GENEVA: Guinea and Sierra Leone each recorded a single cases of Ebola in the past week, putting a year-end goal of ending the deadly epidemic within reach although risks remain, the World Health Organization (WHO) said on Tuesday. Tight surveillance and tracing contacts of infected people remain crucial, and are especially challenging during the heavy rains in August, WHO Assistant-Director Bruce Aylward said. 'The progress is real ... as of today we have two cases (in the week to Aug. 2),' Aylward told a news briefing upon return from West Africa where the epidemic has killed more than 11,000 people since December 2013. 'It is a realistic goal to have tranmission stopped this year.' In the previous week to July 26, there were seven confirmed cases in the two countries, which had been the lowest in the past year, according to the WHO.