If the two groups consisted of different subjects, you could use a 2-sample t-test. If the subjects receiving both treatments were the same, you would use a paired t-test. Technically, you have Poisson (count) data, but if the counts are in the ballpark of 10 or higher, the normal approximation will allow you to use these tests. If not, you can use a 2-sample Poisson test in place of the 2-sample t-test. If paired, calculate the delta and use the 1-sample Poisson.