The majority of the time, these organisms do not cause any obvious clinical disease.

It is the proteins they produce that trigger clinical disease.

As few as five bacteria can lead to clinical disease.

There is no evidence of clinical disease in humans.

Generally infection is asymptomatic, and there are no reports of clinical disease.

Since then, there have been conflicting results from various studies in regards to whether an association exists between the agent and clinical disease.

So far only one of the ten animals that were subject to identical exposure has succumbed to the clinical disease.

Young calves, added to such a grazing herd in July, may develop clinical disease within 2-3 weeks.

Other populations have a lower prevalence of both the genetic mutation and the clinical disease.

For example, a healthy fish with a newly attached trophozoite will not yet have clinical disease.