Authorities are bracing for possibility of second person in Dallas being infected with Ebola - who was in close contact with the first person. Other immediate family members are also being watched.

Dallas County Health and Human Services Director Zachary Thompson said there is one particular contact of the patient who he fears may have Ebola.

“Let me be real frank to the Dallas County residents: the fact that we have one confirmed case, there may be another case that is a close associate with this particular patient,” Thompson said Wednesday morning in an interview with local ABC affiliate WFAA.

“So this is real. There should be a concern, but it’s contained to the specific family members and close friends at this moment.”

Thompson did not provide further detail about the potential case, only saying that he or she is under strict monitoring as a precaution.

A visitor to Dallas from Liberia was officially diagnosed with Ebola Tuesday afternoon, the first case ever confirmed outside of Africa.

Details are increasingly leaking out about the unidentified man. He arrived in the United States on a commercial flight on Sept. 20 and initially sought care for Ebola-like symptoms on Friday.

The patient was admitted to the hospital on Sunday and placed in isolation. He was staying with family members in the Dallas area, not in a hotel, officials said.

I am suspecting that ER and personal doctors will begin asking their patients whether they’ve had any contact with anyone who has recently been to West Africa, since that is the source of the current outbreak. That’s particularly key since the symptoms of Ebola can mimic those of many other common diseases, from bad colds to the flu and even malaria.

Still, there are those who think that the CDC isn’t reacting swiftly enough and that more precautions must be put in place. It is possible that the FAA may end up putting in more flight restrictions, though there are few direct flights between US and West Africa, but that doesn’t begin to count those flights that are connecting between the US an intermediate city, and the affected areas in West Africa.

It means that public health officials have to be vigilant not only in the US, but at foreign airports, and at the airports in West Africa so that they can screen out potentially infected persons to keep them from infecting others along the way. Given what we know about the poor public health system in Liberia and Sierra Leone, this is a tall task.