As many as 40 people have been discharged from a Boston hospital after having tested positive for the virus, according to local media reports.

The hospital said on Tuesday that some patients had been treated for the deadly virus in the last two days.

Boston Mayor Marty Walsh said on Wednesday that he is still trying to establish whether those patients were infected by a healthcare worker or an infected person.

The Boston Public Health Department said it was aware of the new information, but did not comment further.

A person infected with Ebola could contract the virus in their bloodstream for up to two weeks.

The World Health Organization (WHO) said on Monday that the total number of Ebola cases in the world had crossed 3,300, with more than 3,200 deaths.

It also said the death toll from the outbreak had reached 6,000.

The US Centers for Disease Control and Prevention (CDC) has said that there have been 1,631 confirmed cases, while the death count is 2,039.

The WHO has urged people to stay home and avoid contact with infected people.

A hospital in the US state of Georgia on Wednesday said that a person who was admitted there on Monday had tested positive to Ebola.

It said that the patient was in quarantine but that the virus was not transmitted from person to person.