(NBC NEWS) Liberia confirmed a second case of Ebola on Tuesday, just a day after the first case since the virus was declared eliminated in May.
It's bad news for Liberia, which had worked hard to eliminate the virus. It suggests that Ebola may still be circulating undetected. Liberia's neighbors, Sierra Leone and Guinea, are still recording several new cases every week.
Liberia was declared Ebola-free by the World Health Organization on May 9 and aid workers had closed Ebola treatment units.
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