Two Ebola patients in the US have been released from hospital

Kent Brantly, an American aid worker who was infected by the deadly virus when he was living in West Africa, spent nine days in a local hospital before he was flown to the States to receive treatment three weeks ago. He was released from hospital this week and told reporters he was "thrilled to be alive”.

Another cleared Ebola patient, Nancy Writebol, was also discharged from hospital this week.

While scientists are rushing to develop a drug that combats or prevents an Ebola infection, there is currently no cure on the market. It is one of the deadliest diseases in the world, and during this outbreak - which has killed 1,300 people in West Africa alone - the fatality rate has been between 50 and 60 percent. If left untreated, the rate skyrockets to around 90 percent.

Brantly and Writebol were patients at the Emory University Hospital in Atlanta, Georgia. Under the care of Bruce Ribner, the director of Emory's Infectious Disease Unit, they received an experimental treatment known as ZMapp, which was only ever made in small quantities and had never been tested on humans until the recent outbreak. According to the BBC, the hospital isn't actually sure if the drug was the reason for the patients' recovery.

"Asked about the role the experimental drug may have played in their recoveries, Ribner said doctors "do not know whether it helped them, whether it made no difference" or whether it might have delayed their recovery,” Josh Levs and Jacque Wilson reported at CNN.

Both patients had to submit two blood tests in a two-day period and have them return ‘negative’ in order to be released from hospital.

According to CNN, although their blood, sweat and faeces no longer contain the virus - which are the main causes of transmission in humans - the doctors say there is a slight chance that "the virus could linger for up to three months in vaginal fluid and semen”. They say there’s no evidence to suggest that Ebola can be transmitted via these specific bodily fluids, however both patients have been informed of the possible risk.

Sources: BBC News, CNN