Dallas health officials are bracing for a possible second case of the deadly Ebola virus connected to the infected man now in isolation.
Dallas County Health and Human Services Director Zachary Thompson said there is one particular contact of the patient who he fears may have Ebola.
"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 Sept. 26.
The patient was admitted to the hospital on Sept. 28 and placed in isolation. He was staying with family members in the Dallas area, not in a hotel, officials said.
The case is raising fears about an Ebola outbreak in the Liberian community in Dallas. At least 11 people from the Centers for Disease Control and Prevention (CDC) were dispatched this week to trace the patient's contacts, some of whom were children, according to WFAA. Dallas Mayor Mike Rawlings has reportedly activated the city's emergency operations center.
Three first-responders who cared for the infected man are also under close medical surveillance. Members of the ambulance crew tested negative for Ebola but will still be quarantined until they can be confirmed Ebola-free.
Thompson and CDC Director Thomas Frieden have sought to reassure Texans that they are not at risk. Travelers who may have had contact with the patients are also unlikely to have the virus since no symptoms were present at the time, they said.
Gov. Rick Perry (R-Texas) was expected to echo these comments at a noon press conference on Wednesday.
Still, surveys have shown that Americans do harbor fears about Ebola. A poll released in late August found that nearly four in 10 worried about a large outbreak of the disease in the United States.
Ebola is a hemorrhagic fever that presents with flu-symptoms and eventually causes massive internal bleeding. It is transmitted through bodily fluids and typically kills one in two of the people its infects.