Ebola crisis: US doctor 'very concerned' over Dallas infection

A preliminary test has shown a Texas health worker who treated Ebola victim Thomas Duncan before he died is also infected with the virus, US officials say.

Dr Daniel Varga, chief clinical officer at Texas Health Presbyterian Hospital where the worker was infected, answers journalists' questions at a news conference in Dallas.

He discussed what kind of protective gear the newly infected health worker was wearing, and said the hospital is very concerned about how it happened.