A second health worker at a Texas hospital where a man died of ebola has tested positive for the disease.
The unnamed member of staff reported they had a fever on Tuesday and was immediately isolated at Texas Health Presbyterian Hospital.
The health worker is the second person of 77 who treated Liberian Thomas Eric Duncan, who died on 8 October to have caught the disease.
Nina Pham, who is reported to be in stable condition, has been in isolation at the Dallas hospital since Friday.
The nurse has since received a plasma transfusion donated by Dr Kent Brantly, the first American to return to the US from Liberia to be treated for ebola.
The Texas Department of State Health Services said officials were identifying anybody who may have had contact with the newly infected health worker.
In a news conference, Dallas County judge Clay Jenkins said: "At the hospital we have a situation involving 77 people. Two of them have tested positive for ebola. We are preparing contingencies for more and that is a very real possibility.