SLEONE-HEALTH-EBOLA-WEST-AFRICAOne of the big mysteries in the Ebola outbreak in West Africa is where the virus came from in the first place — and whether it’s changed in any significant ways. These unanswered questions could be making it more difficult to diagnose the disease and find treatments.  Now scientists are starting to get some answers. In a new paper in Science, researchers reveal that they have sequenced the genomes of Ebola from 78 patients in Sierra Leone who contracted the disease in May and June. Those sequences revealed some 300 mutations specific to this outbreak. The new analysis could help determine if the virus’ behavior has changed — and provide information for future diagnostic tests and treatments. Among their findings, the researchers discovered that the current viral strains come from a related strain that left Central Africa within the past ten years. And the research confirms that the virus likely spread into Sierra Leone when women became infected after attending the funeral of a traditional healer who had been treating Guinean Ebola patients. The current Ebola outbreak in West Africa is the worst on record. It has hit four countries, including Sierra Leone, infected approximately 3,000, and killed about 1,500 people. And so far, there is no sign of it slowing down. The fact that the researchers published the sequence of the Ebola genomes in mere months contrasts with the typically slow pace of scientific research. “We’re trying to do this as fast as possible,” says co-senior author Pardis Sabeti, a biologist at MIT and Harvard. This new data increases the number of public Ebola virus sequences fourfold. The main impact of the paper will be as the foundation of research for years to come as other projects try to sort out what all of these genetic sequences — and their hundreds of mutations — really mean. The paper is also a sad reminder of the toll that the virus has taken on those working on the front lines. Five of the authors died of Ebola before it was published. All were affiliated with Kenema Government Hospital in Sierra Leone. More