In a study of the incidence of Ebola virus, 1000 subjects were followed over time, 5 of whom developed Ebola at some point during the study. The date of diagnosis and death or cure is shown for the 5 patients below. The left arrows indicate the date of Ebola diagnosis, and the horizontal lines indicate time spent living with the disease. A. Calculate the prevalence of disease in the overall nenulation on July 1, 2012 (indicated by the second of four vertical dotted lines inside the year 2012), and clearly indicate the numerator and denominator used for this calculation (4pts) B: Calculate the cumulative incidence of disease in the overall nonulation in 2012 (danuary to December- delineated by the solid blue vertical lines. and clearly indicate the numerator and denominator used for this calculation (4pts).

1. In a study of the incidence of Ebola virus, 1000 subjects were followed over time, 5 of whom
developed Ebola at some point during the study. The date of diagnosis and death or cure is
shown for the 5 patients below. The left arrows indicate the date of Ebola diagnosis, and the
horizontal lines indicate time spent living with the disease. A. Calculate the prevalence of disease
in the overall nenulation on July 1, 2012 (indicated by the second of four vertical dotted lines
inside the year 2012), and clearly indicate the numerator and denominator used for this
calculation (4pts) B: Calculate the cumulative incidence of disease in the overall nonulation in
2012 (danuary to December- delineated by the solid blue vertical lines. and clearly indicate the
numerator and denominator used for this calculation (4pts)