Health officials in Texas say about 80 people are being monitored for symptoms of Ebola, those who came in contact with the infected man and their contacts.

Dallas County Health and Human Services spokeswoman Erikka Neroes said Thursday about 80 people are now part of the "contact investigation."

She says the people being monitored are the 12 to 18 people who first came into contact with Thomas Eric Duncan, as well as others those initial people had contact with.

Neroes said none of the people being monitored are showing symptoms.

Health officials are focusing on containment in trying to stem the possibility of the Ebola virus spreading beyond Duncan, who recently travelled from Liberia to Dallas.

With files from Reuters