LAGOS, Nigeria (AP) — Nigerian health authorities acknowledged Tuesday that they did not immediately quarantine a sick airline passenger who later died of Ebola, announcing that eight health workers who had direct contact with him were now in isolation with symptoms of the disease.

Ebola, which can cause victims to bleed from the eyes and mouths before a grisly death, has killed nearly 900 people across four countries in West Africa, a deeply impoverished region with severely limited medical resources.