In Sierra Leone, Medecins Sans Frontieres workers are battling an invisible enemy. Ebola.<br/> <br />The deadly disease has so far claimed more than 600 lives across west Africa, including dozens of health workers.<br/> <br />The fatality rate of the current outbreak is around 60 percent although Ebola can kill up to 90 percent of those who catch it.<br/> <br />(SOUNDBITE) (English) MSF WATER AND SANITATION SPECIALIST, SEBASTIAN STEIN, SAYING:<br/> <br />"To look over this fence right behind you now, and see and look at the patients and you know that their chances are very small. It's horrible."<br/> <br />There are now fears that the disease might spread globally.<br/> <br />On Wednesday, a woman was admitted to hospital in Hong Kong amidst fears that she had contracted the virus.<br/> <br />She tested negative, but city authorities say they are on high alert for a potential outbreak.<br/> <br />(SOUNDBITE) (English) CONSULTANT FOR COMMUNICABLE DISEASES, DEPARTMENT OF HEALTH, DR CHUANG SHUK-KWAN, SAYING:<br/> <br />"Any person w
