Several days after a wedding, an outbreak of cyclosporiasis occurred among attendees. Of the 108 guests at the wedding, 76 were ill and met the case definition.
50 of the 76 who were ill ate the wedding cake.
Three of those who were well ate the wedding cake.
What is the attack rate for those who ate the wedding cake?
A) 65.8%
B) 46.3%
C) 94.3%
D) 70.3%

Question

Quizplus · Accepted Answer

The attack rate is calculated as the number of people who became ill after eating the wedding cake divided by the total number of people who ate the cake. 50 people who ate the cake became ill, and a total of 53 people (50 ill + 3 well) ate the cake. The attack rate is (50/53) * 100 = 94.3%.

Several Days After a Wedding, an Outbreak of Cyclosporiasis Occurred