A two-year-old girl in Mali, who had recently returned from Guinea, became the country’s first case of death by Ebola on Friday. The World Health Organization warned that many people had potentially been exposed to the virus since the little girl was taken across the country while ill, hundreds of kilometers by bus with her grandmother. Health workers are quickly attempting to identify the hundreds of potential contacts to prevent Ebola from taking hold in Mali, now West Africa’s sixth affected nation. Mali’s government confirmed the death in a statement on Friday, though it did not identify the girl. “In this moment of sadness, the government would like to express its condolences to her family and reminds the population that maintain very strict hygiene rules remains the best way to contain this disease,” it said.