In a state that did not require varicella (chickenpox) vacci…

In a state that did not require varicella (chickenpox) vaccination, a boarding school experienced a prolonged outbreak of varicella among its students that began in September and continued through December. To calculate the probabilityor risk of illness among the students, which denominator would you use?

John Snow’s investigation of cholera in 1854 London is consi…

John Snow’s investigation of cholera in 1854 London is considered a model for epidemiologic field investigations because it included a number of key aspects that informs much of modern epidemiology. The one aspect which was NOT RELEVANT in his investigations at that time was: