Mali announced Saturday a new case of Ebola in a man who is fighting for his life in an intensive care unit in the capital Bamako.
"Among two suspected cases who were being tested, one was found negative, the other positive. He was placed in an isolation unit for intensive treatment," the health ministry said in a statement.
Mali, the newest country to be caught up in the epidemic, recorded its seventh Ebola death on Thursday. So far no one who has contracted the deadly tropical pathogen has survived.
The contagion entered the country in October when a two-year-old girl who had come from Guinea died in the western town of Kayes, without spreading the virus any further.
Three weeks later an Islamic cleric, also from Guinea, died in the capital Bamako, transmitting the virus, directly or indirectly, to at least five people, all of whom have now also died.
The health ministry said 310 people were under surveillance as a result of that chain of transmission.
Around 5,500 people have died this year in the west African Ebola outbreak -- almost all in Guinea, Sierra Leone and Liberia -- among more than 15,000 infected.
Ebola, one of the deadliest viruses known to man, is spread through direct contact with the bodily fluids of an infected person showing symptoms such as fever or vomiting.
People caring for the sick or handling the bodies of the infected are particularly vulnerable.
Recent data have shown a decline in cases in Liberia, the worst-hit country, and Guinea, but last week, 533 new cases were reported in Sierra Leone -- the highest weekly tally since the epidemic began in that country.