With all the talk of quarantine being used with the Ebola outbreak in West Africa--and now a separate Ebola outbreak in the DRC--an actual quarantine order was issued in Santa Barbara. It wasn't for Ebola though and it wasn't for an entire region--decisions that are really not evidence-based nor effective.
This order was issued for an individual with drug-resistant tuberculosis who is apparently communicable (i.e. smear positive) who represents a contagion risk to others. According to news reports, he has refused treatment and cannot be located.
Quarantines and isolation orders are difficult topics with many legal nuances however, in my view, they should be used exclusively when solid criteria for contagion with a non-trivial pathogen--not the common cold--are met for individuals (vs. geographic locales) who possess an actual risk of spreading disease. Smear-positive cases of tuberculosis, in which an individual's cough has been shown to harbor the bacteria, can represent such a contagion risk.
Diseases spread through the airborne route, like tuberculosis, necessitate a higher degree of intervention than diseases spread through blood and bodily fluids which are much harder to contract.
These facts should be kept in mind when using government force with respect to contagious infectious diseases.