Another American Doctor Tests Positive for Ebola in West Africa The male doctor worked at the same hospital as Dr. Kent Brantly.

 -- Another American doctor working for the missionary group SIM has tested positive for Ebola in Liberia.

The doctor was treating pregnant women ELWA Hospital in Monrovia, Liberia, according to SIM. But he was not treating Ebola patients in the hospital’s separate Ebola isolation facility, the group said, adding that it was unclear how he contracted the virus.

“My heart was deeply saddened, but my faith was not shaken, when I learned another of our missionary doctors contracted Ebola,” SIM president Bruce Johnson said in a statement.

The doctor "immediately isolated himself" and has since been transferred to the ELWA Ebola ward where he is "doing well and is in good spirits," according to SIM.

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SIM is the same missionary group that Nancy Writebol had been working for when she contracted Ebola in July. Writebol and fellow American Ebola survivor Dr. Kent Brantly, who worked for the aid group Samaritan’s Purse, were evacuated from Liberia to Emory University Hospital in Atlanta for treatment and declared virus-free. Writebol was discharged on Aug. 19 and Brantly went home two days later.

Since March, the deadly virus has killed 1,552 people and sickened 1,517 others, according to the latest numbers from the World Health Organization.

The virus has also sickened at least 240 health workers, half of whom have died, according to WHO.

"Ebola is taking its toll in many ways. It directly kills many who it infects, but indirectly it's killing many more," said ABC News' chief health and medical editor Dr. Richard Besser, who just returned from Monrovia, Liberia. "Emergency rooms are closed, many hospital wards are as well leaving people who are sick with heart disease, trauma, pregnancy complications, pneumonia, malaria and all the everyday health emergencies with nowhere to go."

"I worry that this latest case, an American doctor contracting Ebola while caring for a maternity patient, will lead overseas groups that are providing non-Ebola support to question whether they can safely do so," Besser added. "These countries need more medical support. Any further reduction would be disastrous."