Husband of Ebola patient says she's "doing better bit by bit"

David Writebol, husband of Nancy Writebol -- one of two American missionaries stricken with the Ebola virus -- says his wife's health is improving daily.

Speaking with CBS News via Skype on Wednesday from North Carolina, where he is still under quarantine, Writebol said he is in constant phone contact with his wife. He said her doctors at Emory University Hospital in Atlanta are monitoring a "few things they were concerned about," though he declined to elaborate further.

"I talked to her last evening and again this morning she keeps telling me she's doing better bit by bit; she's sounding stronger each time that I talk to her, just letting me know doctors are giving her good reports," said Writebol, who has been married to his wife for 40 years.

Last week, on Aug. 5, health officials transported Nancy Writebol on a specially-equipped private jet from Liberia to Atlanta, where she is being kept in medical isolation.

David Writebol told reporters last week he wasn't sure exactly how his wife had contracted the virus that has so far killed more than 1,000 people in West Africa. He said his wife worked outside the Ebola unit and was responsible for the decontamination process as well as support for the medical team to make sure they were properly dressed and protected before entering patients' rooms.

To improve her prognosis, doctors administered three doses of an experimental treatment called ZMapp. Some are crediting the drug with helping save the lives of Writebol and her fellow missionary, Dr. Kent Brantly, though studies have not yet been done to assess the drug's efficacy and safety. Writebol and his wife opted to accept the treatment because they believed her case could provide doctors with crucial information to treat people with the virus and save more lives in the future.

Meanwhile, David Writebol waits out the rest of his 21-day quarantine period in an RV on the campus of SIM USA, the missionary group he volunteered with, in Charlotte, North Carolina. He and two other members of the group returned from Liberia on Monday. He is taking his temperature each day and reporting back to his doctors to make sure he's not infected. He said he expects to be cleared soon.

"I've been getting rest, reading, also I call and talk to my wife, my sons and parents and other friends concerned," he told CBS News. "We've been covered by an outpouring of love. I'm not bored."