Introduction to Epidemiology PDF

Epidemiology , disease and injury, etiology and risk factors Epidemiology , disease and injury, etiology and risk factors Epidemiology and Rehabilitation (PT-110)...

Epidemiology , disease and injury, etiology and risk factors Epidemiology , disease and injury, etiology and risk factors Epidemiology and Rehabilitation (PT-110) Unit 1- Introduction to Epidemiology Dr. Rajasekar Sannasi MPT PhD Assistant Professor Department of Physiotherapy College of Health Sciences January 14, 2025 www.gmu.ac.ae College of Health Sciences  What is the meaning of the word epidemiology ? The word epidemiology derived from the Greek word epi (on or upon), demos (people), logos (the study of). It is a study about what is happening (especially bad) to a population with respect to health.  Definition of Epidemiology Epidemiology is the study of diseases in populations of different age group and investigating how, when and why they occur.  Background of Epidemiology In early 1800s, epidemiological methods were began to be applied in the investigation of disease occurrences. At that time, epidemiologists focused mainly on infections (contagious diseases). In the 1940s and 1950s , they had began to survey on non-communicable diseases such as heart attack, lung cancer.  Benefits of epidemiological information It is used to plan and evaluate strategies to identify people at risk of developing disease and prevent it. As a guide to the management of patients in whom disease has already developed.  Disease An abnormal condition that affects structure or function of part or all of the body and is usually associated with specific signs and symptoms Types - Contagious (communicable) and noncontagious (non-communicable) diseases.  Injury Physical harm or damage to someone’s body is termed as injury Injury to the body may be either due to accident or sudden incident and insidiously due to overuse (repetitive) of the body part. Types – acute and overuse injury Measuring occurrence of diseases and injuries Incidence – it is the number of new cases that we see in a defined population in a define period of time ✓ proportion ✓ rate Prevalence – It has two types – Point prevalence and period prevalence ✓ point prevalence is the number of people who have the disease at a point in time. ✓ period prevalence would count the people who already had the disease during the year  Natural History of the disease Natural history is the course or progression of the disease in people over time in the absence of treatment. The period starts from pathological onset (inception) until recovery, disability. There are two phases of natural history. Pre pathogenic phase and pathogenic phase  Pre-pathogenic phase During this phase, the man is not yet diseased. But the agent that contributes to the disease is present in the environment. According to epidemiologic triad, during this period there will be an interaction between agent, host and environment.  Agents factors are may be living or non living things. For example biological agents such as bacteria, virus and fungi, chemical agents such as smoke, alcohol etc, physical agents such as crushing, dislocation due to accident and nutritional agents may be excessive of deficiency of certain food.  Host factors include socio demographic characteristics, biological, social and economical factor and life style factors etc. Environment factors- physical – air, soil, water Biological – co-existence with the ecological system Psychosocial environment – customs, habits, beliefs, religion etc.  Pathogenic phase The agent may enter the body and develop the disease clinically or sub clinically From here, the natural history process may lead to recovery, disability or death.  Aetiology Aetiology – come from Greek word etio means causation – ology means the scientific study of something Aetiology means the cause of a disease or the science that deals with such causes Aetiology divided into intrinsic, extrinsic and idiopathic Car tyre is getting deflated – what do you do?  Causes of infectious diseases Infectious disease caused by virus ✓ common cold , the flu,COIVD-19,stomach flu, hepatitis Infectious disease caused by bacteria ✓ strep throat, whooping cough, gonorrhoea, sexually transmitted infections, urinary tract infections Infectious diseases caused by fungi ✓ ring worm (athlete’s foot), fungal nail infections, vaginal yeast infection  Causes of non-infectious diseases Noninfectious diseases aren’t caused by outside organisms, but by genetics, anatomical differences, getting older, life style and the environment you live in.  What is idiopathic? Idiopathic means any disease or condition that arises spontaneously or for which the cause is unknown. Other term for idiopathic is cryptogenic For example :Idiopathic scoliosis, Idiopathic frozen shoulder are the common conditions treated by physiotherapists.  What is risk for diseases Risk (probability or chance) of getting disease is all around us!! To prevent the heathy problem before it happens, we should aware of risk factors which can predict the problem.  Common risk factors Obesity increases the risk of affected by diabetes, heart attack and osteoarthritis among others Smoking increases the risk of many cancers, hypertension, chronic pain , chronic obstructive lung disease among others.  Determinants of the disease Age Gender Occupation Ethnicity, race Poverty in a society Geographical location Determinants are general. Difficult for an individual to control.  Risk Vs Vulnerability What is your thought? Thank You