New Ebola case in Liberia dashes disease-free hopes

MONROVIA, Liberia, March 21 (UPI) -- A woman in Liberia tested positive for the Ebola virus, dashing hopes the country would soon be declared free of the disease.

Liberia's Acting Head of the Ebola Incident Management Team, Dr. Francis Kateh, told the BBC the 44-year-old woman tested positive for the disease. More concerning is it is unclear how the woman became infected, he said.

The World Health Organization requires 42 days to pass from the last known case before a country can be declared free of the disease. There had been no new cases in Liberia for 20 days before the woman was diagnosed.

"We have to investigate where the person came from," Kateh told NBC News. "Did they travel out of the country?"

Liberia has been devastated by the disease since the outbreak began last year, killing more than 4,000 people.