Introduction to Epidemiology Ashford University Text:Friis, R. H. and Sellers, T. A. (2014).

Epidemiology for public health practice Guided Response: Review your classmates' posts and find two who wrote about different variables than you do. Apply their variable to an example (either real or made-up) where this particular variable was significant in the overall investigation of an outbreak. (That outbreak does not have to be influenza). [For example, if they wrote on "who" you might consider discussing a case where finding the person who is the carrier of a particular disease advantageous in stopping the spread of that disease.]Descriptive epidemiology uses case reports, case series, and cross-sectional studies to describe the prevalence and distribution of disease in populations.

Descriptive characteristics about the disease or illness (what); the person with the disease or illness (who); the place related to the disease outbreak (where); and the time when the disease or illness presents (when) are studies and defined. Analytic epidemiology explores the determinants or causes of the disease in populations.

This kind of epidemiological study goals to answer how and why questions related to the disease (Friis & Sellers, 2014). For this discussion, I selected the descriptive epidemiologic variables of When and Where detailed in the Centers for Disease Control's Flu Activity and Surveillance reporting.

When People can catch the flu at any time, but there are periods (flu seasons) where influenza activity elevates. In the United States, time-related tracking of influenza cases from 1982 - 2016 defines the flu season from October thru March, with the top 3 months of peak activity of February followed by December and March Where The FLUVIEW activity map clearly and graphically presents the geographic spread of influenza activity estimates for the selected period Knowledge of the timing of increased flu outbreaks aids the planning of treatment services and preventative activities.

For example, health care facilities and providers can prepare for increased visits and hospitalizations during the flu season. Before the flu season hits, targetted health education on vaccination, hand washing and other preventative measures the public can take to protect themselves from the flu can be increased.

The When data indicates that May is outside of the flu season. The flu activity map mirrors this trend. Week 20 of the 2016-2017 season, (Week Ending May 20), the nation was void of widespread influenza activity; four states and the U.S. Virgin Islands reported no influenza activity; there was local influenza activity in 9 states and Puerto Rico, two states and Guam had regional activity, and the rest of the nation reported cases of influenza at a sporadic level (Centers for Disease Control and Prevention, 2017). The states on the map link to the state department of health site for detailed reporting.

Location information helps track the spread of disease, and it supports comparative analysis helpful for resource allocation, and containment efforts. References Centers for Disease Control and Prevention. (2017). Graph of Peak Month of Flu Activity 1982-1983 through 2015-2016.

Centers for Disease Control and Prevention. (2017). US Map Showing Influenza Activity Estimates for Week Ending May 20, 2017.

Friis, R. H. and Sellers, T. A. (2014). Epidemiology for public health practice. Burlington, MA: Jones and Bartlett Learning.