A second Spanish priest to be diagnosed with Ebola was airlifted Monday to Spain from Sierra Leone for treatment. The move followed the Sierra Leone government's decision to end a three-day lockdown that began Friday as part of its fight against controlling the spread of the virus, Associated Press, or AP, reported.

Garcia Viejo reportedly contracted Ebola while working as director of San Juan de Dios Hospital in Sierra Leone, and is the second Spanish priest after Miguel Pajares, a 75-year-old priest who died in Madrid last month, to contract the deadly virus. The 69-year-old Viejo is now being treated at Carlos III hospital, where Pajares was also treated, AP reported. The situation in Sierra Leone remains tense as nearly 21,000 health workers went door-to-door to deliver supplies, spread awareness and identified 200 infected patients after the lockdown, even as aid workers in a rural area were reportedly attacked over the weekend.

There are no tested treatments or vaccines against Ebola yet but limited doses of the experimental drug ZMapp are being used to treat patients. The virus has mainly affected populations in Liberia, Sierra Leone, Guinea, and has also spread to Nigeria and Senegal.

The disease has claimed the lives of nearly 2,500 people so far. And, according to estimates by the U.S. Centers for Disease Control and Prevention, more than 500,000 people could be infected with the Ebola virus by the end of January. Last week, the United Nations estimated that $1 billion is needed to end the Ebola epidemic.

"We requested about $100m a month ago and now it is $1bn, so our ask has gone up 10 times in a month," David Nabarro, the U.N.'s Ebola coordinator, said, adding: "Because of the way the outbreak is advancing, the level of surge we need to do is unprecedented, it is massive."