Dr. Kent Brantly's health is steadily improving since his transport to the United States on Saturday, his wife reported Monday.

Brantly is one of two Americans living with the Ebola virus. He is receiving treatment at Emory University Hospital in Atlanta, Georgia.

Dr. Brantly's wife, Amber, said that she has been allowed to visit her husband every day.

"I am thankful for the professionalism and kindness of Dr. Ribner and his team at Emory University Hospital," she said in a statement. "I know that Kent is receiving the very best medical treatment available."

Dr Brantly is the medical director for the Samaritan's Purse Ebola Consolidated Case Management Center. He spent hours caring for the centre's three Ebola-stricken patients in Monrovia, Liberia before becoming infected himself.

The second American with the Ebola virus is Nancy Writebol, who also worked at the Case Management Center, but through the organisation Serving in Mission (SIM). She was brought to the US for treatment on Tuesday.

University of Kansas Hospital Chief Medical Officer Dr Lee Norman described why it is imperative that Brantly and Writebol be brought back to the States.

"The quality of care here in the United States certainly far, far, far surpasses any that they're able to receive in those western African nations where they're having so much turmoil as well as so much illness and so few resources," he told People Magazine.

Mrs. Brantly expressed pleasure in Writebol's arrival.

"I am also thrilled to see that Nancy arrived safely in Atlanta today," she said. "Our families are united in our faith in Jesus, and we will walk through this recovery time together.

"Please continue to pray for Kent, Nancy, and the people of Liberia."

BBC News reported that the most recent Ebola outbreak began in southern Guinea in February, and quickly spread to Liberia and Sierra Leone. At least 729 people have been killed by the virus, and there is no cure. The mortality rate of the current outbreak is 60 per cent.

The deadly and contagious virus typically causes fever, diarrhea, vomiting, headache, joint pain, and other symptoms. The disease is transmitted by coming into contact with the bodily fluid of an infected person, or touching objects such as needles that have come into contact with infected bodily fluid. The CDC recommends proper sterilization of medical equipment, and wearing protective clothing to decrease the chances of infection.