Gag orders were given to all quarantined Ebola suspects?

What would be a practical reason for a gag order in the first place?

There is an answer other than a gag order. Nurse Pham was around Duncan at an advanced stage of the disease, when Duncan was shedding millions, if not billions, of virus. Duncan's family, while around Duncan while he was showing symptoms, were around Duncan in the early stages of the disease.

Michael Monnig was cleared of having ebola.