Hello to all my readers! In this article, I present to you some important terms that are essential for the budding biologists to understand what is epidemiology. This will introduce you to some key words that will help you understand epidemiology better and why is it an important subject in the field of public health. Hope you guys like it! 🙂
Epidemiology – Science that evaluates the occurrence, determinants, distribution and control of health and disease in a defined human population
Descriptive epidemiology – Entails collecting data that describes the occurrence of the disease under study
Analytical epidemiology – Analyses a particular disease to determine its probable cause
Experimental epidemiology – Begins with a hypothesis about a particular disease and experiments to test the hypothesis are then conducted
Systematic epidemiology – Focuses on ecological and social factors that influence the development of emerging and re-emerging diseases
Sporadic disease – When disease occurs occasionally and at irregular intervals in human population. Example – bacterial meningitis
Endemic disease – When it maintains a steady low-level frequency at a moderately regular interval in a certain place. Example – common cold
Hyper-endemic disease – Diseases that gradually increase in occurrence frequency beyond the endemic level but not upto epidemic level. Example – common cold during winter months
Outbreak – Sudden, unexpected occurrence of a disease usually focally or in a limited segment of a population. Example – Legionnaire’s disease
Epidemic disease – An outbreak affecting many people at once. Example – Influenza that may occur suddenly and unexpectedly in a family often achieving epidemic status in a community
Index case – First case of a disease
Pandemic case – Increase in disease occurrence within a large population over a wide region. They spread among continents. Example – H1N1 influenza outbreak of 1918
Statistics – Branch of mathematics dealing with collection, organization and interpretation of numerical data
Morbidity rate – Measures the number of individuals that become ill due to a specific disease within a susceptible population during a specific time interval
Morbidity rate = (no.of new cases of a disease) / (no.of individuals in population)
Prevalence rate – Refers to the total number of individuals infected in a population at any one time no matter when the disease began
Mortality rate – Refers to the number of deaths due to a specific disease to the total number of cases of the disease
Mortality rate = (no.of deaths in a population) / (size of the population with the same disease)
Emerging and Reemerging diseases – New, resurfacing or drug-resistant infections whose incidences in humans have increased within the past 3 decades or whose incidence threatens to increase in the near future
Signs – Objective changes in the body such as fever, rash etc. that can be directly observed
Symptoms – Subjective changes in the body such as pain, loss of appetite etc. that are personally experienced by the patient
Disease syndrome – Set of signs and symptoms that are characteristics of the disease