Only 27 of the cases have occurred outside the three worst-hit countries, Sierra Leone, Liberia and Guinea.
Those three countries account for all but 10 of the fatalities.
Mali became the latest nation to record a death, a two-year-old girl.
More than 40 people known to have come into contact with her have been quarantined.
The latest WHO situation report says that Liberia remains the worst affected country, with 2,705 deaths. Sierra Leone has had 1,281 fatalities and there have been 926 in Guinea.
Nigeria has recorded eight deaths and there has been one in Mali and one in the United States.
The WHO said the number of cases was now 10,141 but that the figure could be much higher, as many families were keeping relatives at home rather than taking them to treatment centres. It said many of the centres were overcrowded.
And the latest report also shows no change in the number of cases and deaths in Liberia from the WHO’s previous report, three days ago.
Eight countries have registered cases in the outbreak. In West Africa, Senegal and Nigeria have now been declared virus-free by the WHO.
In the US, the governors of the states of New York and New Jersey have
ordered a mandatory 21-day quarantine period for all doctors and other
travellers who have had contact with Ebola victims in West Africa.
In Mali, authorities continue to try to trace anyone who may have had contact with the victim there.
The child had travelled more than 1,000 km (600 miles) from Guinea through the capital, Bamako, to Kayes.
“The child’s symptomatic state during the bus journey is especially
concerning, as it presented multiple opportunities for exposures,
including high-risk exposures, involving many people,” the WHO said.
The girl’s mother died in Guinea a few weeks ago and the child was then brought by relatives to Mali.
Malian President Ibrahim Boubacar Keita told French radio on Saturday: “We are doing everything to prevent panic and psychosis.
“Since the start of this epidemic, we in Mali took all measures to be
safe, but we never hermetically sealed ourselves from this.”
He said the border with Guinea would remain open.