Epidemiology

Question

An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fifty-seven students reported symptoms including vomiting, diarrhea, nausea, and low-grade fever between 10 p.m. on September 24 and 8 p.m. on September 25. The ill students lived in dormitories that housed 723 of the students. The table below provides information on the number of students per type of residence and the number reporting illnesses consistent with the described symptoms and onset time. What is the proportion of total cases occurring in boys

 

Residence # of Students # of Cases
Boys dormitory (all boys) 380 40
Girls dormitory (all girls) 343 12
Day Students (live at home) 123 (46 boys, 77 girls) 5 (3 boys, 2 girls)
Total 846 57

Answer 1

Total cases in boys would be:

 

TOTAL cases in boys in dormitories / TOTAL boys in dormitories

 

(40) / (380) = 40/380