A summary of an actual outbreak of a disease follows. Your discussion group will be part of the investigative team searching for the etiology of the outbreak. Based on the summary data provided, individually post your own hypothesis of what could possibly explain the outbreak, how you would test your preferred hypothesis (aka study design), and the control measures needed to prevent further cases if your hypothesis is correct.. We will provide the actual explanation of this outbreak after this assignment is completed.
Background information: A private physician’s office manager reported 7 cases of a yet undiagnosed disease to the local health department epidemiology department. In the following weeks, a diagnosis of Q fever was determined and 50 laboratory confirmed cases identified throughout the area. Over the previous ten years, morbidity rates for Q fever in Sample City averaged 4.8 cases per year. Thus, the identified 50 cases clearly met the definition of an epidemic/outbreak. Demographic information of the city and for each case was reported and maps of the area were collected (actual tables and figures have been provided to you under the course assignment section). This information can be viewed but is summarized below.
Table A: males in the age 40-64 group had the highest attack rate of Q-fever in Sample City, March through September (seven times greater than other age groups).
Table B: persons belonging to the upper socioeconomic level had the highest attack rate.
Table C: whites had a higher incidence of attack over all other races combined.
Table D: highest rates of attack peaked in May.
Table E: highest rates of attack occurred (in descending order) census 11, 7, 20, and 3 (western/central area of Sample City).
Table F: the cases of Q-fever did not occur with any exceptional frequency in any of the various occupational groups but instead are highly diverse.
Figure 1 depicts the census tracts of Sample City.
