as, “risk factors”. Determinants are of two types;
Primary determinants are those w/o which disease cannot occur. Secondary determinants only help in the occurrence of the disease.
In addition to these two major types, determinants can be Intrinsic or Extrinsic. Determinants may also be Host or Environment related based on the types of agents.
Frequency …. No. of occurrences of any disease in a year.
Prevention …. Take actions to prevent disease before occurrence.
Control ………treatment of the disease to reduce morbidity and mortality.
Eradication ….complete removal of disease from an area.
Endemic…...occurrence of a disease with stable and constant frequency. E.g. 2% cases of FMD are present every time.
Epidemic……. It is sudden, unpredictable increase in occurrence of the disease. E.g. Actinobacillosis.
Outbreak…… occurrence of a disease in a specific area.
Sporadic……. Irregular occurrence of disease.
Pandemic…... world wide occurrence of the disease. E.g. Avian Influenza, FMD.
Incidence…... No. of new cases of disease in an area.
Prevalence…. No. of all the cases of disease in an area.