July 30, 2014 -- One of the leading physicians in the fight against an outbreak of deadly Ebola virus in Sierra Leone has himself died after battling the illness. According to the Associated Press, physician Dr. Sheik Humarr Khan died Tuesday after being hospitalized in quarantine.
Ebola spreads easily between people and kills up to 90 percent of those infected. The World Health Organization says that, as of July 23, a total of 672 people have died in the outbreak in Guinea, Liberia and Sierra Leone.
One man also died soon after arriving by plane in Lagos, Nigeria. According to the AP, Patrick Sawyer, an American of Liberian descent, boarded an ASKY airlines plane from Liberia to Ghana, then flew to Lagos after a stop in Togo. He was visibly sick during these flights and died in Lagos on Friday. Health officials are tracking anyone who may have come into contact with Sawyer, the AP said.
Two Americans are also fighting for their lives against Ebola, which currently has no cure or antivirus.
Dr. Kent Brantly, who was treating victims of the Ebola outbreak in Liberia, is currently being treated in an isolation unit in the Liberian capital, Monrovia, the AP reported Tuesday.
"I'm praying fervently that God will help me survive this disease," Brantly said in an email Monday to Dr. David Mcray, the director of maternal-child health at John Peter Smith Hospital in Fort Worth, Texas. The Texas-born Brantly, 33, completed a four-year medical residency at the hospital, the AP said.
Brantly's wife and two young children left Liberia to return to Abilene, Texas, days before he began to show symptoms of Ebola. They are being monitored for any signs of fever, a City of Abilene spokeswoman told the AP.
A second American, aid worker Nancy Writebol of Charlotte, N.C., is also stricken with Ebola, according to CBS/AP. Writebol had been working as a hygienist to help decontaminate people at an Ebola care center in Monrovia.