Bill and Melinda Gates Foundation are stepping in to help fight the Ebola virus by pledging $50 million, Wednesday, Philly.com reported.

At the same time, officials of the United States and World Health Organization (WHO) said that the number of being infected by the disease might go up in Guinea, Liberia, Nigeria and Sierra Leone by the way it is being spread.

According to Dr. Tom Frierden, US Centers for Disease Control and Prevention, Ebola has a danger is spreading fast through caregivers and the unsanitary burial rituals.

The money from the Gates Foundation meanwhile will be used to purchase supplies and fund emergency operations, the press statement said.

It will also be utilized for therapies; development of vaccines, which will help combat the Ebola epidemic that has already claimed more than 2,000, lives in West Africa. WHO said that the disease has already infected over 4,000 people and is spreading fast.

In related news, the Boston Globe reported that the American physician, who got infected with the disease while on a medical mission Liberia, is recovering well and has donated blood to another physician who is suffering from the virus.

Dr. Rick Sacra, who has undergone experimental treatments, has given blood to Dr. Kent Brantly.

The report said that Brantly might be able to fight off the disease using Sacra's blood, which contains antibodies.

According to reports, Sacra is responding well to treatment and are now being treated at the Nebraska hospital.

"His progress has been remarkable," Dr. Angela Hewlett said at a news conference at the Omaha medical center, where Sacra is being treated, the Boston Globe added.

The report further stated that there are four more American medical workers infected while on a medical mission in West Africa.

Dr. Sacra has been given an experimental drug every night. The drug's name has not been revealed yet because Smith said, "we don't know that this drug had any impact at all," she said.

Ebola outbreak has affected Liberia, Sierra Leone, Guinea, Nigeria and Senegal.