Medical staff working with Medecins sans Frontieres (MSF) put on their protective gear before entering an isolation area at the MSF Ebola treatment centre in Kailahun July 20, 2014.    REUTERS-Tommy TrenchardJenneh became a nurse in Sierra Leone 15 years ago with the hope of saving lives in one of the world’s poorest countries. Now she fears for her own after three of her colleagues died of Ebola. Health workers like Jenneh are on the frontline of the battle against the world’s worst ever outbreak of the deadly hemorrhagic fever that has killed 729 people in Sierra Leone, neighboring Liberia, Guinea and Nigeria so far. With West Africa’s hospitals lacking trained staff, and international aid agencies already over stretched, the rising number of deaths among healthcare staff is shaking morale and undermining efforts to control the outbreak. More than 100 health workers have been infected by the viral disease, which has no known cure, including two American medics working for charity Samaritan’s Purse. More than half of those have died, among them Sierra Leone’s leading doctor in the fight against Ebola, Sheik Umar Khan, a national hero.  “We’re very worried, now that our leader has died from the same disease we’ve been fighting,” said Jenneh, who asked for her real name not to be used. “Two of my very close nursing friends have also been killed … I feel like quitting the profession this minute.” Jenneh works at a 64-bed emergency clinic set up by the medical charity Medecins Sans Frontieres (MSF) in Kailahun town in eastern Sierra Leone, at the center of the outbreak. She said she didn’t know why so many doctors were dying from the virus, which in its most deadly strain can kill 90 percent of those it infects. In the current outbreak, the rate is running at about 60 percent. But like other carers interviewed by Reuters, she is worried the fabric of the yellow full-body suits used to protect workers on isolation wards is too flimsy to block the virus. “Improper personal protective gear is a serious issue here,” she said. More