Epidemiology and Death Investigation:
Epidemiology studies all factors that affect health and illness in populations of people. What the studies reveal serve as the foundation of interventions that are to be made in the interest of public health and preventive measures. Epidemiology is considered to be the very cornerstone of public health research and provides evidence-based proof identifying disease risk factors and appropriate treatments.
Epidemiologists work on both communicable and noncommunicable disease outbreaks, ranging from the initial outbreak investigation to designing how the study is to be implemented, data collection, analysis, testing of hypotheses, and documentation of results to be published in professional journals. They use numerous disciplines such as biology to understand the disease process they have encountered, to social science disciplines to better understand the factors that will affect the situation both short-term and long-term. Epidemiologists also work on issues that affect health in general such as vehicle accidents and workplace injuries.
Epidemiology is the study of the health in human populations rather than in individuals. The study encompasses the causes of illnesses, how diseases are spread, and how best to control it. Epidemiology, really, is the study of epidemics.
Epidemiology is called the "Basic Science" of Public Health
Epidemiologists must be able to:
- Apply descriptive and analytic epidemiology to any situation.
- Calculate and interpret incidence rates, mortality rates, prevalence, and years of potential life lost.
- Calculate data.
- Apply the processes, uses, and evaluation of public health surveillance.
- Establish the steps in an outbreak investigation.
Uses of Epidemiology:
Population/community health assessment. In order to set policy, public health officials must assess the health of a community and evaluate whether health services are available, effective, accessible, and effective. They must ask questions about the actual and potential health problems for the community. Where are the problems? Who is at risk? Are problems declining or increasing? Are the patterns changing? By providing answers through the application of epidemiology, public health officials can make educated decisions that will improve the health of the community they serve.
Individual decisions. Many people do not realize that they use epidemiological information when making daily health decisions. Deciding to stop smoking, to take the stairs, to order a salad rather than a hamburger and shake are all decisions that are affected and influenced by epidemiologists and their evaluation of potential risk.
World War II has seen a great advance in the science of epidemiology, though there have been some isolated examples of epidemiology through history contributing to the better health of people of a given community. In the 1950s the general public was informed of the increased lung cancer risks when smoking cigarettes. HIV was isolated in the 1980s and was associated with certain sexual practices or drug-related behaviors. Ongoing choices regarding health are due to the association of proper diet and exercise in reducing the risk of diabetes and cardiovascular disease. Such choices will affect you over your entire lifetime.
The clinical picture. When evaluating a disease outbreak, epidemiologists work closely with clinical physicians and laboratory scientists in order to develop the correct diagnosis for the individual patients. Epidemiologists help physicians to understand the clinical picture and the natural course and history of the disease they now face.
In late 1989, three patients in New Mexico had severe muscle pain and increased eosinophil counts (one type of white blood cell). Their physician was unable to identify the cause of their symptoms. Epidemiologists began to look for similar cases and within a few weeks found more cases of the eosinophilia-myalgia syndrome so that they could describe the illness, the complications that the patients were experiencing and the rate of mortality (i.e. how many patients died compared to the number of patients infected with the disease).
In a similar manner, epidemiologists have charted the course of HIV infection from the initial exposure, or time of infection to the development of a wide variety of clinical symptoms when put together create a syndrome that became known as AIDS - acquired immunodeficiency syndrome.
Epidemiologists are also responsible for documenting the myriad of conditions that are associated with cigarette smoking from pulmonary and heart disease to lung cancer and emphysema.
A New Outbreak:
When first investigating a new disease, it must be established what is known and what is not known. The following table will help you to see where and how priorities are set in terms of how much versus how much control needs to be done.
This table shows the relative priority of investigative and control
efforts during an outbreak based on what is known about the
source of the disease, the mode of transmission, and the
The source or mode of transmission is indicated on the top row of the table, and reading down, that is either known or unknown.
The causative agent on the left hand column is either known or unknown as read from left to right on the column.
If the investigative team knows little about the source and mode of transmission, as demonstrated in the far right hand column, they must further investigate before appropriate control measures can be designed. If they know more about the source/mode of transmission, then control measures can be put into place right away.
However, If the causative agent is not known, as shown in the bottom row, they must investigate further in order to identify the causative agent. The epidemiologist is responsible for establishing the cause of a new outbreak or epidemic, and then putting into place the appropriate measures to stem the spread of infection.