Rwanda has reported nine deaths from its first-ever Marburg virus outbreak and confirmed 18 patients are in isolation, according to its health ministry.

Most of the fatalities have been healthcare workers from an intensive care unit in the capital, Kigali. To curb its spread, Rwandan authorities have restricted funeral sizes no more than 50 people.

The World Health Organization said on Saturday it would deliver a consignment of clinical care and infection-prevention and control supplies to support Rwanda’s “already robust public health emergency response system.”

The virus that causes severe haemorrhagic fever kills about 88% of those infected. Symptoms includes lethargy, fever, severe headaches, vomiting and diarrhoea. Many patients develop severe bleeding at the end of the first week of symptoms.

The disease was first recognized nearly six decades ago, when outbreaks occurred simultaneously in laboratories in Marburg and Frankfurt, both in Germany, and in the Serbian capital, Belgrade. Other recent outbreaks have occurred in Uganda, Ghana and Tanzania.