U.S. health officials have fielded inquiries about as many as 100 potential cases of Ebola since the first patient with the deadly virus was detected in the country, but no new infections have been identified, a senior health official said on Saturday.

Dr Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, said news of the Ebola patient in Dallas has raised the awareness of hospitals nationwide to check incoming patients for potential risks, particularly those who have recently traveled from the epicenter of the outbreak in West Africa.

CDC has identified nine people who have had contact with the Dallas patient and therefore may have been exposed to the virus, an additional 40 are being monitored as potential contacts. None have shown symptoms.