The Ebola outbreak that's claimed at least 500 lives in West Africa may have been lurking a while before going on its killing spree, NBC News reports. Researchers figured this by studying blood samples from old cases of viral illnesses in Liberia, Sierra Leone, and Guinea, and finding possible signs of Ebola. The results aren't 100%—the samples were old, after all—but evidence suggests that an Ebola outbreak could be spotted ahead of time. "It makes us realize that you don’t have to see an outbreak" to know it's there, said Randal Schoepp, a US Army researcher. "In Africa, it is easy for a disease to smolder because there is so much disease."
This is Ebola's first outbreak in West Africa, but other dangerous diseases like dengue, malaria, and particularly Lassa fever are common there. Lassa fever also comes with Ebola-like symptoms such as internal and external bleeding, vomiting, and high fever. Analyzing 253 blood samples from 2006 to 2008, Schoepp's crew found that almost 9% of samples cleared of other ailments tested positive for Ebola antibodies. Another challenge is educating West Africans about Ebola, for odd rumors are spreading there—like the notion that Nescafe can cure it when mixed with sugar and coca, the Washington Post reports. But Susan Sered writes at Salon that the biggest challenge may be educating Americans, who could easily afford to "support local governments in building functioning public health infrastructures." (Read about Guinea's rather odd means of curbing Ebola.)