Health workers have gone on strike at a major state-run Ebola treatment center in Sierra Leone, hospital staffers said on Saturday, a further blow to efforts to contain the deadly virus.

Faced with the worst Ebola outbreak in history, West African governments have struggled to find an effective response. More than 1,550 people have died from the hemorrhagic fever since it was first detected in the forests of Guinea in March.

Transmitted through the blood, sweat and vomit of the sick, Ebola has spread quickly among health care workers, who often lack the equipment to protect themselves from the virus.