The number of people who have contracted Ebola in West Africa has surpassed 5,000, the World Health Organization (WHO) says.

Suspected and confirmed cases stood at 5,335 in Guinea, Liberia and Sierra Leone as of Sunday, the UN health agency says, citing the latest available data.

The death toll has risen to 2,622 in these countries.

The spread of the virus has taken the heaviest toll in Liberia, where infections and deaths have been surging in the capital Monrovia, according to WHO.