A flu outbreak occurred in a military barracks that housed 20 soldiers. Case A was diagnosed on October 1 and Case B was diagnosed on October 2. After approximately 10 days, 12 additional cases occurred during approximately a 1 week time span. Military epidemiologists believe that this second group of 12 cases represented another generation of cases. None of the 20 soldiers was known to be immune to the disease. Calculate the secondary attack rate using the forgoing data.
A local health department epidemiologist investigated an outbreak of gastrointestinal illness thought to be associated with a college cafeteria. There were many complaints about the quality of the cafeteria’s offerings, and it appeared that the student’s worst expectations were confirmed when several students visited the college’s infirmary during the middle of the night and the following day complaining of nausea, diarrhea, fever, vomiting, and cramps. The health department’s investigation revealed that 24 students had eaten in the cafeteria and the development of active symptoms ranged from 24 to 36 hours. A list of foods eaten, the number of persons eating the foods, and the tabulations of illness are presented. Fill in the attack rates where indicated. On the basis of your calculations answer the following questions:
What food or foods would you suspect caused the problem?
Based on the description of the clinical symptoms what agent(s) do you think was (were) responsible? ( Your best guess, no points will be deducted for wrong answers to this question)
Calculate the rate of illness in those who ate the food and those who did not eat the food