ABSTRACT
Quantitative epidemiology strives to quantify the distribution of diseases and associated factors in terms of individuals, place, and time and explore potentially causal associations. Ecological epidemiology focuses on understanding factors that affect transmission and maintenance of disease agents in the environment. Etiologic epidemiology is primarily concerned with exploring causal relationships for diseases of undetermined origin. Medical curricula, both human and veterinary, tend to focus on the mechanisms of disease in the individual through the study of anatomy, physiology, microbiology, immunology, and other basic sciences. The science of epidemiology evolved from the need to study naturally occurring health and disease in populations. The study of health and disease away from the controlled environment of the laboratory increases the likelihood that bias, confounding, and chance will influence our findings. The design of animal disease surveillance programs is influenced by sampling and detection statistics.
