Jimma university Department of public health Epidemiology Assignment Group one

1) Describe concepts of disease causation and Hill’s criteria? Cause of disease: is an event, condition, characteristic or a combination of these factors which plays an important role in producing the disease. The causes of disease can be classified in to two: 1. Primary causes – these are the factors which are necessary for a disease to occur, in whose absence the disease will not occur. The term ”etiologic agent” can be used instead of primary cause for Infectious causes of diseases. For example “Mycobacterium tuberculosis” is the primary cause (etiologic agent) of pulmonary tuberculosis. 2. Risk factors (contributing, predisposing, or aggravating factors). There are different models that describe the disease causation CONCEPTS OF DISEASE CAUSATION: Germ theory of Disease.The concept of cause in germ theory of disease is generally referred to a one to one relationship between causal agent and disease. Disease agent → Man → Disease Epidemiological triad: The Epidemiologic Triangle model is useful in identifying the factors that contribute to the spread of infectious diseases. By understanding these factors, we can develop strategies to prevent and control the spread of diseases. For example, if we know that a particular microbe is responsible for a disease, we can develop treatments or vaccines to target t