The World Health Organisation (WHO) on Thursday revised downwards the toll from the outbreak of Marburg Fever in Angola to 312 deaths among 351 cases.

The U.N. agency reported in mid-June that there were 356 deaths among 422 cases of the Ebola-like disease, but spokesman Dick Thompson said that the new toll came after careful review of all cases and laboratory samples.

“Initially there is a broad case definition to bring all people under observation and identify all contacts so people do not slip through the net,” said Thompson. “Now we have a more realistic sense of what is going on.”

The WHO also said it was following up on 64 people who might have had contact with the deadly Marburg virus or victims in northern Uige province, epicentre of the world’s worst outbreak which began late last year.

“The team continues to receive and investigate alerts to potential cases,” it said in a brief statement.

The rare haemorrhagic fever is transmitted through bodily fluids including blood, sweat, saliva and tears. Most people usually die within days after massive bleeding. There is no cure.

Experts say many cases have been contracted by people caring for loved ones in the final stages of illness or through washing and kissing bodies after death in accordance with local custom.