Today's society is full of disease that are of different natures including genetic, infectious and metabolic etc. Every disease has its own mechanisms of affecting humans and different prevention mechanisms as per disease nature. These factors are included in epidemiology of disease. Other factors include prevalence and incidence of diseases in different populations. Exactly knowing about disease epidemiology helps governing authorities to prevent the disease. Unfortunately, under-developed and developing nations are not focusing on diseases epidemiology. On the other hand, all developing nations developed best public health practices based on diseases epidemiology data. These studies may vary from basic epidemiological surveys to identification of microorganism strains etc.