Table 1: Attack rates of listeriosis among pregnant women exposed to contaminated cantaloupe, estimated using three methods, Colorado, 2011.

Method (equation)aPregnancy-associated listeriosisEstimated exposed womenbEstimated attack rate
(per 10,000 exposed pregnant women)

(1) Colorado cantaloupe distributed nationally (3)16,5001.5
(2) Grocery store chains (4)112,0000.9
(3) Pregnant residents and cantaloupe consumption (5)17,2001.4

See Section 2.4 for explanations and equations.
bCalculated using unrounded estimates; results rounded to two significant figures.