Epidemiology is the study of patterns in health-related events in society. It allows identification of the risk factors for disease, and determination of best approaches for treatment and prevention. For both communicable and non-communicable diseases, epidemiologists conduct investigations of disease outbreaks, collect data, perform statistical analysis, and document these results in reports. A number of such reports and data prepared by the Epidemiology (EPI) Program at the Knox County Health Department can be read on-line or download.
The EPI Program conducts surveillance and follow-up investigations of 54 Reportable Diseases1that are required by law in the state of Tennessee to be reported to public health authorities (excluding STDs, TB, and HIV/AIDS which are followed by staff in our Communicable Disease Clinic). Local physicians, hospitals, and labs report cases of reportable diseases to the EPI program using a standardized Reportable Disease Report Form2. A nurse in the EPI Program interviews each case to determine likely sources and risk factors for contracting the disease, to ensure that the patient receives adequate treatment and education about preventing disease transmission, and to determine the need for follow-up and treatment of contacts if required. EPI staff also respond to foodborne and other disease outbreaks, and respond to reports of disease or unhealthy conditions throughout the county.
Chronic disease epidemiology deals with diseases that last a long time such as arthritis, asthma or diabetes. The three leading causes of death in Knox County are heart disease, cancer, and stroke - all forms of chronic diseases. Reducing risk factors such as obesity, tobacco use, unhealthy nutritional choices and a sedentary lifestyle may help avoid many common chronic diseases such as heart disease, Type II diabetes, and some forms of cancer. The surveillance of injuries and body mass index levels in Knox County is also a function of chronic disease epidemiology.
Environmental epidemiology is the study of the health effects of environmental exposures. Environmental factors affecting human health may be natural or may result from human activity. Environmental exposures may directly lead to a health condition, such as exposures to chemicals, physical agents (e.g. radiation or noise), and biological organisms, or may contribute to poor health conditions over a period of time, such as social conditions or climate change. The geographical and temporal distribution of health conditions and causative factors is also studied.
Syndromic surveillance uses individual and population health indicators that are available before confirmed diagnoses or laboratory results to identify outbreaks or health events and to monitor the health status of a community. By automating public health data collection, syndromic surveillance provides public health information in near real time, often sooner than a laboratory test can even be completed. This allows KCHD to detect and respond to outbreaks and health events more rapidly than would otherwise be possible. In addition to rapid response, the syndromic surveillance data provides information for longer term, ongoing monitoring of chronic conditions such as heart disease and diabetes, injuries, and the use of healthcare services.3
The EPI program works with many different partners throughout the community to provide and assess data related to public health. This assists our partners to evaluate community needs, program performance, make policy decisions and plan for the future.
Additionally, the continual gathering data through surveillance, investigations, and surveys allows the EPI program to produce reports and respond to data requests on specific subjects from elected officials, other government entities, researchers and the community. The reports and information on obtaining data on a specific subject can be found on the Reports and Data page.
Working with other health departments at the local, state, or national level, the EPI program assists with the investigations of regional or national disease outbreaks, environmental situations like the coal ash spill in Roane County, and in the aftermath of disasters like hurricanes or tornadoes that may require a large, coordinated response.
Staff in the EPI Program can be reached by calling (865) 215-5093.
- Tennessee Department of Health. Reportable Diseases. Available at
https://apps.health.tn.gov/ReportableDiseases/. Accessed May 2, 2012.
- Tennessee Department of Health. Reportable Diseases and Events. Available at
http://health.state.tn.us/Downloads/ph-1600.pdf. Accessed May 2, 2012.
- CDC. 2012. Syndromic Surveillance. Available at
http://www.cdc.gov/ehrmeaningfuluse/Syndromic.html. Accessed May 2, 2012.