A total of 4,493 people have died from the world’s worst Ebola outbreak on record, and the situation in Guinea, Liberia and Sierra Leone is deteriorating, the World Health Organization said.

WHO said a total of 8,997 confirmed, probable and suspected cases of Ebola had been reported in seven countries as of Oct. 12, with the vast majority of these in the three West African nations.

An Ebola victim being taken out of Sierra Leone

In Spain and the United States, a handful of healthcare workers are ill, while Senegal and Nigeria appear to have prevented further spread of the disease, the WHO said.

“It is clear…that the situation in Guinea, Liberia, and Sierra Leone is deteriorating, with widespread and persistent transmission of (Ebola),” the WHO report stated.

In Guinea 843 people have died of the disease and an increase in new cases was driven by a spike in infection in the coastal capital Conakry and the nearby district of Coyah.

In Liberia, the U.N. health agency said that problems with data gathering made it hard to draw conclusions about the evolution of the epidemic, with the number of cases in the capital Monrovia almost certainly significantly under-reported.

The United States is deploying up to 4,000 troops to West Africa to help contain an outbreak of the haemorrhagic fever with the bulk of the effort targeting Liberia.