According to the latest official toll released on Wednesday, the Congolese health ministry confirmed 25 deaths so far and said most of the deaths were recorded in the town of Mbomo.
The remaining victims were from the small village of Mbanza, where the outbreak began late last month.
Forty seven other cases have been identified so far.
An additional 98 people are being held for observation in Mbomo, the main town in the Cuvette West region, after direct contact with Ebola patients or the bodies of those who have died.
Terrible infectious disease
Ebola, which is characterised by high fever, diarrhoea and bleeding from the nose and gums, can induce massive internal haemorrhages.
The deadly disease is thought to be contracted by people who eat the flesh of infected animals in the central African rain forest.
Most of the patients are receiving treatment at home by health ministry teams sent to the affected region near the border with Gabon and more than 800km from the capital, Brazzaville.
Health workers seeking to contain the outbreak are urging people to renounce traditional funeral rites, which include washing and kissing the bodies of the dead.
The latest outbreak began on 31 October in Mbomo after hunters ate a wild boar they had found dead in the bush.
In 2002, the Cuvette West region was quarantined due to an Ebola outbreak that claimed more than 100 lives.