A medical practitioner from Uganda who has been involved in the fight against the spread of the Ebola virus in Liberia has died of the disease, a health official said late on Wednesday.

Dr. Sam Mokoro, who had worked at the state-owned Redemption Hospital, died at the John F. Kennedy Hospital where he has been undergoing treatment for nearly two weeks, the West African country's Assistant Minister of Health for Preventive Services, Tolbert Nyesuah told Xinhua in Monrovia, the nation's capital city.

A nurse of the same hospital last month died after contracting the disease. She had been treating Ebola patients when she fell ill.

On Monday, Liberia's ministry of health reported that 49 persons have died from the Ebola disease in Liberia out of 90 confirmed cases as of June 29.

There is still no cure for the deadly Ebola virus disease which has an incubation period between two and 21 days and carries a fatality rate of up to 90 percent.

Ebola virus was first discovered in 1976 in two simultaneous outbreaks in Sudan and in the Democratic Republic of Congo, taking its name from the Ebola River where the DR Congo outbreak was found in a nearby village.

The World Health Organization (WHO) defines the Ebola virus disease, formerly known as Ebola haemorrhagic fever, as "a severe, often fatal illness" and "one of the world's most virulent diseases."