Question

On January 1, 2000 there were 20 Optometry students with Influenza A and there were a total of 600 students in the class. These 20 students were immune from contracting Influenza A again during the next nine months. From January 2, 2000 through April 2, 2000, 30 more students developed Influenza A and the class size remained at 600.

a. What was the cumulative incidence of Influenza A from January 2, 2000 through April 2, 2000?

b. What was the prevalence of Influenza A on January 1, 2000?

c. what was the period prevalence of influenza A?

Answer 1

Cumulative incidence - it is defined as proportion of person who develop a condition during particular period of time

So the cumulative incidence of influenza A from January 2 2000 to apri 2 2000 is 30

Prevalence - it is defined as proportion of person who have a condition during particular time

So prevalence of influenza A on January 1 2000 is 20

Period prevalence - number of individuals identified as cases during the particular period of time divided by total number of population

So the period prevalence of influenza A is 0.08