How many cases of Ebola ?

The answer is: "We don't know"

That's right. If we were to look at coded data from the admissions to US hospitals regarding patients who were treated for Ebola, we wouldn't be able to know who or how many. Why?

Because, in ICD-9, Ebola codes to (078.89) other specified diseases due to viruses. In other words, it's lumped with a myriad of other viral diseases. State or other public health officials wouldn't be able to know or track the evolution of the disease.
 

In ICD-10, there a specific code (A98.4 - Ebola virus disease) to code Ebola. 

Obviously, because Ebola was such a publicized disease in 2014, we know (from NY Times and Reuters) that there were 10 cases treated in the US (4 doctors, 2 nurses, a visitor, a missionary, an aid worker and an NBC cameraman). Obviously, the NY Times won't track every viral disease on their spreadsheets.