Epidemiological TriangleEpidemiolog

Epidemiological Triangle

Epidemiological studies on infectious diseases have helped epidemiologists identify
the core factors involved in the disease process. Agent, host, and environment (as well
as time) are most important in a disease’s transmission (Figure 1-6). The agent is a
microorganism that has the ability to cause disease. The host is generally either a human
or animal infected by the agent. The agent survives on the resources of the host
or is attacked by the host’s immune system. Environmental factors such as air, water,
soil, chemicals, diet, and genetics influence the disease transmission process. The time
taken for the appearance of signs and symptoms caused by an agent in the host is the
incubation period. The study of the epidemiological triad components of a disease helps
the epidemiologist plan for an effective intervention to interrupt the transmission
process and stop further evolution of the disease