An American doctor stricken by Ebola in West Africa arrived home for treatment in Atlanta on Saturday, and U.S. government officials are urging the public to remain confident in the health-care system’s ability to keep the deadly disease isolated. A charity organization, Samaritan’s Purse, said two Americans in serious condition with the disease were being evacuated: Kent Brantly, a Fort Worth doctor who had been treating Ebola victims in Liberia, and Nancy Writebol, a missionary from Charlotte. Brantly and Writebol have been hospitalized in serious condition in Monrovia, the Liberian capital. Brantly was brought back to the United States first,...