'ZERO RISK MEANS NEVER COMING TO LIBERIA'

But she offered no particulars of how he might have contracted the virus, which is transmitted through contact with the bodily fluids of someone who is infected and symptomatic.

Snyderman said journalists in Liberia carry thermometers for regularly taking their temperatures and observe such precautions as avoiding handshakes and hugs, as well as washing their hands with diluted bleach and water and dipping their feet into bleach solution before entering hotels or other public places.

She said she wore a biohazard suit recently when visiting an Ebola ward, and was helped out of it afterward by two nurses who "meticulously" removed the suit from her body.

"Obviously zero risk means never coming to Liberia," she said.

The four other Americans who have been infected were doctors or relief workers who were sent back to the United States for medical treatment.

Aid workers Dr. Kent Brantly and Nancy Writebol contracted the disease at a relief agency in Monrovia in July. Last month, Dr. Rick Sacra tested positive after working in a Liberian hospital. They have all since been released.

An American doctor diagnosed with Ebola in the neighboring country of Sierra Leone arrived at Emory University Hospital in Atlanta for treatment on Sept. 9 and is still being treated. He has not been publicly identified.

A Liberian man visiting relatives in Dallas recently became the first Ebola patient to be diagnosed in the United States.